From 03e601f48b2da6fb44d0f7b86957a8f6bacfb347 Mon Sep 17 00:00:00 2001
From: Toke Høiland-Jørgensen <toke@redhat.com>
Date: Wed, 1 Sep 2021 13:48:12 +0200
Subject: libbpf: Don't crash on object files with no symbol tables
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

If libbpf encounters an ELF file that has been stripped of its symbol
table, it will crash in bpf_object__add_programs() when trying to
dereference the obj->efile.symbols pointer.

Fix this by erroring out of bpf_object__elf_collect() if it is not able
able to find the symbol table.

v2:
  - Move check into bpf_object__elf_collect() and add nice error message

Fixes: 6245947c1b3c ("libbpf: Allow gaps in BPF program sections to support overriden weak functions")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210901114812.204720-1-toke@redhat.com
---
 tools/lib/bpf/libbpf.c | 6 ++++++
 1 file changed, 6 insertions(+)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 88d8825fc6f6..8f579c6666b2 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -2993,6 +2993,12 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 		}
 	}
 
+	if (!obj->efile.symbols) {
+		pr_warn("elf: couldn't find symbol table in %s, stripped object file?\n",
+			obj->path);
+		return -ENOENT;
+	}
+
 	scn = NULL;
 	while ((scn = elf_nextscn(elf, scn)) != NULL) {
 		idx++;
-- 
cgit v1.2.3


From 08a6f22ef6f843d0ea7252087787b5ab04610bec Mon Sep 17 00:00:00 2001
From: Matt Smith <alastorze@fb.com>
Date: Wed, 1 Sep 2021 12:44:37 -0700
Subject: libbpf: Change bpf_object_skeleton data field to const pointer

This change was necessary to enforce the implied contract
that bpf_object_skeleton->data should not be mutated.  The data
will be cast to `void *` during assignment to handle the case
where a user is compiling with older libbpf headers to avoid
a compiler warning of `const void *` data being cast to `void *`

Signed-off-by: Matt Smith <alastorze@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210901194439.3853238-2-alastorze@fb.com
---
 tools/lib/bpf/libbpf.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index f177d897c5f7..2f6f0e15d1e7 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -854,7 +854,7 @@ struct bpf_object_skeleton {
 	size_t sz; /* size of this struct, for forward/backward compatibility */
 
 	const char *name;
-	void *data;
+	const void *data;
 	size_t data_sz;
 
 	struct bpf_object **obj;
-- 
cgit v1.2.3


From 006a5099fc18a43792b01d002e1e45c5541ea666 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Tue, 7 Sep 2021 15:10:23 -0700
Subject: libbpf: Fix build with latest gcc/binutils with LTO

After updating to binutils 2.35, the build began to fail with an
assembler error. A bug was opened on the Red Hat Bugzilla a few days
later for the same issue.

Work around the problem by using the new `symver` attribute (introduced
in GCC 10) as needed instead of assembler directives.

This addresses Red Hat ([0]) and OpenSUSE ([1]) bug reports, as well as libbpf
issue ([2]).

  [0]: https://bugzilla.redhat.com/show_bug.cgi?id=1863059
  [1]: https://bugzilla.opensuse.org/show_bug.cgi?id=1188749
  [2]: Closes: https://github.com/libbpf/libbpf/issues/338

Co-developed-by: Patrick McCarty <patrick.mccarty@intel.com>
Co-developed-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Patrick McCarty <patrick.mccarty@intel.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210907221023.2660953-1-andrii@kernel.org
---
 tools/lib/bpf/libbpf_internal.h | 25 +++++++++++++++++++------
 tools/lib/bpf/xsk.c             |  4 ++--
 2 files changed, 21 insertions(+), 8 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index 533b0211f40a..4f6ff5c23695 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -90,17 +90,30 @@
 /* Symbol versioning is different between static and shared library.
  * Properly versioned symbols are needed for shared library, but
  * only the symbol of the new version is needed for static library.
+ * Starting with GNU C 10, use symver attribute instead of .symver assembler
+ * directive, which works better with GCC LTO builds.
  */
-#ifdef SHARED
-# define COMPAT_VERSION(internal_name, api_name, version) \
+#if defined(SHARED) && defined(__GNUC__) && __GNUC__ >= 10
+
+#define DEFAULT_VERSION(internal_name, api_name, version) \
+	__attribute__((symver(#api_name "@@" #version)))
+#define COMPAT_VERSION(internal_name, api_name, version) \
+	__attribute__((symver(#api_name "@" #version)))
+
+#elif defined(SHARED)
+
+#define COMPAT_VERSION(internal_name, api_name, version) \
 	asm(".symver " #internal_name "," #api_name "@" #version);
-# define DEFAULT_VERSION(internal_name, api_name, version) \
+#define DEFAULT_VERSION(internal_name, api_name, version) \
 	asm(".symver " #internal_name "," #api_name "@@" #version);
-#else
-# define COMPAT_VERSION(internal_name, api_name, version)
-# define DEFAULT_VERSION(internal_name, api_name, version) \
+
+#else /* !SHARED */
+
+#define COMPAT_VERSION(internal_name, api_name, version)
+#define DEFAULT_VERSION(internal_name, api_name, version) \
 	extern typeof(internal_name) api_name \
 	__attribute__((alias(#internal_name)));
+
 #endif
 
 extern void libbpf_print(enum libbpf_print_level level,
diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c
index e9b619aa0cdf..a2111696ba91 100644
--- a/tools/lib/bpf/xsk.c
+++ b/tools/lib/bpf/xsk.c
@@ -281,6 +281,7 @@ out_mmap:
 	return err;
 }
 
+DEFAULT_VERSION(xsk_umem__create_v0_0_4, xsk_umem__create, LIBBPF_0.0.4)
 int xsk_umem__create_v0_0_4(struct xsk_umem **umem_ptr, void *umem_area,
 			    __u64 size, struct xsk_ring_prod *fill,
 			    struct xsk_ring_cons *comp,
@@ -345,6 +346,7 @@ struct xsk_umem_config_v1 {
 	__u32 frame_headroom;
 };
 
+COMPAT_VERSION(xsk_umem__create_v0_0_2, xsk_umem__create, LIBBPF_0.0.2)
 int xsk_umem__create_v0_0_2(struct xsk_umem **umem_ptr, void *umem_area,
 			    __u64 size, struct xsk_ring_prod *fill,
 			    struct xsk_ring_cons *comp,
@@ -358,8 +360,6 @@ int xsk_umem__create_v0_0_2(struct xsk_umem **umem_ptr, void *umem_area,
 	return xsk_umem__create_v0_0_4(umem_ptr, umem_area, size, fill, comp,
 					&config);
 }
-COMPAT_VERSION(xsk_umem__create_v0_0_2, xsk_umem__create, LIBBPF_0.0.2)
-DEFAULT_VERSION(xsk_umem__create_v0_0_4, xsk_umem__create, LIBBPF_0.0.4)
 
 static enum xsk_prog get_xsk_prog(void)
 {
-- 
cgit v1.2.3


From 0b46b755056043dccfe078b96b256502b88f2464 Mon Sep 17 00:00:00 2001
From: Quentin Monnet <quentin@isovalent.com>
Date: Wed, 8 Sep 2021 14:32:26 -0700
Subject: libbpf: Add LIBBPF_DEPRECATED_SINCE macro for scheduling API
 deprecations

Introduce a macro LIBBPF_DEPRECATED_SINCE(major, minor, message) to prepare
the deprecation of two API functions. This macro marks functions as deprecated
when libbpf's version reaches the values passed as an argument.

As part of this change libbpf_version.h header is added with recorded major
(LIBBPF_MAJOR_VERSION) and minor (LIBBPF_MINOR_VERSION) libbpf version macros.
They are now part of libbpf public API and can be relied upon by user code.
libbpf_version.h is installed system-wide along other libbpf public headers.

Due to this new build-time auto-generated header, in-kernel applications
relying on libbpf (resolve_btfids, bpftool, bpf_preload) are updated to
include libbpf's output directory as part of a list of include search paths.
Better fix would be to use libbpf's make_install target to install public API
headers, but that clean up is left out as a future improvement. The build
changes were tested by building kernel (with KBUILD_OUTPUT and O= specified
explicitly), bpftool, libbpf, selftests/bpf, and resolve_btfids builds. No
problems were detected.

Note that because of the constraints of the C preprocessor we have to write
a few lines of macro magic for each version used to prepare deprecation (0.6
for now).

Also, use LIBBPF_DEPRECATED_SINCE() to schedule deprecation of
btf__get_from_id() and btf__load(), which are replaced by
btf__load_from_kernel_by_id() and btf__load_into_kernel(), respectively,
starting from future libbpf v0.6. This is part of libbpf 1.0 effort ([0]).

  [0] Closes: https://github.com/libbpf/libbpf/issues/278

Co-developed-by: Quentin Monnet <quentin@isovalent.com>
Co-developed-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210908213226.1871016-1-andrii@kernel.org
---
 kernel/bpf/preload/Makefile          |  7 +++++--
 tools/bpf/bpftool/Makefile           |  4 ++++
 tools/bpf/resolve_btfids/Makefile    |  6 ++++--
 tools/lib/bpf/Makefile               | 24 +++++++++++++++++-------
 tools/lib/bpf/btf.h                  |  2 ++
 tools/lib/bpf/libbpf_common.h        | 19 +++++++++++++++++++
 tools/testing/selftests/bpf/Makefile |  4 ++--
 7 files changed, 53 insertions(+), 13 deletions(-)

(limited to 'tools/lib')

diff --git a/kernel/bpf/preload/Makefile b/kernel/bpf/preload/Makefile
index 1951332dd15f..ac29d4e9a384 100644
--- a/kernel/bpf/preload/Makefile
+++ b/kernel/bpf/preload/Makefile
@@ -10,12 +10,15 @@ LIBBPF_OUT = $(abspath $(obj))
 $(LIBBPF_A):
 	$(Q)$(MAKE) -C $(LIBBPF_SRCS) O=$(LIBBPF_OUT)/ OUTPUT=$(LIBBPF_OUT)/ $(LIBBPF_OUT)/libbpf.a
 
-userccflags += -I $(srctree)/tools/include/ -I $(srctree)/tools/include/uapi \
+userccflags += -I$(LIBBPF_OUT) -I $(srctree)/tools/include/ \
+	-I $(srctree)/tools/include/uapi \
 	-I $(srctree)/tools/lib/ -Wno-unused-result
 
 userprogs := bpf_preload_umd
 
-clean-files := $(userprogs) bpf_helper_defs.h FEATURE-DUMP.libbpf staticobjs/ feature/
+clean-files := $(userprogs) libbpf_version.h bpf_helper_defs.h FEATURE-DUMP.libbpf staticobjs/ feature/
+
+$(obj)/iterators/iterators.o: $(LIBBPF_A)
 
 bpf_preload_umd-objs := iterators/iterators.o
 bpf_preload_umd-userldlibs := $(LIBBPF_A) -lelf -lz
diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index d73232be1e99..06aa1616dabe 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -60,6 +60,7 @@ CFLAGS += -W -Wall -Wextra -Wno-unused-parameter -Wno-missing-field-initializers
 CFLAGS += $(filter-out -Wswitch-enum -Wnested-externs,$(EXTRA_WARNINGS))
 CFLAGS += -DPACKAGE='"bpftool"' -D__EXPORTED_HEADERS__ \
 	-I$(if $(OUTPUT),$(OUTPUT),.) \
+	$(if $(LIBBPF_OUTPUT),-I$(LIBBPF_OUTPUT)) \
 	-I$(srctree)/kernel/bpf/ \
 	-I$(srctree)/tools/include \
 	-I$(srctree)/tools/include/uapi \
@@ -137,7 +138,10 @@ endif
 BPFTOOL_BOOTSTRAP := $(BOOTSTRAP_OUTPUT)bpftool
 
 BOOTSTRAP_OBJS = $(addprefix $(BOOTSTRAP_OUTPUT),main.o common.o json_writer.o gen.o btf.o xlated_dumper.o btf_dumper.o disasm.o)
+$(BOOTSTRAP_OBJS): $(LIBBPF_BOOTSTRAP)
+
 OBJS = $(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o
+$(OBJS): $(LIBBPF)
 
 VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux)				\
 		     $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux)	\
diff --git a/tools/bpf/resolve_btfids/Makefile b/tools/bpf/resolve_btfids/Makefile
index bb9fa8de7e62..edc0c329cf74 100644
--- a/tools/bpf/resolve_btfids/Makefile
+++ b/tools/bpf/resolve_btfids/Makefile
@@ -26,6 +26,7 @@ LIBBPF_SRC := $(srctree)/tools/lib/bpf/
 SUBCMD_SRC := $(srctree)/tools/lib/subcmd/
 
 BPFOBJ     := $(OUTPUT)/libbpf/libbpf.a
+LIBBPF_OUT := $(abspath $(dir $(BPFOBJ)))/
 SUBCMDOBJ  := $(OUTPUT)/libsubcmd/libsubcmd.a
 
 BINARY     := $(OUTPUT)/resolve_btfids
@@ -41,11 +42,12 @@ $(SUBCMDOBJ): fixdep FORCE | $(OUTPUT)/libsubcmd
 	$(Q)$(MAKE) -C $(SUBCMD_SRC) OUTPUT=$(abspath $(dir $@))/ $(abspath $@)
 
 $(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(OUTPUT)/libbpf
-	$(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC)  OUTPUT=$(abspath $(dir $@))/ $(abspath $@)
+	$(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC)  OUTPUT=$(LIBBPF_OUT) $(abspath $@)
 
 CFLAGS := -g \
           -I$(srctree)/tools/include \
           -I$(srctree)/tools/include/uapi \
+          -I$(LIBBPF_OUT) \
           -I$(LIBBPF_SRC) \
           -I$(SUBCMD_SRC)
 
@@ -54,7 +56,7 @@ LIBS = -lelf -lz
 export srctree OUTPUT CFLAGS Q
 include $(srctree)/tools/build/Makefile.include
 
-$(BINARY_IN): fixdep FORCE | $(OUTPUT)
+$(BINARY_IN): $(BPFOBJ) fixdep FORCE | $(OUTPUT)
 	$(Q)$(MAKE) $(build)=resolve_btfids
 
 $(BINARY): $(BPFOBJ) $(SUBCMDOBJ) $(BINARY_IN)
diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index 74c3b73a5fbe..dab21e0c7cc2 100644
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -8,7 +8,8 @@ VERSION_SCRIPT := libbpf.map
 LIBBPF_VERSION := $(shell \
 	grep -oE '^LIBBPF_([0-9.]+)' $(VERSION_SCRIPT) | \
 	sort -rV | head -n1 | cut -d'_' -f2)
-LIBBPF_MAJOR_VERSION := $(firstword $(subst ., ,$(LIBBPF_VERSION)))
+LIBBPF_MAJOR_VERSION := $(word 1,$(subst ., ,$(LIBBPF_VERSION)))
+LIBBPF_MINOR_VERSION := $(word 2,$(subst ., ,$(LIBBPF_VERSION)))
 
 MAKEFLAGS += --no-print-directory
 
@@ -59,7 +60,8 @@ ifndef VERBOSE
   VERBOSE = 0
 endif
 
-INCLUDES = -I. -I$(srctree)/tools/include -I$(srctree)/tools/include/uapi
+INCLUDES = -I$(if $(OUTPUT),$(OUTPUT),.)				\
+	   -I$(srctree)/tools/include -I$(srctree)/tools/include/uapi
 
 export prefix libdir src obj
 
@@ -111,7 +113,9 @@ SHARED_OBJDIR	:= $(OUTPUT)sharedobjs/
 STATIC_OBJDIR	:= $(OUTPUT)staticobjs/
 BPF_IN_SHARED	:= $(SHARED_OBJDIR)libbpf-in.o
 BPF_IN_STATIC	:= $(STATIC_OBJDIR)libbpf-in.o
+VERSION_HDR	:= $(OUTPUT)libbpf_version.h
 BPF_HELPER_DEFS	:= $(OUTPUT)bpf_helper_defs.h
+BPF_GENERATED	:= $(BPF_HELPER_DEFS) $(VERSION_HDR)
 
 LIB_TARGET	:= $(addprefix $(OUTPUT),$(LIB_TARGET))
 LIB_FILE	:= $(addprefix $(OUTPUT),$(LIB_FILE))
@@ -136,7 +140,7 @@ all: fixdep
 
 all_cmd: $(CMD_TARGETS) check
 
-$(BPF_IN_SHARED): force $(BPF_HELPER_DEFS)
+$(BPF_IN_SHARED): force $(BPF_GENERATED)
 	@(test -f ../../include/uapi/linux/bpf.h -a -f ../../../include/uapi/linux/bpf.h && ( \
 	(diff -B ../../include/uapi/linux/bpf.h ../../../include/uapi/linux/bpf.h >/dev/null) || \
 	echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/bpf.h' differs from latest version at 'include/uapi/linux/bpf.h'" >&2 )) || true
@@ -154,13 +158,19 @@ $(BPF_IN_SHARED): force $(BPF_HELPER_DEFS)
 	echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/if_xdp.h' differs from latest version at 'include/uapi/linux/if_xdp.h'" >&2 )) || true
 	$(Q)$(MAKE) $(build)=libbpf OUTPUT=$(SHARED_OBJDIR) CFLAGS="$(CFLAGS) $(SHLIB_FLAGS)"
 
-$(BPF_IN_STATIC): force $(BPF_HELPER_DEFS)
+$(BPF_IN_STATIC): force $(BPF_GENERATED)
 	$(Q)$(MAKE) $(build)=libbpf OUTPUT=$(STATIC_OBJDIR)
 
 $(BPF_HELPER_DEFS): $(srctree)/tools/include/uapi/linux/bpf.h
 	$(QUIET_GEN)$(srctree)/scripts/bpf_doc.py --header \
 		--file $(srctree)/tools/include/uapi/linux/bpf.h > $(BPF_HELPER_DEFS)
 
+$(VERSION_HDR): force
+	$(QUIET_GEN)echo "/* This file was auto-generated. */" > $@
+	@echo "" >> $@
+	@echo "#define LIBBPF_MAJOR_VERSION $(LIBBPF_MAJOR_VERSION)" >> $@
+	@echo "#define LIBBPF_MINOR_VERSION $(LIBBPF_MINOR_VERSION)" >> $@
+
 $(OUTPUT)libbpf.so: $(OUTPUT)libbpf.so.$(LIBBPF_VERSION)
 
 $(OUTPUT)libbpf.so.$(LIBBPF_VERSION): $(BPF_IN_SHARED) $(VERSION_SCRIPT)
@@ -224,10 +234,10 @@ install_lib: all_cmd
 		cp -fpR $(LIB_FILE) $(DESTDIR)$(libdir_SQ)
 
 INSTALL_HEADERS = bpf.h libbpf.h btf.h libbpf_common.h libbpf_legacy.h xsk.h \
-		  bpf_helpers.h $(BPF_HELPER_DEFS) bpf_tracing.h	     \
+		  bpf_helpers.h $(BPF_GENERATED) bpf_tracing.h	     \
 		  bpf_endian.h bpf_core_read.h skel_internal.h
 
-install_headers: $(BPF_HELPER_DEFS)
+install_headers: $(BPF_GENERATED)
 	$(call QUIET_INSTALL, headers)					     \
 		$(foreach hdr,$(INSTALL_HEADERS),			     \
 			$(call do_install,$(hdr),$(prefix)/include/bpf,644);)
@@ -240,7 +250,7 @@ install: install_lib install_pkgconfig install_headers
 
 clean:
 	$(call QUIET_CLEAN, libbpf) $(RM) -rf $(CMD_TARGETS)		     \
-		*~ .*.d .*.cmd LIBBPF-CFLAGS $(BPF_HELPER_DEFS)		     \
+		*~ .*.d .*.cmd LIBBPF-CFLAGS $(BPF_GENERATED)		     \
 		$(SHARED_OBJDIR) $(STATIC_OBJDIR)			     \
 		$(addprefix $(OUTPUT),					     \
 			    *.o *.a *.so *.so.$(LIBBPF_MAJOR_VERSION) *.pc)
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 4a711f990904..f2e2fab950b7 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -50,9 +50,11 @@ LIBBPF_API struct btf *libbpf_find_kernel_btf(void);
 
 LIBBPF_API struct btf *btf__load_from_kernel_by_id(__u32 id);
 LIBBPF_API struct btf *btf__load_from_kernel_by_id_split(__u32 id, struct btf *base_btf);
+LIBBPF_DEPRECATED_SINCE(0, 6, "use btf__load_from_kernel_by_id instead")
 LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
 
 LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf);
+LIBBPF_DEPRECATED_SINCE(0, 6, "use btf__load_into_kernel instead")
 LIBBPF_API int btf__load(struct btf *btf);
 LIBBPF_API int btf__load_into_kernel(struct btf *btf);
 LIBBPF_API __s32 btf__find_by_name(const struct btf *btf,
diff --git a/tools/lib/bpf/libbpf_common.h b/tools/lib/bpf/libbpf_common.h
index 947d8bd8a7bb..36ac77f2bea2 100644
--- a/tools/lib/bpf/libbpf_common.h
+++ b/tools/lib/bpf/libbpf_common.h
@@ -10,6 +10,7 @@
 #define __LIBBPF_LIBBPF_COMMON_H
 
 #include <string.h>
+#include "libbpf_version.h"
 
 #ifndef LIBBPF_API
 #define LIBBPF_API __attribute__((visibility("default")))
@@ -17,6 +18,24 @@
 
 #define LIBBPF_DEPRECATED(msg) __attribute__((deprecated(msg)))
 
+/* Mark a symbol as deprecated when libbpf version is >= {major}.{minor} */
+#define LIBBPF_DEPRECATED_SINCE(major, minor, msg)			    \
+	__LIBBPF_MARK_DEPRECATED_ ## major ## _ ## minor		    \
+		(LIBBPF_DEPRECATED("libbpf v" # major "." # minor "+: " msg))
+
+#define __LIBBPF_CURRENT_VERSION_GEQ(major, minor)			    \
+	(LIBBPF_MAJOR_VERSION > (major) ||				    \
+	 (LIBBPF_MAJOR_VERSION == (major) && LIBBPF_MINOR_VERSION >= (minor)))
+
+/* Add checks for other versions below when planning deprecation of API symbols
+ * with the LIBBPF_DEPRECATED_SINCE macro.
+ */
+#if __LIBBPF_CURRENT_VERSION_GEQ(0, 6)
+#define __LIBBPF_MARK_DEPRECATED_0_6(X) X
+#else
+#define __LIBBPF_MARK_DEPRECATED_0_6(X)
+#endif
+
 /* Helper macro to declare and initialize libbpf options struct
  *
  * This dance with uninitialized declaration, followed by memset to zero,
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 866531c08e4f..1a4d30ff3275 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -512,14 +512,14 @@ $(OUTPUT)/test_cpp: test_cpp.cpp $(OUTPUT)/test_core_extern.skel.h $(BPFOBJ)
 	$(Q)$(CXX) $(CFLAGS) $(filter %.a %.o %.cpp,$^) $(LDLIBS) -o $@
 
 # Benchmark runner
-$(OUTPUT)/bench_%.o: benchs/bench_%.c bench.h
+$(OUTPUT)/bench_%.o: benchs/bench_%.c bench.h $(BPFOBJ)
 	$(call msg,CC,,$@)
 	$(Q)$(CC) $(CFLAGS) -c $(filter %.c,$^) $(LDLIBS) -o $@
 $(OUTPUT)/bench_rename.o: $(OUTPUT)/test_overhead.skel.h
 $(OUTPUT)/bench_trigger.o: $(OUTPUT)/trigger_bench.skel.h
 $(OUTPUT)/bench_ringbufs.o: $(OUTPUT)/ringbuf_bench.skel.h \
 			    $(OUTPUT)/perfbuf_bench.skel.h
-$(OUTPUT)/bench.o: bench.h testing_helpers.h
+$(OUTPUT)/bench.o: bench.h testing_helpers.h $(BPFOBJ)
 $(OUTPUT)/bench: LDLIBS += -lm
 $(OUTPUT)/bench: $(OUTPUT)/bench.o $(OUTPUT)/testing_helpers.o \
 		 $(OUTPUT)/bench_count.o \
-- 
cgit v1.2.3


From 2f383041278672332ab57c78570c30c47d6f35fd Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Mon, 13 Sep 2021 15:23:09 -0700
Subject: libbpf: Make libbpf_version.h non-auto-generated

Turn previously auto-generated libbpf_version.h header into a normal
header file. This prevents various tricky Makefile integration issues,
simplifies the overall build process, but also allows to further extend
it with some more versioning-related APIs in the future.

To prevent accidental out-of-sync versions as defined by libbpf.map and
libbpf_version.h, Makefile checks their consistency at build time.

Simultaneously with this change bump libbpf.map to v0.6.

Also undo adding libbpf's output directory into include path for
kernel/bpf/preload, bpftool, and resolve_btfids, which is not necessary
because libbpf_version.h is just a normal header like any other.

Fixes: 0b46b7550560 ("libbpf: Add LIBBPF_DEPRECATED_SINCE macro for scheduling API deprecations")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210913222309.3220849-1-andrii@kernel.org
---
 kernel/bpf/preload/Makefile       |  7 ++-----
 tools/bpf/bpftool/Makefile        |  1 -
 tools/bpf/resolve_btfids/Makefile |  1 -
 tools/lib/bpf/.gitignore          |  1 -
 tools/lib/bpf/Makefile            | 33 +++++++++++++++++++++------------
 tools/lib/bpf/libbpf.map          |  3 +++
 tools/lib/bpf/libbpf_version.h    |  9 +++++++++
 7 files changed, 35 insertions(+), 20 deletions(-)
 create mode 100644 tools/lib/bpf/libbpf_version.h

(limited to 'tools/lib')

diff --git a/kernel/bpf/preload/Makefile b/kernel/bpf/preload/Makefile
index ac29d4e9a384..1951332dd15f 100644
--- a/kernel/bpf/preload/Makefile
+++ b/kernel/bpf/preload/Makefile
@@ -10,15 +10,12 @@ LIBBPF_OUT = $(abspath $(obj))
 $(LIBBPF_A):
 	$(Q)$(MAKE) -C $(LIBBPF_SRCS) O=$(LIBBPF_OUT)/ OUTPUT=$(LIBBPF_OUT)/ $(LIBBPF_OUT)/libbpf.a
 
-userccflags += -I$(LIBBPF_OUT) -I $(srctree)/tools/include/ \
-	-I $(srctree)/tools/include/uapi \
+userccflags += -I $(srctree)/tools/include/ -I $(srctree)/tools/include/uapi \
 	-I $(srctree)/tools/lib/ -Wno-unused-result
 
 userprogs := bpf_preload_umd
 
-clean-files := $(userprogs) libbpf_version.h bpf_helper_defs.h FEATURE-DUMP.libbpf staticobjs/ feature/
-
-$(obj)/iterators/iterators.o: $(LIBBPF_A)
+clean-files := $(userprogs) bpf_helper_defs.h FEATURE-DUMP.libbpf staticobjs/ feature/
 
 bpf_preload_umd-objs := iterators/iterators.o
 bpf_preload_umd-userldlibs := $(LIBBPF_A) -lelf -lz
diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index 06aa1616dabe..1fcf5b01a193 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -60,7 +60,6 @@ CFLAGS += -W -Wall -Wextra -Wno-unused-parameter -Wno-missing-field-initializers
 CFLAGS += $(filter-out -Wswitch-enum -Wnested-externs,$(EXTRA_WARNINGS))
 CFLAGS += -DPACKAGE='"bpftool"' -D__EXPORTED_HEADERS__ \
 	-I$(if $(OUTPUT),$(OUTPUT),.) \
-	$(if $(LIBBPF_OUTPUT),-I$(LIBBPF_OUTPUT)) \
 	-I$(srctree)/kernel/bpf/ \
 	-I$(srctree)/tools/include \
 	-I$(srctree)/tools/include/uapi \
diff --git a/tools/bpf/resolve_btfids/Makefile b/tools/bpf/resolve_btfids/Makefile
index edc0c329cf74..08b75e314ae7 100644
--- a/tools/bpf/resolve_btfids/Makefile
+++ b/tools/bpf/resolve_btfids/Makefile
@@ -47,7 +47,6 @@ $(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(OUTPUT)/l
 CFLAGS := -g \
           -I$(srctree)/tools/include \
           -I$(srctree)/tools/include/uapi \
-          -I$(LIBBPF_OUT) \
           -I$(LIBBPF_SRC) \
           -I$(SUBCMD_SRC)
 
diff --git a/tools/lib/bpf/.gitignore b/tools/lib/bpf/.gitignore
index 5d4cfac671d5..0da84cb9e66d 100644
--- a/tools/lib/bpf/.gitignore
+++ b/tools/lib/bpf/.gitignore
@@ -1,5 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0-only
-libbpf_version.h
 libbpf.pc
 libbpf.so.*
 TAGS
diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index dab21e0c7cc2..0f766345506f 100644
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -113,9 +113,8 @@ SHARED_OBJDIR	:= $(OUTPUT)sharedobjs/
 STATIC_OBJDIR	:= $(OUTPUT)staticobjs/
 BPF_IN_SHARED	:= $(SHARED_OBJDIR)libbpf-in.o
 BPF_IN_STATIC	:= $(STATIC_OBJDIR)libbpf-in.o
-VERSION_HDR	:= $(OUTPUT)libbpf_version.h
 BPF_HELPER_DEFS	:= $(OUTPUT)bpf_helper_defs.h
-BPF_GENERATED	:= $(BPF_HELPER_DEFS) $(VERSION_HDR)
+BPF_GENERATED	:= $(BPF_HELPER_DEFS)
 
 LIB_TARGET	:= $(addprefix $(OUTPUT),$(LIB_TARGET))
 LIB_FILE	:= $(addprefix $(OUTPUT),$(LIB_FILE))
@@ -165,12 +164,6 @@ $(BPF_HELPER_DEFS): $(srctree)/tools/include/uapi/linux/bpf.h
 	$(QUIET_GEN)$(srctree)/scripts/bpf_doc.py --header \
 		--file $(srctree)/tools/include/uapi/linux/bpf.h > $(BPF_HELPER_DEFS)
 
-$(VERSION_HDR): force
-	$(QUIET_GEN)echo "/* This file was auto-generated. */" > $@
-	@echo "" >> $@
-	@echo "#define LIBBPF_MAJOR_VERSION $(LIBBPF_MAJOR_VERSION)" >> $@
-	@echo "#define LIBBPF_MINOR_VERSION $(LIBBPF_MINOR_VERSION)" >> $@
-
 $(OUTPUT)libbpf.so: $(OUTPUT)libbpf.so.$(LIBBPF_VERSION)
 
 $(OUTPUT)libbpf.so.$(LIBBPF_VERSION): $(BPF_IN_SHARED) $(VERSION_SCRIPT)
@@ -189,7 +182,7 @@ $(OUTPUT)libbpf.pc:
 		-e "s|@VERSION@|$(LIBBPF_VERSION)|" \
 		< libbpf.pc.template > $@
 
-check: check_abi
+check: check_abi check_version
 
 check_abi: $(OUTPUT)libbpf.so $(VERSION_SCRIPT)
 	@if [ "$(GLOBAL_SYM_COUNT)" != "$(VERSIONED_SYM_COUNT)" ]; then	 \
@@ -215,6 +208,21 @@ check_abi: $(OUTPUT)libbpf.so $(VERSION_SCRIPT)
 		exit 1;							 \
 	fi
 
+HDR_MAJ_VERSION := $(shell grep -oE '^\#define LIBBPF_MAJOR_VERSION ([0-9]+)$$' libbpf_version.h | cut -d' ' -f3)
+HDR_MIN_VERSION := $(shell grep -oE '^\#define LIBBPF_MINOR_VERSION ([0-9]+)$$' libbpf_version.h | cut -d' ' -f3)
+
+check_version: $(VERSION_SCRIPT) libbpf_version.h
+	@if [ "$(HDR_MAJ_VERSION)" != "$(LIBBPF_MAJOR_VERSION)" ]; then        \
+		echo "Error: libbpf major version mismatch detected: "	       \
+		     "'$(HDR_MAJ_VERSION)' != '$(LIBBPF_MAJOR_VERSION)'" >&2;  \
+		exit 1;							       \
+	fi
+	@if [ "$(HDR_MIN_VERSION)" != "$(LIBBPF_MINOR_VERSION)" ]; then	       \
+		echo "Error: libbpf minor version mismatch detected: "	       \
+		     "'$(HDR_MIN_VERSION)' != '$(LIBBPF_MINOR_VERSION)'" >&2;  \
+		exit 1;							       \
+	fi
+
 define do_install_mkdir
 	if [ ! -d '$(DESTDIR_SQ)$1' ]; then		\
 		$(INSTALL) -d -m 755 '$(DESTDIR_SQ)$1';	\
@@ -234,8 +242,9 @@ install_lib: all_cmd
 		cp -fpR $(LIB_FILE) $(DESTDIR)$(libdir_SQ)
 
 INSTALL_HEADERS = bpf.h libbpf.h btf.h libbpf_common.h libbpf_legacy.h xsk.h \
-		  bpf_helpers.h $(BPF_GENERATED) bpf_tracing.h	     \
-		  bpf_endian.h bpf_core_read.h skel_internal.h
+		  bpf_helpers.h $(BPF_GENERATED) bpf_tracing.h		     \
+		  bpf_endian.h bpf_core_read.h skel_internal.h		     \
+		  libbpf_version.h
 
 install_headers: $(BPF_GENERATED)
 	$(call QUIET_INSTALL, headers)					     \
@@ -255,7 +264,7 @@ clean:
 		$(addprefix $(OUTPUT),					     \
 			    *.o *.a *.so *.so.$(LIBBPF_MAJOR_VERSION) *.pc)
 
-PHONY += force cscope tags
+PHONY += force cscope tags check check_abi check_version
 force:
 
 cscope:
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index bbc53bb25f68..78ea62c9346f 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -386,3 +386,6 @@ LIBBPF_0.5.0 {
 		btf_dump__dump_type_data;
 		libbpf_set_strict_mode;
 } LIBBPF_0.4.0;
+
+LIBBPF_0.6.0 {
+} LIBBPF_0.5.0;
diff --git a/tools/lib/bpf/libbpf_version.h b/tools/lib/bpf/libbpf_version.h
new file mode 100644
index 000000000000..dd56d76f291c
--- /dev/null
+++ b/tools/lib/bpf/libbpf_version.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+/* Copyright (C) 2021 Facebook */
+#ifndef __LIBBPF_VERSION_H
+#define __LIBBPF_VERSION_H
+
+#define LIBBPF_MAJOR_VERSION 0
+#define LIBBPF_MINOR_VERSION 6
+
+#endif /* __LIBBPF_VERSION_H */
-- 
cgit v1.2.3


From ca304b40c20d5750f08200f0ad3445384646620c Mon Sep 17 00:00:00 2001
From: Rafael David Tinoco <rafaeldtinoco@gmail.com>
Date: Sun, 12 Sep 2021 03:48:44 -0300
Subject: libbpf: Introduce legacy kprobe events support

Allow kprobe tracepoint events creation through legacy interface, as the
kprobe dynamic PMUs support, used by default, was only created in v4.17.

Store legacy kprobe name in struct bpf_perf_link, instead of creating
a new "subclass" off of bpf_perf_link. This is ok as it's just two new
fields, which are also going to be reused for legacy uprobe support in
follow up patches.

Signed-off-by: Rafael David Tinoco <rafaeldtinoco@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210912064844.3181742-1-rafaeldtinoco@gmail.com
---
 tools/lib/bpf/libbpf.c | 128 +++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 124 insertions(+), 4 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 8f579c6666b2..9d99183bffba 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -8993,9 +8993,57 @@ int bpf_link__unpin(struct bpf_link *link)
 	return 0;
 }
 
+static int poke_kprobe_events(bool add, const char *name, bool retprobe, uint64_t offset)
+{
+	int fd, ret = 0;
+	pid_t p = getpid();
+	char cmd[260], probename[128], probefunc[128];
+	const char *file = "/sys/kernel/debug/tracing/kprobe_events";
+
+	if (retprobe)
+		snprintf(probename, sizeof(probename), "kretprobes/%s_libbpf_%u", name, p);
+	else
+		snprintf(probename, sizeof(probename), "kprobes/%s_libbpf_%u", name, p);
+
+	if (offset)
+		snprintf(probefunc, sizeof(probefunc), "%s+%zu", name, (size_t)offset);
+
+	if (add) {
+		snprintf(cmd, sizeof(cmd), "%c:%s %s",
+			 retprobe ? 'r' : 'p',
+			 probename,
+			 offset ? probefunc : name);
+	} else {
+		snprintf(cmd, sizeof(cmd), "-:%s", probename);
+	}
+
+	fd = open(file, O_WRONLY | O_APPEND, 0);
+	if (!fd)
+		return -errno;
+	ret = write(fd, cmd, strlen(cmd));
+	if (ret < 0)
+		ret = -errno;
+	close(fd);
+
+	return ret;
+}
+
+static inline int add_kprobe_event_legacy(const char *name, bool retprobe, uint64_t offset)
+{
+	return poke_kprobe_events(true, name, retprobe, offset);
+}
+
+static inline int remove_kprobe_event_legacy(const char *name, bool retprobe)
+{
+	return poke_kprobe_events(false, name, retprobe, 0);
+}
+
 struct bpf_link_perf {
 	struct bpf_link link;
 	int perf_event_fd;
+	/* legacy kprobe support: keep track of probe identifier and type */
+	char *legacy_probe_name;
+	bool legacy_is_retprobe;
 };
 
 static int bpf_link_perf_detach(struct bpf_link *link)
@@ -9010,13 +9058,19 @@ static int bpf_link_perf_detach(struct bpf_link *link)
 		close(perf_link->perf_event_fd);
 	close(link->fd);
 
-	return libbpf_err(err);
+	/* legacy kprobe needs to be removed after perf event fd closure */
+	if (perf_link->legacy_probe_name)
+		err = remove_kprobe_event_legacy(perf_link->legacy_probe_name,
+						 perf_link->legacy_is_retprobe);
+
+	return err;
 }
 
 static void bpf_link_perf_dealloc(struct bpf_link *link)
 {
 	struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link);
 
+	free(perf_link->legacy_probe_name);
 	free(perf_link);
 }
 
@@ -9130,6 +9184,18 @@ static int parse_uint_from_file(const char *file, const char *fmt)
 	return ret;
 }
 
+static int determine_kprobe_perf_type_legacy(const char *func_name, bool is_retprobe)
+{
+	char file[192];
+
+	snprintf(file, sizeof(file),
+		 "/sys/kernel/debug/tracing/events/%s/%s_libbpf_%d/id",
+		 is_retprobe ? "kretprobes" : "kprobes",
+		 func_name, getpid());
+
+	return parse_uint_from_file(file, "%d\n");
+}
+
 static int determine_kprobe_perf_type(void)
 {
 	const char *file = "/sys/bus/event_source/devices/kprobe/type";
@@ -9212,6 +9278,41 @@ static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name,
 	return pfd;
 }
 
+static int perf_event_kprobe_open_legacy(bool retprobe, const char *name, uint64_t offset, int pid)
+{
+	struct perf_event_attr attr = {};
+	char errmsg[STRERR_BUFSIZE];
+	int type, pfd, err;
+
+	err = add_kprobe_event_legacy(name, retprobe, offset);
+	if (err < 0) {
+		pr_warn("failed to add legacy kprobe event: %s\n",
+			libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
+		return err;
+	}
+	type = determine_kprobe_perf_type_legacy(name, retprobe);
+	if (type < 0) {
+		pr_warn("failed to determine legacy kprobe event id: %s\n",
+			libbpf_strerror_r(type, errmsg, sizeof(errmsg)));
+		return type;
+	}
+	attr.size = sizeof(attr);
+	attr.config = type;
+	attr.type = PERF_TYPE_TRACEPOINT;
+
+	pfd = syscall(__NR_perf_event_open, &attr,
+		      pid < 0 ? -1 : pid, /* pid */
+		      pid == -1 ? 0 : -1, /* cpu */
+		      -1 /* group_fd */,  PERF_FLAG_FD_CLOEXEC);
+	if (pfd < 0) {
+		err = -errno;
+		pr_warn("legacy kprobe perf_event_open() failed: %s\n",
+			libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
+		return err;
+	}
+	return pfd;
+}
+
 struct bpf_link *
 bpf_program__attach_kprobe_opts(struct bpf_program *prog,
 				const char *func_name,
@@ -9219,9 +9320,10 @@ bpf_program__attach_kprobe_opts(struct bpf_program *prog,
 {
 	DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts);
 	char errmsg[STRERR_BUFSIZE];
+	char *legacy_probe = NULL;
 	struct bpf_link *link;
 	unsigned long offset;
-	bool retprobe;
+	bool retprobe, legacy;
 	int pfd, err;
 
 	if (!OPTS_VALID(opts, bpf_kprobe_opts))
@@ -9231,8 +9333,19 @@ bpf_program__attach_kprobe_opts(struct bpf_program *prog,
 	offset = OPTS_GET(opts, offset, 0);
 	pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0);
 
-	pfd = perf_event_open_probe(false /* uprobe */, retprobe, func_name,
-				    offset, -1 /* pid */, 0 /* ref_ctr_off */);
+	legacy = determine_kprobe_perf_type() < 0;
+	if (!legacy) {
+		pfd = perf_event_open_probe(false /* uprobe */, retprobe,
+					    func_name, offset,
+					    -1 /* pid */, 0 /* ref_ctr_off */);
+	} else {
+		legacy_probe = strdup(func_name);
+		if (!legacy_probe)
+			return libbpf_err_ptr(-ENOMEM);
+
+		pfd = perf_event_kprobe_open_legacy(retprobe, func_name,
+						    offset, -1 /* pid */);
+	}
 	if (pfd < 0) {
 		pr_warn("prog '%s': failed to create %s '%s' perf event: %s\n",
 			prog->name, retprobe ? "kretprobe" : "kprobe", func_name,
@@ -9248,6 +9361,13 @@ bpf_program__attach_kprobe_opts(struct bpf_program *prog,
 			libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
 		return libbpf_err_ptr(err);
 	}
+	if (legacy) {
+		struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link);
+
+		perf_link->legacy_probe_name = legacy_probe;
+		perf_link->legacy_is_retprobe = retprobe;
+	}
+
 	return link;
 }
 
-- 
cgit v1.2.3


From 91b4d1d1d54431c72f3a7ff034f30a635f787426 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Mon, 13 Sep 2021 18:47:31 -0700
Subject: libbpf: Ensure BPF prog types are set before relocations

Refactor bpf_object__open() sequencing to perform BPF program type
detection based on SEC() definitions before we get to relocations
collection. This allows to have more information about BPF program by
the time we get to, say, struct_ops relocation gathering. This,
subsequently, simplifies struct_ops logic and removes the need to
perform extra find_sec_def() resolution.

With this patch libbpf will require all struct_ops BPF programs to be
marked with SEC("struct_ops") or SEC("struct_ops/xxx") annotations.
Real-world applications are already doing that through something like
selftests's BPF_STRUCT_OPS() macro. This change streamlines libbpf's
internal handling of SEC() definitions and is in the sprit of
upcoming libbpf-1.0 section strictness changes ([0]).

  [0] https://github.com/libbpf/libbpf/wiki/Libbpf:-the-road-to-v1.0#stricter-and-more-uniform-bpf-program-section-name-sec-handling

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210914014733.2768-3-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c | 93 +++++++++++++++++++++++++++-----------------------
 1 file changed, 51 insertions(+), 42 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 9d99183bffba..6abfbf283092 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -6373,12 +6373,37 @@ bpf_object__load_progs(struct bpf_object *obj, int log_level)
 
 static const struct bpf_sec_def *find_sec_def(const char *sec_name);
 
+static int bpf_object_init_progs(struct bpf_object *obj, const struct bpf_object_open_opts *opts)
+{
+	struct bpf_program *prog;
+
+	bpf_object__for_each_program(prog, obj) {
+		prog->sec_def = find_sec_def(prog->sec_name);
+		if (!prog->sec_def) {
+			/* couldn't guess, but user might manually specify */
+			pr_debug("prog '%s': unrecognized ELF section name '%s'\n",
+				prog->name, prog->sec_name);
+			continue;
+		}
+
+		if (prog->sec_def->is_sleepable)
+			prog->prog_flags |= BPF_F_SLEEPABLE;
+		bpf_program__set_type(prog, prog->sec_def->prog_type);
+		bpf_program__set_expected_attach_type(prog, prog->sec_def->expected_attach_type);
+
+		if (prog->sec_def->prog_type == BPF_PROG_TYPE_TRACING ||
+		    prog->sec_def->prog_type == BPF_PROG_TYPE_EXT)
+			prog->attach_prog_fd = OPTS_GET(opts, attach_prog_fd, 0);
+	}
+
+	return 0;
+}
+
 static struct bpf_object *
 __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz,
 		   const struct bpf_object_open_opts *opts)
 {
 	const char *obj_name, *kconfig, *btf_tmp_path;
-	struct bpf_program *prog;
 	struct bpf_object *obj;
 	char tmp_name[64];
 	int err;
@@ -6436,30 +6461,12 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz,
 	err = err ? : bpf_object__collect_externs(obj);
 	err = err ? : bpf_object__finalize_btf(obj);
 	err = err ? : bpf_object__init_maps(obj, opts);
+	err = err ? : bpf_object_init_progs(obj, opts);
 	err = err ? : bpf_object__collect_relos(obj);
 	if (err)
 		goto out;
-	bpf_object__elf_finish(obj);
 
-	bpf_object__for_each_program(prog, obj) {
-		prog->sec_def = find_sec_def(prog->sec_name);
-		if (!prog->sec_def) {
-			/* couldn't guess, but user might manually specify */
-			pr_debug("prog '%s': unrecognized ELF section name '%s'\n",
-				prog->name, prog->sec_name);
-			continue;
-		}
-
-		if (prog->sec_def->is_sleepable)
-			prog->prog_flags |= BPF_F_SLEEPABLE;
-		bpf_program__set_type(prog, prog->sec_def->prog_type);
-		bpf_program__set_expected_attach_type(prog,
-				prog->sec_def->expected_attach_type);
-
-		if (prog->sec_def->prog_type == BPF_PROG_TYPE_TRACING ||
-		    prog->sec_def->prog_type == BPF_PROG_TYPE_EXT)
-			prog->attach_prog_fd = OPTS_GET(opts, attach_prog_fd, 0);
-	}
+	bpf_object__elf_finish(obj);
 
 	return obj;
 out:
@@ -8250,35 +8257,37 @@ static int bpf_object__collect_st_ops_relos(struct bpf_object *obj,
 			return -EINVAL;
 		}
 
-		if (prog->type == BPF_PROG_TYPE_UNSPEC) {
-			const struct bpf_sec_def *sec_def;
-
-			sec_def = find_sec_def(prog->sec_name);
-			if (sec_def &&
-			    sec_def->prog_type != BPF_PROG_TYPE_STRUCT_OPS) {
-				/* for pr_warn */
-				prog->type = sec_def->prog_type;
-				goto invalid_prog;
-			}
+		/* prevent the use of BPF prog with invalid type */
+		if (prog->type != BPF_PROG_TYPE_STRUCT_OPS) {
+			pr_warn("struct_ops reloc %s: prog %s is not struct_ops BPF program\n",
+				map->name, prog->name);
+			return -EINVAL;
+		}
 
-			prog->type = BPF_PROG_TYPE_STRUCT_OPS;
+		/* if we haven't yet processed this BPF program, record proper
+		 * attach_btf_id and member_idx
+		 */
+		if (!prog->attach_btf_id) {
 			prog->attach_btf_id = st_ops->type_id;
 			prog->expected_attach_type = member_idx;
-		} else if (prog->type != BPF_PROG_TYPE_STRUCT_OPS ||
-			   prog->attach_btf_id != st_ops->type_id ||
-			   prog->expected_attach_type != member_idx) {
-			goto invalid_prog;
 		}
+
+		/* struct_ops BPF prog can be re-used between multiple
+		 * .struct_ops as long as it's the same struct_ops struct
+		 * definition and the same function pointer field
+		 */
+		if (prog->attach_btf_id != st_ops->type_id ||
+		    prog->expected_attach_type != member_idx) {
+			pr_warn("struct_ops reloc %s: cannot use prog %s in sec %s with type %u attach_btf_id %u expected_attach_type %u for func ptr %s\n",
+				map->name, prog->name, prog->sec_name, prog->type,
+				prog->attach_btf_id, prog->expected_attach_type, name);
+			return -EINVAL;
+		}
+
 		st_ops->progs[member_idx] = prog;
 	}
 
 	return 0;
-
-invalid_prog:
-	pr_warn("struct_ops reloc %s: cannot use prog %s in sec %s with type %u attach_btf_id %u expected_attach_type %u for func ptr %s\n",
-		map->name, prog->name, prog->sec_name, prog->type,
-		prog->attach_btf_id, prog->expected_attach_type, name);
-	return -EINVAL;
 }
 
 #define BTF_TRACE_PREFIX "btf_trace_"
-- 
cgit v1.2.3


From 5532dfd42e4846e84d346a6dfe01e477e35baa65 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Mon, 13 Sep 2021 18:47:32 -0700
Subject: libbpf: Simplify BPF program auto-attach code

Remove the need to explicitly pass bpf_sec_def for auto-attachable BPF
programs, as it is already recorded at bpf_object__open() time for all
recognized type of BPF programs. This further reduces number of explicit
calls to find_sec_def(), simplifying further refactorings.

No functional changes are done by this patch.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210914014733.2768-4-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c | 61 ++++++++++++++++++--------------------------------
 1 file changed, 22 insertions(+), 39 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 6abfbf283092..e473fbd2b361 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -218,8 +218,7 @@ struct reloc_desc {
 
 struct bpf_sec_def;
 
-typedef struct bpf_link *(*attach_fn_t)(const struct bpf_sec_def *sec,
-					struct bpf_program *prog);
+typedef struct bpf_link *(*attach_fn_t)(struct bpf_program *prog);
 
 struct bpf_sec_def {
 	const char *sec;
@@ -7920,18 +7919,12 @@ void bpf_program__set_expected_attach_type(struct bpf_program *prog,
 	__VA_ARGS__							    \
 }
 
-static struct bpf_link *attach_kprobe(const struct bpf_sec_def *sec,
-				      struct bpf_program *prog);
-static struct bpf_link *attach_tp(const struct bpf_sec_def *sec,
-				  struct bpf_program *prog);
-static struct bpf_link *attach_raw_tp(const struct bpf_sec_def *sec,
-				      struct bpf_program *prog);
-static struct bpf_link *attach_trace(const struct bpf_sec_def *sec,
-				     struct bpf_program *prog);
-static struct bpf_link *attach_lsm(const struct bpf_sec_def *sec,
-				   struct bpf_program *prog);
-static struct bpf_link *attach_iter(const struct bpf_sec_def *sec,
-				    struct bpf_program *prog);
+static struct bpf_link *attach_kprobe(struct bpf_program *prog);
+static struct bpf_link *attach_tp(struct bpf_program *prog);
+static struct bpf_link *attach_raw_tp(struct bpf_program *prog);
+static struct bpf_link *attach_trace(struct bpf_program *prog);
+static struct bpf_link *attach_lsm(struct bpf_program *prog);
+static struct bpf_link *attach_iter(struct bpf_program *prog);
 
 static const struct bpf_sec_def section_defs[] = {
 	BPF_PROG_SEC("socket",			BPF_PROG_TYPE_SOCKET_FILTER),
@@ -9391,8 +9384,7 @@ struct bpf_link *bpf_program__attach_kprobe(struct bpf_program *prog,
 	return bpf_program__attach_kprobe_opts(prog, func_name, &opts);
 }
 
-static struct bpf_link *attach_kprobe(const struct bpf_sec_def *sec,
-				      struct bpf_program *prog)
+static struct bpf_link *attach_kprobe(struct bpf_program *prog)
 {
 	DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts);
 	unsigned long offset = 0;
@@ -9401,8 +9393,8 @@ static struct bpf_link *attach_kprobe(const struct bpf_sec_def *sec,
 	char *func;
 	int n, err;
 
-	func_name = prog->sec_name + sec->len;
-	opts.retprobe = strcmp(sec->sec, "kretprobe/") == 0;
+	func_name = prog->sec_name + prog->sec_def->len;
+	opts.retprobe = strcmp(prog->sec_def->sec, "kretprobe/") == 0;
 
 	n = sscanf(func_name, "%m[a-zA-Z0-9_.]+%li", &func, &offset);
 	if (n < 1) {
@@ -9565,8 +9557,7 @@ struct bpf_link *bpf_program__attach_tracepoint(struct bpf_program *prog,
 	return bpf_program__attach_tracepoint_opts(prog, tp_category, tp_name, NULL);
 }
 
-static struct bpf_link *attach_tp(const struct bpf_sec_def *sec,
-				  struct bpf_program *prog)
+static struct bpf_link *attach_tp(struct bpf_program *prog)
 {
 	char *sec_name, *tp_cat, *tp_name;
 	struct bpf_link *link;
@@ -9576,7 +9567,7 @@ static struct bpf_link *attach_tp(const struct bpf_sec_def *sec,
 		return libbpf_err_ptr(-ENOMEM);
 
 	/* extract "tp/<category>/<name>" */
-	tp_cat = sec_name + sec->len;
+	tp_cat = sec_name + prog->sec_def->len;
 	tp_name = strchr(tp_cat, '/');
 	if (!tp_name) {
 		free(sec_name);
@@ -9620,10 +9611,9 @@ struct bpf_link *bpf_program__attach_raw_tracepoint(struct bpf_program *prog,
 	return link;
 }
 
-static struct bpf_link *attach_raw_tp(const struct bpf_sec_def *sec,
-				      struct bpf_program *prog)
+static struct bpf_link *attach_raw_tp(struct bpf_program *prog)
 {
-	const char *tp_name = prog->sec_name + sec->len;
+	const char *tp_name = prog->sec_name + prog->sec_def->len;
 
 	return bpf_program__attach_raw_tracepoint(prog, tp_name);
 }
@@ -9668,14 +9658,12 @@ struct bpf_link *bpf_program__attach_lsm(struct bpf_program *prog)
 	return bpf_program__attach_btf_id(prog);
 }
 
-static struct bpf_link *attach_trace(const struct bpf_sec_def *sec,
-				     struct bpf_program *prog)
+static struct bpf_link *attach_trace(struct bpf_program *prog)
 {
 	return bpf_program__attach_trace(prog);
 }
 
-static struct bpf_link *attach_lsm(const struct bpf_sec_def *sec,
-				   struct bpf_program *prog)
+static struct bpf_link *attach_lsm(struct bpf_program *prog)
 {
 	return bpf_program__attach_lsm(prog);
 }
@@ -9806,21 +9794,17 @@ bpf_program__attach_iter(struct bpf_program *prog,
 	return link;
 }
 
-static struct bpf_link *attach_iter(const struct bpf_sec_def *sec,
-				    struct bpf_program *prog)
+static struct bpf_link *attach_iter(struct bpf_program *prog)
 {
 	return bpf_program__attach_iter(prog, NULL);
 }
 
 struct bpf_link *bpf_program__attach(struct bpf_program *prog)
 {
-	const struct bpf_sec_def *sec_def;
-
-	sec_def = find_sec_def(prog->sec_name);
-	if (!sec_def || !sec_def->attach_fn)
+	if (!prog->sec_def || !prog->sec_def->attach_fn)
 		return libbpf_err_ptr(-ESRCH);
 
-	return sec_def->attach_fn(sec_def, prog);
+	return prog->sec_def->attach_fn(prog);
 }
 
 static int bpf_link__detach_struct_ops(struct bpf_link *link)
@@ -10899,16 +10883,15 @@ int bpf_object__attach_skeleton(struct bpf_object_skeleton *s)
 	for (i = 0; i < s->prog_cnt; i++) {
 		struct bpf_program *prog = *s->progs[i].prog;
 		struct bpf_link **link = s->progs[i].link;
-		const struct bpf_sec_def *sec_def;
 
 		if (!prog->load)
 			continue;
 
-		sec_def = find_sec_def(prog->sec_name);
-		if (!sec_def || !sec_def->attach_fn)
+		/* auto-attaching not supported for this program */
+		if (!prog->sec_def || !prog->sec_def->attach_fn)
 			continue;
 
-		*link = sec_def->attach_fn(sec_def, prog);
+		*link = prog->sec_def->attach_fn(prog);
 		err = libbpf_get_error(*link);
 		if (err) {
 			pr_warn("failed to auto-attach program '%s': %d\n",
-- 
cgit v1.2.3


From b6291a6f30d35bd4459dc35aac2f30669a4356ac Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Mon, 13 Sep 2021 18:47:33 -0700
Subject: libbpf: Minimize explicit iterator of section definition array

Remove almost all the code that explicitly iterated BPF program section
definitions in favor of using find_sec_def(). The only remaining user of
section_defs is libbpf_get_type_names that has to iterate all of them to
construct its result.

Having one internal API entry point for section definitions will
simplify further refactorings around libbpf's program section
definitions parsing.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210914014733.2768-5-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c | 46 +++++++++++++++++++---------------------------
 1 file changed, 19 insertions(+), 27 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index e473fbd2b361..62ed073ea944 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -8438,22 +8438,13 @@ static int libbpf_find_attach_btf_id(struct bpf_program *prog, int *btf_obj_fd,
 	__u32 attach_prog_fd = prog->attach_prog_fd;
 	const char *name = prog->sec_name, *attach_name;
 	const struct bpf_sec_def *sec = NULL;
-	int i, err = 0;
+	int err = 0;
 
 	if (!name)
 		return -EINVAL;
 
-	for (i = 0; i < ARRAY_SIZE(section_defs); i++) {
-		if (!section_defs[i].is_attach_btf)
-			continue;
-		if (strncmp(name, section_defs[i].sec, section_defs[i].len))
-			continue;
-
-		sec = &section_defs[i];
-		break;
-	}
-
-	if (!sec) {
+	sec = find_sec_def(name);
+	if (!sec || !sec->is_attach_btf) {
 		pr_warn("failed to identify BTF ID based on ELF section name '%s'\n", name);
 		return -ESRCH;
 	}
@@ -8491,27 +8482,28 @@ int libbpf_attach_type_by_name(const char *name,
 			       enum bpf_attach_type *attach_type)
 {
 	char *type_names;
-	int i;
+	const struct bpf_sec_def *sec_def;
 
 	if (!name)
 		return libbpf_err(-EINVAL);
 
-	for (i = 0; i < ARRAY_SIZE(section_defs); i++) {
-		if (strncmp(name, section_defs[i].sec, section_defs[i].len))
-			continue;
-		if (!section_defs[i].is_attachable)
-			return libbpf_err(-EINVAL);
-		*attach_type = section_defs[i].expected_attach_type;
-		return 0;
-	}
-	pr_debug("failed to guess attach type based on ELF section name '%s'\n", name);
-	type_names = libbpf_get_type_names(true);
-	if (type_names != NULL) {
-		pr_debug("attachable section(type) names are:%s\n", type_names);
-		free(type_names);
+	sec_def = find_sec_def(name);
+	if (!sec_def) {
+		pr_debug("failed to guess attach type based on ELF section name '%s'\n", name);
+		type_names = libbpf_get_type_names(true);
+		if (type_names != NULL) {
+			pr_debug("attachable section(type) names are:%s\n", type_names);
+			free(type_names);
+		}
+
+		return libbpf_err(-EINVAL);
 	}
 
-	return libbpf_err(-EINVAL);
+	if (!sec_def->is_attachable)
+		return libbpf_err(-EINVAL);
+
+	*attach_type = sec_def->expected_attach_type;
+	return 0;
 }
 
 int bpf_map__fd(const struct bpf_map *map)
-- 
cgit v1.2.3


From 30025e8bd80fdc5a4159ec7f9511121ea561f456 Mon Sep 17 00:00:00 2001
From: Yonghong Song <yhs@fb.com>
Date: Tue, 14 Sep 2021 15:30:20 -0700
Subject: libbpf: Rename btf_{hash,equal}_int to btf_{hash,equal}_int_tag

This patch renames functions btf_{hash,equal}_int() to
btf_{hash,equal}_int_tag() so they can be reused for
BTF_KIND_TAG support. There is no functionality change for
this patch.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210914223020.245829-1-yhs@fb.com
---
 tools/lib/bpf/btf.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 77dc24d58302..7cb6ebf1be37 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -3256,8 +3256,8 @@ static bool btf_equal_common(struct btf_type *t1, struct btf_type *t2)
 	       t1->size == t2->size;
 }
 
-/* Calculate type signature hash of INT. */
-static long btf_hash_int(struct btf_type *t)
+/* Calculate type signature hash of INT or TAG. */
+static long btf_hash_int_tag(struct btf_type *t)
 {
 	__u32 info = *(__u32 *)(t + 1);
 	long h;
@@ -3267,8 +3267,8 @@ static long btf_hash_int(struct btf_type *t)
 	return h;
 }
 
-/* Check structural equality of two INTs. */
-static bool btf_equal_int(struct btf_type *t1, struct btf_type *t2)
+/* Check structural equality of two INTs or TAGs. */
+static bool btf_equal_int_tag(struct btf_type *t1, struct btf_type *t2)
 {
 	__u32 info1, info2;
 
@@ -3535,7 +3535,7 @@ static int btf_dedup_prep(struct btf_dedup *d)
 			h = btf_hash_common(t);
 			break;
 		case BTF_KIND_INT:
-			h = btf_hash_int(t);
+			h = btf_hash_int_tag(t);
 			break;
 		case BTF_KIND_ENUM:
 			h = btf_hash_enum(t);
@@ -3593,11 +3593,11 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id)
 		return 0;
 
 	case BTF_KIND_INT:
-		h = btf_hash_int(t);
+		h = btf_hash_int_tag(t);
 		for_each_dedup_cand(d, hash_entry, h) {
 			cand_id = (__u32)(long)hash_entry->value;
 			cand = btf_type_by_id(d->btf, cand_id);
-			if (btf_equal_int(t, cand)) {
+			if (btf_equal_int_tag(t, cand)) {
 				new_id = cand_id;
 				break;
 			}
@@ -3881,7 +3881,7 @@ static int btf_dedup_is_equiv(struct btf_dedup *d, __u32 cand_id,
 
 	switch (cand_kind) {
 	case BTF_KIND_INT:
-		return btf_equal_int(cand_type, canon_type);
+		return btf_equal_int_tag(cand_type, canon_type);
 
 	case BTF_KIND_ENUM:
 		if (d->opts.dont_resolve_fwds)
-- 
cgit v1.2.3


From 5b84bd10363e36ceb7c4c1ae749a3fc8adf8df45 Mon Sep 17 00:00:00 2001
From: Yonghong Song <yhs@fb.com>
Date: Tue, 14 Sep 2021 15:30:25 -0700
Subject: libbpf: Add support for BTF_KIND_TAG

Add BTF_KIND_TAG support for parsing and dedup.
Also added sanitization for BTF_KIND_TAG. If BTF_KIND_TAG is not
supported in the kernel, sanitize it to INTs.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210914223025.246687-1-yhs@fb.com
---
 tools/lib/bpf/btf.c             | 68 +++++++++++++++++++++++++++++++++++++++++
 tools/lib/bpf/btf.h             | 15 +++++++++
 tools/lib/bpf/btf_dump.c        |  3 ++
 tools/lib/bpf/libbpf.c          | 31 +++++++++++++++++--
 tools/lib/bpf/libbpf.map        |  2 ++
 tools/lib/bpf/libbpf_internal.h |  2 ++
 6 files changed, 118 insertions(+), 3 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 7cb6ebf1be37..6ad63e4d418a 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -304,6 +304,8 @@ static int btf_type_size(const struct btf_type *t)
 		return base_size + sizeof(struct btf_var);
 	case BTF_KIND_DATASEC:
 		return base_size + vlen * sizeof(struct btf_var_secinfo);
+	case BTF_KIND_TAG:
+		return base_size + sizeof(struct btf_tag);
 	default:
 		pr_debug("Unsupported BTF_KIND:%u\n", btf_kind(t));
 		return -EINVAL;
@@ -376,6 +378,9 @@ static int btf_bswap_type_rest(struct btf_type *t)
 			v->size = bswap_32(v->size);
 		}
 		return 0;
+	case BTF_KIND_TAG:
+		btf_tag(t)->component_idx = bswap_32(btf_tag(t)->component_idx);
+		return 0;
 	default:
 		pr_debug("Unsupported BTF_KIND:%u\n", btf_kind(t));
 		return -EINVAL;
@@ -586,6 +591,7 @@ __s64 btf__resolve_size(const struct btf *btf, __u32 type_id)
 		case BTF_KIND_CONST:
 		case BTF_KIND_RESTRICT:
 		case BTF_KIND_VAR:
+		case BTF_KIND_TAG:
 			type_id = t->type;
 			break;
 		case BTF_KIND_ARRAY:
@@ -2440,6 +2446,48 @@ int btf__add_datasec_var_info(struct btf *btf, int var_type_id, __u32 offset, __
 	return 0;
 }
 
+/*
+ * Append new BTF_KIND_TAG type with:
+ *   - *value* - non-empty/non-NULL string;
+ *   - *ref_type_id* - referenced type ID, it might not exist yet;
+ *   - *component_idx* - -1 for tagging reference type, otherwise struct/union
+ *     member or function argument index;
+ * Returns:
+ *   - >0, type ID of newly added BTF type;
+ *   - <0, on error.
+ */
+int btf__add_tag(struct btf *btf, const char *value, int ref_type_id,
+		 int component_idx)
+{
+	struct btf_type *t;
+	int sz, value_off;
+
+	if (!value || !value[0] || component_idx < -1)
+		return libbpf_err(-EINVAL);
+
+	if (validate_type_id(ref_type_id))
+		return libbpf_err(-EINVAL);
+
+	if (btf_ensure_modifiable(btf))
+		return libbpf_err(-ENOMEM);
+
+	sz = sizeof(struct btf_type) + sizeof(struct btf_tag);
+	t = btf_add_type_mem(btf, sz);
+	if (!t)
+		return libbpf_err(-ENOMEM);
+
+	value_off = btf__add_str(btf, value);
+	if (value_off < 0)
+		return value_off;
+
+	t->name_off = value_off;
+	t->info = btf_type_info(BTF_KIND_TAG, 0, false);
+	t->type = ref_type_id;
+	btf_tag(t)->component_idx = component_idx;
+
+	return btf_commit_type(btf, sz);
+}
+
 struct btf_ext_sec_setup_param {
 	__u32 off;
 	__u32 len;
@@ -3535,6 +3583,7 @@ static int btf_dedup_prep(struct btf_dedup *d)
 			h = btf_hash_common(t);
 			break;
 		case BTF_KIND_INT:
+		case BTF_KIND_TAG:
 			h = btf_hash_int_tag(t);
 			break;
 		case BTF_KIND_ENUM:
@@ -3590,6 +3639,7 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id)
 	case BTF_KIND_FUNC_PROTO:
 	case BTF_KIND_VAR:
 	case BTF_KIND_DATASEC:
+	case BTF_KIND_TAG:
 		return 0;
 
 	case BTF_KIND_INT:
@@ -4210,6 +4260,23 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id)
 		}
 		break;
 
+	case BTF_KIND_TAG:
+		ref_type_id = btf_dedup_ref_type(d, t->type);
+		if (ref_type_id < 0)
+			return ref_type_id;
+		t->type = ref_type_id;
+
+		h = btf_hash_int_tag(t);
+		for_each_dedup_cand(d, hash_entry, h) {
+			cand_id = (__u32)(long)hash_entry->value;
+			cand = btf_type_by_id(d->btf, cand_id);
+			if (btf_equal_int_tag(t, cand)) {
+				new_id = cand_id;
+				break;
+			}
+		}
+		break;
+
 	case BTF_KIND_ARRAY: {
 		struct btf_array *info = btf_array(t);
 
@@ -4482,6 +4549,7 @@ int btf_type_visit_type_ids(struct btf_type *t, type_id_visit_fn visit, void *ct
 	case BTF_KIND_TYPEDEF:
 	case BTF_KIND_FUNC:
 	case BTF_KIND_VAR:
+	case BTF_KIND_TAG:
 		return visit(&t->type, ctx);
 
 	case BTF_KIND_ARRAY: {
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index f2e2fab950b7..659ea8a2769b 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -143,6 +143,10 @@ LIBBPF_API int btf__add_datasec(struct btf *btf, const char *name, __u32 byte_sz
 LIBBPF_API int btf__add_datasec_var_info(struct btf *btf, int var_type_id,
 					 __u32 offset, __u32 byte_sz);
 
+/* tag construction API */
+LIBBPF_API int btf__add_tag(struct btf *btf, const char *value, int ref_type_id,
+			    int component_idx);
+
 struct btf_dedup_opts {
 	unsigned int dedup_table_size;
 	bool dont_resolve_fwds;
@@ -330,6 +334,11 @@ static inline bool btf_is_float(const struct btf_type *t)
 	return btf_kind(t) == BTF_KIND_FLOAT;
 }
 
+static inline bool btf_is_tag(const struct btf_type *t)
+{
+	return btf_kind(t) == BTF_KIND_TAG;
+}
+
 static inline __u8 btf_int_encoding(const struct btf_type *t)
 {
 	return BTF_INT_ENCODING(*(__u32 *)(t + 1));
@@ -398,6 +407,12 @@ btf_var_secinfos(const struct btf_type *t)
 	return (struct btf_var_secinfo *)(t + 1);
 }
 
+struct btf_tag;
+static inline struct btf_tag *btf_tag(const struct btf_type *t)
+{
+	return (struct btf_tag *)(t + 1);
+}
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif
diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index e4b483f15fb9..ad6df97295ae 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -316,6 +316,7 @@ static int btf_dump_mark_referenced(struct btf_dump *d)
 		case BTF_KIND_TYPEDEF:
 		case BTF_KIND_FUNC:
 		case BTF_KIND_VAR:
+		case BTF_KIND_TAG:
 			d->type_states[t->type].referenced = 1;
 			break;
 
@@ -583,6 +584,7 @@ static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr)
 	case BTF_KIND_FUNC:
 	case BTF_KIND_VAR:
 	case BTF_KIND_DATASEC:
+	case BTF_KIND_TAG:
 		d->type_states[id].order_state = ORDERED;
 		return 0;
 
@@ -2215,6 +2217,7 @@ static int btf_dump_dump_type_data(struct btf_dump *d,
 	case BTF_KIND_FWD:
 	case BTF_KIND_FUNC:
 	case BTF_KIND_FUNC_PROTO:
+	case BTF_KIND_TAG:
 		err = btf_dump_unsupported_data(d, t, id);
 		break;
 	case BTF_KIND_INT:
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 62ed073ea944..62a43c408d73 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -195,6 +195,8 @@ enum kern_feature_id {
 	FEAT_BTF_FLOAT,
 	/* BPF perf link support */
 	FEAT_PERF_LINK,
+	/* BTF_KIND_TAG support */
+	FEAT_BTF_TAG,
 	__FEAT_CNT,
 };
 
@@ -1986,6 +1988,7 @@ static const char *__btf_kind_str(__u16 kind)
 	case BTF_KIND_VAR: return "var";
 	case BTF_KIND_DATASEC: return "datasec";
 	case BTF_KIND_FLOAT: return "float";
+	case BTF_KIND_TAG: return "tag";
 	default: return "unknown";
 	}
 }
@@ -2485,8 +2488,9 @@ static bool btf_needs_sanitization(struct bpf_object *obj)
 	bool has_datasec = kernel_supports(obj, FEAT_BTF_DATASEC);
 	bool has_float = kernel_supports(obj, FEAT_BTF_FLOAT);
 	bool has_func = kernel_supports(obj, FEAT_BTF_FUNC);
+	bool has_tag = kernel_supports(obj, FEAT_BTF_TAG);
 
-	return !has_func || !has_datasec || !has_func_global || !has_float;
+	return !has_func || !has_datasec || !has_func_global || !has_float || !has_tag;
 }
 
 static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
@@ -2495,14 +2499,15 @@ static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
 	bool has_datasec = kernel_supports(obj, FEAT_BTF_DATASEC);
 	bool has_float = kernel_supports(obj, FEAT_BTF_FLOAT);
 	bool has_func = kernel_supports(obj, FEAT_BTF_FUNC);
+	bool has_tag = kernel_supports(obj, FEAT_BTF_TAG);
 	struct btf_type *t;
 	int i, j, vlen;
 
 	for (i = 1; i <= btf__get_nr_types(btf); i++) {
 		t = (struct btf_type *)btf__type_by_id(btf, i);
 
-		if (!has_datasec && btf_is_var(t)) {
-			/* replace VAR with INT */
+		if ((!has_datasec && btf_is_var(t)) || (!has_tag && btf_is_tag(t))) {
+			/* replace VAR/TAG with INT */
 			t->info = BTF_INFO_ENC(BTF_KIND_INT, 0, 0);
 			/*
 			 * using size = 1 is the safest choice, 4 will be too
@@ -4212,6 +4217,23 @@ static int probe_kern_btf_float(void)
 					     strs, sizeof(strs)));
 }
 
+static int probe_kern_btf_tag(void)
+{
+	static const char strs[] = "\0tag";
+	__u32 types[] = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),  /* [1] */
+		/* VAR x */                                     /* [2] */
+		BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_VAR, 0, 0), 1),
+		BTF_VAR_STATIC,
+		/* attr */
+		BTF_TYPE_TAG_ENC(1, 2, -1),
+	};
+
+	return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
+					     strs, sizeof(strs)));
+}
+
 static int probe_kern_array_mmap(void)
 {
 	struct bpf_create_map_attr attr = {
@@ -4428,6 +4450,9 @@ static struct kern_feature_desc {
 	[FEAT_PERF_LINK] = {
 		"BPF perf link support", probe_perf_link,
 	},
+	[FEAT_BTF_TAG] = {
+		"BTF_KIND_TAG support", probe_kern_btf_tag,
+	},
 };
 
 static bool kernel_supports(const struct bpf_object *obj, enum kern_feature_id feat_id)
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 78ea62c9346f..9e649cf9e771 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -388,4 +388,6 @@ LIBBPF_0.5.0 {
 } LIBBPF_0.4.0;
 
 LIBBPF_0.6.0 {
+	global:
+		btf__add_tag;
 } LIBBPF_0.5.0;
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index 4f6ff5c23695..ceb0c98979bc 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -69,6 +69,8 @@
 #define BTF_VAR_SECINFO_ENC(type, offset, size) (type), (offset), (size)
 #define BTF_TYPE_FLOAT_ENC(name, sz) \
 	BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_FLOAT, 0, 0), sz)
+#define BTF_TYPE_TAG_ENC(value, type, component_idx) \
+	BTF_TYPE_ENC(value, BTF_INFO_ENC(BTF_KIND_TAG, 0, 0), type), (component_idx)
 
 #ifndef likely
 #define likely(x) __builtin_expect(!!(x), 1)
-- 
cgit v1.2.3


From 69cd823956ba8ce266a901170b1060db8073bddd Mon Sep 17 00:00:00 2001
From: Grant Seltzer <grantseltzer@gmail.com>
Date: Tue, 14 Sep 2021 22:19:52 -0400
Subject: libbpf: Add sphinx code documentation comments

This adds comments above five functions in btf.h which document
their uses. These comments are of a format that doxygen and sphinx
can pick up and render. These are rendered by libbpf.readthedocs.org

Signed-off-by: Grant Seltzer <grantseltzer@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210915021951.117186-1-grantseltzer@gmail.com
---
 tools/lib/bpf/btf.h | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 659ea8a2769b..2cfe31327920 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
 /* Copyright (c) 2018 Facebook */
+/*! \file */
 
 #ifndef __LIBBPF_BTF_H
 #define __LIBBPF_BTF_H
@@ -30,11 +31,80 @@ enum btf_endianness {
 	BTF_BIG_ENDIAN = 1,
 };
 
+/**
+ * @brief **btf__free()** frees all data of a BTF object
+ * @param btf BTF object to free
+ */
 LIBBPF_API void btf__free(struct btf *btf);
 
+/**
+ * @brief **btf__new()** creates a new instance of a BTF object from the raw
+ * bytes of an ELF's BTF section
+ * @param data raw bytes
+ * @param size number of bytes passed in `data`
+ * @return new BTF object instance which has to be eventually freed with
+ * **btf__free()**
+ *
+ * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract
+ * error code from such a pointer `libbpf_get_error()` should be used. If
+ * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is
+ * returned on error instead. In both cases thread-local `errno` variable is
+ * always set to error code as well.
+ */
 LIBBPF_API struct btf *btf__new(const void *data, __u32 size);
+
+/**
+ * @brief **btf__new_split()** create a new instance of a BTF object from the
+ * provided raw data bytes. It takes another BTF instance, **base_btf**, which
+ * serves as a base BTF, which is extended by types in a newly created BTF
+ * instance
+ * @param data raw bytes
+ * @param size length of raw bytes
+ * @param base_btf the base BTF object
+ * @return new BTF object instance which has to be eventually freed with
+ * **btf__free()**
+ *
+ * If *base_btf* is NULL, `btf__new_split()` is equivalent to `btf__new()` and
+ * creates non-split BTF.
+ *
+ * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract
+ * error code from such a pointer `libbpf_get_error()` should be used. If
+ * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is
+ * returned on error instead. In both cases thread-local `errno` variable is
+ * always set to error code as well.
+ */
 LIBBPF_API struct btf *btf__new_split(const void *data, __u32 size, struct btf *base_btf);
+
+/**
+ * @brief **btf__new_empty()** creates an empty BTF object.  Use
+ * `btf__add_*()` to populate such BTF object.
+ * @return new BTF object instance which has to be eventually freed with
+ * **btf__free()**
+ *
+ * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract
+ * error code from such a pointer `libbpf_get_error()` should be used. If
+ * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is
+ * returned on error instead. In both cases thread-local `errno` variable is
+ * always set to error code as well.
+ */
 LIBBPF_API struct btf *btf__new_empty(void);
+
+/**
+ * @brief **btf__new_empty_split()** creates an unpopulated BTF object from an
+ * ELF BTF section except with a base BTF on top of which split BTF should be
+ * based
+ * @return new BTF object instance which has to be eventually freed with
+ * **btf__free()**
+ *
+ * If *base_btf* is NULL, `btf__new_empty_split()` is equivalent to
+ * `btf__new_empty()` and creates non-split BTF.
+ *
+ * On error, error-code-encoded-as-pointer is returned, not a NULL. To extract
+ * error code from such a pointer `libbpf_get_error()` should be used. If
+ * `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)` is enabled, NULL is
+ * returned on error instead. In both cases thread-local `errno` variable is
+ * always set to error code as well.
+ */
 LIBBPF_API struct btf *btf__new_empty_split(struct btf *base_btf);
 
 LIBBPF_API struct btf *btf__parse(const char *path, struct btf_ext **btf_ext);
-- 
cgit v1.2.3


From f11f86a3931b5d533aed1be1720fbd55bd63174d Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Wed, 15 Sep 2021 18:58:30 -0700
Subject: libbpf: Use pre-setup sec_def in libbpf_find_attach_btf_id()

Don't perform another search for sec_def inside
libbpf_find_attach_btf_id(), as each recognized bpf_program already has
prog->sec_def set.

Also remove unnecessary NULL check for prog->sec_name, as it can never
be NULL.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210916015836.1248906-2-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 62a43c408d73..5ba11b249e9b 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -8461,19 +8461,15 @@ static int libbpf_find_attach_btf_id(struct bpf_program *prog, int *btf_obj_fd,
 {
 	enum bpf_attach_type attach_type = prog->expected_attach_type;
 	__u32 attach_prog_fd = prog->attach_prog_fd;
-	const char *name = prog->sec_name, *attach_name;
-	const struct bpf_sec_def *sec = NULL;
+	const char *attach_name;
 	int err = 0;
 
-	if (!name)
-		return -EINVAL;
-
-	sec = find_sec_def(name);
-	if (!sec || !sec->is_attach_btf) {
-		pr_warn("failed to identify BTF ID based on ELF section name '%s'\n", name);
+	if (!prog->sec_def || !prog->sec_def->is_attach_btf) {
+		pr_warn("failed to identify BTF ID based on ELF section name '%s'\n",
+			prog->sec_name);
 		return -ESRCH;
 	}
-	attach_name = name + sec->len;
+	attach_name = prog->sec_name + prog->sec_def->len;
 
 	/* BPF program's BTF ID */
 	if (attach_prog_fd) {
-- 
cgit v1.2.3


From 277641859e833549722eb82c97cbc2d55421df7c Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Wed, 15 Sep 2021 18:58:32 -0700
Subject: libbpf: Deprecated bpf_object_open_opts.relaxed_core_relocs

It's relevant and hasn't been doing anything for a long while now.
Deprecated it.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210916015836.1248906-4-andrii@kernel.org
---
 tools/lib/bpf/libbpf.h | 1 +
 1 file changed, 1 insertion(+)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 2f6f0e15d1e7..7111e8d651de 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -83,6 +83,7 @@ struct bpf_object_open_opts {
 	 * Non-relocatable instructions are replaced with invalid ones to
 	 * prevent accidental errors.
 	 * */
+	LIBBPF_DEPRECATED_SINCE(0, 6, "field has no effect")
 	bool relaxed_core_relocs;
 	/* maps that set the 'pinning' attribute in their definition will have
 	 * their pin_path attribute set to a file in this directory, and be
-- 
cgit v1.2.3


From 2d5ec1c66e25f0b4dd895a211e651a12dec2ef4f Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Wed, 15 Sep 2021 18:58:33 -0700
Subject: libbpf: Allow skipping attach_func_name in
 bpf_program__set_attach_target()

Allow to use bpf_program__set_attach_target to only set target attach
program FD, while letting libbpf to use target attach function name from
SEC() definition. This might be useful for some scenarios where
bpf_object contains multiple related freplace BPF programs intended to
replace different sub-programs in target BPF program. In such case all
programs will have the same attach_prog_fd, but different
attach_func_name. It's convenient to specify such target function names
declaratively in SEC() definitions, but attach_prog_fd is a dynamic
runtime setting.

To simplify such scenario, allow bpf_program__set_attach_target() to
delay BTF ID resolution till the BPF program load time by providing NULL
attach_func_name. In that case the behavior will be similar to using
bpf_object_open_opts.attach_prog_fd (which is marked deprecated since
v0.7), but has the benefit of allowing more control by user in what is
attached to what. Such setup allows having BPF programs attached to
different target attach_prog_fd with target functions still declaratively
recorded in BPF source code in SEC() definitions.

Selftests changes in the next patch should make this more obvious.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210916015836.1248906-5-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 5ba11b249e9b..552d05a85cbb 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -10643,18 +10643,29 @@ int bpf_program__set_attach_target(struct bpf_program *prog,
 {
 	int btf_obj_fd = 0, btf_id = 0, err;
 
-	if (!prog || attach_prog_fd < 0 || !attach_func_name)
+	if (!prog || attach_prog_fd < 0)
 		return libbpf_err(-EINVAL);
 
 	if (prog->obj->loaded)
 		return libbpf_err(-EINVAL);
 
+	if (attach_prog_fd && !attach_func_name) {
+		/* remember attach_prog_fd and let bpf_program__load() find
+		 * BTF ID during the program load
+		 */
+		prog->attach_prog_fd = attach_prog_fd;
+		return 0;
+	}
+
 	if (attach_prog_fd) {
 		btf_id = libbpf_find_prog_btf_id(attach_func_name,
 						 attach_prog_fd);
 		if (btf_id < 0)
 			return libbpf_err(btf_id);
 	} else {
+		if (!attach_func_name)
+			return libbpf_err(-EINVAL);
+
 		/* load btf_vmlinux, if not yet */
 		err = bpf_object__load_vmlinux_btf(prog->obj, true);
 		if (err)
-- 
cgit v1.2.3


From 91b555d73e53879fc6d4cf82c8c0e14c00ce212d Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Wed, 15 Sep 2021 18:58:35 -0700
Subject: libbpf: Schedule open_opts.attach_prog_fd deprecation since v0.7

bpf_object_open_opts.attach_prog_fd makes a pretty strong assumption
that bpf_object contains either only single freplace BPF program or all
of BPF programs in BPF object are freplaces intended to replace
different subprograms of the same target BPF program. This seems both
a bit confusing, too assuming, and limiting.

We've had bpf_program__set_attach_target() API which allows more
fine-grained control over this, on a per-program level. As such, mark
open_opts.attach_prog_fd as deprecated starting from v0.7, so that we
have one more universal way of setting freplace targets. With previous
change to allow NULL attach_func_name argument, and especially combined
with BPF skeleton, arguable bpf_program__set_attach_target() is a more
convenient and explicit API as well.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210916015836.1248906-7-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c        | 3 +++
 tools/lib/bpf/libbpf.h        | 2 ++
 tools/lib/bpf/libbpf_common.h | 5 +++++
 3 files changed, 10 insertions(+)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 552d05a85cbb..6aeeb0e82acc 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -6415,9 +6415,12 @@ static int bpf_object_init_progs(struct bpf_object *obj, const struct bpf_object
 		bpf_program__set_type(prog, prog->sec_def->prog_type);
 		bpf_program__set_expected_attach_type(prog, prog->sec_def->expected_attach_type);
 
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
 		if (prog->sec_def->prog_type == BPF_PROG_TYPE_TRACING ||
 		    prog->sec_def->prog_type == BPF_PROG_TYPE_EXT)
 			prog->attach_prog_fd = OPTS_GET(opts, attach_prog_fd, 0);
+#pragma GCC diagnostic pop
 	}
 
 	return 0;
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 7111e8d651de..52b7ee090037 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -90,6 +90,8 @@ struct bpf_object_open_opts {
 	 * auto-pinned to that path on load; defaults to "/sys/fs/bpf".
 	 */
 	const char *pin_root_path;
+
+	LIBBPF_DEPRECATED_SINCE(0, 7, "use bpf_program__set_attach_target() on each individual bpf_program")
 	__u32 attach_prog_fd;
 	/* Additional kernel config content that augments and overrides
 	 * system Kconfig for CONFIG_xxx externs.
diff --git a/tools/lib/bpf/libbpf_common.h b/tools/lib/bpf/libbpf_common.h
index 36ac77f2bea2..aaa1efbf6f51 100644
--- a/tools/lib/bpf/libbpf_common.h
+++ b/tools/lib/bpf/libbpf_common.h
@@ -35,6 +35,11 @@
 #else
 #define __LIBBPF_MARK_DEPRECATED_0_6(X)
 #endif
+#if __LIBBPF_CURRENT_VERSION_GEQ(0, 7)
+#define __LIBBPF_MARK_DEPRECATED_0_7(X) X
+#else
+#define __LIBBPF_MARK_DEPRECATED_0_7(X)
+#endif
 
 /* Helper macro to declare and initialize libbpf options struct
  *
-- 
cgit v1.2.3


From 942025c9f37ee45e69eb5f39a2877afab66d9555 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Wed, 15 Sep 2021 18:58:36 -0700
Subject: libbpf: Constify all high-level program attach APIs

Attach APIs shouldn't need to modify bpf_program/bpf_map structs, so
change all struct bpf_program and struct bpf_map pointers to const
pointers. This is completely backwards compatible with no functional
change.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210916015836.1248906-8-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c | 68 +++++++++++++++++++++++++-------------------------
 tools/lib/bpf/libbpf.h | 36 +++++++++++++-------------
 2 files changed, 52 insertions(+), 52 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 6aeeb0e82acc..da65a1666a5e 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -220,7 +220,7 @@ struct reloc_desc {
 
 struct bpf_sec_def;
 
-typedef struct bpf_link *(*attach_fn_t)(struct bpf_program *prog);
+typedef struct bpf_link *(*attach_fn_t)(const struct bpf_program *prog);
 
 struct bpf_sec_def {
 	const char *sec;
@@ -7947,12 +7947,12 @@ void bpf_program__set_expected_attach_type(struct bpf_program *prog,
 	__VA_ARGS__							    \
 }
 
-static struct bpf_link *attach_kprobe(struct bpf_program *prog);
-static struct bpf_link *attach_tp(struct bpf_program *prog);
-static struct bpf_link *attach_raw_tp(struct bpf_program *prog);
-static struct bpf_link *attach_trace(struct bpf_program *prog);
-static struct bpf_link *attach_lsm(struct bpf_program *prog);
-static struct bpf_link *attach_iter(struct bpf_program *prog);
+static struct bpf_link *attach_kprobe(const struct bpf_program *prog);
+static struct bpf_link *attach_tp(const struct bpf_program *prog);
+static struct bpf_link *attach_raw_tp(const struct bpf_program *prog);
+static struct bpf_link *attach_trace(const struct bpf_program *prog);
+static struct bpf_link *attach_lsm(const struct bpf_program *prog);
+static struct bpf_link *attach_iter(const struct bpf_program *prog);
 
 static const struct bpf_sec_def section_defs[] = {
 	BPF_PROG_SEC("socket",			BPF_PROG_TYPE_SOCKET_FILTER),
@@ -9092,7 +9092,7 @@ static void bpf_link_perf_dealloc(struct bpf_link *link)
 	free(perf_link);
 }
 
-struct bpf_link *bpf_program__attach_perf_event_opts(struct bpf_program *prog, int pfd,
+struct bpf_link *bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd,
 						     const struct bpf_perf_event_opts *opts)
 {
 	char errmsg[STRERR_BUFSIZE];
@@ -9167,7 +9167,7 @@ err_out:
 	return libbpf_err_ptr(err);
 }
 
-struct bpf_link *bpf_program__attach_perf_event(struct bpf_program *prog, int pfd)
+struct bpf_link *bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd)
 {
 	return bpf_program__attach_perf_event_opts(prog, pfd, NULL);
 }
@@ -9332,7 +9332,7 @@ static int perf_event_kprobe_open_legacy(bool retprobe, const char *name, uint64
 }
 
 struct bpf_link *
-bpf_program__attach_kprobe_opts(struct bpf_program *prog,
+bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
 				const char *func_name,
 				const struct bpf_kprobe_opts *opts)
 {
@@ -9389,7 +9389,7 @@ bpf_program__attach_kprobe_opts(struct bpf_program *prog,
 	return link;
 }
 
-struct bpf_link *bpf_program__attach_kprobe(struct bpf_program *prog,
+struct bpf_link *bpf_program__attach_kprobe(const struct bpf_program *prog,
 					    bool retprobe,
 					    const char *func_name)
 {
@@ -9400,7 +9400,7 @@ struct bpf_link *bpf_program__attach_kprobe(struct bpf_program *prog,
 	return bpf_program__attach_kprobe_opts(prog, func_name, &opts);
 }
 
-static struct bpf_link *attach_kprobe(struct bpf_program *prog)
+static struct bpf_link *attach_kprobe(const struct bpf_program *prog)
 {
 	DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts);
 	unsigned long offset = 0;
@@ -9432,7 +9432,7 @@ static struct bpf_link *attach_kprobe(struct bpf_program *prog)
 }
 
 LIBBPF_API struct bpf_link *
-bpf_program__attach_uprobe_opts(struct bpf_program *prog, pid_t pid,
+bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
 				const char *binary_path, size_t func_offset,
 				const struct bpf_uprobe_opts *opts)
 {
@@ -9472,7 +9472,7 @@ bpf_program__attach_uprobe_opts(struct bpf_program *prog, pid_t pid,
 	return link;
 }
 
-struct bpf_link *bpf_program__attach_uprobe(struct bpf_program *prog,
+struct bpf_link *bpf_program__attach_uprobe(const struct bpf_program *prog,
 					    bool retprobe, pid_t pid,
 					    const char *binary_path,
 					    size_t func_offset)
@@ -9532,7 +9532,7 @@ static int perf_event_open_tracepoint(const char *tp_category,
 	return pfd;
 }
 
-struct bpf_link *bpf_program__attach_tracepoint_opts(struct bpf_program *prog,
+struct bpf_link *bpf_program__attach_tracepoint_opts(const struct bpf_program *prog,
 						     const char *tp_category,
 						     const char *tp_name,
 						     const struct bpf_tracepoint_opts *opts)
@@ -9566,14 +9566,14 @@ struct bpf_link *bpf_program__attach_tracepoint_opts(struct bpf_program *prog,
 	return link;
 }
 
-struct bpf_link *bpf_program__attach_tracepoint(struct bpf_program *prog,
+struct bpf_link *bpf_program__attach_tracepoint(const struct bpf_program *prog,
 						const char *tp_category,
 						const char *tp_name)
 {
 	return bpf_program__attach_tracepoint_opts(prog, tp_category, tp_name, NULL);
 }
 
-static struct bpf_link *attach_tp(struct bpf_program *prog)
+static struct bpf_link *attach_tp(const struct bpf_program *prog)
 {
 	char *sec_name, *tp_cat, *tp_name;
 	struct bpf_link *link;
@@ -9597,7 +9597,7 @@ static struct bpf_link *attach_tp(struct bpf_program *prog)
 	return link;
 }
 
-struct bpf_link *bpf_program__attach_raw_tracepoint(struct bpf_program *prog,
+struct bpf_link *bpf_program__attach_raw_tracepoint(const struct bpf_program *prog,
 						    const char *tp_name)
 {
 	char errmsg[STRERR_BUFSIZE];
@@ -9627,7 +9627,7 @@ struct bpf_link *bpf_program__attach_raw_tracepoint(struct bpf_program *prog,
 	return link;
 }
 
-static struct bpf_link *attach_raw_tp(struct bpf_program *prog)
+static struct bpf_link *attach_raw_tp(const struct bpf_program *prog)
 {
 	const char *tp_name = prog->sec_name + prog->sec_def->len;
 
@@ -9635,7 +9635,7 @@ static struct bpf_link *attach_raw_tp(struct bpf_program *prog)
 }
 
 /* Common logic for all BPF program types that attach to a btf_id */
-static struct bpf_link *bpf_program__attach_btf_id(struct bpf_program *prog)
+static struct bpf_link *bpf_program__attach_btf_id(const struct bpf_program *prog)
 {
 	char errmsg[STRERR_BUFSIZE];
 	struct bpf_link *link;
@@ -9664,28 +9664,28 @@ static struct bpf_link *bpf_program__attach_btf_id(struct bpf_program *prog)
 	return (struct bpf_link *)link;
 }
 
-struct bpf_link *bpf_program__attach_trace(struct bpf_program *prog)
+struct bpf_link *bpf_program__attach_trace(const struct bpf_program *prog)
 {
 	return bpf_program__attach_btf_id(prog);
 }
 
-struct bpf_link *bpf_program__attach_lsm(struct bpf_program *prog)
+struct bpf_link *bpf_program__attach_lsm(const struct bpf_program *prog)
 {
 	return bpf_program__attach_btf_id(prog);
 }
 
-static struct bpf_link *attach_trace(struct bpf_program *prog)
+static struct bpf_link *attach_trace(const struct bpf_program *prog)
 {
 	return bpf_program__attach_trace(prog);
 }
 
-static struct bpf_link *attach_lsm(struct bpf_program *prog)
+static struct bpf_link *attach_lsm(const struct bpf_program *prog)
 {
 	return bpf_program__attach_lsm(prog);
 }
 
 static struct bpf_link *
-bpf_program__attach_fd(struct bpf_program *prog, int target_fd, int btf_id,
+bpf_program__attach_fd(const struct bpf_program *prog, int target_fd, int btf_id,
 		       const char *target_name)
 {
 	DECLARE_LIBBPF_OPTS(bpf_link_create_opts, opts,
@@ -9721,24 +9721,24 @@ bpf_program__attach_fd(struct bpf_program *prog, int target_fd, int btf_id,
 }
 
 struct bpf_link *
-bpf_program__attach_cgroup(struct bpf_program *prog, int cgroup_fd)
+bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd)
 {
 	return bpf_program__attach_fd(prog, cgroup_fd, 0, "cgroup");
 }
 
 struct bpf_link *
-bpf_program__attach_netns(struct bpf_program *prog, int netns_fd)
+bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd)
 {
 	return bpf_program__attach_fd(prog, netns_fd, 0, "netns");
 }
 
-struct bpf_link *bpf_program__attach_xdp(struct bpf_program *prog, int ifindex)
+struct bpf_link *bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex)
 {
 	/* target_fd/target_ifindex use the same field in LINK_CREATE */
 	return bpf_program__attach_fd(prog, ifindex, 0, "xdp");
 }
 
-struct bpf_link *bpf_program__attach_freplace(struct bpf_program *prog,
+struct bpf_link *bpf_program__attach_freplace(const struct bpf_program *prog,
 					      int target_fd,
 					      const char *attach_func_name)
 {
@@ -9771,7 +9771,7 @@ struct bpf_link *bpf_program__attach_freplace(struct bpf_program *prog,
 }
 
 struct bpf_link *
-bpf_program__attach_iter(struct bpf_program *prog,
+bpf_program__attach_iter(const struct bpf_program *prog,
 			 const struct bpf_iter_attach_opts *opts)
 {
 	DECLARE_LIBBPF_OPTS(bpf_link_create_opts, link_create_opts);
@@ -9810,12 +9810,12 @@ bpf_program__attach_iter(struct bpf_program *prog,
 	return link;
 }
 
-static struct bpf_link *attach_iter(struct bpf_program *prog)
+static struct bpf_link *attach_iter(const struct bpf_program *prog)
 {
 	return bpf_program__attach_iter(prog, NULL);
 }
 
-struct bpf_link *bpf_program__attach(struct bpf_program *prog)
+struct bpf_link *bpf_program__attach(const struct bpf_program *prog)
 {
 	if (!prog->sec_def || !prog->sec_def->attach_fn)
 		return libbpf_err_ptr(-ESRCH);
@@ -9833,7 +9833,7 @@ static int bpf_link__detach_struct_ops(struct bpf_link *link)
 	return 0;
 }
 
-struct bpf_link *bpf_map__attach_struct_ops(struct bpf_map *map)
+struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map)
 {
 	struct bpf_struct_ops *st_ops;
 	struct bpf_link *link;
@@ -10918,7 +10918,7 @@ int bpf_object__attach_skeleton(struct bpf_object_skeleton *s)
 		if (!prog->sec_def || !prog->sec_def->attach_fn)
 			continue;
 
-		*link = prog->sec_def->attach_fn(prog);
+		*link = bpf_program__attach(prog);
 		err = libbpf_get_error(*link);
 		if (err) {
 			pr_warn("failed to auto-attach program '%s': %d\n",
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 52b7ee090037..c90e3d79e72c 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -246,7 +246,7 @@ LIBBPF_API int bpf_link__detach(struct bpf_link *link);
 LIBBPF_API int bpf_link__destroy(struct bpf_link *link);
 
 LIBBPF_API struct bpf_link *
-bpf_program__attach(struct bpf_program *prog);
+bpf_program__attach(const struct bpf_program *prog);
 
 struct bpf_perf_event_opts {
 	/* size of this struct, for forward/backward compatiblity */
@@ -257,10 +257,10 @@ struct bpf_perf_event_opts {
 #define bpf_perf_event_opts__last_field bpf_cookie
 
 LIBBPF_API struct bpf_link *
-bpf_program__attach_perf_event(struct bpf_program *prog, int pfd);
+bpf_program__attach_perf_event(const struct bpf_program *prog, int pfd);
 
 LIBBPF_API struct bpf_link *
-bpf_program__attach_perf_event_opts(struct bpf_program *prog, int pfd,
+bpf_program__attach_perf_event_opts(const struct bpf_program *prog, int pfd,
 				    const struct bpf_perf_event_opts *opts);
 
 struct bpf_kprobe_opts {
@@ -277,10 +277,10 @@ struct bpf_kprobe_opts {
 #define bpf_kprobe_opts__last_field retprobe
 
 LIBBPF_API struct bpf_link *
-bpf_program__attach_kprobe(struct bpf_program *prog, bool retprobe,
+bpf_program__attach_kprobe(const struct bpf_program *prog, bool retprobe,
 			   const char *func_name);
 LIBBPF_API struct bpf_link *
-bpf_program__attach_kprobe_opts(struct bpf_program *prog,
+bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
                                 const char *func_name,
                                 const struct bpf_kprobe_opts *opts);
 
@@ -300,11 +300,11 @@ struct bpf_uprobe_opts {
 #define bpf_uprobe_opts__last_field retprobe
 
 LIBBPF_API struct bpf_link *
-bpf_program__attach_uprobe(struct bpf_program *prog, bool retprobe,
+bpf_program__attach_uprobe(const struct bpf_program *prog, bool retprobe,
 			   pid_t pid, const char *binary_path,
 			   size_t func_offset);
 LIBBPF_API struct bpf_link *
-bpf_program__attach_uprobe_opts(struct bpf_program *prog, pid_t pid,
+bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
 				const char *binary_path, size_t func_offset,
 				const struct bpf_uprobe_opts *opts);
 
@@ -317,35 +317,35 @@ struct bpf_tracepoint_opts {
 #define bpf_tracepoint_opts__last_field bpf_cookie
 
 LIBBPF_API struct bpf_link *
-bpf_program__attach_tracepoint(struct bpf_program *prog,
+bpf_program__attach_tracepoint(const struct bpf_program *prog,
 			       const char *tp_category,
 			       const char *tp_name);
 LIBBPF_API struct bpf_link *
-bpf_program__attach_tracepoint_opts(struct bpf_program *prog,
+bpf_program__attach_tracepoint_opts(const struct bpf_program *prog,
 				    const char *tp_category,
 				    const char *tp_name,
 				    const struct bpf_tracepoint_opts *opts);
 
 LIBBPF_API struct bpf_link *
-bpf_program__attach_raw_tracepoint(struct bpf_program *prog,
+bpf_program__attach_raw_tracepoint(const struct bpf_program *prog,
 				   const char *tp_name);
 LIBBPF_API struct bpf_link *
-bpf_program__attach_trace(struct bpf_program *prog);
+bpf_program__attach_trace(const struct bpf_program *prog);
 LIBBPF_API struct bpf_link *
-bpf_program__attach_lsm(struct bpf_program *prog);
+bpf_program__attach_lsm(const struct bpf_program *prog);
 LIBBPF_API struct bpf_link *
-bpf_program__attach_cgroup(struct bpf_program *prog, int cgroup_fd);
+bpf_program__attach_cgroup(const struct bpf_program *prog, int cgroup_fd);
 LIBBPF_API struct bpf_link *
-bpf_program__attach_netns(struct bpf_program *prog, int netns_fd);
+bpf_program__attach_netns(const struct bpf_program *prog, int netns_fd);
 LIBBPF_API struct bpf_link *
-bpf_program__attach_xdp(struct bpf_program *prog, int ifindex);
+bpf_program__attach_xdp(const struct bpf_program *prog, int ifindex);
 LIBBPF_API struct bpf_link *
-bpf_program__attach_freplace(struct bpf_program *prog,
+bpf_program__attach_freplace(const struct bpf_program *prog,
 			     int target_fd, const char *attach_func_name);
 
 struct bpf_map;
 
-LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(struct bpf_map *map);
+LIBBPF_API struct bpf_link *bpf_map__attach_struct_ops(const struct bpf_map *map);
 
 struct bpf_iter_attach_opts {
 	size_t sz; /* size of this struct for forward/backward compatibility */
@@ -355,7 +355,7 @@ struct bpf_iter_attach_opts {
 #define bpf_iter_attach_opts__last_field link_info_len
 
 LIBBPF_API struct bpf_link *
-bpf_program__attach_iter(struct bpf_program *prog,
+bpf_program__attach_iter(const struct bpf_program *prog,
 			 const struct bpf_iter_attach_opts *opts);
 
 struct bpf_insn;
-- 
cgit v1.2.3


From c2758baa9798bf75d79a9aad8792edb8b694373e Mon Sep 17 00:00:00 2001
From: Dave Marchevsky <davemarchevsky@fb.com>
Date: Fri, 17 Sep 2021 11:29:06 -0700
Subject: libbpf: Modify bpf_printk to choose helper based on arg count

Instead of being a thin wrapper which calls into bpf_trace_printk,
libbpf's bpf_printk convenience macro now chooses between
bpf_trace_printk and bpf_trace_vprintk. If the arg count (excluding
format string) is >3, use bpf_trace_vprintk, otherwise use the older
helper.

The motivation behind this added complexity - instead of migrating
entirely to bpf_trace_vprintk - is to maintain good developer experience
for users compiling against new libbpf but running on older kernels.
Users who are passing <=3 args to bpf_printk will see no change in their
bytecode.

__bpf_vprintk functions similarly to BPF_SEQ_PRINTF and BPF_SNPRINTF
macros elsewhere in the file - it allows use of bpf_trace_vprintk
without manual conversion of varargs to u64 array. Previous
implementation of bpf_printk macro is moved to __bpf_printk for use by
the new implementation.

This does change behavior of bpf_printk calls with >3 args in the "new
libbpf, old kernels" scenario. Before this patch, attempting to use 4
args to bpf_printk results in a compile-time error. After this patch,
using bpf_printk with 4 args results in a trace_vprintk helper call
being emitted and a load-time failure on older kernels.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210917182911.2426606-5-davemarchevsky@fb.com
---
 tools/lib/bpf/bpf_helpers.h | 45 +++++++++++++++++++++++++++++++++++++--------
 1 file changed, 37 insertions(+), 8 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index b9987c3efa3c..55a308796625 100644
--- a/tools/lib/bpf/bpf_helpers.h
+++ b/tools/lib/bpf/bpf_helpers.h
@@ -14,14 +14,6 @@
 #define __type(name, val) typeof(val) *name
 #define __array(name, val) typeof(val) *name[]
 
-/* Helper macro to print out debug messages */
-#define bpf_printk(fmt, ...)				\
-({							\
-	char ____fmt[] = fmt;				\
-	bpf_trace_printk(____fmt, sizeof(____fmt),	\
-			 ##__VA_ARGS__);		\
-})
-
 /*
  * Helper macro to place programs, maps, license in
  * different sections in elf_bpf file. Section names
@@ -224,4 +216,41 @@ enum libbpf_tristate {
 		     ___param, sizeof(___param));		\
 })
 
+#define __bpf_printk(fmt, ...)				\
+({							\
+	char ____fmt[] = fmt;				\
+	bpf_trace_printk(____fmt, sizeof(____fmt),	\
+			 ##__VA_ARGS__);		\
+})
+
+/*
+ * __bpf_vprintk wraps the bpf_trace_vprintk helper with variadic arguments
+ * instead of an array of u64.
+ */
+#define __bpf_vprintk(fmt, args...)				\
+({								\
+	static const char ___fmt[] = fmt;			\
+	unsigned long long ___param[___bpf_narg(args)];		\
+								\
+	_Pragma("GCC diagnostic push")				\
+	_Pragma("GCC diagnostic ignored \"-Wint-conversion\"")	\
+	___bpf_fill(___param, args);				\
+	_Pragma("GCC diagnostic pop")				\
+								\
+	bpf_trace_vprintk(___fmt, sizeof(___fmt),		\
+			  ___param, sizeof(___param));		\
+})
+
+/* Use __bpf_printk when bpf_printk call has 3 or fewer fmt args
+ * Otherwise use __bpf_vprintk
+ */
+#define ___bpf_pick_printk(...) \
+	___bpf_nth(_, ##__VA_ARGS__, __bpf_vprintk, __bpf_vprintk, __bpf_vprintk,	\
+		   __bpf_vprintk, __bpf_vprintk, __bpf_vprintk, __bpf_vprintk,		\
+		   __bpf_vprintk, __bpf_vprintk, __bpf_printk /*3*/, __bpf_printk /*2*/,\
+		   __bpf_printk /*1*/, __bpf_printk /*0*/)
+
+/* Helper macro to print out debug messages */
+#define bpf_printk(fmt, args...) ___bpf_pick_printk(args)(fmt, ##args)
+
 #endif
-- 
cgit v1.2.3


From 6c66b0e7c91a1320c1b85ad8150bdd534eb4ddae Mon Sep 17 00:00:00 2001
From: Dave Marchevsky <davemarchevsky@fb.com>
Date: Fri, 17 Sep 2021 11:29:07 -0700
Subject: libbpf: Use static const fmt string in __bpf_printk

The __bpf_printk convenience macro was using a 'char' fmt string holder
as it predates support for globals in libbpf. Move to more efficient
'static const char', but provide a fallback to the old way via
BPF_NO_GLOBAL_DATA so users on old kernels can still use the macro.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210917182911.2426606-6-davemarchevsky@fb.com
---
 tools/lib/bpf/bpf_helpers.h | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/bpf_helpers.h b/tools/lib/bpf/bpf_helpers.h
index 55a308796625..963b1060d944 100644
--- a/tools/lib/bpf/bpf_helpers.h
+++ b/tools/lib/bpf/bpf_helpers.h
@@ -216,9 +216,15 @@ enum libbpf_tristate {
 		     ___param, sizeof(___param));		\
 })
 
+#ifdef BPF_NO_GLOBAL_DATA
+#define BPF_PRINTK_FMT_MOD
+#else
+#define BPF_PRINTK_FMT_MOD static const
+#endif
+
 #define __bpf_printk(fmt, ...)				\
 ({							\
-	char ____fmt[] = fmt;				\
+	BPF_PRINTK_FMT_MOD char ____fmt[] = fmt;	\
 	bpf_trace_printk(____fmt, sizeof(____fmt),	\
 			 ##__VA_ARGS__);		\
 })
-- 
cgit v1.2.3


From 97c140d94e2e5f050d5f418317cc34f83da3d0f5 Mon Sep 17 00:00:00 2001
From: Grant Seltzer <grantseltzer@gmail.com>
Date: Fri, 17 Sep 2021 23:14:58 -0400
Subject: libbpf: Add doc comments in libbpf.h

This adds comments above functions in libbpf.h which document
their uses. These comments are of a format that doxygen and sphinx
can pick up and render. These are rendered by libbpf.readthedocs.org

These doc comments are for:
- bpf_object__find_map_by_name()
- bpf_map__fd()
- bpf_map__is_internal()
- libbpf_get_error()
- libbpf_num_possible_cpus()

Signed-off-by: Grant Seltzer <grantseltzer@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210918031457.36204-1-grantseltzer@gmail.com
---
 tools/lib/bpf/libbpf.h | 65 +++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 57 insertions(+), 8 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index c90e3d79e72c..d0bedd673273 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -481,9 +481,13 @@ struct bpf_map_def {
 	unsigned int map_flags;
 };
 
-/*
- * The 'struct bpf_map' in include/linux/bpf.h is internal to the kernel,
- * so no need to worry about a name clash.
+/**
+ * @brief **bpf_object__find_map_by_name()** returns BPF map of
+ * the given name, if it exists within the passed BPF object
+ * @param obj BPF object
+ * @param name name of the BPF map
+ * @return BPF map instance, if such map exists within the BPF object;
+ * or NULL otherwise.
  */
 LIBBPF_API struct bpf_map *
 bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name);
@@ -509,7 +513,12 @@ bpf_map__next(const struct bpf_map *map, const struct bpf_object *obj);
 LIBBPF_API struct bpf_map *
 bpf_map__prev(const struct bpf_map *map, const struct bpf_object *obj);
 
-/* get/set map FD */
+/**
+ * @brief **bpf_map__fd()** gets the file descriptor of the passed
+ * BPF map
+ * @param map the BPF map instance
+ * @return the file descriptor; or -EINVAL in case of an error
+ */
 LIBBPF_API int bpf_map__fd(const struct bpf_map *map);
 LIBBPF_API int bpf_map__reuse_fd(struct bpf_map *map, int fd);
 /* get map definition */
@@ -550,6 +559,14 @@ LIBBPF_API int bpf_map__set_initial_value(struct bpf_map *map,
 					  const void *data, size_t size);
 LIBBPF_API const void *bpf_map__initial_value(struct bpf_map *map, size_t *psize);
 LIBBPF_API bool bpf_map__is_offload_neutral(const struct bpf_map *map);
+
+/**
+ * @brief **bpf_map__is_internal()** tells the caller whether or not the
+ * passed map is a special map created by libbpf automatically for things like
+ * global variables, __ksym externs, Kconfig values, etc
+ * @param map the bpf_map
+ * @return true, if the map is an internal map; false, otherwise
+ */
 LIBBPF_API bool bpf_map__is_internal(const struct bpf_map *map);
 LIBBPF_API int bpf_map__set_pin_path(struct bpf_map *map, const char *path);
 LIBBPF_API const char *bpf_map__get_pin_path(const struct bpf_map *map);
@@ -561,6 +578,38 @@ LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);
 LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd);
 LIBBPF_API struct bpf_map *bpf_map__inner_map(struct bpf_map *map);
 
+/**
+ * @brief **libbpf_get_error()** extracts the error code from the passed
+ * pointer
+ * @param ptr pointer returned from libbpf API function
+ * @return error code; or 0 if no error occured
+ *
+ * Many libbpf API functions which return pointers have logic to encode error
+ * codes as pointers, and do not return NULL. Meaning **libbpf_get_error()**
+ * should be used on the return value from these functions immediately after
+ * calling the API function, with no intervening calls that could clobber the
+ * `errno` variable. Consult the individual functions documentation to verify
+ * if this logic applies should be used.
+ *
+ * For these API functions, if `libbpf_set_strict_mode(LIBBPF_STRICT_CLEAN_PTRS)`
+ * is enabled, NULL is returned on error instead.
+ *
+ * If ptr is NULL, then errno should be already set by the failing
+ * API, because libbpf never returns NULL on success and it now always
+ * sets errno on error.
+ *
+ * Example usage:
+ *
+ *   struct perf_buffer *pb;
+ *
+ *   pb = perf_buffer__new(bpf_map__fd(obj->maps.events), PERF_BUFFER_PAGES, &opts);
+ *   err = libbpf_get_error(pb);
+ *   if (err) {
+ *	  pb = NULL;
+ *	  fprintf(stderr, "failed to open perf buffer: %d\n", err);
+ *	  goto cleanup;
+ *   }
+ */
 LIBBPF_API long libbpf_get_error(const void *ptr);
 
 struct bpf_prog_load_attr {
@@ -825,9 +874,10 @@ bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear);
 LIBBPF_API void
 bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear);
 
-/*
- * A helper function to get the number of possible CPUs before looking up
- * per-CPU maps. Negative errno is returned on failure.
+/**
+ * @brief **libbpf_num_possible_cpus()** is a helper function to get the
+ * number of possible CPUs that the host kernel supports and expects.
+ * @return number of possible CPUs; or error code on failure
  *
  * Example usage:
  *
@@ -837,7 +887,6 @@ bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear);
  *     }
  *     long values[ncpus];
  *     bpf_map_lookup_elem(per_cpu_map_fd, key, values);
- *
  */
 LIBBPF_API int libbpf_num_possible_cpus(void);
 
-- 
cgit v1.2.3


From 303a257223a3bbd7cc6ccc2b7777179c8d9f3989 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Tue, 21 Sep 2021 14:00:33 -0700
Subject: libbpf: Fix memory leak in legacy kprobe attach logic

In some error scenarios legacy_probe string won't be free()'d. Fix this.
This was reported by Coverity static analysis.

Fixes: ca304b40c20d ("libbpf: Introduce legacy kprobe events support")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210921210036.1545557-2-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index da65a1666a5e..6d2f12db6034 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -9365,10 +9365,11 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
 						    offset, -1 /* pid */);
 	}
 	if (pfd < 0) {
+		err = pfd;
 		pr_warn("prog '%s': failed to create %s '%s' perf event: %s\n",
 			prog->name, retprobe ? "kretprobe" : "kprobe", func_name,
-			libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
-		return libbpf_err_ptr(pfd);
+			libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
+		goto err_out;
 	}
 	link = bpf_program__attach_perf_event_opts(prog, pfd, &pe_opts);
 	err = libbpf_get_error(link);
@@ -9377,7 +9378,7 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
 		pr_warn("prog '%s': failed to attach to %s '%s': %s\n",
 			prog->name, retprobe ? "kretprobe" : "kprobe", func_name,
 			libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
-		return libbpf_err_ptr(err);
+		goto err_out;
 	}
 	if (legacy) {
 		struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link);
@@ -9387,6 +9388,9 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
 	}
 
 	return link;
+err_out:
+	free(legacy_probe);
+	return libbpf_err_ptr(err);
 }
 
 struct bpf_link *bpf_program__attach_kprobe(const struct bpf_program *prog,
-- 
cgit v1.2.3


From 46ed5fc33db966aa1a46e8ae9d96b08b756a2546 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Tue, 21 Sep 2021 14:00:35 -0700
Subject: libbpf: Refactor and simplify legacy kprobe code

Refactor legacy kprobe handling code to follow the same logic as uprobe
legacy logic added in the next patchs:
  - add append_to_file() helper that makes it simpler to work with
    tracefs file-based interface for creating and deleting probes;
  - move out probe/event name generation outside of the code that
    adds/removes it, which simplifies bookkeeping significantly;
  - change the probe name format to start with "libbpf_" prefix and
    include offset within kernel function;
  - switch 'unsigned long' to 'size_t' for specifying kprobe offsets,
    which is consistent with how uprobes define that, simplifies
    printf()-ing internally, and also avoids unnecessary complications on
    architectures where sizeof(long) != sizeof(void *).

This patch also implicitly fixes the problem with invalid open() error
handling present in poke_kprobe_events(), which (the function) this
patch removes.

Fixes: ca304b40c20d ("libbpf: Introduce legacy kprobe events support")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210921210036.1545557-4-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c | 159 +++++++++++++++++++++++++++----------------------
 tools/lib/bpf/libbpf.h |   2 +-
 2 files changed, 88 insertions(+), 73 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 6d2f12db6034..aa842f0721cb 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -9011,59 +9011,17 @@ int bpf_link__unpin(struct bpf_link *link)
 	return 0;
 }
 
-static int poke_kprobe_events(bool add, const char *name, bool retprobe, uint64_t offset)
-{
-	int fd, ret = 0;
-	pid_t p = getpid();
-	char cmd[260], probename[128], probefunc[128];
-	const char *file = "/sys/kernel/debug/tracing/kprobe_events";
-
-	if (retprobe)
-		snprintf(probename, sizeof(probename), "kretprobes/%s_libbpf_%u", name, p);
-	else
-		snprintf(probename, sizeof(probename), "kprobes/%s_libbpf_%u", name, p);
-
-	if (offset)
-		snprintf(probefunc, sizeof(probefunc), "%s+%zu", name, (size_t)offset);
-
-	if (add) {
-		snprintf(cmd, sizeof(cmd), "%c:%s %s",
-			 retprobe ? 'r' : 'p',
-			 probename,
-			 offset ? probefunc : name);
-	} else {
-		snprintf(cmd, sizeof(cmd), "-:%s", probename);
-	}
-
-	fd = open(file, O_WRONLY | O_APPEND, 0);
-	if (!fd)
-		return -errno;
-	ret = write(fd, cmd, strlen(cmd));
-	if (ret < 0)
-		ret = -errno;
-	close(fd);
-
-	return ret;
-}
-
-static inline int add_kprobe_event_legacy(const char *name, bool retprobe, uint64_t offset)
-{
-	return poke_kprobe_events(true, name, retprobe, offset);
-}
-
-static inline int remove_kprobe_event_legacy(const char *name, bool retprobe)
-{
-	return poke_kprobe_events(false, name, retprobe, 0);
-}
-
 struct bpf_link_perf {
 	struct bpf_link link;
 	int perf_event_fd;
 	/* legacy kprobe support: keep track of probe identifier and type */
 	char *legacy_probe_name;
+	bool legacy_is_kprobe;
 	bool legacy_is_retprobe;
 };
 
+static int remove_kprobe_event_legacy(const char *probe_name, bool retprobe);
+
 static int bpf_link_perf_detach(struct bpf_link *link)
 {
 	struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link);
@@ -9077,9 +9035,12 @@ static int bpf_link_perf_detach(struct bpf_link *link)
 	close(link->fd);
 
 	/* legacy kprobe needs to be removed after perf event fd closure */
-	if (perf_link->legacy_probe_name)
-		err = remove_kprobe_event_legacy(perf_link->legacy_probe_name,
-						 perf_link->legacy_is_retprobe);
+	if (perf_link->legacy_probe_name) {
+		if (perf_link->legacy_is_kprobe) {
+			err = remove_kprobe_event_legacy(perf_link->legacy_probe_name,
+							 perf_link->legacy_is_retprobe);
+		}
+	}
 
 	return err;
 }
@@ -9202,18 +9163,6 @@ static int parse_uint_from_file(const char *file, const char *fmt)
 	return ret;
 }
 
-static int determine_kprobe_perf_type_legacy(const char *func_name, bool is_retprobe)
-{
-	char file[192];
-
-	snprintf(file, sizeof(file),
-		 "/sys/kernel/debug/tracing/events/%s/%s_libbpf_%d/id",
-		 is_retprobe ? "kretprobes" : "kprobes",
-		 func_name, getpid());
-
-	return parse_uint_from_file(file, "%d\n");
-}
-
 static int determine_kprobe_perf_type(void)
 {
 	const char *file = "/sys/bus/event_source/devices/kprobe/type";
@@ -9296,21 +9245,79 @@ static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name,
 	return pfd;
 }
 
-static int perf_event_kprobe_open_legacy(bool retprobe, const char *name, uint64_t offset, int pid)
+static int append_to_file(const char *file, const char *fmt, ...)
+{
+	int fd, n, err = 0;
+	va_list ap;
+
+	fd = open(file, O_WRONLY | O_APPEND, 0);
+	if (fd < 0)
+		return -errno;
+
+	va_start(ap, fmt);
+	n = vdprintf(fd, fmt, ap);
+	va_end(ap);
+
+	if (n < 0)
+		err = -errno;
+
+	close(fd);
+	return err;
+}
+
+static void gen_kprobe_legacy_event_name(char *buf, size_t buf_sz,
+					 const char *kfunc_name, size_t offset)
+{
+	snprintf(buf, buf_sz, "libbpf_%u_%s_0x%zx", getpid(), kfunc_name, offset);
+}
+
+static int add_kprobe_event_legacy(const char *probe_name, bool retprobe,
+				   const char *kfunc_name, size_t offset)
+{
+	const char *file = "/sys/kernel/debug/tracing/kprobe_events";
+
+	return append_to_file(file, "%c:%s/%s %s+0x%zx",
+			      retprobe ? 'r' : 'p',
+			      retprobe ? "kretprobes" : "kprobes",
+			      probe_name, kfunc_name, offset);
+}
+
+static int remove_kprobe_event_legacy(const char *probe_name, bool retprobe)
+{
+	const char *file = "/sys/kernel/debug/tracing/kprobe_events";
+
+	return append_to_file(file, "-:%s/%s", retprobe ? "kretprobes" : "kprobes", probe_name);
+}
+
+static int determine_kprobe_perf_type_legacy(const char *probe_name, bool retprobe)
+{
+	char file[256];
+
+	snprintf(file, sizeof(file),
+		 "/sys/kernel/debug/tracing/events/%s/%s/id",
+		 retprobe ? "kretprobes" : "kprobes", probe_name);
+
+	return parse_uint_from_file(file, "%d\n");
+}
+
+static int perf_event_kprobe_open_legacy(const char *probe_name, bool retprobe,
+					 const char *kfunc_name, size_t offset, int pid)
 {
 	struct perf_event_attr attr = {};
 	char errmsg[STRERR_BUFSIZE];
 	int type, pfd, err;
 
-	err = add_kprobe_event_legacy(name, retprobe, offset);
+	err = add_kprobe_event_legacy(probe_name, retprobe, kfunc_name, offset);
 	if (err < 0) {
-		pr_warn("failed to add legacy kprobe event: %s\n",
+		pr_warn("failed to add legacy kprobe event for '%s+0x%zx': %s\n",
+			kfunc_name, offset,
 			libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
 		return err;
 	}
-	type = determine_kprobe_perf_type_legacy(name, retprobe);
+	type = determine_kprobe_perf_type_legacy(probe_name, retprobe);
 	if (type < 0) {
-		pr_warn("failed to determine legacy kprobe event id: %s\n",
+		pr_warn("failed to determine legacy kprobe event id for '%s+0x%zx': %s\n",
+			kfunc_name, offset,
 			libbpf_strerror_r(type, errmsg, sizeof(errmsg)));
 		return type;
 	}
@@ -9340,7 +9347,7 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
 	char errmsg[STRERR_BUFSIZE];
 	char *legacy_probe = NULL;
 	struct bpf_link *link;
-	unsigned long offset;
+	size_t offset;
 	bool retprobe, legacy;
 	int pfd, err;
 
@@ -9357,17 +9364,23 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
 					    func_name, offset,
 					    -1 /* pid */, 0 /* ref_ctr_off */);
 	} else {
+		char probe_name[256];
+
+		gen_kprobe_legacy_event_name(probe_name, sizeof(probe_name),
+					     func_name, offset);
+
 		legacy_probe = strdup(func_name);
 		if (!legacy_probe)
 			return libbpf_err_ptr(-ENOMEM);
 
-		pfd = perf_event_kprobe_open_legacy(retprobe, func_name,
+		pfd = perf_event_kprobe_open_legacy(legacy_probe, retprobe, func_name,
 						    offset, -1 /* pid */);
 	}
 	if (pfd < 0) {
-		err = pfd;
-		pr_warn("prog '%s': failed to create %s '%s' perf event: %s\n",
-			prog->name, retprobe ? "kretprobe" : "kprobe", func_name,
+		err = -errno;
+		pr_warn("prog '%s': failed to create %s '%s+0x%zx' perf event: %s\n",
+			prog->name, retprobe ? "kretprobe" : "kprobe",
+			func_name, offset,
 			libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
 		goto err_out;
 	}
@@ -9375,8 +9388,9 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
 	err = libbpf_get_error(link);
 	if (err) {
 		close(pfd);
-		pr_warn("prog '%s': failed to attach to %s '%s': %s\n",
-			prog->name, retprobe ? "kretprobe" : "kprobe", func_name,
+		pr_warn("prog '%s': failed to attach to %s '%s+0x%zx': %s\n",
+			prog->name, retprobe ? "kretprobe" : "kprobe",
+			func_name, offset,
 			libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
 		goto err_out;
 	}
@@ -9384,6 +9398,7 @@ bpf_program__attach_kprobe_opts(const struct bpf_program *prog,
 		struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link);
 
 		perf_link->legacy_probe_name = legacy_probe;
+		perf_link->legacy_is_kprobe = true;
 		perf_link->legacy_is_retprobe = retprobe;
 	}
 
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index d0bedd673273..e35490c54eb3 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -269,7 +269,7 @@ struct bpf_kprobe_opts {
 	/* custom user-provided value fetchable through bpf_get_attach_cookie() */
 	__u64 bpf_cookie;
 	/* function's offset to install kprobe to */
-	unsigned long offset;
+	size_t offset;
 	/* kprobe is return probe */
 	bool retprobe;
 	size_t :0;
-- 
cgit v1.2.3


From cc10623c681019c608c0cb30e2b38994e2c90b2a Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Tue, 21 Sep 2021 14:00:36 -0700
Subject: libbpf: Add legacy uprobe attaching support

Similarly to recently added legacy kprobe attach interface support
through tracefs, support attaching uprobes using the legacy interface if
host kernel doesn't support newer FD-based interface.

For uprobes event name consists of "libbpf_" prefix, PID, sanitized
binary path and offset within that binary. Structuraly the code is
aligned with kprobe logic refactoring in previous patch. struct
bpf_link_perf is re-used and all the same legacy_probe_name and
legacy_is_retprobe fields are used to ensure proper cleanup on
bpf_link__destroy().

Users should be aware, though, that on old kernels which don't support
FD-based interface for kprobe/uprobe attachment, if the application
crashes before bpf_link__destroy() is called, uprobe legacy
events will be left in tracefs. This is the same limitation as with
legacy kprobe interfaces.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210921210036.1545557-5-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c | 130 ++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 122 insertions(+), 8 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index aa842f0721cb..ef5db34bf913 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -9021,6 +9021,7 @@ struct bpf_link_perf {
 };
 
 static int remove_kprobe_event_legacy(const char *probe_name, bool retprobe);
+static int remove_uprobe_event_legacy(const char *probe_name, bool retprobe);
 
 static int bpf_link_perf_detach(struct bpf_link *link)
 {
@@ -9034,11 +9035,14 @@ static int bpf_link_perf_detach(struct bpf_link *link)
 		close(perf_link->perf_event_fd);
 	close(link->fd);
 
-	/* legacy kprobe needs to be removed after perf event fd closure */
+	/* legacy uprobe/kprobe needs to be removed after perf event fd closure */
 	if (perf_link->legacy_probe_name) {
 		if (perf_link->legacy_is_kprobe) {
 			err = remove_kprobe_event_legacy(perf_link->legacy_probe_name,
 							 perf_link->legacy_is_retprobe);
+		} else {
+			err = remove_uprobe_event_legacy(perf_link->legacy_probe_name,
+							 perf_link->legacy_is_retprobe);
 		}
 	}
 
@@ -9450,17 +9454,96 @@ static struct bpf_link *attach_kprobe(const struct bpf_program *prog)
 	return link;
 }
 
+static void gen_uprobe_legacy_event_name(char *buf, size_t buf_sz,
+					 const char *binary_path, uint64_t offset)
+{
+	int i;
+
+	snprintf(buf, buf_sz, "libbpf_%u_%s_0x%zx", getpid(), binary_path, (size_t)offset);
+
+	/* sanitize binary_path in the probe name */
+	for (i = 0; buf[i]; i++) {
+		if (!isalnum(buf[i]))
+			buf[i] = '_';
+	}
+}
+
+static inline int add_uprobe_event_legacy(const char *probe_name, bool retprobe,
+					  const char *binary_path, size_t offset)
+{
+	const char *file = "/sys/kernel/debug/tracing/uprobe_events";
+
+	return append_to_file(file, "%c:%s/%s %s:0x%zx",
+			      retprobe ? 'r' : 'p',
+			      retprobe ? "uretprobes" : "uprobes",
+			      probe_name, binary_path, offset);
+}
+
+static inline int remove_uprobe_event_legacy(const char *probe_name, bool retprobe)
+{
+	const char *file = "/sys/kernel/debug/tracing/uprobe_events";
+
+	return append_to_file(file, "-:%s/%s", retprobe ? "uretprobes" : "uprobes", probe_name);
+}
+
+static int determine_uprobe_perf_type_legacy(const char *probe_name, bool retprobe)
+{
+	char file[512];
+
+	snprintf(file, sizeof(file),
+		 "/sys/kernel/debug/tracing/events/%s/%s/id",
+		 retprobe ? "uretprobes" : "uprobes", probe_name);
+
+	return parse_uint_from_file(file, "%d\n");
+}
+
+static int perf_event_uprobe_open_legacy(const char *probe_name, bool retprobe,
+					 const char *binary_path, size_t offset, int pid)
+{
+	struct perf_event_attr attr;
+	int type, pfd, err;
+
+	err = add_uprobe_event_legacy(probe_name, retprobe, binary_path, offset);
+	if (err < 0) {
+		pr_warn("failed to add legacy uprobe event for %s:0x%zx: %d\n",
+			binary_path, (size_t)offset, err);
+		return err;
+	}
+	type = determine_uprobe_perf_type_legacy(probe_name, retprobe);
+	if (type < 0) {
+		pr_warn("failed to determine legacy uprobe event id for %s:0x%zx: %d\n",
+			binary_path, offset, err);
+		return type;
+	}
+
+	memset(&attr, 0, sizeof(attr));
+	attr.size = sizeof(attr);
+	attr.config = type;
+	attr.type = PERF_TYPE_TRACEPOINT;
+
+	pfd = syscall(__NR_perf_event_open, &attr,
+		      pid < 0 ? -1 : pid, /* pid */
+		      pid == -1 ? 0 : -1, /* cpu */
+		      -1 /* group_fd */,  PERF_FLAG_FD_CLOEXEC);
+	if (pfd < 0) {
+		err = -errno;
+		pr_warn("legacy uprobe perf_event_open() failed: %d\n", err);
+		return err;
+	}
+	return pfd;
+}
+
 LIBBPF_API struct bpf_link *
 bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
 				const char *binary_path, size_t func_offset,
 				const struct bpf_uprobe_opts *opts)
 {
 	DECLARE_LIBBPF_OPTS(bpf_perf_event_opts, pe_opts);
-	char errmsg[STRERR_BUFSIZE];
+	char errmsg[STRERR_BUFSIZE], *legacy_probe = NULL;
 	struct bpf_link *link;
 	size_t ref_ctr_off;
 	int pfd, err;
-	bool retprobe;
+	bool retprobe, legacy;
 
 	if (!OPTS_VALID(opts, bpf_uprobe_opts))
 		return libbpf_err_ptr(-EINVAL);
@@ -9469,15 +9552,35 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
 	ref_ctr_off = OPTS_GET(opts, ref_ctr_offset, 0);
 	pe_opts.bpf_cookie = OPTS_GET(opts, bpf_cookie, 0);
 
-	pfd = perf_event_open_probe(true /* uprobe */, retprobe, binary_path,
-				    func_offset, pid, ref_ctr_off);
+	legacy = determine_uprobe_perf_type() < 0;
+	if (!legacy) {
+		pfd = perf_event_open_probe(true /* uprobe */, retprobe, binary_path,
+					    func_offset, pid, ref_ctr_off);
+	} else {
+		char probe_name[512];
+
+		if (ref_ctr_off)
+			return libbpf_err_ptr(-EINVAL);
+
+		gen_uprobe_legacy_event_name(probe_name, sizeof(probe_name),
+					     binary_path, func_offset);
+
+		legacy_probe = strdup(probe_name);
+		if (!legacy_probe)
+			return libbpf_err_ptr(-ENOMEM);
+
+		pfd = perf_event_uprobe_open_legacy(legacy_probe, retprobe,
+						    binary_path, func_offset, pid);
+	}
 	if (pfd < 0) {
+		err = -errno;
 		pr_warn("prog '%s': failed to create %s '%s:0x%zx' perf event: %s\n",
 			prog->name, retprobe ? "uretprobe" : "uprobe",
 			binary_path, func_offset,
-			libbpf_strerror_r(pfd, errmsg, sizeof(errmsg)));
-		return libbpf_err_ptr(pfd);
+			libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
+		goto err_out;
 	}
+
 	link = bpf_program__attach_perf_event_opts(prog, pfd, &pe_opts);
 	err = libbpf_get_error(link);
 	if (err) {
@@ -9486,9 +9589,20 @@ bpf_program__attach_uprobe_opts(const struct bpf_program *prog, pid_t pid,
 			prog->name, retprobe ? "uretprobe" : "uprobe",
 			binary_path, func_offset,
 			libbpf_strerror_r(err, errmsg, sizeof(errmsg)));
-		return libbpf_err_ptr(err);
+		goto err_out;
+	}
+	if (legacy) {
+		struct bpf_link_perf *perf_link = container_of(link, struct bpf_link_perf, link);
+
+		perf_link->legacy_probe_name = legacy_probe;
+		perf_link->legacy_is_kprobe = false;
+		perf_link->legacy_is_retprobe = retprobe;
 	}
 	return link;
+err_out:
+	free(legacy_probe);
+	return libbpf_err_ptr(err);
+
 }
 
 struct bpf_link *bpf_program__attach_uprobe(const struct bpf_program *prog,
-- 
cgit v1.2.3


From c3e8c44a90631d2479fec6ecc6ba37e3188f487d Mon Sep 17 00:00:00 2001
From: Toke Høiland-Jørgensen <toke@redhat.com>
Date: Mon, 27 Sep 2021 22:58:10 +0200
Subject: libbpf: Ignore STT_SECTION symbols in 'maps' section
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

When parsing legacy map definitions, libbpf would error out when
encountering an STT_SECTION symbol. This becomes a problem because some
versions of binutils will produce SECTION symbols for every section when
processing an ELF file, so BPF files run through 'strip' will end up with
such symbols, making libbpf refuse to load them.

There's not really any reason why erroring out is strictly necessary, so
change libbpf to just ignore SECTION symbols when parsing the ELF.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210927205810.715656-1-toke@redhat.com
---
 tools/lib/bpf/libbpf.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index ef5db34bf913..453148fe8b4b 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1869,6 +1869,8 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
 			continue;
 		if (sym.st_shndx != obj->efile.maps_shndx)
 			continue;
+		if (GELF_ST_TYPE(sym.st_info) == STT_SECTION)
+			continue;
 
 		map = bpf_object__add_map(obj);
 		if (IS_ERR(map))
@@ -1881,8 +1883,7 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
 			return -LIBBPF_ERRNO__FORMAT;
 		}
 
-		if (GELF_ST_TYPE(sym.st_info) == STT_SECTION
-		    || GELF_ST_BIND(sym.st_info) == STB_LOCAL) {
+		if (GELF_ST_BIND(sym.st_info) == STB_LOCAL) {
 			pr_warn("map '%s' (legacy): static maps are not supported\n", map_name);
 			return -ENOTSUP;
 		}
-- 
cgit v1.2.3


From 9673268f03ba72efcc00fa95f3fe3744fcae0dd0 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Tue, 28 Sep 2021 09:19:37 -0700
Subject: libbpf: Add "tc" SEC_DEF which is a better name for "classifier"

As argued in [0], add "tc" ELF section definition for SCHED_CLS BPF
program type. "classifier" is a misleading terminology and should be
migrated away from.

  [0] https://lore.kernel.org/bpf/270e27b1-e5be-5b1c-b343-51bd644d0747@iogearbox.net/

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-2-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c | 1 +
 1 file changed, 1 insertion(+)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 453148fe8b4b..0bcd0a4c867a 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -7968,6 +7968,7 @@ static const struct bpf_sec_def section_defs[] = {
 		.attach_fn = attach_kprobe),
 	BPF_PROG_SEC("uretprobe/",		BPF_PROG_TYPE_KPROBE),
 	BPF_PROG_SEC("classifier",		BPF_PROG_TYPE_SCHED_CLS),
+	BPF_PROG_SEC("tc",			BPF_PROG_TYPE_SCHED_CLS),
 	BPF_PROG_SEC("action",			BPF_PROG_TYPE_SCHED_ACT),
 	SEC_DEF("tracepoint/", TRACEPOINT,
 		.attach_fn = attach_tp),
-- 
cgit v1.2.3


From 12d9466d8bf3d1d4b4fd0f5733b6fa0cc5ee1013 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Tue, 28 Sep 2021 09:19:41 -0700
Subject: libbpf: Refactor internal sec_def handling to enable pluggability

Refactor internals of libbpf to allow adding custom SEC() handling logic
easily from outside of libbpf. To that effect, each SEC()-handling
registration sets mandatory program type/expected attach type for
a given prefix and can provide three callbacks called at different
points of BPF program lifetime:

  - init callback for right after bpf_program is initialized and
  prog_type/expected_attach_type is set. This happens during
  bpf_object__open() step, close to the very end of constructing
  bpf_object, so all the libbpf APIs for querying and updating
  bpf_program properties should be available;

  - pre-load callback is called right before BPF_PROG_LOAD command is
  called in the kernel. This callbacks has ability to set both
  bpf_program properties, as well as program load attributes, overriding
  and augmenting the standard libbpf handling of them;

  - optional auto-attach callback, which makes a given SEC() handler
  support auto-attachment of a BPF program through bpf_program__attach()
  API and/or BPF skeletons <skel>__attach() method.

Each callbacks gets a `long cookie` parameter passed in, which is
specified during SEC() handling. This can be used by callbacks to lookup
whatever additional information is necessary.

This is not yet completely ready to be exposed to the outside world,
mainly due to non-public nature of struct bpf_prog_load_params. Instead
of making it part of public API, we'll wait until the planned low-level
libbpf API improvements for BPF_PROG_LOAD and other typical bpf()
syscall APIs, at which point we'll have a public, probably OPTS-based,
way to fully specify BPF program load parameters, which will be used as
an interface for custom pre-load callbacks.

But this change itself is already a good first step to unify the BPF
program hanling logic even within the libbpf itself. As one example, all
the extra per-program type handling (sleepable bit, attach_btf_id
resolution, unsetting optional expected attach type) is now more obvious
and is gathered in one place.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-6-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c | 129 +++++++++++++++++++++++++++++++++----------------
 1 file changed, 87 insertions(+), 42 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 0bcd0a4c867a..d4d56536dc4b 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -220,7 +220,9 @@ struct reloc_desc {
 
 struct bpf_sec_def;
 
-typedef struct bpf_link *(*attach_fn_t)(const struct bpf_program *prog);
+typedef int (*init_fn_t)(struct bpf_program *prog, long cookie);
+typedef int (*preload_fn_t)(struct bpf_program *prog, struct bpf_prog_load_params *attr, long cookie);
+typedef struct bpf_link *(*attach_fn_t)(const struct bpf_program *prog, long cookie);
 
 struct bpf_sec_def {
 	const char *sec;
@@ -231,7 +233,11 @@ struct bpf_sec_def {
 	bool is_attachable;
 	bool is_attach_btf;
 	bool is_sleepable;
+
+	init_fn_t init_fn;
+	preload_fn_t preload_fn;
 	attach_fn_t attach_fn;
+	long cookie;
 };
 
 /*
@@ -6095,6 +6101,44 @@ static int bpf_object__sanitize_prog(struct bpf_object *obj, struct bpf_program
 	return 0;
 }
 
+static int libbpf_find_attach_btf_id(struct bpf_program *prog, int *btf_obj_fd, int *btf_type_id);
+
+/* this is called as prog->sec_def->preload_fn for libbpf-supported sec_defs */
+static int libbpf_preload_prog(struct bpf_program *prog,
+			       struct bpf_prog_load_params *attr, long cookie)
+{
+	/* old kernels might not support specifying expected_attach_type */
+	if (prog->sec_def->is_exp_attach_type_optional &&
+	    !kernel_supports(prog->obj, FEAT_EXP_ATTACH_TYPE))
+		attr->expected_attach_type = 0;
+
+	if (prog->sec_def->is_sleepable)
+		attr->prog_flags |= BPF_F_SLEEPABLE;
+
+	if ((prog->type == BPF_PROG_TYPE_TRACING ||
+	     prog->type == BPF_PROG_TYPE_LSM ||
+	     prog->type == BPF_PROG_TYPE_EXT) && !prog->attach_btf_id) {
+		int btf_obj_fd = 0, btf_type_id = 0, err;
+
+		err = libbpf_find_attach_btf_id(prog, &btf_obj_fd, &btf_type_id);
+		if (err)
+			return err;
+
+		/* cache resolved BTF FD and BTF type ID in the prog */
+		prog->attach_btf_obj_fd = btf_obj_fd;
+		prog->attach_btf_id = btf_type_id;
+
+		/* but by now libbpf common logic is not utilizing
+		 * prog->atach_btf_obj_fd/prog->attach_btf_id anymore because
+		 * this callback is called after attrs were populated by
+		 * libbpf, so this callback has to update attr explicitly here
+		 */
+		attr->attach_btf_obj_fd = btf_obj_fd;
+		attr->attach_btf_id = btf_type_id;
+	}
+	return 0;
+}
+
 static int
 load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
 	     char *license, __u32 kern_version, int *pfd)
@@ -6103,7 +6147,7 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
 	char *cp, errmsg[STRERR_BUFSIZE];
 	size_t log_buf_size = 0;
 	char *log_buf = NULL;
-	int btf_fd, ret;
+	int btf_fd, ret, err;
 
 	if (prog->type == BPF_PROG_TYPE_UNSPEC) {
 		/*
@@ -6119,22 +6163,15 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
 		return -EINVAL;
 
 	load_attr.prog_type = prog->type;
-	/* old kernels might not support specifying expected_attach_type */
-	if (!kernel_supports(prog->obj, FEAT_EXP_ATTACH_TYPE) && prog->sec_def &&
-	    prog->sec_def->is_exp_attach_type_optional)
-		load_attr.expected_attach_type = 0;
-	else
-		load_attr.expected_attach_type = prog->expected_attach_type;
+	load_attr.expected_attach_type = prog->expected_attach_type;
 	if (kernel_supports(prog->obj, FEAT_PROG_NAME))
 		load_attr.name = prog->name;
 	load_attr.insns = insns;
 	load_attr.insn_cnt = insns_cnt;
 	load_attr.license = license;
 	load_attr.attach_btf_id = prog->attach_btf_id;
-	if (prog->attach_prog_fd)
-		load_attr.attach_prog_fd = prog->attach_prog_fd;
-	else
-		load_attr.attach_btf_obj_fd = prog->attach_btf_obj_fd;
+	load_attr.attach_prog_fd = prog->attach_prog_fd;
+	load_attr.attach_btf_obj_fd = prog->attach_btf_obj_fd;
 	load_attr.attach_btf_id = prog->attach_btf_id;
 	load_attr.kern_version = kern_version;
 	load_attr.prog_ifindex = prog->prog_ifindex;
@@ -6153,6 +6190,16 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
 	load_attr.log_level = prog->log_level;
 	load_attr.prog_flags = prog->prog_flags;
 
+	/* adjust load_attr if sec_def provides custom preload callback */
+	if (prog->sec_def && prog->sec_def->preload_fn) {
+		err = prog->sec_def->preload_fn(prog, &load_attr, prog->sec_def->cookie);
+		if (err < 0) {
+			pr_warn("prog '%s': failed to prepare load attributes: %d\n",
+				prog->name, err);
+			return err;
+		}
+	}
+
 	if (prog->obj->gen_loader) {
 		bpf_gen__prog_load(prog->obj->gen_loader, &load_attr,
 				   prog - prog->obj->programs);
@@ -6268,8 +6315,6 @@ static int bpf_program__record_externs(struct bpf_program *prog)
 	return 0;
 }
 
-static int libbpf_find_attach_btf_id(struct bpf_program *prog, int *btf_obj_fd, int *btf_type_id);
-
 int bpf_program__load(struct bpf_program *prog, char *license, __u32 kern_ver)
 {
 	int err = 0, fd, i;
@@ -6279,19 +6324,6 @@ int bpf_program__load(struct bpf_program *prog, char *license, __u32 kern_ver)
 		return libbpf_err(-EINVAL);
 	}
 
-	if ((prog->type == BPF_PROG_TYPE_TRACING ||
-	     prog->type == BPF_PROG_TYPE_LSM ||
-	     prog->type == BPF_PROG_TYPE_EXT) && !prog->attach_btf_id) {
-		int btf_obj_fd = 0, btf_type_id = 0;
-
-		err = libbpf_find_attach_btf_id(prog, &btf_obj_fd, &btf_type_id);
-		if (err)
-			return libbpf_err(err);
-
-		prog->attach_btf_obj_fd = btf_obj_fd;
-		prog->attach_btf_id = btf_type_id;
-	}
-
 	if (prog->instances.nr < 0 || !prog->instances.fds) {
 		if (prog->preprocessor) {
 			pr_warn("Internal error: can't load program '%s'\n",
@@ -6401,6 +6433,7 @@ static const struct bpf_sec_def *find_sec_def(const char *sec_name);
 static int bpf_object_init_progs(struct bpf_object *obj, const struct bpf_object_open_opts *opts)
 {
 	struct bpf_program *prog;
+	int err;
 
 	bpf_object__for_each_program(prog, obj) {
 		prog->sec_def = find_sec_def(prog->sec_name);
@@ -6411,8 +6444,6 @@ static int bpf_object_init_progs(struct bpf_object *obj, const struct bpf_object
 			continue;
 		}
 
-		if (prog->sec_def->is_sleepable)
-			prog->prog_flags |= BPF_F_SLEEPABLE;
 		bpf_program__set_type(prog, prog->sec_def->prog_type);
 		bpf_program__set_expected_attach_type(prog, prog->sec_def->expected_attach_type);
 
@@ -6422,6 +6453,18 @@ static int bpf_object_init_progs(struct bpf_object *obj, const struct bpf_object
 		    prog->sec_def->prog_type == BPF_PROG_TYPE_EXT)
 			prog->attach_prog_fd = OPTS_GET(opts, attach_prog_fd, 0);
 #pragma GCC diagnostic pop
+
+		/* sec_def can have custom callback which should be called
+		 * after bpf_program is initialized to adjust its properties
+		 */
+		if (prog->sec_def->init_fn) {
+			err = prog->sec_def->init_fn(prog, prog->sec_def->cookie);
+			if (err < 0) {
+				pr_warn("prog '%s': failed to initialize: %d\n",
+					prog->name, err);
+				return err;
+			}
+		}
 	}
 
 	return 0;
@@ -7919,6 +7962,7 @@ void bpf_program__set_expected_attach_type(struct bpf_program *prog,
 		.is_exp_attach_type_optional = eatype_optional,		    \
 		.is_attachable = attachable,				    \
 		.is_attach_btf = attach_btf,				    \
+		.preload_fn = libbpf_preload_prog,			    \
 	}
 
 /* Programs that can NOT be attached. */
@@ -7945,15 +7989,16 @@ void bpf_program__set_expected_attach_type(struct bpf_program *prog,
 	.sec = sec_pfx,							    \
 	.len = sizeof(sec_pfx) - 1,					    \
 	.prog_type = BPF_PROG_TYPE_##ptype,				    \
+	.preload_fn = libbpf_preload_prog,				    \
 	__VA_ARGS__							    \
 }
 
-static struct bpf_link *attach_kprobe(const struct bpf_program *prog);
-static struct bpf_link *attach_tp(const struct bpf_program *prog);
-static struct bpf_link *attach_raw_tp(const struct bpf_program *prog);
-static struct bpf_link *attach_trace(const struct bpf_program *prog);
-static struct bpf_link *attach_lsm(const struct bpf_program *prog);
-static struct bpf_link *attach_iter(const struct bpf_program *prog);
+static struct bpf_link *attach_kprobe(const struct bpf_program *prog, long cookie);
+static struct bpf_link *attach_tp(const struct bpf_program *prog, long cookie);
+static struct bpf_link *attach_raw_tp(const struct bpf_program *prog, long cookie);
+static struct bpf_link *attach_trace(const struct bpf_program *prog, long cookie);
+static struct bpf_link *attach_lsm(const struct bpf_program *prog, long cookie);
+static struct bpf_link *attach_iter(const struct bpf_program *prog, long cookie);
 
 static const struct bpf_sec_def section_defs[] = {
 	BPF_PROG_SEC("socket",			BPF_PROG_TYPE_SOCKET_FILTER),
@@ -9425,7 +9470,7 @@ struct bpf_link *bpf_program__attach_kprobe(const struct bpf_program *prog,
 	return bpf_program__attach_kprobe_opts(prog, func_name, &opts);
 }
 
-static struct bpf_link *attach_kprobe(const struct bpf_program *prog)
+static struct bpf_link *attach_kprobe(const struct bpf_program *prog, long cookie)
 {
 	DECLARE_LIBBPF_OPTS(bpf_kprobe_opts, opts);
 	unsigned long offset = 0;
@@ -9708,7 +9753,7 @@ struct bpf_link *bpf_program__attach_tracepoint(const struct bpf_program *prog,
 	return bpf_program__attach_tracepoint_opts(prog, tp_category, tp_name, NULL);
 }
 
-static struct bpf_link *attach_tp(const struct bpf_program *prog)
+static struct bpf_link *attach_tp(const struct bpf_program *prog, long cookie)
 {
 	char *sec_name, *tp_cat, *tp_name;
 	struct bpf_link *link;
@@ -9762,7 +9807,7 @@ struct bpf_link *bpf_program__attach_raw_tracepoint(const struct bpf_program *pr
 	return link;
 }
 
-static struct bpf_link *attach_raw_tp(const struct bpf_program *prog)
+static struct bpf_link *attach_raw_tp(const struct bpf_program *prog, long cookie)
 {
 	const char *tp_name = prog->sec_name + prog->sec_def->len;
 
@@ -9809,12 +9854,12 @@ struct bpf_link *bpf_program__attach_lsm(const struct bpf_program *prog)
 	return bpf_program__attach_btf_id(prog);
 }
 
-static struct bpf_link *attach_trace(const struct bpf_program *prog)
+static struct bpf_link *attach_trace(const struct bpf_program *prog, long cookie)
 {
 	return bpf_program__attach_trace(prog);
 }
 
-static struct bpf_link *attach_lsm(const struct bpf_program *prog)
+static struct bpf_link *attach_lsm(const struct bpf_program *prog, long cookie)
 {
 	return bpf_program__attach_lsm(prog);
 }
@@ -9945,7 +9990,7 @@ bpf_program__attach_iter(const struct bpf_program *prog,
 	return link;
 }
 
-static struct bpf_link *attach_iter(const struct bpf_program *prog)
+static struct bpf_link *attach_iter(const struct bpf_program *prog, long cookie)
 {
 	return bpf_program__attach_iter(prog, NULL);
 }
@@ -9955,7 +10000,7 @@ struct bpf_link *bpf_program__attach(const struct bpf_program *prog)
 	if (!prog->sec_def || !prog->sec_def->attach_fn)
 		return libbpf_err_ptr(-ESRCH);
 
-	return prog->sec_def->attach_fn(prog);
+	return prog->sec_def->attach_fn(prog, prog->sec_def->cookie);
 }
 
 static int bpf_link__detach_struct_ops(struct bpf_link *link)
-- 
cgit v1.2.3


From 13d35a0cf1741431333ba4aa9bce9c5bbc88f63b Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Tue, 28 Sep 2021 09:19:42 -0700
Subject: libbpf: Reduce reliance of attach_fns on sec_def internals

Move closer to not relying on bpf_sec_def internals that won't be part
of public API, when pluggable SEC() handlers will be allowed. Drop
pre-calculated prefix length, and in various helpers don't rely on this
prefix length availability. Also minimize reliance on knowing
bpf_sec_def's prefix for few places where section prefix shortcuts are
supported (e.g., tp vs tracepoint, raw_tp vs raw_tracepoint).

Given checking some string for having a given string-constant prefix is
such a common operation and so annoying to be done with pure C code, add
a small macro helper, str_has_pfx(), and reuse it throughout libbpf.c
where prefix comparison is performed. With __builtin_constant_p() it's
possible to have a convenient helper that checks some string for having
a given prefix, where prefix is either string literal (or compile-time
known string due to compiler optimization) or just a runtime string
pointer, which is quite convenient and saves a lot of typing and string
literal duplication.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-7-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c          | 41 +++++++++++++++++++++++------------------
 tools/lib/bpf/libbpf_internal.h |  7 +++++++
 2 files changed, 30 insertions(+), 18 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index d4d56536dc4b..f87ffd4d7eab 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -226,7 +226,6 @@ typedef struct bpf_link *(*attach_fn_t)(const struct bpf_program *prog, long coo
 
 struct bpf_sec_def {
 	const char *sec;
-	size_t len;
 	enum bpf_prog_type prog_type;
 	enum bpf_attach_type expected_attach_type;
 	bool is_exp_attach_type_optional;
@@ -1671,7 +1670,7 @@ static int bpf_object__process_kconfig_line(struct bpf_object *obj,
 	void *ext_val;
 	__u64 num;
 
-	if (strncmp(buf, "CONFIG_", 7))
+	if (!str_has_pfx(buf, "CONFIG_"))
 		return 0;
 
 	sep = strchr(buf, '=');
@@ -2920,7 +2919,7 @@ static Elf_Data *elf_sec_data(const struct bpf_object *obj, Elf_Scn *scn)
 static bool is_sec_name_dwarf(const char *name)
 {
 	/* approximation, but the actual list is too long */
-	return strncmp(name, ".debug_", sizeof(".debug_") - 1) == 0;
+	return str_has_pfx(name, ".debug_");
 }
 
 static bool ignore_elf_section(GElf_Shdr *hdr, const char *name)
@@ -2942,7 +2941,7 @@ static bool ignore_elf_section(GElf_Shdr *hdr, const char *name)
 	if (is_sec_name_dwarf(name))
 		return true;
 
-	if (strncmp(name, ".rel", sizeof(".rel") - 1) == 0) {
+	if (str_has_pfx(name, ".rel")) {
 		name += sizeof(".rel") - 1;
 		/* DWARF section relocations */
 		if (is_sec_name_dwarf(name))
@@ -6891,8 +6890,7 @@ static int bpf_object__resolve_externs(struct bpf_object *obj,
 			if (err)
 				return err;
 			pr_debug("extern (kcfg) %s=0x%x\n", ext->name, kver);
-		} else if (ext->type == EXT_KCFG &&
-			   strncmp(ext->name, "CONFIG_", 7) == 0) {
+		} else if (ext->type == EXT_KCFG && str_has_pfx(ext->name, "CONFIG_")) {
 			need_config = true;
 		} else if (ext->type == EXT_KSYM) {
 			if (ext->ksym.type_id)
@@ -7956,7 +7954,6 @@ void bpf_program__set_expected_attach_type(struct bpf_program *prog,
 			  attachable, attach_btf)			    \
 	{								    \
 		.sec = string,						    \
-		.len = sizeof(string) - 1,				    \
 		.prog_type = ptype,					    \
 		.expected_attach_type = eatype,				    \
 		.is_exp_attach_type_optional = eatype_optional,		    \
@@ -7987,7 +7984,6 @@ void bpf_program__set_expected_attach_type(struct bpf_program *prog,
 
 #define SEC_DEF(sec_pfx, ptype, ...) {					    \
 	.sec = sec_pfx,							    \
-	.len = sizeof(sec_pfx) - 1,					    \
 	.prog_type = BPF_PROG_TYPE_##ptype,				    \
 	.preload_fn = libbpf_preload_prog,				    \
 	__VA_ARGS__							    \
@@ -8162,10 +8158,8 @@ static const struct bpf_sec_def *find_sec_def(const char *sec_name)
 	int i, n = ARRAY_SIZE(section_defs);
 
 	for (i = 0; i < n; i++) {
-		if (strncmp(sec_name,
-			    section_defs[i].sec, section_defs[i].len))
-			continue;
-		return &section_defs[i];
+		if (str_has_pfx(sec_name, section_defs[i].sec))
+			return &section_defs[i];
 	}
 	return NULL;
 }
@@ -8519,7 +8513,7 @@ static int libbpf_find_attach_btf_id(struct bpf_program *prog, int *btf_obj_fd,
 			prog->sec_name);
 		return -ESRCH;
 	}
-	attach_name = prog->sec_name + prog->sec_def->len;
+	attach_name = prog->sec_name + strlen(prog->sec_def->sec);
 
 	/* BPF program's BTF ID */
 	if (attach_prog_fd) {
@@ -9479,8 +9473,11 @@ static struct bpf_link *attach_kprobe(const struct bpf_program *prog, long cooki
 	char *func;
 	int n, err;
 
-	func_name = prog->sec_name + prog->sec_def->len;
-	opts.retprobe = strcmp(prog->sec_def->sec, "kretprobe/") == 0;
+	opts.retprobe = str_has_pfx(prog->sec_name, "kretprobe/");
+	if (opts.retprobe)
+		func_name = prog->sec_name + sizeof("kretprobe/") - 1;
+	else
+		func_name = prog->sec_name + sizeof("kprobe/") - 1;
 
 	n = sscanf(func_name, "%m[a-zA-Z0-9_.]+%li", &func, &offset);
 	if (n < 1) {
@@ -9762,8 +9759,11 @@ static struct bpf_link *attach_tp(const struct bpf_program *prog, long cookie)
 	if (!sec_name)
 		return libbpf_err_ptr(-ENOMEM);
 
-	/* extract "tp/<category>/<name>" */
-	tp_cat = sec_name + prog->sec_def->len;
+	/* extract "tp/<category>/<name>" or "tracepoint/<category>/<name>" */
+	if (str_has_pfx(prog->sec_name, "tp/"))
+		tp_cat = sec_name + sizeof("tp/") - 1;
+	else
+		tp_cat = sec_name + sizeof("tracepoint/") - 1;
 	tp_name = strchr(tp_cat, '/');
 	if (!tp_name) {
 		free(sec_name);
@@ -9809,7 +9809,12 @@ struct bpf_link *bpf_program__attach_raw_tracepoint(const struct bpf_program *pr
 
 static struct bpf_link *attach_raw_tp(const struct bpf_program *prog, long cookie)
 {
-	const char *tp_name = prog->sec_name + prog->sec_def->len;
+	const char *tp_name;
+
+	if (str_has_pfx(prog->sec_name, "raw_tp/"))
+		tp_name = prog->sec_name + sizeof("raw_tp/") - 1;
+	else
+		tp_name = prog->sec_name + sizeof("raw_tracepoint/") - 1;
 
 	return bpf_program__attach_raw_tracepoint(prog, tp_name);
 }
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index ceb0c98979bc..ec79400517d4 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -89,6 +89,13 @@
 	(offsetof(TYPE, FIELD) + sizeof(((TYPE *)0)->FIELD))
 #endif
 
+/* Check whether a string `str` has prefix `pfx`, regardless if `pfx` is
+ * a string literal known at compilation time or char * pointer known only at
+ * runtime.
+ */
+#define str_has_pfx(str, pfx) \
+	(strncmp(str, pfx, __builtin_constant_p(pfx) ? sizeof(pfx) - 1 : strlen(pfx)) == 0)
+
 /* Symbol versioning is different between static and shared library.
  * Properly versioned symbols are needed for shared library, but
  * only the symbol of the new version is needed for static library.
-- 
cgit v1.2.3


From 15ea31fadd7f5b1076b4f91f75562bc319799c24 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Tue, 28 Sep 2021 09:19:43 -0700
Subject: libbpf: Refactor ELF section handler definitions

Refactor ELF section handler definitions table to use a set of flags and
unified SEC_DEF() macro. This allows for more succinct and table-like
set of definitions, and allows to more easily extend the logic without
adding more verbosity (this is utilized in later patches in the series).

This approach is also making libbpf-internal program pre-load callback
not rely on bpf_sec_def definition, which demonstrates that future
pluggable ELF section handlers will be able to achieve similar level of
integration without libbpf having to expose extra types and APIs.

For starters, update SEC_DEF() definitions and make them more succinct.
Also convert BPF_PROG_SEC() and BPF_APROG_COMPAT() definitions to
a common SEC_DEF() use.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-8-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c | 195 +++++++++++++++++++++----------------------------
 1 file changed, 84 insertions(+), 111 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index f87ffd4d7eab..954c135a8adf 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -224,19 +224,35 @@ typedef int (*init_fn_t)(struct bpf_program *prog, long cookie);
 typedef int (*preload_fn_t)(struct bpf_program *prog, struct bpf_prog_load_params *attr, long cookie);
 typedef struct bpf_link *(*attach_fn_t)(const struct bpf_program *prog, long cookie);
 
+/* stored as sec_def->cookie for all libbpf-supported SEC()s */
+enum sec_def_flags {
+	SEC_NONE = 0,
+	/* expected_attach_type is optional, if kernel doesn't support that */
+	SEC_EXP_ATTACH_OPT = 1,
+	/* legacy, only used by libbpf_get_type_names() and
+	 * libbpf_attach_type_by_name(), not used by libbpf itself at all.
+	 * This used to be associated with cgroup (and few other) BPF programs
+	 * that were attachable through BPF_PROG_ATTACH command. Pretty
+	 * meaningless nowadays, though.
+	 */
+	SEC_ATTACHABLE = 2,
+	SEC_ATTACHABLE_OPT = SEC_ATTACHABLE | SEC_EXP_ATTACH_OPT,
+	/* attachment target is specified through BTF ID in either kernel or
+	 * other BPF program's BTF object */
+	SEC_ATTACH_BTF = 4,
+	/* BPF program type allows sleeping/blocking in kernel */
+	SEC_SLEEPABLE = 8,
+};
+
 struct bpf_sec_def {
 	const char *sec;
 	enum bpf_prog_type prog_type;
 	enum bpf_attach_type expected_attach_type;
-	bool is_exp_attach_type_optional;
-	bool is_attachable;
-	bool is_attach_btf;
-	bool is_sleepable;
+	long cookie;
 
 	init_fn_t init_fn;
 	preload_fn_t preload_fn;
 	attach_fn_t attach_fn;
-	long cookie;
 };
 
 /*
@@ -6100,26 +6116,30 @@ static int bpf_object__sanitize_prog(struct bpf_object *obj, struct bpf_program
 	return 0;
 }
 
-static int libbpf_find_attach_btf_id(struct bpf_program *prog, int *btf_obj_fd, int *btf_type_id);
+static int libbpf_find_attach_btf_id(struct bpf_program *prog, const char *attach_name,
+				     int *btf_obj_fd, int *btf_type_id);
 
 /* this is called as prog->sec_def->preload_fn for libbpf-supported sec_defs */
 static int libbpf_preload_prog(struct bpf_program *prog,
 			       struct bpf_prog_load_params *attr, long cookie)
 {
+	enum sec_def_flags def = cookie;
+
 	/* old kernels might not support specifying expected_attach_type */
-	if (prog->sec_def->is_exp_attach_type_optional &&
-	    !kernel_supports(prog->obj, FEAT_EXP_ATTACH_TYPE))
+	if ((def & SEC_EXP_ATTACH_OPT) && !kernel_supports(prog->obj, FEAT_EXP_ATTACH_TYPE))
 		attr->expected_attach_type = 0;
 
-	if (prog->sec_def->is_sleepable)
+	if (def & SEC_SLEEPABLE)
 		attr->prog_flags |= BPF_F_SLEEPABLE;
 
 	if ((prog->type == BPF_PROG_TYPE_TRACING ||
 	     prog->type == BPF_PROG_TYPE_LSM ||
 	     prog->type == BPF_PROG_TYPE_EXT) && !prog->attach_btf_id) {
 		int btf_obj_fd = 0, btf_type_id = 0, err;
+		const char *attach_name;
 
-		err = libbpf_find_attach_btf_id(prog, &btf_obj_fd, &btf_type_id);
+		attach_name = strchr(prog->sec_name, '/') + 1;
+		err = libbpf_find_attach_btf_id(prog, attach_name, &btf_obj_fd, &btf_type_id);
 		if (err)
 			return err;
 
@@ -7956,15 +7976,14 @@ void bpf_program__set_expected_attach_type(struct bpf_program *prog,
 		.sec = string,						    \
 		.prog_type = ptype,					    \
 		.expected_attach_type = eatype,				    \
-		.is_exp_attach_type_optional = eatype_optional,		    \
-		.is_attachable = attachable,				    \
-		.is_attach_btf = attach_btf,				    \
+		.cookie = (long) (					    \
+			(eatype_optional ? SEC_EXP_ATTACH_OPT : 0) |   \
+			(attachable ? SEC_ATTACHABLE : 0) |		    \
+			(attach_btf ? SEC_ATTACH_BTF : 0)		    \
+		),							    \
 		.preload_fn = libbpf_preload_prog,			    \
 	}
 
-/* Programs that can NOT be attached. */
-#define BPF_PROG_SEC(string, ptype) BPF_PROG_SEC_IMPL(string, ptype, 0, 0, 0, 0)
-
 /* Programs that can be attached. */
 #define BPF_APROG_SEC(string, ptype, atype) \
 	BPF_PROG_SEC_IMPL(string, ptype, atype, true, 1, 0)
@@ -7977,14 +7996,11 @@ void bpf_program__set_expected_attach_type(struct bpf_program *prog,
 #define BPF_PROG_BTF(string, ptype, eatype) \
 	BPF_PROG_SEC_IMPL(string, ptype, eatype, false, 0, 1)
 
-/* Programs that can be attached but attach type can't be identified by section
- * name. Kept for backward compatibility.
- */
-#define BPF_APROG_COMPAT(string, ptype) BPF_PROG_SEC(string, ptype)
-
-#define SEC_DEF(sec_pfx, ptype, ...) {					    \
+#define SEC_DEF(sec_pfx, ptype, atype, flags, ...) {			    \
 	.sec = sec_pfx,							    \
 	.prog_type = BPF_PROG_TYPE_##ptype,				    \
+	.expected_attach_type = atype,					    \
+	.cookie = (long)(flags),					    \
 	.preload_fn = libbpf_preload_prog,				    \
 	__VA_ARGS__							    \
 }
@@ -7997,93 +8013,50 @@ static struct bpf_link *attach_lsm(const struct bpf_program *prog, long cookie);
 static struct bpf_link *attach_iter(const struct bpf_program *prog, long cookie);
 
 static const struct bpf_sec_def section_defs[] = {
-	BPF_PROG_SEC("socket",			BPF_PROG_TYPE_SOCKET_FILTER),
+	SEC_DEF("socket",		SOCKET_FILTER, 0, SEC_NONE),
 	BPF_EAPROG_SEC("sk_reuseport/migrate",	BPF_PROG_TYPE_SK_REUSEPORT,
 						BPF_SK_REUSEPORT_SELECT_OR_MIGRATE),
 	BPF_EAPROG_SEC("sk_reuseport",		BPF_PROG_TYPE_SK_REUSEPORT,
 						BPF_SK_REUSEPORT_SELECT),
-	SEC_DEF("kprobe/", KPROBE,
-		.attach_fn = attach_kprobe),
-	BPF_PROG_SEC("uprobe/",			BPF_PROG_TYPE_KPROBE),
-	SEC_DEF("kretprobe/", KPROBE,
-		.attach_fn = attach_kprobe),
-	BPF_PROG_SEC("uretprobe/",		BPF_PROG_TYPE_KPROBE),
-	BPF_PROG_SEC("classifier",		BPF_PROG_TYPE_SCHED_CLS),
-	BPF_PROG_SEC("tc",			BPF_PROG_TYPE_SCHED_CLS),
-	BPF_PROG_SEC("action",			BPF_PROG_TYPE_SCHED_ACT),
-	SEC_DEF("tracepoint/", TRACEPOINT,
-		.attach_fn = attach_tp),
-	SEC_DEF("tp/", TRACEPOINT,
-		.attach_fn = attach_tp),
-	SEC_DEF("raw_tracepoint/", RAW_TRACEPOINT,
-		.attach_fn = attach_raw_tp),
-	SEC_DEF("raw_tp/", RAW_TRACEPOINT,
-		.attach_fn = attach_raw_tp),
-	SEC_DEF("tp_btf/", TRACING,
-		.expected_attach_type = BPF_TRACE_RAW_TP,
-		.is_attach_btf = true,
-		.attach_fn = attach_trace),
-	SEC_DEF("fentry/", TRACING,
-		.expected_attach_type = BPF_TRACE_FENTRY,
-		.is_attach_btf = true,
-		.attach_fn = attach_trace),
-	SEC_DEF("fmod_ret/", TRACING,
-		.expected_attach_type = BPF_MODIFY_RETURN,
-		.is_attach_btf = true,
-		.attach_fn = attach_trace),
-	SEC_DEF("fexit/", TRACING,
-		.expected_attach_type = BPF_TRACE_FEXIT,
-		.is_attach_btf = true,
-		.attach_fn = attach_trace),
-	SEC_DEF("fentry.s/", TRACING,
-		.expected_attach_type = BPF_TRACE_FENTRY,
-		.is_attach_btf = true,
-		.is_sleepable = true,
-		.attach_fn = attach_trace),
-	SEC_DEF("fmod_ret.s/", TRACING,
-		.expected_attach_type = BPF_MODIFY_RETURN,
-		.is_attach_btf = true,
-		.is_sleepable = true,
-		.attach_fn = attach_trace),
-	SEC_DEF("fexit.s/", TRACING,
-		.expected_attach_type = BPF_TRACE_FEXIT,
-		.is_attach_btf = true,
-		.is_sleepable = true,
-		.attach_fn = attach_trace),
-	SEC_DEF("freplace/", EXT,
-		.is_attach_btf = true,
-		.attach_fn = attach_trace),
-	SEC_DEF("lsm/", LSM,
-		.is_attach_btf = true,
-		.expected_attach_type = BPF_LSM_MAC,
-		.attach_fn = attach_lsm),
-	SEC_DEF("lsm.s/", LSM,
-		.is_attach_btf = true,
-		.is_sleepable = true,
-		.expected_attach_type = BPF_LSM_MAC,
-		.attach_fn = attach_lsm),
-	SEC_DEF("iter/", TRACING,
-		.expected_attach_type = BPF_TRACE_ITER,
-		.is_attach_btf = true,
-		.attach_fn = attach_iter),
-	SEC_DEF("syscall", SYSCALL,
-		.is_sleepable = true),
+	SEC_DEF("kprobe/",		KPROBE,	0, SEC_NONE, attach_kprobe),
+	SEC_DEF("uprobe/",		KPROBE,	0, SEC_NONE),
+	SEC_DEF("kretprobe/",		KPROBE, 0, SEC_NONE, attach_kprobe),
+	SEC_DEF("uretprobe/",		KPROBE, 0, SEC_NONE),
+	SEC_DEF("classifier",		SCHED_CLS, 0, SEC_NONE),
+	SEC_DEF("tc",			SCHED_CLS, 0, SEC_NONE),
+	SEC_DEF("action",		SCHED_ACT, 0, SEC_NONE),
+	SEC_DEF("tracepoint/",		TRACEPOINT, 0, SEC_NONE, attach_tp),
+	SEC_DEF("tp/",			TRACEPOINT, 0, SEC_NONE, attach_tp),
+	SEC_DEF("raw_tracepoint/",	RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp),
+	SEC_DEF("raw_tp/",		RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp),
+	SEC_DEF("tp_btf/",		TRACING, BPF_TRACE_RAW_TP, SEC_ATTACH_BTF, attach_trace),
+	SEC_DEF("fentry/",		TRACING, BPF_TRACE_FENTRY, SEC_ATTACH_BTF, attach_trace),
+	SEC_DEF("fmod_ret/",		TRACING, BPF_MODIFY_RETURN, SEC_ATTACH_BTF, attach_trace),
+	SEC_DEF("fexit/",		TRACING, BPF_TRACE_FEXIT, SEC_ATTACH_BTF, attach_trace),
+	SEC_DEF("fentry.s/",		TRACING, BPF_TRACE_FENTRY, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace),
+	SEC_DEF("fmod_ret.s/",		TRACING, BPF_MODIFY_RETURN, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace),
+	SEC_DEF("fexit.s/",		TRACING, BPF_TRACE_FEXIT, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_trace),
+	SEC_DEF("freplace/",		EXT, 0, SEC_ATTACH_BTF, attach_trace),
+	SEC_DEF("lsm/",			LSM, BPF_LSM_MAC, SEC_ATTACH_BTF, attach_lsm),
+	SEC_DEF("lsm.s/",		LSM, BPF_LSM_MAC, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_lsm),
+	SEC_DEF("iter/",		TRACING, BPF_TRACE_ITER, SEC_ATTACH_BTF, attach_iter),
+	SEC_DEF("syscall",		SYSCALL, 0, SEC_SLEEPABLE),
 	BPF_EAPROG_SEC("xdp_devmap/",		BPF_PROG_TYPE_XDP,
 						BPF_XDP_DEVMAP),
 	BPF_EAPROG_SEC("xdp_cpumap/",		BPF_PROG_TYPE_XDP,
 						BPF_XDP_CPUMAP),
 	BPF_APROG_SEC("xdp",			BPF_PROG_TYPE_XDP,
 						BPF_XDP),
-	BPF_PROG_SEC("perf_event",		BPF_PROG_TYPE_PERF_EVENT),
-	BPF_PROG_SEC("lwt_in",			BPF_PROG_TYPE_LWT_IN),
-	BPF_PROG_SEC("lwt_out",			BPF_PROG_TYPE_LWT_OUT),
-	BPF_PROG_SEC("lwt_xmit",		BPF_PROG_TYPE_LWT_XMIT),
-	BPF_PROG_SEC("lwt_seg6local",		BPF_PROG_TYPE_LWT_SEG6LOCAL),
+	SEC_DEF("perf_event",		PERF_EVENT, 0, SEC_NONE),
+	SEC_DEF("lwt_in",		LWT_IN, 0, SEC_NONE),
+	SEC_DEF("lwt_out",		LWT_OUT, 0, SEC_NONE),
+	SEC_DEF("lwt_xmit",		LWT_XMIT, 0, SEC_NONE),
+	SEC_DEF("lwt_seg6local",	LWT_SEG6LOCAL, 0, SEC_NONE),
 	BPF_APROG_SEC("cgroup_skb/ingress",	BPF_PROG_TYPE_CGROUP_SKB,
 						BPF_CGROUP_INET_INGRESS),
 	BPF_APROG_SEC("cgroup_skb/egress",	BPF_PROG_TYPE_CGROUP_SKB,
 						BPF_CGROUP_INET_EGRESS),
-	BPF_APROG_COMPAT("cgroup/skb",		BPF_PROG_TYPE_CGROUP_SKB),
+	SEC_DEF("cgroup/skb",		CGROUP_SKB, 0, SEC_NONE),
 	BPF_EAPROG_SEC("cgroup/sock_create",	BPF_PROG_TYPE_CGROUP_SOCK,
 						BPF_CGROUP_INET_SOCK_CREATE),
 	BPF_EAPROG_SEC("cgroup/sock_release",	BPF_PROG_TYPE_CGROUP_SOCK,
@@ -8102,7 +8075,7 @@ static const struct bpf_sec_def section_defs[] = {
 						BPF_SK_SKB_STREAM_PARSER),
 	BPF_APROG_SEC("sk_skb/stream_verdict",	BPF_PROG_TYPE_SK_SKB,
 						BPF_SK_SKB_STREAM_VERDICT),
-	BPF_APROG_COMPAT("sk_skb",		BPF_PROG_TYPE_SK_SKB),
+	SEC_DEF("sk_skb",		SK_SKB, 0, SEC_NONE),
 	BPF_APROG_SEC("sk_msg",			BPF_PROG_TYPE_SK_MSG,
 						BPF_SK_MSG_VERDICT),
 	BPF_APROG_SEC("lirc_mode2",		BPF_PROG_TYPE_LIRC_MODE2,
@@ -8139,16 +8112,14 @@ static const struct bpf_sec_def section_defs[] = {
 						BPF_CGROUP_GETSOCKOPT),
 	BPF_EAPROG_SEC("cgroup/setsockopt",	BPF_PROG_TYPE_CGROUP_SOCKOPT,
 						BPF_CGROUP_SETSOCKOPT),
-	BPF_PROG_SEC("struct_ops",		BPF_PROG_TYPE_STRUCT_OPS),
+	SEC_DEF("struct_ops",		STRUCT_OPS, 0, SEC_NONE),
 	BPF_EAPROG_SEC("sk_lookup/",		BPF_PROG_TYPE_SK_LOOKUP,
 						BPF_SK_LOOKUP),
 };
 
 #undef BPF_PROG_SEC_IMPL
-#undef BPF_PROG_SEC
 #undef BPF_APROG_SEC
 #undef BPF_EAPROG_SEC
-#undef BPF_APROG_COMPAT
 #undef SEC_DEF
 
 #define MAX_TYPE_NAME_SIZE 32
@@ -8176,8 +8147,15 @@ static char *libbpf_get_type_names(bool attach_type)
 	buf[0] = '\0';
 	/* Forge string buf with all available names */
 	for (i = 0; i < ARRAY_SIZE(section_defs); i++) {
-		if (attach_type && !section_defs[i].is_attachable)
-			continue;
+		const struct bpf_sec_def *sec_def = &section_defs[i];
+
+		if (attach_type) {
+			if (sec_def->preload_fn != libbpf_preload_prog)
+				continue;
+
+			if (!(sec_def->cookie & SEC_ATTACHABLE))
+				continue;
+		}
 
 		if (strlen(buf) + strlen(section_defs[i].sec) + 2 > len) {
 			free(buf);
@@ -8501,20 +8479,13 @@ static int find_kernel_btf_id(struct bpf_object *obj, const char *attach_name,
 	return -ESRCH;
 }
 
-static int libbpf_find_attach_btf_id(struct bpf_program *prog, int *btf_obj_fd, int *btf_type_id)
+static int libbpf_find_attach_btf_id(struct bpf_program *prog, const char *attach_name,
+				     int *btf_obj_fd, int *btf_type_id)
 {
 	enum bpf_attach_type attach_type = prog->expected_attach_type;
 	__u32 attach_prog_fd = prog->attach_prog_fd;
-	const char *attach_name;
 	int err = 0;
 
-	if (!prog->sec_def || !prog->sec_def->is_attach_btf) {
-		pr_warn("failed to identify BTF ID based on ELF section name '%s'\n",
-			prog->sec_name);
-		return -ESRCH;
-	}
-	attach_name = prog->sec_name + strlen(prog->sec_def->sec);
-
 	/* BPF program's BTF ID */
 	if (attach_prog_fd) {
 		err = libbpf_find_prog_btf_id(attach_name, attach_prog_fd);
@@ -8564,7 +8535,9 @@ int libbpf_attach_type_by_name(const char *name,
 		return libbpf_err(-EINVAL);
 	}
 
-	if (!sec_def->is_attachable)
+	if (sec_def->preload_fn != libbpf_preload_prog)
+		return libbpf_err(-EINVAL);
+	if (!(sec_def->cookie & SEC_ATTACHABLE))
 		return libbpf_err(-EINVAL);
 
 	*attach_type = sec_def->expected_attach_type;
-- 
cgit v1.2.3


From d41ea045a6e461673d1b2fad106b8cd04c3ba863 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Tue, 28 Sep 2021 09:19:44 -0700
Subject: libbpf: Complete SEC() table unification for
 BPF_APROG_SEC/BPF_EAPROG_SEC

Complete SEC() table refactoring towards unified form by rewriting
BPF_APROG_SEC and BPF_EAPROG_SEC definitions with
SEC_DEF(SEC_ATTACHABLE_OPT) (for optional expected_attach_type) and
SEC_DEF(SEC_ATTACHABLE) (mandatory expected_attach_type), respectively.
Drop BPF_APROG_SEC, BPF_EAPROG_SEC, and BPF_PROG_SEC_IMPL macros after
that, leaving SEC_DEF() macro as the only one used.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-9-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c | 136 +++++++++++++------------------------------------
 1 file changed, 35 insertions(+), 101 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 954c135a8adf..4ba67dff6b0d 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -7970,32 +7970,6 @@ void bpf_program__set_expected_attach_type(struct bpf_program *prog,
 	prog->expected_attach_type = type;
 }
 
-#define BPF_PROG_SEC_IMPL(string, ptype, eatype, eatype_optional,	    \
-			  attachable, attach_btf)			    \
-	{								    \
-		.sec = string,						    \
-		.prog_type = ptype,					    \
-		.expected_attach_type = eatype,				    \
-		.cookie = (long) (					    \
-			(eatype_optional ? SEC_EXP_ATTACH_OPT : 0) |   \
-			(attachable ? SEC_ATTACHABLE : 0) |		    \
-			(attach_btf ? SEC_ATTACH_BTF : 0)		    \
-		),							    \
-		.preload_fn = libbpf_preload_prog,			    \
-	}
-
-/* Programs that can be attached. */
-#define BPF_APROG_SEC(string, ptype, atype) \
-	BPF_PROG_SEC_IMPL(string, ptype, atype, true, 1, 0)
-
-/* Programs that must specify expected attach type at load time. */
-#define BPF_EAPROG_SEC(string, ptype, eatype) \
-	BPF_PROG_SEC_IMPL(string, ptype, eatype, false, 1, 0)
-
-/* Programs that use BTF to identify attach point */
-#define BPF_PROG_BTF(string, ptype, eatype) \
-	BPF_PROG_SEC_IMPL(string, ptype, eatype, false, 0, 1)
-
 #define SEC_DEF(sec_pfx, ptype, atype, flags, ...) {			    \
 	.sec = sec_pfx,							    \
 	.prog_type = BPF_PROG_TYPE_##ptype,				    \
@@ -8014,10 +7988,8 @@ static struct bpf_link *attach_iter(const struct bpf_program *prog, long cookie)
 
 static const struct bpf_sec_def section_defs[] = {
 	SEC_DEF("socket",		SOCKET_FILTER, 0, SEC_NONE),
-	BPF_EAPROG_SEC("sk_reuseport/migrate",	BPF_PROG_TYPE_SK_REUSEPORT,
-						BPF_SK_REUSEPORT_SELECT_OR_MIGRATE),
-	BPF_EAPROG_SEC("sk_reuseport",		BPF_PROG_TYPE_SK_REUSEPORT,
-						BPF_SK_REUSEPORT_SELECT),
+	SEC_DEF("sk_reuseport/migrate",	SK_REUSEPORT, BPF_SK_REUSEPORT_SELECT_OR_MIGRATE, SEC_ATTACHABLE),
+	SEC_DEF("sk_reuseport",		SK_REUSEPORT, BPF_SK_REUSEPORT_SELECT, SEC_ATTACHABLE),
 	SEC_DEF("kprobe/",		KPROBE,	0, SEC_NONE, attach_kprobe),
 	SEC_DEF("uprobe/",		KPROBE,	0, SEC_NONE),
 	SEC_DEF("kretprobe/",		KPROBE, 0, SEC_NONE, attach_kprobe),
@@ -8041,87 +8013,49 @@ static const struct bpf_sec_def section_defs[] = {
 	SEC_DEF("lsm.s/",		LSM, BPF_LSM_MAC, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_lsm),
 	SEC_DEF("iter/",		TRACING, BPF_TRACE_ITER, SEC_ATTACH_BTF, attach_iter),
 	SEC_DEF("syscall",		SYSCALL, 0, SEC_SLEEPABLE),
-	BPF_EAPROG_SEC("xdp_devmap/",		BPF_PROG_TYPE_XDP,
-						BPF_XDP_DEVMAP),
-	BPF_EAPROG_SEC("xdp_cpumap/",		BPF_PROG_TYPE_XDP,
-						BPF_XDP_CPUMAP),
-	BPF_APROG_SEC("xdp",			BPF_PROG_TYPE_XDP,
-						BPF_XDP),
+	SEC_DEF("xdp_devmap/",		XDP, BPF_XDP_DEVMAP, SEC_ATTACHABLE),
+	SEC_DEF("xdp_cpumap/",		XDP, BPF_XDP_CPUMAP, SEC_ATTACHABLE),
+	SEC_DEF("xdp",			XDP, BPF_XDP, SEC_ATTACHABLE_OPT),
 	SEC_DEF("perf_event",		PERF_EVENT, 0, SEC_NONE),
 	SEC_DEF("lwt_in",		LWT_IN, 0, SEC_NONE),
 	SEC_DEF("lwt_out",		LWT_OUT, 0, SEC_NONE),
 	SEC_DEF("lwt_xmit",		LWT_XMIT, 0, SEC_NONE),
 	SEC_DEF("lwt_seg6local",	LWT_SEG6LOCAL, 0, SEC_NONE),
-	BPF_APROG_SEC("cgroup_skb/ingress",	BPF_PROG_TYPE_CGROUP_SKB,
-						BPF_CGROUP_INET_INGRESS),
-	BPF_APROG_SEC("cgroup_skb/egress",	BPF_PROG_TYPE_CGROUP_SKB,
-						BPF_CGROUP_INET_EGRESS),
+	SEC_DEF("cgroup_skb/ingress",	CGROUP_SKB, BPF_CGROUP_INET_INGRESS, SEC_ATTACHABLE_OPT),
+	SEC_DEF("cgroup_skb/egress",	CGROUP_SKB, BPF_CGROUP_INET_EGRESS, SEC_ATTACHABLE_OPT),
 	SEC_DEF("cgroup/skb",		CGROUP_SKB, 0, SEC_NONE),
-	BPF_EAPROG_SEC("cgroup/sock_create",	BPF_PROG_TYPE_CGROUP_SOCK,
-						BPF_CGROUP_INET_SOCK_CREATE),
-	BPF_EAPROG_SEC("cgroup/sock_release",	BPF_PROG_TYPE_CGROUP_SOCK,
-						BPF_CGROUP_INET_SOCK_RELEASE),
-	BPF_APROG_SEC("cgroup/sock",		BPF_PROG_TYPE_CGROUP_SOCK,
-						BPF_CGROUP_INET_SOCK_CREATE),
-	BPF_EAPROG_SEC("cgroup/post_bind4",	BPF_PROG_TYPE_CGROUP_SOCK,
-						BPF_CGROUP_INET4_POST_BIND),
-	BPF_EAPROG_SEC("cgroup/post_bind6",	BPF_PROG_TYPE_CGROUP_SOCK,
-						BPF_CGROUP_INET6_POST_BIND),
-	BPF_APROG_SEC("cgroup/dev",		BPF_PROG_TYPE_CGROUP_DEVICE,
-						BPF_CGROUP_DEVICE),
-	BPF_APROG_SEC("sockops",		BPF_PROG_TYPE_SOCK_OPS,
-						BPF_CGROUP_SOCK_OPS),
-	BPF_APROG_SEC("sk_skb/stream_parser",	BPF_PROG_TYPE_SK_SKB,
-						BPF_SK_SKB_STREAM_PARSER),
-	BPF_APROG_SEC("sk_skb/stream_verdict",	BPF_PROG_TYPE_SK_SKB,
-						BPF_SK_SKB_STREAM_VERDICT),
+	SEC_DEF("cgroup/sock_create",	CGROUP_SOCK, BPF_CGROUP_INET_SOCK_CREATE, SEC_ATTACHABLE),
+	SEC_DEF("cgroup/sock_release",	CGROUP_SOCK, BPF_CGROUP_INET_SOCK_RELEASE, SEC_ATTACHABLE),
+	SEC_DEF("cgroup/sock",		CGROUP_SOCK, BPF_CGROUP_INET_SOCK_CREATE, SEC_ATTACHABLE_OPT),
+	SEC_DEF("cgroup/post_bind4",	CGROUP_SOCK, BPF_CGROUP_INET4_POST_BIND, SEC_ATTACHABLE),
+	SEC_DEF("cgroup/post_bind6",	CGROUP_SOCK, BPF_CGROUP_INET6_POST_BIND, SEC_ATTACHABLE),
+	SEC_DEF("cgroup/dev",		CGROUP_DEVICE, BPF_CGROUP_DEVICE, SEC_ATTACHABLE_OPT),
+	SEC_DEF("sockops",		SOCK_OPS, BPF_CGROUP_SOCK_OPS, SEC_ATTACHABLE_OPT),
+	SEC_DEF("sk_skb/stream_parser",	SK_SKB, BPF_SK_SKB_STREAM_PARSER, SEC_ATTACHABLE_OPT),
+	SEC_DEF("sk_skb/stream_verdict",SK_SKB, BPF_SK_SKB_STREAM_VERDICT, SEC_ATTACHABLE_OPT),
 	SEC_DEF("sk_skb",		SK_SKB, 0, SEC_NONE),
-	BPF_APROG_SEC("sk_msg",			BPF_PROG_TYPE_SK_MSG,
-						BPF_SK_MSG_VERDICT),
-	BPF_APROG_SEC("lirc_mode2",		BPF_PROG_TYPE_LIRC_MODE2,
-						BPF_LIRC_MODE2),
-	BPF_APROG_SEC("flow_dissector",		BPF_PROG_TYPE_FLOW_DISSECTOR,
-						BPF_FLOW_DISSECTOR),
-	BPF_EAPROG_SEC("cgroup/bind4",		BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_INET4_BIND),
-	BPF_EAPROG_SEC("cgroup/bind6",		BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_INET6_BIND),
-	BPF_EAPROG_SEC("cgroup/connect4",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_INET4_CONNECT),
-	BPF_EAPROG_SEC("cgroup/connect6",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_INET6_CONNECT),
-	BPF_EAPROG_SEC("cgroup/sendmsg4",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_UDP4_SENDMSG),
-	BPF_EAPROG_SEC("cgroup/sendmsg6",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_UDP6_SENDMSG),
-	BPF_EAPROG_SEC("cgroup/recvmsg4",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_UDP4_RECVMSG),
-	BPF_EAPROG_SEC("cgroup/recvmsg6",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_UDP6_RECVMSG),
-	BPF_EAPROG_SEC("cgroup/getpeername4",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_INET4_GETPEERNAME),
-	BPF_EAPROG_SEC("cgroup/getpeername6",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_INET6_GETPEERNAME),
-	BPF_EAPROG_SEC("cgroup/getsockname4",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_INET4_GETSOCKNAME),
-	BPF_EAPROG_SEC("cgroup/getsockname6",	BPF_PROG_TYPE_CGROUP_SOCK_ADDR,
-						BPF_CGROUP_INET6_GETSOCKNAME),
-	BPF_EAPROG_SEC("cgroup/sysctl",		BPF_PROG_TYPE_CGROUP_SYSCTL,
-						BPF_CGROUP_SYSCTL),
-	BPF_EAPROG_SEC("cgroup/getsockopt",	BPF_PROG_TYPE_CGROUP_SOCKOPT,
-						BPF_CGROUP_GETSOCKOPT),
-	BPF_EAPROG_SEC("cgroup/setsockopt",	BPF_PROG_TYPE_CGROUP_SOCKOPT,
-						BPF_CGROUP_SETSOCKOPT),
+	SEC_DEF("sk_msg",		SK_MSG, BPF_SK_MSG_VERDICT, SEC_ATTACHABLE_OPT),
+	SEC_DEF("lirc_mode2",		LIRC_MODE2, BPF_LIRC_MODE2, SEC_ATTACHABLE_OPT),
+	SEC_DEF("flow_dissector",	FLOW_DISSECTOR, BPF_FLOW_DISSECTOR, SEC_ATTACHABLE_OPT),
+	SEC_DEF("cgroup/bind4",		CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_BIND, SEC_ATTACHABLE),
+	SEC_DEF("cgroup/bind6",		CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_BIND, SEC_ATTACHABLE),
+	SEC_DEF("cgroup/connect4",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_CONNECT, SEC_ATTACHABLE),
+	SEC_DEF("cgroup/connect6",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_CONNECT, SEC_ATTACHABLE),
+	SEC_DEF("cgroup/sendmsg4",	CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_SENDMSG, SEC_ATTACHABLE),
+	SEC_DEF("cgroup/sendmsg6",	CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_SENDMSG, SEC_ATTACHABLE),
+	SEC_DEF("cgroup/recvmsg4",	CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_RECVMSG, SEC_ATTACHABLE),
+	SEC_DEF("cgroup/recvmsg6",	CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_RECVMSG, SEC_ATTACHABLE),
+	SEC_DEF("cgroup/getpeername4",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_GETPEERNAME, SEC_ATTACHABLE),
+	SEC_DEF("cgroup/getpeername6",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_GETPEERNAME, SEC_ATTACHABLE),
+	SEC_DEF("cgroup/getsockname4",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_GETSOCKNAME, SEC_ATTACHABLE),
+	SEC_DEF("cgroup/getsockname6",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_GETSOCKNAME, SEC_ATTACHABLE),
+	SEC_DEF("cgroup/sysctl",	CGROUP_SYSCTL, BPF_CGROUP_SYSCTL, SEC_ATTACHABLE),
+	SEC_DEF("cgroup/getsockopt",	CGROUP_SOCKOPT, BPF_CGROUP_GETSOCKOPT, SEC_ATTACHABLE),
+	SEC_DEF("cgroup/setsockopt",	CGROUP_SOCKOPT, BPF_CGROUP_SETSOCKOPT, SEC_ATTACHABLE),
 	SEC_DEF("struct_ops",		STRUCT_OPS, 0, SEC_NONE),
-	BPF_EAPROG_SEC("sk_lookup/",		BPF_PROG_TYPE_SK_LOOKUP,
-						BPF_SK_LOOKUP),
+	SEC_DEF("sk_lookup/",		SK_LOOKUP, BPF_SK_LOOKUP, SEC_ATTACHABLE),
 };
 
-#undef BPF_PROG_SEC_IMPL
-#undef BPF_APROG_SEC
-#undef BPF_EAPROG_SEC
-#undef SEC_DEF
-
 #define MAX_TYPE_NAME_SIZE 32
 
 static const struct bpf_sec_def *find_sec_def(const char *sec_name)
-- 
cgit v1.2.3


From dd94d45cf0acb1d82748b17e1106b2c8b487b28b Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Tue, 28 Sep 2021 09:19:45 -0700
Subject: libbpf: Add opt-in strict BPF program section name handling logic

Implement strict ELF section name handling for BPF programs. It utilizes
`libbpf_set_strict_mode()` framework and adds new flag: LIBBPF_STRICT_SEC_NAME.

If this flag is set, libbpf will enforce exact section name matching for
a lot of program types that previously allowed just partial prefix
match. E.g., if previously SEC("xdp_whatever_i_want") was allowed, now
in strict mode only SEC("xdp") will be accepted, which makes SEC("")
definitions cleaner and more structured. SEC() now won't be used as yet
another way to uniquely encode BPF program identifier (for that
C function name is better and is guaranteed to be unique within
bpf_object). Now SEC() is strictly BPF program type and, depending on
program type, extra load/attach parameter specification.

Libbpf completely supports multiple BPF programs in the same ELF
section, so multiple BPF programs of the same type/specification easily
co-exist together within the same bpf_object scope.

Additionally, a new (for now internal) convention is introduced: section
name that can be a stand-alone exact BPF program type specificator, but
also could have extra parameters after '/' delimiter. An example of such
section is "struct_ops", which can be specified by itself, but also
allows to specify the intended operation to be attached to, e.g.,
"struct_ops/dctcp_init". Note, that "struct_ops_some_op" is not allowed.
Such section definition is specified as "struct_ops+".

This change is part of libbpf 1.0 effort ([0], [1]).

  [0] Closes: https://github.com/libbpf/libbpf/issues/271
  [1] https://github.com/libbpf/libbpf/wiki/Libbpf:-the-road-to-v1.0#stricter-and-more-uniform-bpf-program-section-name-sec-handling

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-10-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c        | 136 ++++++++++++++++++++++++++++--------------
 tools/lib/bpf/libbpf_legacy.h |   9 +++
 2 files changed, 99 insertions(+), 46 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 4ba67dff6b0d..3e1f6211b9b9 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -242,6 +242,8 @@ enum sec_def_flags {
 	SEC_ATTACH_BTF = 4,
 	/* BPF program type allows sleeping/blocking in kernel */
 	SEC_SLEEPABLE = 8,
+	/* allow non-strict prefix matching */
+	SEC_SLOPPY_PFX = 16,
 };
 
 struct bpf_sec_def {
@@ -7987,16 +7989,16 @@ static struct bpf_link *attach_lsm(const struct bpf_program *prog, long cookie);
 static struct bpf_link *attach_iter(const struct bpf_program *prog, long cookie);
 
 static const struct bpf_sec_def section_defs[] = {
-	SEC_DEF("socket",		SOCKET_FILTER, 0, SEC_NONE),
-	SEC_DEF("sk_reuseport/migrate",	SK_REUSEPORT, BPF_SK_REUSEPORT_SELECT_OR_MIGRATE, SEC_ATTACHABLE),
-	SEC_DEF("sk_reuseport",		SK_REUSEPORT, BPF_SK_REUSEPORT_SELECT, SEC_ATTACHABLE),
+	SEC_DEF("socket",		SOCKET_FILTER, 0, SEC_NONE | SEC_SLOPPY_PFX),
+	SEC_DEF("sk_reuseport/migrate",	SK_REUSEPORT, BPF_SK_REUSEPORT_SELECT_OR_MIGRATE, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("sk_reuseport",		SK_REUSEPORT, BPF_SK_REUSEPORT_SELECT, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
 	SEC_DEF("kprobe/",		KPROBE,	0, SEC_NONE, attach_kprobe),
 	SEC_DEF("uprobe/",		KPROBE,	0, SEC_NONE),
 	SEC_DEF("kretprobe/",		KPROBE, 0, SEC_NONE, attach_kprobe),
 	SEC_DEF("uretprobe/",		KPROBE, 0, SEC_NONE),
-	SEC_DEF("classifier",		SCHED_CLS, 0, SEC_NONE),
 	SEC_DEF("tc",			SCHED_CLS, 0, SEC_NONE),
-	SEC_DEF("action",		SCHED_ACT, 0, SEC_NONE),
+	SEC_DEF("classifier",		SCHED_CLS, 0, SEC_NONE | SEC_SLOPPY_PFX),
+	SEC_DEF("action",		SCHED_ACT, 0, SEC_NONE | SEC_SLOPPY_PFX),
 	SEC_DEF("tracepoint/",		TRACEPOINT, 0, SEC_NONE, attach_tp),
 	SEC_DEF("tp/",			TRACEPOINT, 0, SEC_NONE, attach_tp),
 	SEC_DEF("raw_tracepoint/",	RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp),
@@ -8015,44 +8017,44 @@ static const struct bpf_sec_def section_defs[] = {
 	SEC_DEF("syscall",		SYSCALL, 0, SEC_SLEEPABLE),
 	SEC_DEF("xdp_devmap/",		XDP, BPF_XDP_DEVMAP, SEC_ATTACHABLE),
 	SEC_DEF("xdp_cpumap/",		XDP, BPF_XDP_CPUMAP, SEC_ATTACHABLE),
-	SEC_DEF("xdp",			XDP, BPF_XDP, SEC_ATTACHABLE_OPT),
-	SEC_DEF("perf_event",		PERF_EVENT, 0, SEC_NONE),
-	SEC_DEF("lwt_in",		LWT_IN, 0, SEC_NONE),
-	SEC_DEF("lwt_out",		LWT_OUT, 0, SEC_NONE),
-	SEC_DEF("lwt_xmit",		LWT_XMIT, 0, SEC_NONE),
-	SEC_DEF("lwt_seg6local",	LWT_SEG6LOCAL, 0, SEC_NONE),
-	SEC_DEF("cgroup_skb/ingress",	CGROUP_SKB, BPF_CGROUP_INET_INGRESS, SEC_ATTACHABLE_OPT),
-	SEC_DEF("cgroup_skb/egress",	CGROUP_SKB, BPF_CGROUP_INET_EGRESS, SEC_ATTACHABLE_OPT),
-	SEC_DEF("cgroup/skb",		CGROUP_SKB, 0, SEC_NONE),
-	SEC_DEF("cgroup/sock_create",	CGROUP_SOCK, BPF_CGROUP_INET_SOCK_CREATE, SEC_ATTACHABLE),
-	SEC_DEF("cgroup/sock_release",	CGROUP_SOCK, BPF_CGROUP_INET_SOCK_RELEASE, SEC_ATTACHABLE),
-	SEC_DEF("cgroup/sock",		CGROUP_SOCK, BPF_CGROUP_INET_SOCK_CREATE, SEC_ATTACHABLE_OPT),
-	SEC_DEF("cgroup/post_bind4",	CGROUP_SOCK, BPF_CGROUP_INET4_POST_BIND, SEC_ATTACHABLE),
-	SEC_DEF("cgroup/post_bind6",	CGROUP_SOCK, BPF_CGROUP_INET6_POST_BIND, SEC_ATTACHABLE),
-	SEC_DEF("cgroup/dev",		CGROUP_DEVICE, BPF_CGROUP_DEVICE, SEC_ATTACHABLE_OPT),
-	SEC_DEF("sockops",		SOCK_OPS, BPF_CGROUP_SOCK_OPS, SEC_ATTACHABLE_OPT),
-	SEC_DEF("sk_skb/stream_parser",	SK_SKB, BPF_SK_SKB_STREAM_PARSER, SEC_ATTACHABLE_OPT),
-	SEC_DEF("sk_skb/stream_verdict",SK_SKB, BPF_SK_SKB_STREAM_VERDICT, SEC_ATTACHABLE_OPT),
-	SEC_DEF("sk_skb",		SK_SKB, 0, SEC_NONE),
-	SEC_DEF("sk_msg",		SK_MSG, BPF_SK_MSG_VERDICT, SEC_ATTACHABLE_OPT),
-	SEC_DEF("lirc_mode2",		LIRC_MODE2, BPF_LIRC_MODE2, SEC_ATTACHABLE_OPT),
-	SEC_DEF("flow_dissector",	FLOW_DISSECTOR, BPF_FLOW_DISSECTOR, SEC_ATTACHABLE_OPT),
-	SEC_DEF("cgroup/bind4",		CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_BIND, SEC_ATTACHABLE),
-	SEC_DEF("cgroup/bind6",		CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_BIND, SEC_ATTACHABLE),
-	SEC_DEF("cgroup/connect4",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_CONNECT, SEC_ATTACHABLE),
-	SEC_DEF("cgroup/connect6",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_CONNECT, SEC_ATTACHABLE),
-	SEC_DEF("cgroup/sendmsg4",	CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_SENDMSG, SEC_ATTACHABLE),
-	SEC_DEF("cgroup/sendmsg6",	CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_SENDMSG, SEC_ATTACHABLE),
-	SEC_DEF("cgroup/recvmsg4",	CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_RECVMSG, SEC_ATTACHABLE),
-	SEC_DEF("cgroup/recvmsg6",	CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_RECVMSG, SEC_ATTACHABLE),
-	SEC_DEF("cgroup/getpeername4",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_GETPEERNAME, SEC_ATTACHABLE),
-	SEC_DEF("cgroup/getpeername6",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_GETPEERNAME, SEC_ATTACHABLE),
-	SEC_DEF("cgroup/getsockname4",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_GETSOCKNAME, SEC_ATTACHABLE),
-	SEC_DEF("cgroup/getsockname6",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_GETSOCKNAME, SEC_ATTACHABLE),
-	SEC_DEF("cgroup/sysctl",	CGROUP_SYSCTL, BPF_CGROUP_SYSCTL, SEC_ATTACHABLE),
-	SEC_DEF("cgroup/getsockopt",	CGROUP_SOCKOPT, BPF_CGROUP_GETSOCKOPT, SEC_ATTACHABLE),
-	SEC_DEF("cgroup/setsockopt",	CGROUP_SOCKOPT, BPF_CGROUP_SETSOCKOPT, SEC_ATTACHABLE),
-	SEC_DEF("struct_ops",		STRUCT_OPS, 0, SEC_NONE),
+	SEC_DEF("xdp",			XDP, BPF_XDP, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("perf_event",		PERF_EVENT, 0, SEC_NONE | SEC_SLOPPY_PFX),
+	SEC_DEF("lwt_in",		LWT_IN, 0, SEC_NONE | SEC_SLOPPY_PFX),
+	SEC_DEF("lwt_out",		LWT_OUT, 0, SEC_NONE | SEC_SLOPPY_PFX),
+	SEC_DEF("lwt_xmit",		LWT_XMIT, 0, SEC_NONE | SEC_SLOPPY_PFX),
+	SEC_DEF("lwt_seg6local",	LWT_SEG6LOCAL, 0, SEC_NONE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup_skb/ingress",	CGROUP_SKB, BPF_CGROUP_INET_INGRESS, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup_skb/egress",	CGROUP_SKB, BPF_CGROUP_INET_EGRESS, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/skb",		CGROUP_SKB, 0, SEC_NONE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/sock_create",	CGROUP_SOCK, BPF_CGROUP_INET_SOCK_CREATE, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/sock_release",	CGROUP_SOCK, BPF_CGROUP_INET_SOCK_RELEASE, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/sock",		CGROUP_SOCK, BPF_CGROUP_INET_SOCK_CREATE, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/post_bind4",	CGROUP_SOCK, BPF_CGROUP_INET4_POST_BIND, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/post_bind6",	CGROUP_SOCK, BPF_CGROUP_INET6_POST_BIND, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/dev",		CGROUP_DEVICE, BPF_CGROUP_DEVICE, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("sockops",		SOCK_OPS, BPF_CGROUP_SOCK_OPS, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("sk_skb/stream_parser",	SK_SKB, BPF_SK_SKB_STREAM_PARSER, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("sk_skb/stream_verdict",SK_SKB, BPF_SK_SKB_STREAM_VERDICT, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("sk_skb",		SK_SKB, 0, SEC_NONE | SEC_SLOPPY_PFX),
+	SEC_DEF("sk_msg",		SK_MSG, BPF_SK_MSG_VERDICT, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("lirc_mode2",		LIRC_MODE2, BPF_LIRC_MODE2, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("flow_dissector",	FLOW_DISSECTOR, BPF_FLOW_DISSECTOR, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/bind4",		CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_BIND, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/bind6",		CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_BIND, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/connect4",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_CONNECT, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/connect6",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_CONNECT, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/sendmsg4",	CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_SENDMSG, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/sendmsg6",	CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_SENDMSG, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/recvmsg4",	CGROUP_SOCK_ADDR, BPF_CGROUP_UDP4_RECVMSG, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/recvmsg6",	CGROUP_SOCK_ADDR, BPF_CGROUP_UDP6_RECVMSG, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/getpeername4",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_GETPEERNAME, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/getpeername6",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_GETPEERNAME, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/getsockname4",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET4_GETSOCKNAME, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/getsockname6",	CGROUP_SOCK_ADDR, BPF_CGROUP_INET6_GETSOCKNAME, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/sysctl",	CGROUP_SYSCTL, BPF_CGROUP_SYSCTL, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/getsockopt",	CGROUP_SOCKOPT, BPF_CGROUP_GETSOCKOPT, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("cgroup/setsockopt",	CGROUP_SOCKOPT, BPF_CGROUP_SETSOCKOPT, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
+	SEC_DEF("struct_ops+",		STRUCT_OPS, 0, SEC_NONE),
 	SEC_DEF("sk_lookup/",		SK_LOOKUP, BPF_SK_LOOKUP, SEC_ATTACHABLE),
 };
 
@@ -8060,11 +8062,53 @@ static const struct bpf_sec_def section_defs[] = {
 
 static const struct bpf_sec_def *find_sec_def(const char *sec_name)
 {
-	int i, n = ARRAY_SIZE(section_defs);
+	const struct bpf_sec_def *sec_def;
+	enum sec_def_flags sec_flags;
+	int i, n = ARRAY_SIZE(section_defs), len;
+	bool strict = libbpf_mode & LIBBPF_STRICT_SEC_NAME;
 
 	for (i = 0; i < n; i++) {
-		if (str_has_pfx(sec_name, section_defs[i].sec))
-			return &section_defs[i];
+		sec_def = &section_defs[i];
+		sec_flags = sec_def->cookie;
+		len = strlen(sec_def->sec);
+
+		/* "type/" always has to have proper SEC("type/extras") form */
+		if (sec_def->sec[len - 1] == '/') {
+			if (str_has_pfx(sec_name, sec_def->sec))
+				return sec_def;
+			continue;
+		}
+
+		/* "type+" means it can be either exact SEC("type") or
+		 * well-formed SEC("type/extras") with proper '/' separator
+		 */
+		if (sec_def->sec[len - 1] == '+') {
+			len--;
+			/* not even a prefix */
+			if (strncmp(sec_name, sec_def->sec, len) != 0)
+				continue;
+			/* exact match or has '/' separator */
+			if (sec_name[len] == '\0' || sec_name[len] == '/')
+				return sec_def;
+			continue;
+		}
+
+		/* SEC_SLOPPY_PFX definitions are allowed to be just prefix
+		 * matches, unless strict section name mode
+		 * (LIBBPF_STRICT_SEC_NAME) is enabled, in which case the
+		 * match has to be exact.
+		 */
+		if ((sec_flags & SEC_SLOPPY_PFX) && !strict)  {
+			if (str_has_pfx(sec_name, sec_def->sec))
+				return sec_def;
+			continue;
+		}
+
+		/* Definitions not marked SEC_SLOPPY_PFX (e.g.,
+		 * SEC("syscall")) are exact matches in both modes.
+		 */
+		if (strcmp(sec_name, sec_def->sec) == 0)
+			return sec_def;
 	}
 	return NULL;
 }
diff --git a/tools/lib/bpf/libbpf_legacy.h b/tools/lib/bpf/libbpf_legacy.h
index df0d03dcffab..74e6f860f703 100644
--- a/tools/lib/bpf/libbpf_legacy.h
+++ b/tools/lib/bpf/libbpf_legacy.h
@@ -46,6 +46,15 @@ enum libbpf_strict_mode {
 	 */
 	LIBBPF_STRICT_DIRECT_ERRS = 0x02,
 
+	/*
+	 * Enforce strict BPF program section (SEC()) names.
+	 * E.g., while prefiously SEC("xdp_whatever") or SEC("perf_event_blah") were
+	 * allowed, with LIBBPF_STRICT_SEC_PREFIX this will become
+	 * unrecognized by libbpf and would have to be just SEC("xdp") and
+	 * SEC("xdp") and SEC("perf_event").
+	 */
+	LIBBPF_STRICT_SEC_NAME = 0x04,
+
 	__LIBBPF_STRICT_LAST,
 };
 
-- 
cgit v1.2.3


From 7c80c87ad56a05ec56069c3f5d7e60b5b1eb19b4 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Tue, 28 Sep 2021 09:19:46 -0700
Subject: selftests/bpf: Switch sk_lookup selftests to strict SEC("sk_lookup")
 use

Update "sk_lookup/" definition to be a stand-alone type specifier,
with backwards-compatible prefix match logic in non-libbpf-1.0 mode.

Currently in selftests all the "sk_lookup/<whatever>" uses just use
<whatever> for duplicated unique name encoding, which is redundant as
BPF program's name (C function name) uniquely and descriptively
identifies the intended use for such BPF programs.

With libbpf's SEC_DEF("sk_lookup") definition updated, switch existing
sk_lookup programs to use "unqualified" SEC("sk_lookup") section names,
with no random text after it.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Link: https://lore.kernel.org/bpf/20210928161946.2512801-11-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c                             |  2 +-
 tools/testing/selftests/bpf/progs/test_sk_lookup.c | 38 +++++++++++-----------
 2 files changed, 20 insertions(+), 20 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 3e1f6211b9b9..1c859b32968d 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -8055,7 +8055,7 @@ static const struct bpf_sec_def section_defs[] = {
 	SEC_DEF("cgroup/getsockopt",	CGROUP_SOCKOPT, BPF_CGROUP_GETSOCKOPT, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
 	SEC_DEF("cgroup/setsockopt",	CGROUP_SOCKOPT, BPF_CGROUP_SETSOCKOPT, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
 	SEC_DEF("struct_ops+",		STRUCT_OPS, 0, SEC_NONE),
-	SEC_DEF("sk_lookup/",		SK_LOOKUP, BPF_SK_LOOKUP, SEC_ATTACHABLE),
+	SEC_DEF("sk_lookup",		SK_LOOKUP, BPF_SK_LOOKUP, SEC_ATTACHABLE | SEC_SLOPPY_PFX),
 };
 
 #define MAX_TYPE_NAME_SIZE 32
diff --git a/tools/testing/selftests/bpf/progs/test_sk_lookup.c b/tools/testing/selftests/bpf/progs/test_sk_lookup.c
index 6c4d32c56765..48534d810391 100644
--- a/tools/testing/selftests/bpf/progs/test_sk_lookup.c
+++ b/tools/testing/selftests/bpf/progs/test_sk_lookup.c
@@ -72,13 +72,13 @@ static const __u16 DST_PORT = 7007; /* Host byte order */
 static const __u32 DST_IP4 = IP4(127, 0, 0, 1);
 static const __u32 DST_IP6[] = IP6(0xfd000000, 0x0, 0x0, 0x00000001);
 
-SEC("sk_lookup/lookup_pass")
+SEC("sk_lookup")
 int lookup_pass(struct bpf_sk_lookup *ctx)
 {
 	return SK_PASS;
 }
 
-SEC("sk_lookup/lookup_drop")
+SEC("sk_lookup")
 int lookup_drop(struct bpf_sk_lookup *ctx)
 {
 	return SK_DROP;
@@ -97,7 +97,7 @@ int reuseport_drop(struct sk_reuseport_md *ctx)
 }
 
 /* Redirect packets destined for port DST_PORT to socket at redir_map[0]. */
-SEC("sk_lookup/redir_port")
+SEC("sk_lookup")
 int redir_port(struct bpf_sk_lookup *ctx)
 {
 	struct bpf_sock *sk;
@@ -116,7 +116,7 @@ int redir_port(struct bpf_sk_lookup *ctx)
 }
 
 /* Redirect packets destined for DST_IP4 address to socket at redir_map[0]. */
-SEC("sk_lookup/redir_ip4")
+SEC("sk_lookup")
 int redir_ip4(struct bpf_sk_lookup *ctx)
 {
 	struct bpf_sock *sk;
@@ -139,7 +139,7 @@ int redir_ip4(struct bpf_sk_lookup *ctx)
 }
 
 /* Redirect packets destined for DST_IP6 address to socket at redir_map[0]. */
-SEC("sk_lookup/redir_ip6")
+SEC("sk_lookup")
 int redir_ip6(struct bpf_sk_lookup *ctx)
 {
 	struct bpf_sock *sk;
@@ -164,7 +164,7 @@ int redir_ip6(struct bpf_sk_lookup *ctx)
 	return err ? SK_DROP : SK_PASS;
 }
 
-SEC("sk_lookup/select_sock_a")
+SEC("sk_lookup")
 int select_sock_a(struct bpf_sk_lookup *ctx)
 {
 	struct bpf_sock *sk;
@@ -179,7 +179,7 @@ int select_sock_a(struct bpf_sk_lookup *ctx)
 	return err ? SK_DROP : SK_PASS;
 }
 
-SEC("sk_lookup/select_sock_a_no_reuseport")
+SEC("sk_lookup")
 int select_sock_a_no_reuseport(struct bpf_sk_lookup *ctx)
 {
 	struct bpf_sock *sk;
@@ -205,7 +205,7 @@ int select_sock_b(struct sk_reuseport_md *ctx)
 }
 
 /* Check that bpf_sk_assign() returns -EEXIST if socket already selected. */
-SEC("sk_lookup/sk_assign_eexist")
+SEC("sk_lookup")
 int sk_assign_eexist(struct bpf_sk_lookup *ctx)
 {
 	struct bpf_sock *sk;
@@ -238,7 +238,7 @@ out:
 }
 
 /* Check that bpf_sk_assign(BPF_SK_LOOKUP_F_REPLACE) can override selection. */
-SEC("sk_lookup/sk_assign_replace_flag")
+SEC("sk_lookup")
 int sk_assign_replace_flag(struct bpf_sk_lookup *ctx)
 {
 	struct bpf_sock *sk;
@@ -270,7 +270,7 @@ out:
 }
 
 /* Check that bpf_sk_assign(sk=NULL) is accepted. */
-SEC("sk_lookup/sk_assign_null")
+SEC("sk_lookup")
 int sk_assign_null(struct bpf_sk_lookup *ctx)
 {
 	struct bpf_sock *sk = NULL;
@@ -313,7 +313,7 @@ out:
 }
 
 /* Check that selected sk is accessible through context. */
-SEC("sk_lookup/access_ctx_sk")
+SEC("sk_lookup")
 int access_ctx_sk(struct bpf_sk_lookup *ctx)
 {
 	struct bpf_sock *sk1 = NULL, *sk2 = NULL;
@@ -379,7 +379,7 @@ out:
  * are not covered because they give bogus results, that is the
  * verifier ignores the offset.
  */
-SEC("sk_lookup/ctx_narrow_access")
+SEC("sk_lookup")
 int ctx_narrow_access(struct bpf_sk_lookup *ctx)
 {
 	struct bpf_sock *sk;
@@ -553,7 +553,7 @@ int ctx_narrow_access(struct bpf_sk_lookup *ctx)
 }
 
 /* Check that sk_assign rejects SERVER_A socket with -ESOCKNOSUPPORT */
-SEC("sk_lookup/sk_assign_esocknosupport")
+SEC("sk_lookup")
 int sk_assign_esocknosupport(struct bpf_sk_lookup *ctx)
 {
 	struct bpf_sock *sk;
@@ -578,28 +578,28 @@ out:
 	return ret;
 }
 
-SEC("sk_lookup/multi_prog_pass1")
+SEC("sk_lookup")
 int multi_prog_pass1(struct bpf_sk_lookup *ctx)
 {
 	bpf_map_update_elem(&run_map, &KEY_PROG1, &PROG_DONE, BPF_ANY);
 	return SK_PASS;
 }
 
-SEC("sk_lookup/multi_prog_pass2")
+SEC("sk_lookup")
 int multi_prog_pass2(struct bpf_sk_lookup *ctx)
 {
 	bpf_map_update_elem(&run_map, &KEY_PROG2, &PROG_DONE, BPF_ANY);
 	return SK_PASS;
 }
 
-SEC("sk_lookup/multi_prog_drop1")
+SEC("sk_lookup")
 int multi_prog_drop1(struct bpf_sk_lookup *ctx)
 {
 	bpf_map_update_elem(&run_map, &KEY_PROG1, &PROG_DONE, BPF_ANY);
 	return SK_DROP;
 }
 
-SEC("sk_lookup/multi_prog_drop2")
+SEC("sk_lookup")
 int multi_prog_drop2(struct bpf_sk_lookup *ctx)
 {
 	bpf_map_update_elem(&run_map, &KEY_PROG2, &PROG_DONE, BPF_ANY);
@@ -623,7 +623,7 @@ static __always_inline int select_server_a(struct bpf_sk_lookup *ctx)
 	return SK_PASS;
 }
 
-SEC("sk_lookup/multi_prog_redir1")
+SEC("sk_lookup")
 int multi_prog_redir1(struct bpf_sk_lookup *ctx)
 {
 	int ret;
@@ -633,7 +633,7 @@ int multi_prog_redir1(struct bpf_sk_lookup *ctx)
 	return SK_PASS;
 }
 
-SEC("sk_lookup/multi_prog_redir2")
+SEC("sk_lookup")
 int multi_prog_redir2(struct bpf_sk_lookup *ctx)
 {
 	int ret;
-- 
cgit v1.2.3


From 66fe33241726d1f872e55d95a35c063d58602ae1 Mon Sep 17 00:00:00 2001
From: Alexei Starovoitov <ast@kernel.org>
Date: Mon, 27 Sep 2021 20:29:37 +0530
Subject: libbpf: Make gen_loader data aligned.

Align gen_loader data to 8 byte boundary to make sure union bpf_attr,
bpf_insns and other structs are aligned.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210927145941.1383001-9-memxor@gmail.com
---
 tools/lib/bpf/gen_loader.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/gen_loader.c b/tools/lib/bpf/gen_loader.c
index 8df718a6b142..80087b13877f 100644
--- a/tools/lib/bpf/gen_loader.c
+++ b/tools/lib/bpf/gen_loader.c
@@ -5,6 +5,7 @@
 #include <string.h>
 #include <errno.h>
 #include <linux/filter.h>
+#include <sys/param.h>
 #include "btf.h"
 #include "bpf.h"
 #include "libbpf.h"
@@ -135,13 +136,17 @@ void bpf_gen__init(struct bpf_gen *gen, int log_level)
 
 static int add_data(struct bpf_gen *gen, const void *data, __u32 size)
 {
+	__u32 size8 = roundup(size, 8);
+	__u64 zero = 0;
 	void *prev;
 
-	if (realloc_data_buf(gen, size))
+	if (realloc_data_buf(gen, size8))
 		return 0;
 	prev = gen->data_cur;
 	memcpy(gen->data_cur, data, size);
 	gen->data_cur += size;
+	memcpy(gen->data_cur, &zero, size8 - size);
+	gen->data_cur += size8 - size;
 	return prev - gen->data_start;
 }
 
-- 
cgit v1.2.3


From 161ecd537948a7003129889b04a3a0858687bc70 Mon Sep 17 00:00:00 2001
From: Toke Høiland-Jørgensen <toke@redhat.com>
Date: Wed, 29 Sep 2021 23:38:37 +0200
Subject: libbpf: Properly ignore STT_SECTION symbols in legacy map definitions
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

The previous patch to ignore STT_SECTION symbols only added the ignore
condition in one of them. This fails if there's more than one map
definition in the 'maps' section, because the subsequent modulus check will
fail, resulting in error messages like:

libbpf: elf: unable to determine legacy map definition size in ./xdpdump_xdp.o

Fix this by also ignoring STT_SECTION in the first loop.

Fixes: c3e8c44a9063 ("libbpf: Ignore STT_SECTION symbols in 'maps' section")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210929213837.832449-1-toke@redhat.com
---
 tools/lib/bpf/libbpf.c | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 1c859b32968d..7544d7d09160 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1868,6 +1868,8 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
 			continue;
 		if (sym.st_shndx != obj->efile.maps_shndx)
 			continue;
+		if (GELF_ST_TYPE(sym.st_info) == STT_SECTION)
+			continue;
 		nr_maps++;
 	}
 	/* Assume equally sized map definitions */
-- 
cgit v1.2.3


From e68ac0082787f4e8ee6ae5b19076ec7709ce715b Mon Sep 17 00:00:00 2001
From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: Mon, 27 Sep 2021 20:29:39 +0530
Subject: libbpf: Fix skel_internal.h to set errno on loader retval < 0

When the loader indicates an internal error (result of a checked bpf
system call), it returns the result in attr.test.retval. However, tests
that rely on ASSERT_OK_PTR on NULL (returned from light skeleton) may
miss that NULL denotes an error if errno is set to 0. This would result
in skel pointer being NULL, while ASSERT_OK_PTR returning 1, leading to
a SEGV on dereference of skel, because libbpf_get_error relies on the
assumption that errno is always set in case of error for ptr == NULL.

In particular, this was observed for the ksyms_module test. When
executed using `./test_progs -t ksyms`, prior tests manipulated errno
and the test didn't crash when it failed at ksyms_module load, while
using `./test_progs -t ksyms_module` crashed due to errno being
untouched.

Fixes: 67234743736a (libbpf: Generate loader program out of BPF ELF file.)
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210927145941.1383001-11-memxor@gmail.com
---
 tools/lib/bpf/skel_internal.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/skel_internal.h b/tools/lib/bpf/skel_internal.h
index b22b50c1b173..9cf66702fa8d 100644
--- a/tools/lib/bpf/skel_internal.h
+++ b/tools/lib/bpf/skel_internal.h
@@ -105,10 +105,12 @@ static inline int bpf_load_and_run(struct bpf_load_and_run_opts *opts)
 	err = skel_sys_bpf(BPF_PROG_RUN, &attr, sizeof(attr));
 	if (err < 0 || (int)attr.test.retval < 0) {
 		opts->errstr = "failed to execute loader prog";
-		if (err < 0)
+		if (err < 0) {
 			err = -errno;
-		else
+		} else {
 			err = (int)attr.test.retval;
+			errno = -err;
+		}
 		goto out;
 	}
 	err = 0;
-- 
cgit v1.2.3


From f731052325efc3726577feb743c7495f880ae07d Mon Sep 17 00:00:00 2001
From: Hengqi Chen <hengqi.chen@gmail.com>
Date: Fri, 1 Oct 2021 00:14:55 +0800
Subject: libbpf: Support uniform BTF-defined key/value specification across
 all BPF maps

A bunch of BPF maps do not support specifying BTF types for key and value.
This is non-uniform and inconvenient[0]. Currently, libbpf uses a retry
logic which removes BTF type IDs when BPF map creation failed. Instead
of retrying, this commit recognizes those specialized maps and removes
BTF type IDs when creating BPF map.

  [0] Closes: https://github.com/libbpf/libbpf/issues/355

Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210930161456.3444544-2-hengqi.chen@gmail.com
---
 tools/lib/bpf/libbpf.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 7544d7d09160..e23f1b6b9402 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -4669,6 +4669,30 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b
 			create_attr.inner_map_fd = map->inner_map_fd;
 	}
 
+	switch (def->type) {
+	case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
+	case BPF_MAP_TYPE_CGROUP_ARRAY:
+	case BPF_MAP_TYPE_STACK_TRACE:
+	case BPF_MAP_TYPE_ARRAY_OF_MAPS:
+	case BPF_MAP_TYPE_HASH_OF_MAPS:
+	case BPF_MAP_TYPE_DEVMAP:
+	case BPF_MAP_TYPE_DEVMAP_HASH:
+	case BPF_MAP_TYPE_CPUMAP:
+	case BPF_MAP_TYPE_XSKMAP:
+	case BPF_MAP_TYPE_SOCKMAP:
+	case BPF_MAP_TYPE_SOCKHASH:
+	case BPF_MAP_TYPE_QUEUE:
+	case BPF_MAP_TYPE_STACK:
+	case BPF_MAP_TYPE_RINGBUF:
+		create_attr.btf_fd = 0;
+		create_attr.btf_key_type_id = 0;
+		create_attr.btf_value_type_id = 0;
+		map->btf_key_type_id = 0;
+		map->btf_value_type_id = 0;
+	default:
+		break;
+	}
+
 	if (obj->gen_loader) {
 		bpf_gen__map_create(obj->gen_loader, &create_attr, is_inner ? -1 : map - obj->maps);
 		/* Pretend to have valid FD to pass various fd >= 0 checks.
-- 
cgit v1.2.3


From 9dbe6015636c19f929a7f7b742f27f303ff6069d Mon Sep 17 00:00:00 2001
From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: Sat, 2 Oct 2021 06:47:54 +0530
Subject: libbpf: Support kernel module function calls

This patch adds libbpf support for kernel module function call support.
The fd_array parameter is used during BPF program load to pass module
BTFs referenced by the program. insn->off is set to index into this
array, but starts from 1, because insn->off as 0 is reserved for
btf_vmlinux.

We try to use existing insn->off for a module, since the kernel limits
the maximum distinct module BTFs for kfuncs to 256, and also because
index must never exceed the maximum allowed value that can fit in
insn->off (INT16_MAX). In the future, if kernel interprets signed offset
as unsigned for kfunc calls, this limit can be increased to UINT16_MAX.

Also introduce a btf__find_by_name_kind_own helper to start searching
from module BTF's start id when we know that the BTF ID is not present
in vmlinux BTF (in find_ksym_btf_id).

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-7-memxor@gmail.com
---
 tools/lib/bpf/bpf.c             |  1 +
 tools/lib/bpf/btf.c             | 18 ++++++++--
 tools/lib/bpf/libbpf.c          | 74 +++++++++++++++++++++++++++++------------
 tools/lib/bpf/libbpf_internal.h |  3 ++
 4 files changed, 72 insertions(+), 24 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 2401fad090c5..7d1741ceaa32 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -264,6 +264,7 @@ int libbpf__bpf_prog_load(const struct bpf_prog_load_params *load_attr)
 	attr.line_info_rec_size = load_attr->line_info_rec_size;
 	attr.line_info_cnt = load_attr->line_info_cnt;
 	attr.line_info = ptr_to_u64(load_attr->line_info);
+	attr.fd_array = ptr_to_u64(load_attr->fd_array);
 
 	if (load_attr->name)
 		memcpy(attr.prog_name, load_attr->name,
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 6ad63e4d418a..7774f99afa6e 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -695,15 +695,15 @@ __s32 btf__find_by_name(const struct btf *btf, const char *type_name)
 	return libbpf_err(-ENOENT);
 }
 
-__s32 btf__find_by_name_kind(const struct btf *btf, const char *type_name,
-			     __u32 kind)
+static __s32 btf_find_by_name_kind(const struct btf *btf, int start_id,
+				   const char *type_name, __u32 kind)
 {
 	__u32 i, nr_types = btf__get_nr_types(btf);
 
 	if (kind == BTF_KIND_UNKN || !strcmp(type_name, "void"))
 		return 0;
 
-	for (i = 1; i <= nr_types; i++) {
+	for (i = start_id; i <= nr_types; i++) {
 		const struct btf_type *t = btf__type_by_id(btf, i);
 		const char *name;
 
@@ -717,6 +717,18 @@ __s32 btf__find_by_name_kind(const struct btf *btf, const char *type_name,
 	return libbpf_err(-ENOENT);
 }
 
+__s32 btf__find_by_name_kind_own(const struct btf *btf, const char *type_name,
+				 __u32 kind)
+{
+	return btf_find_by_name_kind(btf, btf->start_id, type_name, kind);
+}
+
+__s32 btf__find_by_name_kind(const struct btf *btf, const char *type_name,
+			     __u32 kind)
+{
+	return btf_find_by_name_kind(btf, 1, type_name, kind);
+}
+
 static bool btf_is_modifiable(const struct btf *btf)
 {
 	return (void *)btf->hdr != btf->raw_data;
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index e23f1b6b9402..ea1c51dbc0f3 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -443,6 +443,11 @@ struct extern_desc {
 
 			/* local btf_id of the ksym extern's type. */
 			__u32 type_id;
+			/* BTF fd index to be patched in for insn->off, this is
+			 * 0 for vmlinux BTF, index in obj->fd_array for module
+			 * BTF
+			 */
+			__s16 btf_fd_idx;
 		} ksym;
 	};
 };
@@ -454,6 +459,7 @@ struct module_btf {
 	char *name;
 	__u32 id;
 	int fd;
+	int fd_array_idx;
 };
 
 struct bpf_object {
@@ -539,6 +545,10 @@ struct bpf_object {
 	void *priv;
 	bpf_object_clear_priv_t clear_priv;
 
+	int *fd_array;
+	size_t fd_array_cap;
+	size_t fd_array_cnt;
+
 	char path[];
 };
 #define obj_elf_valid(o)	((o)->efile.elf)
@@ -5407,6 +5417,7 @@ bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog)
 			ext = &obj->externs[relo->sym_off];
 			insn[0].src_reg = BPF_PSEUDO_KFUNC_CALL;
 			insn[0].imm = ext->ksym.kernel_btf_id;
+			insn[0].off = ext->ksym.btf_fd_idx;
 			break;
 		case RELO_SUBPROG_ADDR:
 			if (insn[0].src_reg != BPF_PSEUDO_FUNC) {
@@ -6236,6 +6247,7 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
 	}
 	load_attr.log_level = prog->log_level;
 	load_attr.prog_flags = prog->prog_flags;
+	load_attr.fd_array = prog->obj->fd_array;
 
 	/* adjust load_attr if sec_def provides custom preload callback */
 	if (prog->sec_def && prog->sec_def->preload_fn) {
@@ -6752,13 +6764,14 @@ out:
 
 static int find_ksym_btf_id(struct bpf_object *obj, const char *ksym_name,
 			    __u16 kind, struct btf **res_btf,
-			    int *res_btf_fd)
+			    struct module_btf **res_mod_btf)
 {
-	int i, id, btf_fd, err;
+	struct module_btf *mod_btf;
 	struct btf *btf;
+	int i, id, err;
 
 	btf = obj->btf_vmlinux;
-	btf_fd = 0;
+	mod_btf = NULL;
 	id = btf__find_by_name_kind(btf, ksym_name, kind);
 
 	if (id == -ENOENT) {
@@ -6767,10 +6780,10 @@ static int find_ksym_btf_id(struct bpf_object *obj, const char *ksym_name,
 			return err;
 
 		for (i = 0; i < obj->btf_module_cnt; i++) {
-			btf = obj->btf_modules[i].btf;
-			/* we assume module BTF FD is always >0 */
-			btf_fd = obj->btf_modules[i].fd;
-			id = btf__find_by_name_kind(btf, ksym_name, kind);
+			/* we assume module_btf's BTF FD is always >0 */
+			mod_btf = &obj->btf_modules[i];
+			btf = mod_btf->btf;
+			id = btf__find_by_name_kind_own(btf, ksym_name, kind);
 			if (id != -ENOENT)
 				break;
 		}
@@ -6779,7 +6792,7 @@ static int find_ksym_btf_id(struct bpf_object *obj, const char *ksym_name,
 		return -ESRCH;
 
 	*res_btf = btf;
-	*res_btf_fd = btf_fd;
+	*res_mod_btf = mod_btf;
 	return id;
 }
 
@@ -6788,11 +6801,12 @@ static int bpf_object__resolve_ksym_var_btf_id(struct bpf_object *obj,
 {
 	const struct btf_type *targ_var, *targ_type;
 	__u32 targ_type_id, local_type_id;
+	struct module_btf *mod_btf = NULL;
 	const char *targ_var_name;
-	int id, btf_fd = 0, err;
 	struct btf *btf = NULL;
+	int id, err;
 
-	id = find_ksym_btf_id(obj, ext->name, BTF_KIND_VAR, &btf, &btf_fd);
+	id = find_ksym_btf_id(obj, ext->name, BTF_KIND_VAR, &btf, &mod_btf);
 	if (id == -ESRCH && ext->is_weak) {
 		return 0;
 	} else if (id < 0) {
@@ -6827,7 +6841,7 @@ static int bpf_object__resolve_ksym_var_btf_id(struct bpf_object *obj,
 	}
 
 	ext->is_set = true;
-	ext->ksym.kernel_btf_obj_fd = btf_fd;
+	ext->ksym.kernel_btf_obj_fd = mod_btf ? mod_btf->fd : 0;
 	ext->ksym.kernel_btf_id = id;
 	pr_debug("extern (var ksym) '%s': resolved to [%d] %s %s\n",
 		 ext->name, id, btf_kind_str(targ_var), targ_var_name);
@@ -6839,26 +6853,20 @@ static int bpf_object__resolve_ksym_func_btf_id(struct bpf_object *obj,
 						struct extern_desc *ext)
 {
 	int local_func_proto_id, kfunc_proto_id, kfunc_id;
+	struct module_btf *mod_btf = NULL;
 	const struct btf_type *kern_func;
 	struct btf *kern_btf = NULL;
-	int ret, kern_btf_fd = 0;
+	int ret;
 
 	local_func_proto_id = ext->ksym.type_id;
 
-	kfunc_id = find_ksym_btf_id(obj, ext->name, BTF_KIND_FUNC,
-				    &kern_btf, &kern_btf_fd);
+	kfunc_id = find_ksym_btf_id(obj, ext->name, BTF_KIND_FUNC, &kern_btf, &mod_btf);
 	if (kfunc_id < 0) {
 		pr_warn("extern (func ksym) '%s': not found in kernel BTF\n",
 			ext->name);
 		return kfunc_id;
 	}
 
-	if (kern_btf != obj->btf_vmlinux) {
-		pr_warn("extern (func ksym) '%s': function in kernel module is not supported\n",
-			ext->name);
-		return -ENOTSUP;
-	}
-
 	kern_func = btf__type_by_id(kern_btf, kfunc_id);
 	kfunc_proto_id = kern_func->type;
 
@@ -6870,9 +6878,30 @@ static int bpf_object__resolve_ksym_func_btf_id(struct bpf_object *obj,
 		return -EINVAL;
 	}
 
+	/* set index for module BTF fd in fd_array, if unset */
+	if (mod_btf && !mod_btf->fd_array_idx) {
+		/* insn->off is s16 */
+		if (obj->fd_array_cnt == INT16_MAX) {
+			pr_warn("extern (func ksym) '%s': module BTF fd index %d too big to fit in bpf_insn offset\n",
+				ext->name, mod_btf->fd_array_idx);
+			return -E2BIG;
+		}
+		/* Cannot use index 0 for module BTF fd */
+		if (!obj->fd_array_cnt)
+			obj->fd_array_cnt = 1;
+
+		ret = libbpf_ensure_mem((void **)&obj->fd_array, &obj->fd_array_cap, sizeof(int),
+					obj->fd_array_cnt + 1);
+		if (ret)
+			return ret;
+		mod_btf->fd_array_idx = obj->fd_array_cnt;
+		/* we assume module BTF FD is always >0 */
+		obj->fd_array[obj->fd_array_cnt++] = mod_btf->fd;
+	}
+
 	ext->is_set = true;
-	ext->ksym.kernel_btf_obj_fd = kern_btf_fd;
 	ext->ksym.kernel_btf_id = kfunc_id;
+	ext->ksym.btf_fd_idx = mod_btf ? mod_btf->fd_array_idx : 0;
 	pr_debug("extern (func ksym) '%s': resolved to kernel [%d]\n",
 		 ext->name, kfunc_id);
 
@@ -7031,6 +7060,9 @@ int bpf_object__load_xattr(struct bpf_object_load_attr *attr)
 			err = bpf_gen__finish(obj->gen_loader);
 	}
 
+	/* clean up fd_array */
+	zfree(&obj->fd_array);
+
 	/* clean up module BTFs */
 	for (i = 0; i < obj->btf_module_cnt; i++) {
 		close(obj->btf_modules[i].fd);
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index ec79400517d4..f7fd3944d46d 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -298,6 +298,7 @@ struct bpf_prog_load_params {
 	__u32 log_level;
 	char *log_buf;
 	size_t log_buf_sz;
+	int *fd_array;
 };
 
 int libbpf__bpf_prog_load(const struct bpf_prog_load_params *load_attr);
@@ -408,6 +409,8 @@ int btf_type_visit_type_ids(struct btf_type *t, type_id_visit_fn visit, void *ct
 int btf_type_visit_str_offs(struct btf_type *t, str_off_visit_fn visit, void *ctx);
 int btf_ext_visit_type_ids(struct btf_ext *btf_ext, type_id_visit_fn visit, void *ctx);
 int btf_ext_visit_str_offs(struct btf_ext *btf_ext, str_off_visit_fn visit, void *ctx);
+__s32 btf__find_by_name_kind_own(const struct btf *btf, const char *type_name,
+				 __u32 kind);
 
 extern enum libbpf_strict_mode libbpf_mode;
 
-- 
cgit v1.2.3


From 466b2e13971ef65cd7b621ca3044be14028b002b Mon Sep 17 00:00:00 2001
From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: Sat, 2 Oct 2021 06:47:55 +0530
Subject: libbpf: Resolve invalid weak kfunc calls with imm = 0, off = 0

Preserve these calls as it allows verifier to succeed in loading the
program if they are determined to be unreachable after dead code
elimination during program load. If not, the verifier will fail at
runtime. This is done for ext->is_weak symbols similar to the case for
variable ksyms.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-8-memxor@gmail.com
---
 tools/lib/bpf/libbpf.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index ea1c51dbc0f3..092cf4bd1879 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -3439,11 +3439,6 @@ static int bpf_object__collect_externs(struct bpf_object *obj)
 				return -ENOTSUP;
 			}
 		} else if (strcmp(sec_name, KSYMS_SEC) == 0) {
-			if (btf_is_func(t) && ext->is_weak) {
-				pr_warn("extern weak function %s is unsupported\n",
-					ext->name);
-				return -ENOTSUP;
-			}
 			ksym_sec = sec;
 			ext->type = EXT_KSYM;
 			skip_mods_and_typedefs(obj->btf, t->type,
@@ -5416,8 +5411,13 @@ bpf_object__relocate_data(struct bpf_object *obj, struct bpf_program *prog)
 		case RELO_EXTERN_FUNC:
 			ext = &obj->externs[relo->sym_off];
 			insn[0].src_reg = BPF_PSEUDO_KFUNC_CALL;
-			insn[0].imm = ext->ksym.kernel_btf_id;
-			insn[0].off = ext->ksym.btf_fd_idx;
+			if (ext->is_set) {
+				insn[0].imm = ext->ksym.kernel_btf_id;
+				insn[0].off = ext->ksym.btf_fd_idx;
+			} else { /* unresolved weak kfunc */
+				insn[0].imm = 0;
+				insn[0].off = 0;
+			}
 			break;
 		case RELO_SUBPROG_ADDR:
 			if (insn[0].src_reg != BPF_PSEUDO_FUNC) {
@@ -6807,9 +6807,9 @@ static int bpf_object__resolve_ksym_var_btf_id(struct bpf_object *obj,
 	int id, err;
 
 	id = find_ksym_btf_id(obj, ext->name, BTF_KIND_VAR, &btf, &mod_btf);
-	if (id == -ESRCH && ext->is_weak) {
-		return 0;
-	} else if (id < 0) {
+	if (id < 0) {
+		if (id == -ESRCH && ext->is_weak)
+			return 0;
 		pr_warn("extern (var ksym) '%s': not found in kernel BTF\n",
 			ext->name);
 		return id;
@@ -6862,7 +6862,9 @@ static int bpf_object__resolve_ksym_func_btf_id(struct bpf_object *obj,
 
 	kfunc_id = find_ksym_btf_id(obj, ext->name, BTF_KIND_FUNC, &kern_btf, &mod_btf);
 	if (kfunc_id < 0) {
-		pr_warn("extern (func ksym) '%s': not found in kernel BTF\n",
+		if (kfunc_id == -ESRCH && ext->is_weak)
+			return 0;
+		pr_warn("extern (func ksym) '%s': not found in kernel or module BTFs\n",
 			ext->name);
 		return kfunc_id;
 	}
-- 
cgit v1.2.3


From 18f4fccbf314fdb07d276f4cd3eaf53f1825550d Mon Sep 17 00:00:00 2001
From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: Sat, 2 Oct 2021 06:47:56 +0530
Subject: libbpf: Update gen_loader to emit BTF_KIND_FUNC relocations

This change updates the BPF syscall loader to relocate BTF_KIND_FUNC
relocations, with support for weak kfunc relocations. The general idea
is to move map_fds to loader map, and also use the data for storing
kfunc BTF fds. Since both reuse the fd_array parameter, they need to be
kept together.

For map_fds, we reserve MAX_USED_MAPS slots in a region, and for kfunc,
we reserve MAX_KFUNC_DESCS. This is done so that insn->off has more
chances of being <= INT16_MAX than treating data map as a sparse array
and adding fd as needed.

When the MAX_KFUNC_DESCS limit is reached, we fall back to the sparse
array model, so that as long as it does remain <= INT16_MAX, we pass an
index relative to the start of fd_array.

We store all ksyms in an array where we try to avoid calling the
bpf_btf_find_by_name_kind helper, and also reuse the BTF fd that was
already stored. This also speeds up the loading process compared to
emitting calls in all cases, in later tests.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211002011757.311265-9-memxor@gmail.com
---
 tools/lib/bpf/bpf_gen_internal.h |  16 +-
 tools/lib/bpf/gen_loader.c       | 314 ++++++++++++++++++++++++++++++++-------
 tools/lib/bpf/libbpf.c           |   8 +-
 3 files changed, 280 insertions(+), 58 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/bpf_gen_internal.h b/tools/lib/bpf/bpf_gen_internal.h
index 615400391e57..70eccbffefb1 100644
--- a/tools/lib/bpf/bpf_gen_internal.h
+++ b/tools/lib/bpf/bpf_gen_internal.h
@@ -7,6 +7,15 @@ struct ksym_relo_desc {
 	const char *name;
 	int kind;
 	int insn_idx;
+	bool is_weak;
+};
+
+struct ksym_desc {
+	const char *name;
+	int ref;
+	int kind;
+	int off;
+	int insn;
 };
 
 struct bpf_gen {
@@ -24,6 +33,10 @@ struct bpf_gen {
 	int relo_cnt;
 	char attach_target[128];
 	int attach_kind;
+	struct ksym_desc *ksyms;
+	__u32 nr_ksyms;
+	int fd_array;
+	int nr_fd_array;
 };
 
 void bpf_gen__init(struct bpf_gen *gen, int log_level);
@@ -36,6 +49,7 @@ void bpf_gen__prog_load(struct bpf_gen *gen, struct bpf_prog_load_params *load_a
 void bpf_gen__map_update_elem(struct bpf_gen *gen, int map_idx, void *value, __u32 value_size);
 void bpf_gen__map_freeze(struct bpf_gen *gen, int map_idx);
 void bpf_gen__record_attach_target(struct bpf_gen *gen, const char *name, enum bpf_attach_type type);
-void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, int kind, int insn_idx);
+void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, bool is_weak, int kind,
+			    int insn_idx);
 
 #endif
diff --git a/tools/lib/bpf/gen_loader.c b/tools/lib/bpf/gen_loader.c
index 80087b13877f..937bfc7db41e 100644
--- a/tools/lib/bpf/gen_loader.c
+++ b/tools/lib/bpf/gen_loader.c
@@ -14,8 +14,10 @@
 #include "bpf_gen_internal.h"
 #include "skel_internal.h"
 
-#define MAX_USED_MAPS 64
-#define MAX_USED_PROGS 32
+#define MAX_USED_MAPS	64
+#define MAX_USED_PROGS	32
+#define MAX_KFUNC_DESCS 256
+#define MAX_FD_ARRAY_SZ (MAX_USED_PROGS + MAX_KFUNC_DESCS)
 
 /* The following structure describes the stack layout of the loader program.
  * In addition R6 contains the pointer to context.
@@ -30,7 +32,6 @@
  */
 struct loader_stack {
 	__u32 btf_fd;
-	__u32 map_fd[MAX_USED_MAPS];
 	__u32 prog_fd[MAX_USED_PROGS];
 	__u32 inner_map_fd;
 };
@@ -143,13 +144,49 @@ static int add_data(struct bpf_gen *gen, const void *data, __u32 size)
 	if (realloc_data_buf(gen, size8))
 		return 0;
 	prev = gen->data_cur;
-	memcpy(gen->data_cur, data, size);
-	gen->data_cur += size;
-	memcpy(gen->data_cur, &zero, size8 - size);
-	gen->data_cur += size8 - size;
+	if (data) {
+		memcpy(gen->data_cur, data, size);
+		memcpy(gen->data_cur + size, &zero, size8 - size);
+	} else {
+		memset(gen->data_cur, 0, size8);
+	}
+	gen->data_cur += size8;
 	return prev - gen->data_start;
 }
 
+/* Get index for map_fd/btf_fd slot in reserved fd_array, or in data relative
+ * to start of fd_array. Caller can decide if it is usable or not.
+ */
+static int add_map_fd(struct bpf_gen *gen)
+{
+	if (!gen->fd_array)
+		gen->fd_array = add_data(gen, NULL, MAX_FD_ARRAY_SZ * sizeof(int));
+	if (gen->nr_maps == MAX_USED_MAPS) {
+		pr_warn("Total maps exceeds %d\n", MAX_USED_MAPS);
+		gen->error = -E2BIG;
+		return 0;
+	}
+	return gen->nr_maps++;
+}
+
+static int add_kfunc_btf_fd(struct bpf_gen *gen)
+{
+	int cur;
+
+	if (!gen->fd_array)
+		gen->fd_array = add_data(gen, NULL, MAX_FD_ARRAY_SZ * sizeof(int));
+	if (gen->nr_fd_array == MAX_KFUNC_DESCS) {
+		cur = add_data(gen, NULL, sizeof(int));
+		return (cur - gen->fd_array) / sizeof(int);
+	}
+	return MAX_USED_MAPS + gen->nr_fd_array++;
+}
+
+static int blob_fd_array_off(struct bpf_gen *gen, int index)
+{
+	return gen->fd_array + index * sizeof(int);
+}
+
 static int insn_bytes_to_bpf_size(__u32 sz)
 {
 	switch (sz) {
@@ -171,14 +208,22 @@ static void emit_rel_store(struct bpf_gen *gen, int off, int data)
 	emit(gen, BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, 0));
 }
 
-/* *(u64 *)(blob + off) = (u64)(void *)(%sp + stack_off) */
-static void emit_rel_store_sp(struct bpf_gen *gen, int off, int stack_off)
+static void move_blob2blob(struct bpf_gen *gen, int off, int size, int blob_off)
 {
-	emit(gen, BPF_MOV64_REG(BPF_REG_0, BPF_REG_10));
-	emit(gen, BPF_ALU64_IMM(BPF_ADD, BPF_REG_0, stack_off));
+	emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_2, BPF_PSEUDO_MAP_IDX_VALUE,
+					 0, 0, 0, blob_off));
+	emit(gen, BPF_LDX_MEM(insn_bytes_to_bpf_size(size), BPF_REG_0, BPF_REG_2, 0));
 	emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE,
 					 0, 0, 0, off));
-	emit(gen, BPF_STX_MEM(BPF_DW, BPF_REG_1, BPF_REG_0, 0));
+	emit(gen, BPF_STX_MEM(insn_bytes_to_bpf_size(size), BPF_REG_1, BPF_REG_0, 0));
+}
+
+static void move_blob2ctx(struct bpf_gen *gen, int ctx_off, int size, int blob_off)
+{
+	emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE,
+					 0, 0, 0, blob_off));
+	emit(gen, BPF_LDX_MEM(insn_bytes_to_bpf_size(size), BPF_REG_0, BPF_REG_1, 0));
+	emit(gen, BPF_STX_MEM(insn_bytes_to_bpf_size(size), BPF_REG_6, BPF_REG_0, ctx_off));
 }
 
 static void move_ctx2blob(struct bpf_gen *gen, int off, int size, int ctx_off,
@@ -326,11 +371,11 @@ int bpf_gen__finish(struct bpf_gen *gen)
 			       offsetof(struct bpf_prog_desc, prog_fd), 4,
 			       stack_off(prog_fd[i]));
 	for (i = 0; i < gen->nr_maps; i++)
-		move_stack2ctx(gen,
-			       sizeof(struct bpf_loader_ctx) +
-			       sizeof(struct bpf_map_desc) * i +
-			       offsetof(struct bpf_map_desc, map_fd), 4,
-			       stack_off(map_fd[i]));
+		move_blob2ctx(gen,
+			      sizeof(struct bpf_loader_ctx) +
+			      sizeof(struct bpf_map_desc) * i +
+			      offsetof(struct bpf_map_desc, map_fd), 4,
+			      blob_fd_array_off(gen, i));
 	emit(gen, BPF_MOV64_IMM(BPF_REG_0, 0));
 	emit(gen, BPF_EXIT_INSN());
 	pr_debug("gen: finish %d\n", gen->error);
@@ -390,7 +435,7 @@ void bpf_gen__map_create(struct bpf_gen *gen,
 {
 	int attr_size = offsetofend(union bpf_attr, btf_vmlinux_value_type_id);
 	bool close_inner_map_fd = false;
-	int map_create_attr;
+	int map_create_attr, idx;
 	union bpf_attr attr;
 
 	memset(&attr, 0, attr_size);
@@ -467,9 +512,11 @@ void bpf_gen__map_create(struct bpf_gen *gen,
 		gen->error = -EDOM; /* internal bug */
 		return;
 	} else {
-		emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_7,
-				      stack_off(map_fd[map_idx])));
-		gen->nr_maps++;
+		/* add_map_fd does gen->nr_maps++ */
+		idx = add_map_fd(gen);
+		emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE,
+						 0, 0, 0, blob_fd_array_off(gen, idx)));
+		emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_1, BPF_REG_7, 0));
 	}
 	if (close_inner_map_fd)
 		emit_sys_close_stack(gen, stack_off(inner_map_fd));
@@ -511,8 +558,8 @@ static void emit_find_attach_target(struct bpf_gen *gen)
 	 */
 }
 
-void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, int kind,
-			    int insn_idx)
+void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, bool is_weak,
+			    int kind, int insn_idx)
 {
 	struct ksym_relo_desc *relo;
 
@@ -524,38 +571,192 @@ void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, int kind,
 	gen->relos = relo;
 	relo += gen->relo_cnt;
 	relo->name = name;
+	relo->is_weak = is_weak;
 	relo->kind = kind;
 	relo->insn_idx = insn_idx;
 	gen->relo_cnt++;
 }
 
-static void emit_relo(struct bpf_gen *gen, struct ksym_relo_desc *relo, int insns)
+/* returns existing ksym_desc with ref incremented, or inserts a new one */
+static struct ksym_desc *get_ksym_desc(struct bpf_gen *gen, struct ksym_relo_desc *relo)
 {
-	int name, insn, len = strlen(relo->name) + 1;
+	struct ksym_desc *kdesc;
 
-	pr_debug("gen: emit_relo: %s at %d\n", relo->name, relo->insn_idx);
-	name = add_data(gen, relo->name, len);
+	for (int i = 0; i < gen->nr_ksyms; i++) {
+		if (!strcmp(gen->ksyms[i].name, relo->name)) {
+			gen->ksyms[i].ref++;
+			return &gen->ksyms[i];
+		}
+	}
+	kdesc = libbpf_reallocarray(gen->ksyms, gen->nr_ksyms + 1, sizeof(*kdesc));
+	if (!kdesc) {
+		gen->error = -ENOMEM;
+		return NULL;
+	}
+	gen->ksyms = kdesc;
+	kdesc = &gen->ksyms[gen->nr_ksyms++];
+	kdesc->name = relo->name;
+	kdesc->kind = relo->kind;
+	kdesc->ref = 1;
+	kdesc->off = 0;
+	kdesc->insn = 0;
+	return kdesc;
+}
+
+/* Overwrites BPF_REG_{0, 1, 2, 3, 4, 7}
+ * Returns result in BPF_REG_7
+ */
+static void emit_bpf_find_by_name_kind(struct bpf_gen *gen, struct ksym_relo_desc *relo)
+{
+	int name_off, len = strlen(relo->name) + 1;
 
+	name_off = add_data(gen, relo->name, len);
 	emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE,
-					 0, 0, 0, name));
+					 0, 0, 0, name_off));
 	emit(gen, BPF_MOV64_IMM(BPF_REG_2, len));
 	emit(gen, BPF_MOV64_IMM(BPF_REG_3, relo->kind));
 	emit(gen, BPF_MOV64_IMM(BPF_REG_4, 0));
 	emit(gen, BPF_EMIT_CALL(BPF_FUNC_btf_find_by_name_kind));
 	emit(gen, BPF_MOV64_REG(BPF_REG_7, BPF_REG_0));
 	debug_ret(gen, "find_by_name_kind(%s,%d)", relo->name, relo->kind);
-	emit_check_err(gen);
+}
+
+/* Expects:
+ * BPF_REG_8 - pointer to instruction
+ *
+ * We need to reuse BTF fd for same symbol otherwise each relocation takes a new
+ * index, while kernel limits total kfunc BTFs to 256. For duplicate symbols,
+ * this would mean a new BTF fd index for each entry. By pairing symbol name
+ * with index, we get the insn->imm, insn->off pairing that kernel uses for
+ * kfunc_tab, which becomes the effective limit even though all of them may
+ * share same index in fd_array (such that kfunc_btf_tab has 1 element).
+ */
+static void emit_relo_kfunc_btf(struct bpf_gen *gen, struct ksym_relo_desc *relo, int insn)
+{
+	struct ksym_desc *kdesc;
+	int btf_fd_idx;
+
+	kdesc = get_ksym_desc(gen, relo);
+	if (!kdesc)
+		return;
+	/* try to copy from existing bpf_insn */
+	if (kdesc->ref > 1) {
+		move_blob2blob(gen, insn + offsetof(struct bpf_insn, imm), 4,
+			       kdesc->insn + offsetof(struct bpf_insn, imm));
+		move_blob2blob(gen, insn + offsetof(struct bpf_insn, off), 2,
+			       kdesc->insn + offsetof(struct bpf_insn, off));
+		goto log;
+	}
+	/* remember insn offset, so we can copy BTF ID and FD later */
+	kdesc->insn = insn;
+	emit_bpf_find_by_name_kind(gen, relo);
+	if (!relo->is_weak)
+		emit_check_err(gen);
+	/* get index in fd_array to store BTF FD at */
+	btf_fd_idx = add_kfunc_btf_fd(gen);
+	if (btf_fd_idx > INT16_MAX) {
+		pr_warn("BTF fd off %d for kfunc %s exceeds INT16_MAX, cannot process relocation\n",
+			btf_fd_idx, relo->name);
+		gen->error = -E2BIG;
+		return;
+	}
+	kdesc->off = btf_fd_idx;
+	/* set a default value for imm */
+	emit(gen, BPF_ST_MEM(BPF_W, BPF_REG_8, offsetof(struct bpf_insn, imm), 0));
+	/* skip success case store if ret < 0 */
+	emit(gen, BPF_JMP_IMM(BPF_JSLT, BPF_REG_7, 0, 1));
 	/* store btf_id into insn[insn_idx].imm */
-	insn = insns + sizeof(struct bpf_insn) * relo->insn_idx +
-		offsetof(struct bpf_insn, imm);
+	emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_8, BPF_REG_7, offsetof(struct bpf_insn, imm)));
+	/* load fd_array slot pointer */
 	emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_0, BPF_PSEUDO_MAP_IDX_VALUE,
-					 0, 0, 0, insn));
-	emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_0, BPF_REG_7, 0));
-	if (relo->kind == BTF_KIND_VAR) {
-		/* store btf_obj_fd into insn[insn_idx + 1].imm */
-		emit(gen, BPF_ALU64_IMM(BPF_RSH, BPF_REG_7, 32));
-		emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_0, BPF_REG_7,
-				      sizeof(struct bpf_insn)));
+					 0, 0, 0, blob_fd_array_off(gen, btf_fd_idx)));
+	/* skip store of BTF fd if ret < 0 */
+	emit(gen, BPF_JMP_IMM(BPF_JSLT, BPF_REG_7, 0, 3));
+	/* store BTF fd in slot */
+	emit(gen, BPF_MOV64_REG(BPF_REG_9, BPF_REG_7));
+	emit(gen, BPF_ALU64_IMM(BPF_RSH, BPF_REG_9, 32));
+	emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_0, BPF_REG_9, 0));
+	/* set a default value for off */
+	emit(gen, BPF_ST_MEM(BPF_H, BPF_REG_8, offsetof(struct bpf_insn, off), 0));
+	/* skip insn->off store if ret < 0 */
+	emit(gen, BPF_JMP_IMM(BPF_JSLT, BPF_REG_7, 0, 2));
+	/* skip if vmlinux BTF */
+	emit(gen, BPF_JMP_IMM(BPF_JEQ, BPF_REG_9, 0, 1));
+	/* store index into insn[insn_idx].off */
+	emit(gen, BPF_ST_MEM(BPF_H, BPF_REG_8, offsetof(struct bpf_insn, off), btf_fd_idx));
+log:
+	if (!gen->log_level)
+		return;
+	emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_8,
+			      offsetof(struct bpf_insn, imm)));
+	emit(gen, BPF_LDX_MEM(BPF_H, BPF_REG_9, BPF_REG_8,
+			      offsetof(struct bpf_insn, off)));
+	debug_regs(gen, BPF_REG_7, BPF_REG_9, " func (%s:count=%d): imm: %%d, off: %%d",
+		   relo->name, kdesc->ref);
+	emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_0, BPF_PSEUDO_MAP_IDX_VALUE,
+					 0, 0, 0, blob_fd_array_off(gen, kdesc->off)));
+	emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_0, 0));
+	debug_regs(gen, BPF_REG_9, -1, " func (%s:count=%d): btf_fd",
+		   relo->name, kdesc->ref);
+}
+
+/* Expects:
+ * BPF_REG_8 - pointer to instruction
+ */
+static void emit_relo_ksym_btf(struct bpf_gen *gen, struct ksym_relo_desc *relo, int insn)
+{
+	struct ksym_desc *kdesc;
+
+	kdesc = get_ksym_desc(gen, relo);
+	if (!kdesc)
+		return;
+	/* try to copy from existing ldimm64 insn */
+	if (kdesc->ref > 1) {
+		move_blob2blob(gen, insn + offsetof(struct bpf_insn, imm), 4,
+			       kdesc->insn + offsetof(struct bpf_insn, imm));
+		move_blob2blob(gen, insn + sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm), 4,
+			       kdesc->insn + sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm));
+		goto log;
+	}
+	/* remember insn offset, so we can copy BTF ID and FD later */
+	kdesc->insn = insn;
+	emit_bpf_find_by_name_kind(gen, relo);
+	emit_check_err(gen);
+	/* store btf_id into insn[insn_idx].imm */
+	emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_8, BPF_REG_7, offsetof(struct bpf_insn, imm)));
+	/* store btf_obj_fd into insn[insn_idx + 1].imm */
+	emit(gen, BPF_ALU64_IMM(BPF_RSH, BPF_REG_7, 32));
+	emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_8, BPF_REG_7,
+			      sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm)));
+log:
+	if (!gen->log_level)
+		return;
+	emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_8,
+			      offsetof(struct bpf_insn, imm)));
+	emit(gen, BPF_LDX_MEM(BPF_H, BPF_REG_9, BPF_REG_8, sizeof(struct bpf_insn) +
+			      offsetof(struct bpf_insn, imm)));
+	debug_regs(gen, BPF_REG_7, BPF_REG_9, " var (%s:count=%d): imm: %%d, fd: %%d",
+		   relo->name, kdesc->ref);
+}
+
+static void emit_relo(struct bpf_gen *gen, struct ksym_relo_desc *relo, int insns)
+{
+	int insn;
+
+	pr_debug("gen: emit_relo (%d): %s at %d\n", relo->kind, relo->name, relo->insn_idx);
+	insn = insns + sizeof(struct bpf_insn) * relo->insn_idx;
+	emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_8, BPF_PSEUDO_MAP_IDX_VALUE, 0, 0, 0, insn));
+	switch (relo->kind) {
+	case BTF_KIND_VAR:
+		emit_relo_ksym_btf(gen, relo, insn);
+		break;
+	case BTF_KIND_FUNC:
+		emit_relo_kfunc_btf(gen, relo, insn);
+		break;
+	default:
+		pr_warn("Unknown relocation kind '%d'\n", relo->kind);
+		gen->error = -EDOM;
+		return;
 	}
 }
 
@@ -571,14 +772,22 @@ static void cleanup_relos(struct bpf_gen *gen, int insns)
 {
 	int i, insn;
 
-	for (i = 0; i < gen->relo_cnt; i++) {
-		if (gen->relos[i].kind != BTF_KIND_VAR)
-			continue;
-		/* close fd recorded in insn[insn_idx + 1].imm */
-		insn = insns +
-			sizeof(struct bpf_insn) * (gen->relos[i].insn_idx + 1) +
-			offsetof(struct bpf_insn, imm);
-		emit_sys_close_blob(gen, insn);
+	for (i = 0; i < gen->nr_ksyms; i++) {
+		if (gen->ksyms[i].kind == BTF_KIND_VAR) {
+			/* close fd recorded in insn[insn_idx + 1].imm */
+			insn = gen->ksyms[i].insn;
+			insn += sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm);
+			emit_sys_close_blob(gen, insn);
+		} else { /* BTF_KIND_FUNC */
+			emit_sys_close_blob(gen, blob_fd_array_off(gen, gen->ksyms[i].off));
+			if (gen->ksyms[i].off < MAX_FD_ARRAY_SZ)
+				gen->nr_fd_array--;
+		}
+	}
+	if (gen->nr_ksyms) {
+		free(gen->ksyms);
+		gen->nr_ksyms = 0;
+		gen->ksyms = NULL;
 	}
 	if (gen->relo_cnt) {
 		free(gen->relos);
@@ -637,9 +846,8 @@ void bpf_gen__prog_load(struct bpf_gen *gen,
 	/* populate union bpf_attr with a pointer to line_info */
 	emit_rel_store(gen, attr_field(prog_load_attr, line_info), line_info);
 
-	/* populate union bpf_attr fd_array with a pointer to stack where map_fds are saved */
-	emit_rel_store_sp(gen, attr_field(prog_load_attr, fd_array),
-			  stack_off(map_fd[0]));
+	/* populate union bpf_attr fd_array with a pointer to data where map_fds are saved */
+	emit_rel_store(gen, attr_field(prog_load_attr, fd_array), gen->fd_array);
 
 	/* populate union bpf_attr with user provided log details */
 	move_ctx2blob(gen, attr_field(prog_load_attr, log_level), 4,
@@ -706,8 +914,8 @@ void bpf_gen__map_update_elem(struct bpf_gen *gen, int map_idx, void *pvalue,
 	emit(gen, BPF_EMIT_CALL(BPF_FUNC_copy_from_user));
 
 	map_update_attr = add_data(gen, &attr, attr_size);
-	move_stack2blob(gen, attr_field(map_update_attr, map_fd), 4,
-			stack_off(map_fd[map_idx]));
+	move_blob2blob(gen, attr_field(map_update_attr, map_fd), 4,
+		       blob_fd_array_off(gen, map_idx));
 	emit_rel_store(gen, attr_field(map_update_attr, key), key);
 	emit_rel_store(gen, attr_field(map_update_attr, value), value);
 	/* emit MAP_UPDATE_ELEM command */
@@ -725,8 +933,8 @@ void bpf_gen__map_freeze(struct bpf_gen *gen, int map_idx)
 	memset(&attr, 0, attr_size);
 	pr_debug("gen: map_freeze: idx %d\n", map_idx);
 	map_freeze_attr = add_data(gen, &attr, attr_size);
-	move_stack2blob(gen, attr_field(map_freeze_attr, map_fd), 4,
-			stack_off(map_fd[map_idx]));
+	move_blob2blob(gen, attr_field(map_freeze_attr, map_fd), 4,
+		       blob_fd_array_off(gen, map_idx));
 	/* emit MAP_FREEZE command */
 	emit_sys_bpf(gen, BPF_MAP_FREEZE, map_freeze_attr, attr_size);
 	debug_ret(gen, "map_freeze");
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 092cf4bd1879..f32fa51b1e63 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -6360,12 +6360,12 @@ static int bpf_program__record_externs(struct bpf_program *prog)
 					ext->name);
 				return -ENOTSUP;
 			}
-			bpf_gen__record_extern(obj->gen_loader, ext->name, BTF_KIND_VAR,
-					       relo->insn_idx);
+			bpf_gen__record_extern(obj->gen_loader, ext->name, ext->is_weak,
+					       BTF_KIND_VAR, relo->insn_idx);
 			break;
 		case RELO_EXTERN_FUNC:
-			bpf_gen__record_extern(obj->gen_loader, ext->name, BTF_KIND_FUNC,
-					       relo->insn_idx);
+			bpf_gen__record_extern(obj->gen_loader, ext->name, ext->is_weak,
+					       BTF_KIND_FUNC, relo->insn_idx);
 			break;
 		default:
 			continue;
-- 
cgit v1.2.3


From 7ca61121598338ab713a5c705a843f3b8fed9f90 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Tue, 5 Oct 2021 22:11:05 -0700
Subject: libbpf: Add API that copies all BTF types from one BTF object to
 another

Add a bulk copying api, btf__add_btf(), that speeds up and simplifies
appending entire contents of one BTF object to another one, taking care
of copying BTF type data, adjusting resulting BTF type IDs according to
their new locations in the destination BTF object, as well as copying
and deduplicating all the referenced strings and updating all the string
offsets in new BTF types as appropriate.

This API is intended to be used from tools that are generating and
otherwise manipulating BTFs generically, such as pahole. In pahole's
case, this API is useful for speeding up parallelized BTF encoding, as
it allows pahole to offload all the intricacies of BTF type copying to
libbpf and handle the parallelization aspects of the process.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Link: https://lore.kernel.org/bpf/20211006051107.17921-2-andrii@kernel.org
---
 tools/lib/bpf/btf.c      | 114 ++++++++++++++++++++++++++++++++++++++++++++++-
 tools/lib/bpf/btf.h      |  22 +++++++++
 tools/lib/bpf/libbpf.map |   1 +
 3 files changed, 135 insertions(+), 2 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 7774f99afa6e..60fbd1c6d466 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -189,12 +189,17 @@ int libbpf_ensure_mem(void **data, size_t *cap_cnt, size_t elem_sz, size_t need_
 	return 0;
 }
 
+static void *btf_add_type_offs_mem(struct btf *btf, size_t add_cnt)
+{
+	return libbpf_add_mem((void **)&btf->type_offs, &btf->type_offs_cap, sizeof(__u32),
+			      btf->nr_types, BTF_MAX_NR_TYPES, add_cnt);
+}
+
 static int btf_add_type_idx_entry(struct btf *btf, __u32 type_off)
 {
 	__u32 *p;
 
-	p = libbpf_add_mem((void **)&btf->type_offs, &btf->type_offs_cap, sizeof(__u32),
-			   btf->nr_types, BTF_MAX_NR_TYPES, 1);
+	p = btf_add_type_offs_mem(btf, 1);
 	if (!p)
 		return -ENOMEM;
 
@@ -1703,6 +1708,111 @@ int btf__add_type(struct btf *btf, const struct btf *src_btf, const struct btf_t
 	return btf_commit_type(btf, sz);
 }
 
+static int btf_rewrite_type_ids(__u32 *type_id, void *ctx)
+{
+	struct btf *btf = ctx;
+
+	if (!*type_id) /* nothing to do for VOID references */
+		return 0;
+
+	/* we haven't updated btf's type count yet, so
+	 * btf->start_id + btf->nr_types - 1 is the type ID offset we should
+	 * add to all newly added BTF types
+	 */
+	*type_id += btf->start_id + btf->nr_types - 1;
+	return 0;
+}
+
+int btf__add_btf(struct btf *btf, const struct btf *src_btf)
+{
+	struct btf_pipe p = { .src = src_btf, .dst = btf };
+	int data_sz, sz, cnt, i, err, old_strs_len;
+	__u32 *off;
+	void *t;
+
+	/* appending split BTF isn't supported yet */
+	if (src_btf->base_btf)
+		return libbpf_err(-ENOTSUP);
+
+	/* deconstruct BTF, if necessary, and invalidate raw_data */
+	if (btf_ensure_modifiable(btf))
+		return libbpf_err(-ENOMEM);
+
+	/* remember original strings section size if we have to roll back
+	 * partial strings section changes
+	 */
+	old_strs_len = btf->hdr->str_len;
+
+	data_sz = src_btf->hdr->type_len;
+	cnt = btf__get_nr_types(src_btf);
+
+	/* pre-allocate enough memory for new types */
+	t = btf_add_type_mem(btf, data_sz);
+	if (!t)
+		return libbpf_err(-ENOMEM);
+
+	/* pre-allocate enough memory for type offset index for new types */
+	off = btf_add_type_offs_mem(btf, cnt);
+	if (!off)
+		return libbpf_err(-ENOMEM);
+
+	/* bulk copy types data for all types from src_btf */
+	memcpy(t, src_btf->types_data, data_sz);
+
+	for (i = 0; i < cnt; i++) {
+		sz = btf_type_size(t);
+		if (sz < 0) {
+			/* unlikely, has to be corrupted src_btf */
+			err = sz;
+			goto err_out;
+		}
+
+		/* fill out type ID to type offset mapping for lookups by type ID */
+		*off = t - btf->types_data;
+
+		/* add, dedup, and remap strings referenced by this BTF type */
+		err = btf_type_visit_str_offs(t, btf_rewrite_str, &p);
+		if (err)
+			goto err_out;
+
+		/* remap all type IDs referenced from this BTF type */
+		err = btf_type_visit_type_ids(t, btf_rewrite_type_ids, btf);
+		if (err)
+			goto err_out;
+
+		/* go to next type data and type offset index entry */
+		t += sz;
+		off++;
+	}
+
+	/* Up until now any of the copied type data was effectively invisible,
+	 * so if we exited early before this point due to error, BTF would be
+	 * effectively unmodified. There would be extra internal memory
+	 * pre-allocated, but it would not be available for querying.  But now
+	 * that we've copied and rewritten all the data successfully, we can
+	 * update type count and various internal offsets and sizes to
+	 * "commit" the changes and made them visible to the outside world.
+	 */
+	btf->hdr->type_len += data_sz;
+	btf->hdr->str_off += data_sz;
+	btf->nr_types += cnt;
+
+	/* return type ID of the first added BTF type */
+	return btf->start_id + btf->nr_types - cnt;
+err_out:
+	/* zero out preallocated memory as if it was just allocated with
+	 * libbpf_add_mem()
+	 */
+	memset(btf->types_data + btf->hdr->type_len, 0, data_sz);
+	memset(btf->strs_data + old_strs_len, 0, btf->hdr->str_len - old_strs_len);
+
+	/* and now restore original strings section size; types data size
+	 * wasn't modified, so doesn't need restoring, see big comment above */
+	btf->hdr->str_len = old_strs_len;
+
+	return libbpf_err(err);
+}
+
 /*
  * Append new BTF_KIND_INT type with:
  *   - *name* - non-empty, non-NULL type name;
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 2cfe31327920..864eb51753a1 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -173,6 +173,28 @@ LIBBPF_API int btf__find_str(struct btf *btf, const char *s);
 LIBBPF_API int btf__add_str(struct btf *btf, const char *s);
 LIBBPF_API int btf__add_type(struct btf *btf, const struct btf *src_btf,
 			     const struct btf_type *src_type);
+/**
+ * @brief **btf__add_btf()** appends all the BTF types from *src_btf* into *btf*
+ * @param btf BTF object which all the BTF types and strings are added to
+ * @param src_btf BTF object which all BTF types and referenced strings are copied from
+ * @return BTF type ID of the first appended BTF type, or negative error code
+ *
+ * **btf__add_btf()** can be used to simply and efficiently append the entire
+ * contents of one BTF object to another one. All the BTF type data is copied
+ * over, all referenced type IDs are adjusted by adding a necessary ID offset.
+ * Only strings referenced from BTF types are copied over and deduplicated, so
+ * if there were some unused strings in *src_btf*, those won't be copied over,
+ * which is consistent with the general string deduplication semantics of BTF
+ * writing APIs.
+ *
+ * If any error is encountered during this process, the contents of *btf* is
+ * left intact, which means that **btf__add_btf()** follows the transactional
+ * semantics and the operation as a whole is all-or-nothing.
+ *
+ * *src_btf* has to be non-split BTF, as of now copying types from split BTF
+ * is not supported and will result in -ENOTSUP error code returned.
+ */
+LIBBPF_API int btf__add_btf(struct btf *btf, const struct btf *src_btf);
 
 LIBBPF_API int btf__add_int(struct btf *btf, const char *name, size_t byte_sz, int encoding);
 LIBBPF_API int btf__add_float(struct btf *btf, const char *name, size_t byte_sz);
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 9e649cf9e771..f6b0db1e8c8b 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -389,5 +389,6 @@ LIBBPF_0.5.0 {
 
 LIBBPF_0.6.0 {
 	global:
+		btf__add_btf;
 		btf__add_tag;
 } LIBBPF_0.5.0;
-- 
cgit v1.2.3


From 929bef467771d4d5a22b9edb51a2025dc0e49113 Mon Sep 17 00:00:00 2001
From: Quentin Monnet <quentin@isovalent.com>
Date: Wed, 6 Oct 2021 12:10:49 +0100
Subject: bpf: Use $(pound) instead of \# in Makefiles

Recent-ish versions of make do no longer consider number signs ("#") as
comment symbols when they are inserted inside of a macro reference or in
a function invocation. In such cases, the symbols should not be escaped.

There are a few occurrences of "\#" in libbpf's and samples' Makefiles.
In the former, the backslash is harmless, because grep associates no
particular meaning to the escaped symbol and reads it as a regular "#".
In samples' Makefile, recent versions of make will pass the backslash
down to the compiler, making the probe fail all the time and resulting
in the display of a warning about "make headers_install" being required,
even after headers have been installed.

A similar issue has been addressed at some other locations by commit
9564a8cf422d ("Kbuild: fix # escaping in .cmd files for future Make").
Let's address it for libbpf's and samples' Makefiles in the same
fashion, by using a "$(pound)" variable (pulled from
tools/scripts/Makefile.include for libbpf, or re-defined for the
samples).

Reference for the change in make:
https://git.savannah.gnu.org/cgit/make.git/commit/?id=c6966b323811c37acedff05b57

Fixes: 2f3830412786 ("libbpf: Make libbpf_version.h non-auto-generated")
Fixes: 07c3bbdb1a9b ("samples: bpf: print a warning about headers_install")
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211006111049.20708-1-quentin@isovalent.com
---
 samples/bpf/Makefile   | 4 +++-
 tools/lib/bpf/Makefile | 4 ++--
 2 files changed, 5 insertions(+), 3 deletions(-)

(limited to 'tools/lib')

diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 4dc20be5fb96..a5783749ec15 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -3,6 +3,8 @@
 BPF_SAMPLES_PATH ?= $(abspath $(srctree)/$(src))
 TOOLS_PATH := $(BPF_SAMPLES_PATH)/../../tools
 
+pound := \#
+
 # List of programs to build
 tprogs-y := test_lru_dist
 tprogs-y += sock_example
@@ -232,7 +234,7 @@ endif
 
 # Don't evaluate probes and warnings if we need to run make recursively
 ifneq ($(src),)
-HDR_PROBE := $(shell printf "\#include <linux/types.h>\n struct list_head { int a; }; int main() { return 0; }" | \
+HDR_PROBE := $(shell printf "$(pound)include <linux/types.h>\n struct list_head { int a; }; int main() { return 0; }" | \
 	$(CC) $(TPROGS_CFLAGS) $(TPROGS_LDFLAGS) -x c - \
 	-o /dev/null 2>/dev/null && echo okay)
 
diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index 0f766345506f..41e4f78dbad5 100644
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -208,8 +208,8 @@ check_abi: $(OUTPUT)libbpf.so $(VERSION_SCRIPT)
 		exit 1;							 \
 	fi
 
-HDR_MAJ_VERSION := $(shell grep -oE '^\#define LIBBPF_MAJOR_VERSION ([0-9]+)$$' libbpf_version.h | cut -d' ' -f3)
-HDR_MIN_VERSION := $(shell grep -oE '^\#define LIBBPF_MINOR_VERSION ([0-9]+)$$' libbpf_version.h | cut -d' ' -f3)
+HDR_MAJ_VERSION := $(shell grep -oE '^$(pound)define LIBBPF_MAJOR_VERSION ([0-9]+)$$' libbpf_version.h | cut -d' ' -f3)
+HDR_MIN_VERSION := $(shell grep -oE '^$(pound)define LIBBPF_MINOR_VERSION ([0-9]+)$$' libbpf_version.h | cut -d' ' -f3)
 
 check_version: $(VERSION_SCRIPT) libbpf_version.h
 	@if [ "$(HDR_MAJ_VERSION)" != "$(LIBBPF_MAJOR_VERSION)" ]; then        \
-- 
cgit v1.2.3


From 4a404a7e8a3902fc560527241a611186605efb4e Mon Sep 17 00:00:00 2001
From: Hengqi Chen <hengqi.chen@gmail.com>
Date: Sun, 3 Oct 2021 00:10:00 +0800
Subject: libbpf: Deprecate bpf_object__unload() API since v0.6

BPF objects are not reloadable after unload. Users are expected to use
bpf_object__close() to unload and free up resources in one operation.
No need to expose bpf_object__unload() as a public API, deprecate it
([0]).  Add bpf_object__unload() as an alias to internal
bpf_object_unload() and replace all bpf_object__unload() uses to avoid
compilation errors.

  [0] Closes: https://github.com/libbpf/libbpf/issues/290

Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211002161000.3854559-1-hengqi.chen@gmail.com
---
 tools/lib/bpf/libbpf.c | 8 +++++---
 tools/lib/bpf/libbpf.h | 1 +
 2 files changed, 6 insertions(+), 3 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index f32fa51b1e63..4b90878a315f 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -6672,7 +6672,7 @@ bpf_object__open_buffer(const void *obj_buf, size_t obj_buf_sz,
 	return libbpf_ptr(__bpf_object__open(NULL, obj_buf, obj_buf_sz, &opts));
 }
 
-int bpf_object__unload(struct bpf_object *obj)
+static int bpf_object_unload(struct bpf_object *obj)
 {
 	size_t i;
 
@@ -6691,6 +6691,8 @@ int bpf_object__unload(struct bpf_object *obj)
 	return 0;
 }
 
+int bpf_object__unload(struct bpf_object *obj) __attribute__((alias("bpf_object_unload")));
+
 static int bpf_object__sanitize_maps(struct bpf_object *obj)
 {
 	struct bpf_map *m;
@@ -7089,7 +7091,7 @@ out:
 		if (obj->maps[i].pinned && !obj->maps[i].reused)
 			bpf_map__unpin(&obj->maps[i], NULL);
 
-	bpf_object__unload(obj);
+	bpf_object_unload(obj);
 	pr_warn("failed to load object '%s'\n", obj->path);
 	return libbpf_err(err);
 }
@@ -7698,7 +7700,7 @@ void bpf_object__close(struct bpf_object *obj)
 
 	bpf_gen__free(obj->gen_loader);
 	bpf_object__elf_finish(obj);
-	bpf_object__unload(obj);
+	bpf_object_unload(obj);
 	btf__free(obj->btf);
 	btf_ext__free(obj->btf_ext);
 
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index e35490c54eb3..df10d14dbbb8 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -150,6 +150,7 @@ struct bpf_object_load_attr {
 /* Load/unload object into/from kernel */
 LIBBPF_API int bpf_object__load(struct bpf_object *obj);
 LIBBPF_API int bpf_object__load_xattr(struct bpf_object_load_attr *attr);
+LIBBPF_DEPRECATED_SINCE(0, 6, "bpf_object__unload() is deprecated, use bpf_object__close() instead")
 LIBBPF_API int bpf_object__unload(struct bpf_object *obj);
 
 LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj);
-- 
cgit v1.2.3


From 2088a3a71d870115fdfb799c0f7de76d7383ba03 Mon Sep 17 00:00:00 2001
From: Hengqi Chen <hengqi.chen@gmail.com>
Date: Mon, 4 Oct 2021 00:58:43 +0800
Subject: libbpf: Deprecate bpf_{map,program}__{prev,next} APIs since v0.7

Deprecate bpf_{map,program}__{prev,next} APIs. Replace them with
a new set of APIs named bpf_object__{prev,next}_{program,map} which
follow the libbpf API naming convention ([0]). No functionality changes.

  [0] Closes: https://github.com/libbpf/libbpf/issues/296

Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211003165844.4054931-2-hengqi.chen@gmail.com
---
 tools/lib/bpf/libbpf.c   | 24 ++++++++++++++++++++++++
 tools/lib/bpf/libbpf.h   | 35 +++++++++++++++++++++++------------
 tools/lib/bpf/libbpf.map |  4 ++++
 3 files changed, 51 insertions(+), 12 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 4b90878a315f..ed313fd491bd 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -7834,6 +7834,12 @@ __bpf_program__iter(const struct bpf_program *p, const struct bpf_object *obj,
 
 struct bpf_program *
 bpf_program__next(struct bpf_program *prev, const struct bpf_object *obj)
+{
+	return bpf_object__next_program(obj, prev);
+}
+
+struct bpf_program *
+bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prev)
 {
 	struct bpf_program *prog = prev;
 
@@ -7846,6 +7852,12 @@ bpf_program__next(struct bpf_program *prev, const struct bpf_object *obj)
 
 struct bpf_program *
 bpf_program__prev(struct bpf_program *next, const struct bpf_object *obj)
+{
+	return bpf_object__prev_program(obj, next);
+}
+
+struct bpf_program *
+bpf_object__prev_program(const struct bpf_object *obj, struct bpf_program *next)
 {
 	struct bpf_program *prog = next;
 
@@ -8778,6 +8790,12 @@ __bpf_map__iter(const struct bpf_map *m, const struct bpf_object *obj, int i)
 
 struct bpf_map *
 bpf_map__next(const struct bpf_map *prev, const struct bpf_object *obj)
+{
+	return bpf_object__next_map(obj, prev);
+}
+
+struct bpf_map *
+bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *prev)
 {
 	if (prev == NULL)
 		return obj->maps;
@@ -8787,6 +8805,12 @@ bpf_map__next(const struct bpf_map *prev, const struct bpf_object *obj)
 
 struct bpf_map *
 bpf_map__prev(const struct bpf_map *next, const struct bpf_object *obj)
+{
+	return bpf_object__prev_map(obj, next);
+}
+
+struct bpf_map *
+bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *next)
 {
 	if (next == NULL) {
 		if (!obj->nr_maps)
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index df10d14dbbb8..89ca9c83ed4e 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -190,16 +190,22 @@ LIBBPF_API int libbpf_find_vmlinux_btf_id(const char *name,
 
 /* Accessors of bpf_program */
 struct bpf_program;
-LIBBPF_API struct bpf_program *bpf_program__next(struct bpf_program *prog,
-						 const struct bpf_object *obj);
+LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "use bpf_object__next_program() instead")
+struct bpf_program *bpf_program__next(struct bpf_program *prog,
+				      const struct bpf_object *obj);
+LIBBPF_API struct bpf_program *
+bpf_object__next_program(const struct bpf_object *obj, struct bpf_program *prog);
 
-#define bpf_object__for_each_program(pos, obj)		\
-	for ((pos) = bpf_program__next(NULL, (obj));	\
-	     (pos) != NULL;				\
-	     (pos) = bpf_program__next((pos), (obj)))
+#define bpf_object__for_each_program(pos, obj)			\
+	for ((pos) = bpf_object__next_program((obj), NULL);	\
+	     (pos) != NULL;					\
+	     (pos) = bpf_object__next_program((obj), (pos)))
 
-LIBBPF_API struct bpf_program *bpf_program__prev(struct bpf_program *prog,
-						 const struct bpf_object *obj);
+LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "use bpf_object__prev_program() instead")
+struct bpf_program *bpf_program__prev(struct bpf_program *prog,
+				      const struct bpf_object *obj);
+LIBBPF_API struct bpf_program *
+bpf_object__prev_program(const struct bpf_object *obj, struct bpf_program *prog);
 
 typedef void (*bpf_program_clear_priv_t)(struct bpf_program *, void *);
 
@@ -503,16 +509,21 @@ bpf_object__find_map_fd_by_name(const struct bpf_object *obj, const char *name);
 LIBBPF_API struct bpf_map *
 bpf_object__find_map_by_offset(struct bpf_object *obj, size_t offset);
 
+LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "use bpf_object__next_map() instead")
+struct bpf_map *bpf_map__next(const struct bpf_map *map, const struct bpf_object *obj);
 LIBBPF_API struct bpf_map *
-bpf_map__next(const struct bpf_map *map, const struct bpf_object *obj);
+bpf_object__next_map(const struct bpf_object *obj, const struct bpf_map *map);
+
 #define bpf_object__for_each_map(pos, obj)		\
-	for ((pos) = bpf_map__next(NULL, (obj));	\
+	for ((pos) = bpf_object__next_map((obj), NULL);	\
 	     (pos) != NULL;				\
-	     (pos) = bpf_map__next((pos), (obj)))
+	     (pos) = bpf_object__next_map((obj), (pos)))
 #define bpf_map__for_each bpf_object__for_each_map
 
+LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "use bpf_object__prev_map() instead")
+struct bpf_map *bpf_map__prev(const struct bpf_map *map, const struct bpf_object *obj);
 LIBBPF_API struct bpf_map *
-bpf_map__prev(const struct bpf_map *map, const struct bpf_object *obj);
+bpf_object__prev_map(const struct bpf_object *obj, const struct bpf_map *map);
 
 /**
  * @brief **bpf_map__fd()** gets the file descriptor of the passed
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index f6b0db1e8c8b..f270d25e4af3 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -389,6 +389,10 @@ LIBBPF_0.5.0 {
 
 LIBBPF_0.6.0 {
 	global:
+		bpf_object__next_map;
+		bpf_object__next_program;
+		bpf_object__prev_map;
+		bpf_object__prev_program;
 		btf__add_btf;
 		btf__add_tag;
 } LIBBPF_0.5.0;
-- 
cgit v1.2.3


From b79c2ce3baa99beea7f8410ce3154cc23e26dbd8 Mon Sep 17 00:00:00 2001
From: Quentin Monnet <quentin@isovalent.com>
Date: Thu, 7 Oct 2021 20:44:27 +0100
Subject: libbpf: Skip re-installing headers file if source is older than
 target

The "install_headers" target in libbpf's Makefile would unconditionally
export all API headers to the target directory. When those headers are
installed to compile another application, this means that make always
finds newer dependencies for the source files relying on those headers,
and deduces that the targets should be rebuilt.

Avoid that by making "install_headers" depend on the source header
files, and (re-)install them only when necessary.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211007194438.34443-2-quentin@isovalent.com
---
 tools/lib/bpf/Makefile | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index 41e4f78dbad5..9c6804ca5b45 100644
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -241,15 +241,24 @@ install_lib: all_cmd
 		$(call do_install_mkdir,$(libdir_SQ)); \
 		cp -fpR $(LIB_FILE) $(DESTDIR)$(libdir_SQ)
 
-INSTALL_HEADERS = bpf.h libbpf.h btf.h libbpf_common.h libbpf_legacy.h xsk.h \
-		  bpf_helpers.h $(BPF_GENERATED) bpf_tracing.h		     \
-		  bpf_endian.h bpf_core_read.h skel_internal.h		     \
-		  libbpf_version.h
-
-install_headers: $(BPF_GENERATED)
-	$(call QUIET_INSTALL, headers)					     \
-		$(foreach hdr,$(INSTALL_HEADERS),			     \
-			$(call do_install,$(hdr),$(prefix)/include/bpf,644);)
+SRC_HDRS := bpf.h libbpf.h btf.h libbpf_common.h libbpf_legacy.h xsk.h	     \
+	    bpf_helpers.h bpf_tracing.h bpf_endian.h bpf_core_read.h	     \
+	    skel_internal.h libbpf_version.h
+GEN_HDRS := $(BPF_GENERATED)
+
+INSTALL_PFX := $(DESTDIR)$(prefix)/include/bpf
+INSTALL_SRC_HDRS := $(addprefix $(INSTALL_PFX)/, $(SRC_HDRS))
+INSTALL_GEN_HDRS := $(addprefix $(INSTALL_PFX)/, $(notdir $(GEN_HDRS)))
+
+$(INSTALL_SRC_HDRS): $(INSTALL_PFX)/%.h: %.h
+	$(call QUIET_INSTALL, $@) \
+		$(call do_install,$<,$(prefix)/include/bpf,644)
+
+$(INSTALL_GEN_HDRS): $(INSTALL_PFX)/%.h: $(OUTPUT)%.h
+	$(call QUIET_INSTALL, $@) \
+		$(call do_install,$<,$(prefix)/include/bpf,644)
+
+install_headers: $(BPF_GENERATED) $(INSTALL_SRC_HDRS) $(INSTALL_GEN_HDRS)
 
 install_pkgconfig: $(PC_FILE)
 	$(call QUIET_INSTALL, $(PC_FILE)) \
-- 
cgit v1.2.3


From ccaf12d6215a56836472db220520cda8024d6c4f Mon Sep 17 00:00:00 2001
From: Hou Tao <houtao1@huawei.com>
Date: Mon, 4 Oct 2021 17:48:56 +0800
Subject: libbpf: Support detecting and attaching of writable tracepoint
 program

Program on writable tracepoint is BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE,
but its attachment is the same as BPF_PROG_TYPE_RAW_TRACEPOINT.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211004094857.30868-3-hotforest@gmail.com
---
 tools/lib/bpf/libbpf.c | 26 +++++++++++++++++++++-----
 1 file changed, 21 insertions(+), 5 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index ed313fd491bd..ae0889bebe32 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -8077,6 +8077,8 @@ static const struct bpf_sec_def section_defs[] = {
 	SEC_DEF("tp/",			TRACEPOINT, 0, SEC_NONE, attach_tp),
 	SEC_DEF("raw_tracepoint/",	RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp),
 	SEC_DEF("raw_tp/",		RAW_TRACEPOINT, 0, SEC_NONE, attach_raw_tp),
+	SEC_DEF("raw_tracepoint.w/",	RAW_TRACEPOINT_WRITABLE, 0, SEC_NONE, attach_raw_tp),
+	SEC_DEF("raw_tp.w/",		RAW_TRACEPOINT_WRITABLE, 0, SEC_NONE, attach_raw_tp),
 	SEC_DEF("tp_btf/",		TRACING, BPF_TRACE_RAW_TP, SEC_ATTACH_BTF, attach_trace),
 	SEC_DEF("fentry/",		TRACING, BPF_TRACE_FENTRY, SEC_ATTACH_BTF, attach_trace),
 	SEC_DEF("fmod_ret/",		TRACING, BPF_MODIFY_RETURN, SEC_ATTACH_BTF, attach_trace),
@@ -9846,12 +9848,26 @@ struct bpf_link *bpf_program__attach_raw_tracepoint(const struct bpf_program *pr
 
 static struct bpf_link *attach_raw_tp(const struct bpf_program *prog, long cookie)
 {
-	const char *tp_name;
+	static const char *const prefixes[] = {
+		"raw_tp/",
+		"raw_tracepoint/",
+		"raw_tp.w/",
+		"raw_tracepoint.w/",
+	};
+	size_t i;
+	const char *tp_name = NULL;
 
-	if (str_has_pfx(prog->sec_name, "raw_tp/"))
-		tp_name = prog->sec_name + sizeof("raw_tp/") - 1;
-	else
-		tp_name = prog->sec_name + sizeof("raw_tracepoint/") - 1;
+	for (i = 0; i < ARRAY_SIZE(prefixes); i++) {
+		if (str_has_pfx(prog->sec_name, prefixes[i])) {
+			tp_name = prog->sec_name + strlen(prefixes[i]);
+			break;
+		}
+	}
+	if (!tp_name) {
+		pr_warn("prog '%s': invalid section name '%s'\n",
+			prog->name, prog->sec_name);
+		return libbpf_err_ptr(-EINVAL);
+	}
 
 	return bpf_program__attach_raw_tracepoint(prog, tp_name);
 }
-- 
cgit v1.2.3


From 223f903e9c832699f4e5f422281a60756c1c6cfe Mon Sep 17 00:00:00 2001
From: Yonghong Song <yhs@fb.com>
Date: Tue, 12 Oct 2021 09:48:38 -0700
Subject: bpf: Rename BTF_KIND_TAG to BTF_KIND_DECL_TAG

Patch set [1] introduced BTF_KIND_TAG to allow tagging
declarations for struct/union, struct/union field, var, func
and func arguments and these tags will be encoded into
dwarf. They are also encoded to btf by llvm for the bpf target.

After BTF_KIND_TAG is introduced, we intended to use it
for kernel __user attributes. But kernel __user is actually
a type attribute. Upstream and internal discussion showed
it is not a good idea to mix declaration attribute and
type attribute. So we proposed to introduce btf_type_tag
as a type attribute and existing btf_tag renamed to
btf_decl_tag ([2]).

This patch renamed BTF_KIND_TAG to BTF_KIND_DECL_TAG and some
other declarations with *_tag to *_decl_tag to make it clear
the tag is for declaration. In the future, BTF_KIND_TYPE_TAG
might be introduced per [3].

 [1] https://lore.kernel.org/bpf/20210914223004.244411-1-yhs@fb.com/
 [2] https://reviews.llvm.org/D111588
 [3] https://reviews.llvm.org/D111199

Fixes: b5ea834dde6b ("bpf: Support for new btf kind BTF_KIND_TAG")
Fixes: 5b84bd10363e ("libbpf: Add support for BTF_KIND_TAG")
Fixes: 5c07f2fec003 ("bpftool: Add support for BTF_KIND_TAG")
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211012164838.3345699-1-yhs@fb.com
---
 Documentation/bpf/btf.rst                          |  24 ++--
 include/uapi/linux/btf.h                           |   8 +-
 kernel/bpf/btf.c                                   |  44 +++---
 tools/bpf/bpftool/btf.c                            |   6 +-
 tools/include/uapi/linux/btf.h                     |   8 +-
 tools/lib/bpf/btf.c                                |  36 ++---
 tools/lib/bpf/btf.h                                |  12 +-
 tools/lib/bpf/btf_dump.c                           |   6 +-
 tools/lib/bpf/libbpf.c                             |  24 ++--
 tools/lib/bpf/libbpf.map                           |   2 +-
 tools/lib/bpf/libbpf_internal.h                    |   4 +-
 tools/testing/selftests/bpf/README.rst             |   4 +-
 tools/testing/selftests/bpf/btf_helpers.c          |   8 +-
 tools/testing/selftests/bpf/prog_tests/btf.c       | 160 ++++++++++-----------
 tools/testing/selftests/bpf/prog_tests/btf_write.c |  30 ++--
 tools/testing/selftests/bpf/progs/tag.c            |   6 +-
 tools/testing/selftests/bpf/test_btf.h             |   4 +-
 17 files changed, 193 insertions(+), 193 deletions(-)

(limited to 'tools/lib')

diff --git a/Documentation/bpf/btf.rst b/Documentation/bpf/btf.rst
index 1bfe4072f5fc..9e5b4a98af76 100644
--- a/Documentation/bpf/btf.rst
+++ b/Documentation/bpf/btf.rst
@@ -85,7 +85,7 @@ sequentially and type id is assigned to each recognized type starting from id
     #define BTF_KIND_VAR            14      /* Variable     */
     #define BTF_KIND_DATASEC        15      /* Section      */
     #define BTF_KIND_FLOAT          16      /* Floating point       */
-    #define BTF_KIND_TAG            17      /* Tag          */
+    #define BTF_KIND_DECL_TAG       17      /* Decl Tag     */
 
 Note that the type section encodes debug info, not just pure types.
 ``BTF_KIND_FUNC`` is not a type, and it represents a defined subprogram.
@@ -107,7 +107,7 @@ Each type contains the following common data::
          * "size" tells the size of the type it is describing.
          *
          * "type" is used by PTR, TYPEDEF, VOLATILE, CONST, RESTRICT,
-         * FUNC, FUNC_PROTO and TAG.
+         * FUNC, FUNC_PROTO and DECL_TAG.
          * "type" is a type_id referring to another type.
          */
         union {
@@ -466,30 +466,30 @@ map definition.
 
 No additional type data follow ``btf_type``.
 
-2.2.17 BTF_KIND_TAG
-~~~~~~~~~~~~~~~~~~~
+2.2.17 BTF_KIND_DECL_TAG
+~~~~~~~~~~~~~~~~~~~~~~~~
 
 ``struct btf_type`` encoding requirement:
  * ``name_off``: offset to a non-empty string
  * ``info.kind_flag``: 0
- * ``info.kind``: BTF_KIND_TAG
+ * ``info.kind``: BTF_KIND_DECL_TAG
  * ``info.vlen``: 0
  * ``type``: ``struct``, ``union``, ``func`` or ``var``
 
-``btf_type`` is followed by ``struct btf_tag``.::
+``btf_type`` is followed by ``struct btf_decl_tag``.::
 
-    struct btf_tag {
+    struct btf_decl_tag {
         __u32   component_idx;
     };
 
-The ``name_off`` encodes btf_tag attribute string.
+The ``name_off`` encodes btf_decl_tag attribute string.
 The ``type`` should be ``struct``, ``union``, ``func`` or ``var``.
-For ``var`` type, ``btf_tag.component_idx`` must be ``-1``.
-For the other three types, if the btf_tag attribute is
+For ``var`` type, ``btf_decl_tag.component_idx`` must be ``-1``.
+For the other three types, if the btf_decl_tag attribute is
 applied to the ``struct``, ``union`` or ``func`` itself,
-``btf_tag.component_idx`` must be ``-1``. Otherwise,
+``btf_decl_tag.component_idx`` must be ``-1``. Otherwise,
 the attribute is applied to a ``struct``/``union`` member or
-a ``func`` argument, and ``btf_tag.component_idx`` should be a
+a ``func`` argument, and ``btf_decl_tag.component_idx`` should be a
 valid index (starting from 0) pointing to a member or an argument.
 
 3. BTF Kernel API
diff --git a/include/uapi/linux/btf.h b/include/uapi/linux/btf.h
index 642b6ecb37d7..deb12f755f0f 100644
--- a/include/uapi/linux/btf.h
+++ b/include/uapi/linux/btf.h
@@ -43,7 +43,7 @@ struct btf_type {
 	 * "size" tells the size of the type it is describing.
 	 *
 	 * "type" is used by PTR, TYPEDEF, VOLATILE, CONST, RESTRICT,
-	 * FUNC, FUNC_PROTO, VAR and TAG.
+	 * FUNC, FUNC_PROTO, VAR and DECL_TAG.
 	 * "type" is a type_id referring to another type.
 	 */
 	union {
@@ -74,7 +74,7 @@ enum {
 	BTF_KIND_VAR		= 14,	/* Variable	*/
 	BTF_KIND_DATASEC	= 15,	/* Section	*/
 	BTF_KIND_FLOAT		= 16,	/* Floating point	*/
-	BTF_KIND_TAG		= 17,	/* Tag */
+	BTF_KIND_DECL_TAG	= 17,	/* Decl Tag */
 
 	NR_BTF_KINDS,
 	BTF_KIND_MAX		= NR_BTF_KINDS - 1,
@@ -174,14 +174,14 @@ struct btf_var_secinfo {
 	__u32	size;
 };
 
-/* BTF_KIND_TAG is followed by a single "struct btf_tag" to describe
+/* BTF_KIND_DECL_TAG is followed by a single "struct btf_decl_tag" to describe
  * additional information related to the tag applied location.
  * If component_idx == -1, the tag is applied to a struct, union,
  * variable or function. Otherwise, it is applied to a struct/union
  * member or a func argument, and component_idx indicates which member
  * or argument (0 ... vlen-1).
  */
-struct btf_tag {
+struct btf_decl_tag {
        __s32   component_idx;
 };
 
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 2ebffb9f57eb..9059053088b9 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -281,7 +281,7 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = {
 	[BTF_KIND_VAR]		= "VAR",
 	[BTF_KIND_DATASEC]	= "DATASEC",
 	[BTF_KIND_FLOAT]	= "FLOAT",
-	[BTF_KIND_TAG]		= "TAG",
+	[BTF_KIND_DECL_TAG]	= "DECL_TAG",
 };
 
 const char *btf_type_str(const struct btf_type *t)
@@ -460,12 +460,12 @@ static bool btf_type_is_datasec(const struct btf_type *t)
 	return BTF_INFO_KIND(t->info) == BTF_KIND_DATASEC;
 }
 
-static bool btf_type_is_tag(const struct btf_type *t)
+static bool btf_type_is_decl_tag(const struct btf_type *t)
 {
-	return BTF_INFO_KIND(t->info) == BTF_KIND_TAG;
+	return BTF_INFO_KIND(t->info) == BTF_KIND_DECL_TAG;
 }
 
-static bool btf_type_is_tag_target(const struct btf_type *t)
+static bool btf_type_is_decl_tag_target(const struct btf_type *t)
 {
 	return btf_type_is_func(t) || btf_type_is_struct(t) ||
 	       btf_type_is_var(t);
@@ -549,7 +549,7 @@ const struct btf_type *btf_type_resolve_func_ptr(const struct btf *btf,
 static bool btf_type_is_resolve_source_only(const struct btf_type *t)
 {
 	return btf_type_is_var(t) ||
-	       btf_type_is_tag(t) ||
+	       btf_type_is_decl_tag(t) ||
 	       btf_type_is_datasec(t);
 }
 
@@ -576,7 +576,7 @@ static bool btf_type_needs_resolve(const struct btf_type *t)
 	       btf_type_is_struct(t) ||
 	       btf_type_is_array(t) ||
 	       btf_type_is_var(t) ||
-	       btf_type_is_tag(t) ||
+	       btf_type_is_decl_tag(t) ||
 	       btf_type_is_datasec(t);
 }
 
@@ -630,9 +630,9 @@ static const struct btf_var *btf_type_var(const struct btf_type *t)
 	return (const struct btf_var *)(t + 1);
 }
 
-static const struct btf_tag *btf_type_tag(const struct btf_type *t)
+static const struct btf_decl_tag *btf_type_decl_tag(const struct btf_type *t)
 {
-	return (const struct btf_tag *)(t + 1);
+	return (const struct btf_decl_tag *)(t + 1);
 }
 
 static const struct btf_kind_operations *btf_type_ops(const struct btf_type *t)
@@ -3820,11 +3820,11 @@ static const struct btf_kind_operations float_ops = {
 	.show = btf_df_show,
 };
 
-static s32 btf_tag_check_meta(struct btf_verifier_env *env,
+static s32 btf_decl_tag_check_meta(struct btf_verifier_env *env,
 			      const struct btf_type *t,
 			      u32 meta_left)
 {
-	const struct btf_tag *tag;
+	const struct btf_decl_tag *tag;
 	u32 meta_needed = sizeof(*tag);
 	s32 component_idx;
 	const char *value;
@@ -3852,7 +3852,7 @@ static s32 btf_tag_check_meta(struct btf_verifier_env *env,
 		return -EINVAL;
 	}
 
-	component_idx = btf_type_tag(t)->component_idx;
+	component_idx = btf_type_decl_tag(t)->component_idx;
 	if (component_idx < -1) {
 		btf_verifier_log_type(env, t, "Invalid component_idx");
 		return -EINVAL;
@@ -3863,7 +3863,7 @@ static s32 btf_tag_check_meta(struct btf_verifier_env *env,
 	return meta_needed;
 }
 
-static int btf_tag_resolve(struct btf_verifier_env *env,
+static int btf_decl_tag_resolve(struct btf_verifier_env *env,
 			   const struct resolve_vertex *v)
 {
 	const struct btf_type *next_type;
@@ -3874,7 +3874,7 @@ static int btf_tag_resolve(struct btf_verifier_env *env,
 	u32 vlen;
 
 	next_type = btf_type_by_id(btf, next_type_id);
-	if (!next_type || !btf_type_is_tag_target(next_type)) {
+	if (!next_type || !btf_type_is_decl_tag_target(next_type)) {
 		btf_verifier_log_type(env, v->t, "Invalid type_id");
 		return -EINVAL;
 	}
@@ -3883,7 +3883,7 @@ static int btf_tag_resolve(struct btf_verifier_env *env,
 	    !env_type_is_resolved(env, next_type_id))
 		return env_stack_push(env, next_type, next_type_id);
 
-	component_idx = btf_type_tag(t)->component_idx;
+	component_idx = btf_type_decl_tag(t)->component_idx;
 	if (component_idx != -1) {
 		if (btf_type_is_var(next_type)) {
 			btf_verifier_log_type(env, v->t, "Invalid component_idx");
@@ -3909,18 +3909,18 @@ static int btf_tag_resolve(struct btf_verifier_env *env,
 	return 0;
 }
 
-static void btf_tag_log(struct btf_verifier_env *env, const struct btf_type *t)
+static void btf_decl_tag_log(struct btf_verifier_env *env, const struct btf_type *t)
 {
 	btf_verifier_log(env, "type=%u component_idx=%d", t->type,
-			 btf_type_tag(t)->component_idx);
+			 btf_type_decl_tag(t)->component_idx);
 }
 
-static const struct btf_kind_operations tag_ops = {
-	.check_meta = btf_tag_check_meta,
-	.resolve = btf_tag_resolve,
+static const struct btf_kind_operations decl_tag_ops = {
+	.check_meta = btf_decl_tag_check_meta,
+	.resolve = btf_decl_tag_resolve,
 	.check_member = btf_df_check_member,
 	.check_kflag_member = btf_df_check_kflag_member,
-	.log_details = btf_tag_log,
+	.log_details = btf_decl_tag_log,
 	.show = btf_df_show,
 };
 
@@ -4058,7 +4058,7 @@ static const struct btf_kind_operations * const kind_ops[NR_BTF_KINDS] = {
 	[BTF_KIND_VAR] = &var_ops,
 	[BTF_KIND_DATASEC] = &datasec_ops,
 	[BTF_KIND_FLOAT] = &float_ops,
-	[BTF_KIND_TAG] = &tag_ops,
+	[BTF_KIND_DECL_TAG] = &decl_tag_ops,
 };
 
 static s32 btf_check_meta(struct btf_verifier_env *env,
@@ -4143,7 +4143,7 @@ static bool btf_resolve_valid(struct btf_verifier_env *env,
 		return !btf_resolved_type_id(btf, type_id) &&
 		       !btf_resolved_type_size(btf, type_id);
 
-	if (btf_type_is_tag(t))
+	if (btf_type_is_decl_tag(t))
 		return btf_resolved_type_id(btf, type_id) &&
 		       !btf_resolved_type_size(btf, type_id);
 
diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c
index 49743ad96851..7b68d4f65fe6 100644
--- a/tools/bpf/bpftool/btf.c
+++ b/tools/bpf/bpftool/btf.c
@@ -37,7 +37,7 @@ static const char * const btf_kind_str[NR_BTF_KINDS] = {
 	[BTF_KIND_VAR]		= "VAR",
 	[BTF_KIND_DATASEC]	= "DATASEC",
 	[BTF_KIND_FLOAT]	= "FLOAT",
-	[BTF_KIND_TAG]		= "TAG",
+	[BTF_KIND_DECL_TAG]	= "DECL_TAG",
 };
 
 struct btf_attach_table {
@@ -348,8 +348,8 @@ static int dump_btf_type(const struct btf *btf, __u32 id,
 			printf(" size=%u", t->size);
 		break;
 	}
-	case BTF_KIND_TAG: {
-		const struct btf_tag *tag = (const void *)(t + 1);
+	case BTF_KIND_DECL_TAG: {
+		const struct btf_decl_tag *tag = (const void *)(t + 1);
 
 		if (json_output) {
 			jsonw_uint_field(w, "type_id", t->type);
diff --git a/tools/include/uapi/linux/btf.h b/tools/include/uapi/linux/btf.h
index 642b6ecb37d7..deb12f755f0f 100644
--- a/tools/include/uapi/linux/btf.h
+++ b/tools/include/uapi/linux/btf.h
@@ -43,7 +43,7 @@ struct btf_type {
 	 * "size" tells the size of the type it is describing.
 	 *
 	 * "type" is used by PTR, TYPEDEF, VOLATILE, CONST, RESTRICT,
-	 * FUNC, FUNC_PROTO, VAR and TAG.
+	 * FUNC, FUNC_PROTO, VAR and DECL_TAG.
 	 * "type" is a type_id referring to another type.
 	 */
 	union {
@@ -74,7 +74,7 @@ enum {
 	BTF_KIND_VAR		= 14,	/* Variable	*/
 	BTF_KIND_DATASEC	= 15,	/* Section	*/
 	BTF_KIND_FLOAT		= 16,	/* Floating point	*/
-	BTF_KIND_TAG		= 17,	/* Tag */
+	BTF_KIND_DECL_TAG	= 17,	/* Decl Tag */
 
 	NR_BTF_KINDS,
 	BTF_KIND_MAX		= NR_BTF_KINDS - 1,
@@ -174,14 +174,14 @@ struct btf_var_secinfo {
 	__u32	size;
 };
 
-/* BTF_KIND_TAG is followed by a single "struct btf_tag" to describe
+/* BTF_KIND_DECL_TAG is followed by a single "struct btf_decl_tag" to describe
  * additional information related to the tag applied location.
  * If component_idx == -1, the tag is applied to a struct, union,
  * variable or function. Otherwise, it is applied to a struct/union
  * member or a func argument, and component_idx indicates which member
  * or argument (0 ... vlen-1).
  */
-struct btf_tag {
+struct btf_decl_tag {
        __s32   component_idx;
 };
 
diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 60fbd1c6d466..1f6dea11f600 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -309,8 +309,8 @@ static int btf_type_size(const struct btf_type *t)
 		return base_size + sizeof(struct btf_var);
 	case BTF_KIND_DATASEC:
 		return base_size + vlen * sizeof(struct btf_var_secinfo);
-	case BTF_KIND_TAG:
-		return base_size + sizeof(struct btf_tag);
+	case BTF_KIND_DECL_TAG:
+		return base_size + sizeof(struct btf_decl_tag);
 	default:
 		pr_debug("Unsupported BTF_KIND:%u\n", btf_kind(t));
 		return -EINVAL;
@@ -383,8 +383,8 @@ static int btf_bswap_type_rest(struct btf_type *t)
 			v->size = bswap_32(v->size);
 		}
 		return 0;
-	case BTF_KIND_TAG:
-		btf_tag(t)->component_idx = bswap_32(btf_tag(t)->component_idx);
+	case BTF_KIND_DECL_TAG:
+		btf_decl_tag(t)->component_idx = bswap_32(btf_decl_tag(t)->component_idx);
 		return 0;
 	default:
 		pr_debug("Unsupported BTF_KIND:%u\n", btf_kind(t));
@@ -596,7 +596,7 @@ __s64 btf__resolve_size(const struct btf *btf, __u32 type_id)
 		case BTF_KIND_CONST:
 		case BTF_KIND_RESTRICT:
 		case BTF_KIND_VAR:
-		case BTF_KIND_TAG:
+		case BTF_KIND_DECL_TAG:
 			type_id = t->type;
 			break;
 		case BTF_KIND_ARRAY:
@@ -2569,7 +2569,7 @@ int btf__add_datasec_var_info(struct btf *btf, int var_type_id, __u32 offset, __
 }
 
 /*
- * Append new BTF_KIND_TAG type with:
+ * Append new BTF_KIND_DECL_TAG type with:
  *   - *value* - non-empty/non-NULL string;
  *   - *ref_type_id* - referenced type ID, it might not exist yet;
  *   - *component_idx* - -1 for tagging reference type, otherwise struct/union
@@ -2578,7 +2578,7 @@ int btf__add_datasec_var_info(struct btf *btf, int var_type_id, __u32 offset, __
  *   - >0, type ID of newly added BTF type;
  *   - <0, on error.
  */
-int btf__add_tag(struct btf *btf, const char *value, int ref_type_id,
+int btf__add_decl_tag(struct btf *btf, const char *value, int ref_type_id,
 		 int component_idx)
 {
 	struct btf_type *t;
@@ -2593,7 +2593,7 @@ int btf__add_tag(struct btf *btf, const char *value, int ref_type_id,
 	if (btf_ensure_modifiable(btf))
 		return libbpf_err(-ENOMEM);
 
-	sz = sizeof(struct btf_type) + sizeof(struct btf_tag);
+	sz = sizeof(struct btf_type) + sizeof(struct btf_decl_tag);
 	t = btf_add_type_mem(btf, sz);
 	if (!t)
 		return libbpf_err(-ENOMEM);
@@ -2603,9 +2603,9 @@ int btf__add_tag(struct btf *btf, const char *value, int ref_type_id,
 		return value_off;
 
 	t->name_off = value_off;
-	t->info = btf_type_info(BTF_KIND_TAG, 0, false);
+	t->info = btf_type_info(BTF_KIND_DECL_TAG, 0, false);
 	t->type = ref_type_id;
-	btf_tag(t)->component_idx = component_idx;
+	btf_decl_tag(t)->component_idx = component_idx;
 
 	return btf_commit_type(btf, sz);
 }
@@ -3427,7 +3427,7 @@ static bool btf_equal_common(struct btf_type *t1, struct btf_type *t2)
 }
 
 /* Calculate type signature hash of INT or TAG. */
-static long btf_hash_int_tag(struct btf_type *t)
+static long btf_hash_int_decl_tag(struct btf_type *t)
 {
 	__u32 info = *(__u32 *)(t + 1);
 	long h;
@@ -3705,8 +3705,8 @@ static int btf_dedup_prep(struct btf_dedup *d)
 			h = btf_hash_common(t);
 			break;
 		case BTF_KIND_INT:
-		case BTF_KIND_TAG:
-			h = btf_hash_int_tag(t);
+		case BTF_KIND_DECL_TAG:
+			h = btf_hash_int_decl_tag(t);
 			break;
 		case BTF_KIND_ENUM:
 			h = btf_hash_enum(t);
@@ -3761,11 +3761,11 @@ static int btf_dedup_prim_type(struct btf_dedup *d, __u32 type_id)
 	case BTF_KIND_FUNC_PROTO:
 	case BTF_KIND_VAR:
 	case BTF_KIND_DATASEC:
-	case BTF_KIND_TAG:
+	case BTF_KIND_DECL_TAG:
 		return 0;
 
 	case BTF_KIND_INT:
-		h = btf_hash_int_tag(t);
+		h = btf_hash_int_decl_tag(t);
 		for_each_dedup_cand(d, hash_entry, h) {
 			cand_id = (__u32)(long)hash_entry->value;
 			cand = btf_type_by_id(d->btf, cand_id);
@@ -4382,13 +4382,13 @@ static int btf_dedup_ref_type(struct btf_dedup *d, __u32 type_id)
 		}
 		break;
 
-	case BTF_KIND_TAG:
+	case BTF_KIND_DECL_TAG:
 		ref_type_id = btf_dedup_ref_type(d, t->type);
 		if (ref_type_id < 0)
 			return ref_type_id;
 		t->type = ref_type_id;
 
-		h = btf_hash_int_tag(t);
+		h = btf_hash_int_decl_tag(t);
 		for_each_dedup_cand(d, hash_entry, h) {
 			cand_id = (__u32)(long)hash_entry->value;
 			cand = btf_type_by_id(d->btf, cand_id);
@@ -4671,7 +4671,7 @@ int btf_type_visit_type_ids(struct btf_type *t, type_id_visit_fn visit, void *ct
 	case BTF_KIND_TYPEDEF:
 	case BTF_KIND_FUNC:
 	case BTF_KIND_VAR:
-	case BTF_KIND_TAG:
+	case BTF_KIND_DECL_TAG:
 		return visit(&t->type, ctx);
 
 	case BTF_KIND_ARRAY: {
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 864eb51753a1..4011e206e6f7 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -236,7 +236,7 @@ LIBBPF_API int btf__add_datasec_var_info(struct btf *btf, int var_type_id,
 					 __u32 offset, __u32 byte_sz);
 
 /* tag construction API */
-LIBBPF_API int btf__add_tag(struct btf *btf, const char *value, int ref_type_id,
+LIBBPF_API int btf__add_decl_tag(struct btf *btf, const char *value, int ref_type_id,
 			    int component_idx);
 
 struct btf_dedup_opts {
@@ -426,9 +426,9 @@ static inline bool btf_is_float(const struct btf_type *t)
 	return btf_kind(t) == BTF_KIND_FLOAT;
 }
 
-static inline bool btf_is_tag(const struct btf_type *t)
+static inline bool btf_is_decl_tag(const struct btf_type *t)
 {
-	return btf_kind(t) == BTF_KIND_TAG;
+	return btf_kind(t) == BTF_KIND_DECL_TAG;
 }
 
 static inline __u8 btf_int_encoding(const struct btf_type *t)
@@ -499,10 +499,10 @@ btf_var_secinfos(const struct btf_type *t)
 	return (struct btf_var_secinfo *)(t + 1);
 }
 
-struct btf_tag;
-static inline struct btf_tag *btf_tag(const struct btf_type *t)
+struct btf_decl_tag;
+static inline struct btf_decl_tag *btf_decl_tag(const struct btf_type *t)
 {
-	return (struct btf_tag *)(t + 1);
+	return (struct btf_decl_tag *)(t + 1);
 }
 
 #ifdef __cplusplus
diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index ad6df97295ae..5ef42f0abed1 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -316,7 +316,7 @@ static int btf_dump_mark_referenced(struct btf_dump *d)
 		case BTF_KIND_TYPEDEF:
 		case BTF_KIND_FUNC:
 		case BTF_KIND_VAR:
-		case BTF_KIND_TAG:
+		case BTF_KIND_DECL_TAG:
 			d->type_states[t->type].referenced = 1;
 			break;
 
@@ -584,7 +584,7 @@ static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr)
 	case BTF_KIND_FUNC:
 	case BTF_KIND_VAR:
 	case BTF_KIND_DATASEC:
-	case BTF_KIND_TAG:
+	case BTF_KIND_DECL_TAG:
 		d->type_states[id].order_state = ORDERED;
 		return 0;
 
@@ -2217,7 +2217,7 @@ static int btf_dump_dump_type_data(struct btf_dump *d,
 	case BTF_KIND_FWD:
 	case BTF_KIND_FUNC:
 	case BTF_KIND_FUNC_PROTO:
-	case BTF_KIND_TAG:
+	case BTF_KIND_DECL_TAG:
 		err = btf_dump_unsupported_data(d, t, id);
 		break;
 	case BTF_KIND_INT:
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index ae0889bebe32..63d738654ff6 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -195,8 +195,8 @@ enum kern_feature_id {
 	FEAT_BTF_FLOAT,
 	/* BPF perf link support */
 	FEAT_PERF_LINK,
-	/* BTF_KIND_TAG support */
-	FEAT_BTF_TAG,
+	/* BTF_KIND_DECL_TAG support */
+	FEAT_BTF_DECL_TAG,
 	__FEAT_CNT,
 };
 
@@ -2024,7 +2024,7 @@ static const char *__btf_kind_str(__u16 kind)
 	case BTF_KIND_VAR: return "var";
 	case BTF_KIND_DATASEC: return "datasec";
 	case BTF_KIND_FLOAT: return "float";
-	case BTF_KIND_TAG: return "tag";
+	case BTF_KIND_DECL_TAG: return "decl_tag";
 	default: return "unknown";
 	}
 }
@@ -2524,9 +2524,9 @@ static bool btf_needs_sanitization(struct bpf_object *obj)
 	bool has_datasec = kernel_supports(obj, FEAT_BTF_DATASEC);
 	bool has_float = kernel_supports(obj, FEAT_BTF_FLOAT);
 	bool has_func = kernel_supports(obj, FEAT_BTF_FUNC);
-	bool has_tag = kernel_supports(obj, FEAT_BTF_TAG);
+	bool has_decl_tag = kernel_supports(obj, FEAT_BTF_DECL_TAG);
 
-	return !has_func || !has_datasec || !has_func_global || !has_float || !has_tag;
+	return !has_func || !has_datasec || !has_func_global || !has_float || !has_decl_tag;
 }
 
 static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
@@ -2535,15 +2535,15 @@ static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
 	bool has_datasec = kernel_supports(obj, FEAT_BTF_DATASEC);
 	bool has_float = kernel_supports(obj, FEAT_BTF_FLOAT);
 	bool has_func = kernel_supports(obj, FEAT_BTF_FUNC);
-	bool has_tag = kernel_supports(obj, FEAT_BTF_TAG);
+	bool has_decl_tag = kernel_supports(obj, FEAT_BTF_DECL_TAG);
 	struct btf_type *t;
 	int i, j, vlen;
 
 	for (i = 1; i <= btf__get_nr_types(btf); i++) {
 		t = (struct btf_type *)btf__type_by_id(btf, i);
 
-		if ((!has_datasec && btf_is_var(t)) || (!has_tag && btf_is_tag(t))) {
-			/* replace VAR/TAG with INT */
+		if ((!has_datasec && btf_is_var(t)) || (!has_decl_tag && btf_is_decl_tag(t))) {
+			/* replace VAR/DECL_TAG with INT */
 			t->info = BTF_INFO_ENC(BTF_KIND_INT, 0, 0);
 			/*
 			 * using size = 1 is the safest choice, 4 will be too
@@ -4248,7 +4248,7 @@ static int probe_kern_btf_float(void)
 					     strs, sizeof(strs)));
 }
 
-static int probe_kern_btf_tag(void)
+static int probe_kern_btf_decl_tag(void)
 {
 	static const char strs[] = "\0tag";
 	__u32 types[] = {
@@ -4258,7 +4258,7 @@ static int probe_kern_btf_tag(void)
 		BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_VAR, 0, 0), 1),
 		BTF_VAR_STATIC,
 		/* attr */
-		BTF_TYPE_TAG_ENC(1, 2, -1),
+		BTF_TYPE_DECL_TAG_ENC(1, 2, -1),
 	};
 
 	return probe_fd(libbpf__load_raw_btf((char *)types, sizeof(types),
@@ -4481,8 +4481,8 @@ static struct kern_feature_desc {
 	[FEAT_PERF_LINK] = {
 		"BPF perf link support", probe_perf_link,
 	},
-	[FEAT_BTF_TAG] = {
-		"BTF_KIND_TAG support", probe_kern_btf_tag,
+	[FEAT_BTF_DECL_TAG] = {
+		"BTF_KIND_DECL_TAG support", probe_kern_btf_decl_tag,
 	},
 };
 
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index f270d25e4af3..e6fb1ba49369 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -394,5 +394,5 @@ LIBBPF_0.6.0 {
 		bpf_object__prev_map;
 		bpf_object__prev_program;
 		btf__add_btf;
-		btf__add_tag;
+		btf__add_decl_tag;
 } LIBBPF_0.5.0;
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index f7fd3944d46d..f6a5748dd318 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -69,8 +69,8 @@
 #define BTF_VAR_SECINFO_ENC(type, offset, size) (type), (offset), (size)
 #define BTF_TYPE_FLOAT_ENC(name, sz) \
 	BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_FLOAT, 0, 0), sz)
-#define BTF_TYPE_TAG_ENC(value, type, component_idx) \
-	BTF_TYPE_ENC(value, BTF_INFO_ENC(BTF_KIND_TAG, 0, 0), type), (component_idx)
+#define BTF_TYPE_DECL_TAG_ENC(value, type, component_idx) \
+	BTF_TYPE_ENC(value, BTF_INFO_ENC(BTF_KIND_DECL_TAG, 0, 0), type), (component_idx)
 
 #ifndef likely
 #define likely(x) __builtin_expect(!!(x), 1)
diff --git a/tools/testing/selftests/bpf/README.rst b/tools/testing/selftests/bpf/README.rst
index 554553acc6d9..5e287e445f75 100644
--- a/tools/testing/selftests/bpf/README.rst
+++ b/tools/testing/selftests/bpf/README.rst
@@ -204,7 +204,7 @@ __ https://reviews.llvm.org/D93563
 btf_tag test and Clang version
 ==============================
 
-The btf_tag selftest require LLVM support to recognize the btf_tag attribute.
+The btf_tag selftest require LLVM support to recognize the btf_decl_tag attribute.
 It was introduced in `Clang 14`__.
 
 Without it, the btf_tag selftest will be skipped and you will observe:
@@ -213,7 +213,7 @@ Without it, the btf_tag selftest will be skipped and you will observe:
 
   #<test_num> btf_tag:SKIP
 
-__ https://reviews.llvm.org/D106614
+__ https://reviews.llvm.org/D111588
 
 Clang dependencies for static linking tests
 ===========================================
diff --git a/tools/testing/selftests/bpf/btf_helpers.c b/tools/testing/selftests/bpf/btf_helpers.c
index ce103fb0ad1b..668cfa20bb1b 100644
--- a/tools/testing/selftests/bpf/btf_helpers.c
+++ b/tools/testing/selftests/bpf/btf_helpers.c
@@ -24,12 +24,12 @@ static const char * const btf_kind_str_mapping[] = {
 	[BTF_KIND_VAR]		= "VAR",
 	[BTF_KIND_DATASEC]	= "DATASEC",
 	[BTF_KIND_FLOAT]	= "FLOAT",
-	[BTF_KIND_TAG]		= "TAG",
+	[BTF_KIND_DECL_TAG]	= "DECL_TAG",
 };
 
 static const char *btf_kind_str(__u16 kind)
 {
-	if (kind > BTF_KIND_TAG)
+	if (kind > BTF_KIND_DECL_TAG)
 		return "UNKNOWN";
 	return btf_kind_str_mapping[kind];
 }
@@ -178,9 +178,9 @@ int fprintf_btf_type_raw(FILE *out, const struct btf *btf, __u32 id)
 	case BTF_KIND_FLOAT:
 		fprintf(out, " size=%u", t->size);
 		break;
-	case BTF_KIND_TAG:
+	case BTF_KIND_DECL_TAG:
 		fprintf(out, " type_id=%u component_idx=%d",
-			t->type, btf_tag(t)->component_idx);
+			t->type, btf_decl_tag(t)->component_idx);
 		break;
 	default:
 		break;
diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c
index acd33d0cd5d9..fa67f25bbef5 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf.c
@@ -3662,15 +3662,15 @@ static struct btf_raw_test raw_tests[] = {
 },
 
 {
-	.descr = "tag test #1, struct/member, well-formed",
+	.descr = "decl_tag test #1, struct/member, well-formed",
 	.raw_types = {
 		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
 		BTF_STRUCT_ENC(0, 2, 8),			/* [2] */
 		BTF_MEMBER_ENC(NAME_TBD, 1, 0),
 		BTF_MEMBER_ENC(NAME_TBD, 1, 32),
-		BTF_TAG_ENC(NAME_TBD, 2, -1),
-		BTF_TAG_ENC(NAME_TBD, 2, 0),
-		BTF_TAG_ENC(NAME_TBD, 2, 1),
+		BTF_DECL_TAG_ENC(NAME_TBD, 2, -1),
+		BTF_DECL_TAG_ENC(NAME_TBD, 2, 0),
+		BTF_DECL_TAG_ENC(NAME_TBD, 2, 1),
 		BTF_END_RAW,
 	},
 	BTF_STR_SEC("\0m1\0m2\0tag1\0tag2\0tag3"),
@@ -3683,15 +3683,15 @@ static struct btf_raw_test raw_tests[] = {
 	.max_entries = 1,
 },
 {
-	.descr = "tag test #2, union/member, well-formed",
+	.descr = "decl_tag test #2, union/member, well-formed",
 	.raw_types = {
 		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
 		BTF_UNION_ENC(NAME_TBD, 2, 4),			/* [2] */
 		BTF_MEMBER_ENC(NAME_TBD, 1, 0),
 		BTF_MEMBER_ENC(NAME_TBD, 1, 0),
-		BTF_TAG_ENC(NAME_TBD, 2, -1),
-		BTF_TAG_ENC(NAME_TBD, 2, 0),
-		BTF_TAG_ENC(NAME_TBD, 2, 1),
+		BTF_DECL_TAG_ENC(NAME_TBD, 2, -1),
+		BTF_DECL_TAG_ENC(NAME_TBD, 2, 0),
+		BTF_DECL_TAG_ENC(NAME_TBD, 2, 1),
 		BTF_END_RAW,
 	},
 	BTF_STR_SEC("\0t\0m1\0m2\0tag1\0tag2\0tag3"),
@@ -3704,13 +3704,13 @@ static struct btf_raw_test raw_tests[] = {
 	.max_entries = 1,
 },
 {
-	.descr = "tag test #3, variable, well-formed",
+	.descr = "decl_tag test #3, variable, well-formed",
 	.raw_types = {
 		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
 		BTF_VAR_ENC(NAME_TBD, 1, 0),			/* [2] */
 		BTF_VAR_ENC(NAME_TBD, 1, 1),			/* [3] */
-		BTF_TAG_ENC(NAME_TBD, 2, -1),
-		BTF_TAG_ENC(NAME_TBD, 3, -1),
+		BTF_DECL_TAG_ENC(NAME_TBD, 2, -1),
+		BTF_DECL_TAG_ENC(NAME_TBD, 3, -1),
 		BTF_END_RAW,
 	},
 	BTF_STR_SEC("\0local\0global\0tag1\0tag2"),
@@ -3723,16 +3723,16 @@ static struct btf_raw_test raw_tests[] = {
 	.max_entries = 1,
 },
 {
-	.descr = "tag test #4, func/parameter, well-formed",
+	.descr = "decl_tag test #4, func/parameter, well-formed",
 	.raw_types = {
 		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
 		BTF_FUNC_PROTO_ENC(0, 2),			/* [2] */
 			BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1),
 			BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1),
 		BTF_FUNC_ENC(NAME_TBD, 2),			/* [3] */
-		BTF_TAG_ENC(NAME_TBD, 3, -1),
-		BTF_TAG_ENC(NAME_TBD, 3, 0),
-		BTF_TAG_ENC(NAME_TBD, 3, 1),
+		BTF_DECL_TAG_ENC(NAME_TBD, 3, -1),
+		BTF_DECL_TAG_ENC(NAME_TBD, 3, 0),
+		BTF_DECL_TAG_ENC(NAME_TBD, 3, 1),
 		BTF_END_RAW,
 	},
 	BTF_STR_SEC("\0arg1\0arg2\0f\0tag1\0tag2\0tag3"),
@@ -3745,11 +3745,11 @@ static struct btf_raw_test raw_tests[] = {
 	.max_entries = 1,
 },
 {
-	.descr = "tag test #5, invalid value",
+	.descr = "decl_tag test #5, invalid value",
 	.raw_types = {
 		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
 		BTF_VAR_ENC(NAME_TBD, 1, 0),			/* [2] */
-		BTF_TAG_ENC(0, 2, -1),
+		BTF_DECL_TAG_ENC(0, 2, -1),
 		BTF_END_RAW,
 	},
 	BTF_STR_SEC("\0local\0tag"),
@@ -3764,10 +3764,10 @@ static struct btf_raw_test raw_tests[] = {
 	.err_str = "Invalid value",
 },
 {
-	.descr = "tag test #6, invalid target type",
+	.descr = "decl_tag test #6, invalid target type",
 	.raw_types = {
 		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
-		BTF_TAG_ENC(NAME_TBD, 1, -1),
+		BTF_DECL_TAG_ENC(NAME_TBD, 1, -1),
 		BTF_END_RAW,
 	},
 	BTF_STR_SEC("\0tag1"),
@@ -3782,11 +3782,11 @@ static struct btf_raw_test raw_tests[] = {
 	.err_str = "Invalid type",
 },
 {
-	.descr = "tag test #7, invalid vlen",
+	.descr = "decl_tag test #7, invalid vlen",
 	.raw_types = {
 		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
 		BTF_VAR_ENC(NAME_TBD, 1, 0),			/* [2] */
-		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_TAG, 0, 1), 2), (0),
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DECL_TAG, 0, 1), 2), (0),
 		BTF_END_RAW,
 	},
 	BTF_STR_SEC("\0local\0tag1"),
@@ -3801,11 +3801,11 @@ static struct btf_raw_test raw_tests[] = {
 	.err_str = "vlen != 0",
 },
 {
-	.descr = "tag test #8, invalid kflag",
+	.descr = "decl_tag test #8, invalid kflag",
 	.raw_types = {
 		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
 		BTF_VAR_ENC(NAME_TBD, 1, 0),			/* [2] */
-		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_TAG, 1, 0), 2), (-1),
+		BTF_TYPE_ENC(NAME_TBD, BTF_INFO_ENC(BTF_KIND_DECL_TAG, 1, 0), 2), (-1),
 		BTF_END_RAW,
 	},
 	BTF_STR_SEC("\0local\0tag1"),
@@ -3820,11 +3820,11 @@ static struct btf_raw_test raw_tests[] = {
 	.err_str = "Invalid btf_info kind_flag",
 },
 {
-	.descr = "tag test #9, var, invalid component_idx",
+	.descr = "decl_tag test #9, var, invalid component_idx",
 	.raw_types = {
 		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
 		BTF_VAR_ENC(NAME_TBD, 1, 0),			/* [2] */
-		BTF_TAG_ENC(NAME_TBD, 2, 0),
+		BTF_DECL_TAG_ENC(NAME_TBD, 2, 0),
 		BTF_END_RAW,
 	},
 	BTF_STR_SEC("\0local\0tag"),
@@ -3839,13 +3839,13 @@ static struct btf_raw_test raw_tests[] = {
 	.err_str = "Invalid component_idx",
 },
 {
-	.descr = "tag test #10, struct member, invalid component_idx",
+	.descr = "decl_tag test #10, struct member, invalid component_idx",
 	.raw_types = {
 		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
 		BTF_STRUCT_ENC(0, 2, 8),			/* [2] */
 		BTF_MEMBER_ENC(NAME_TBD, 1, 0),
 		BTF_MEMBER_ENC(NAME_TBD, 1, 32),
-		BTF_TAG_ENC(NAME_TBD, 2, 2),
+		BTF_DECL_TAG_ENC(NAME_TBD, 2, 2),
 		BTF_END_RAW,
 	},
 	BTF_STR_SEC("\0m1\0m2\0tag"),
@@ -3860,14 +3860,14 @@ static struct btf_raw_test raw_tests[] = {
 	.err_str = "Invalid component_idx",
 },
 {
-	.descr = "tag test #11, func parameter, invalid component_idx",
+	.descr = "decl_tag test #11, func parameter, invalid component_idx",
 	.raw_types = {
 		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
 		BTF_FUNC_PROTO_ENC(0, 2),			/* [2] */
 			BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1),
 			BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1),
 		BTF_FUNC_ENC(NAME_TBD, 2),			/* [3] */
-		BTF_TAG_ENC(NAME_TBD, 3, 2),
+		BTF_DECL_TAG_ENC(NAME_TBD, 3, 2),
 		BTF_END_RAW,
 	},
 	BTF_STR_SEC("\0arg1\0arg2\0f\0tag"),
@@ -3882,14 +3882,14 @@ static struct btf_raw_test raw_tests[] = {
 	.err_str = "Invalid component_idx",
 },
 {
-	.descr = "tag test #12, < -1 component_idx",
+	.descr = "decl_tag test #12, < -1 component_idx",
 	.raw_types = {
 		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),	/* [1] */
 		BTF_FUNC_PROTO_ENC(0, 2),			/* [2] */
 			BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1),
 			BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 1),
 		BTF_FUNC_ENC(NAME_TBD, 2),			/* [3] */
-		BTF_TAG_ENC(NAME_TBD, 3, -2),
+		BTF_DECL_TAG_ENC(NAME_TBD, 3, -2),
 		BTF_END_RAW,
 	},
 	BTF_STR_SEC("\0arg1\0arg2\0f\0tag"),
@@ -6672,9 +6672,9 @@ const struct btf_dedup_test dedup_tests[] = {
 			/* const -> [1] int */
 			BTF_CONST_ENC(1),						/* [6] */
 			/* tag -> [3] struct s */
-			BTF_TAG_ENC(NAME_NTH(2), 3, -1),				/* [7] */
+			BTF_DECL_TAG_ENC(NAME_NTH(2), 3, -1),				/* [7] */
 			/* tag -> [3] struct s, member 1 */
-			BTF_TAG_ENC(NAME_NTH(2), 3, 1),					/* [8] */
+			BTF_DECL_TAG_ENC(NAME_NTH(2), 3, 1),				/* [8] */
 
 			/* full copy of the above */
 			BTF_TYPE_INT_ENC(NAME_NTH(1), BTF_INT_SIGNED, 0, 32, 4),	/* [9] */
@@ -6689,8 +6689,8 @@ const struct btf_dedup_test dedup_tests[] = {
 			BTF_PTR_ENC(14),						/* [13] */
 			BTF_CONST_ENC(9),						/* [14] */
 			BTF_TYPE_FLOAT_ENC(NAME_NTH(7), 4),				/* [15] */
-			BTF_TAG_ENC(NAME_NTH(2), 11, -1),				/* [16] */
-			BTF_TAG_ENC(NAME_NTH(2), 11, 1),				/* [17] */
+			BTF_DECL_TAG_ENC(NAME_NTH(2), 11, -1),				/* [16] */
+			BTF_DECL_TAG_ENC(NAME_NTH(2), 11, 1),				/* [17] */
 			BTF_END_RAW,
 		},
 		BTF_STR_SEC("\0int\0s\0next\0a\0b\0c\0float\0d"),
@@ -6714,8 +6714,8 @@ const struct btf_dedup_test dedup_tests[] = {
 			BTF_PTR_ENC(6),							/* [5] */
 			/* const -> [1] int */
 			BTF_CONST_ENC(1),						/* [6] */
-			BTF_TAG_ENC(NAME_NTH(2), 3, -1),				/* [7] */
-			BTF_TAG_ENC(NAME_NTH(2), 3, 1),					/* [8] */
+			BTF_DECL_TAG_ENC(NAME_NTH(2), 3, -1),				/* [7] */
+			BTF_DECL_TAG_ENC(NAME_NTH(2), 3, 1),				/* [8] */
 			BTF_TYPE_FLOAT_ENC(NAME_NTH(7), 4),				/* [9] */
 			BTF_END_RAW,
 		},
@@ -6841,8 +6841,8 @@ const struct btf_dedup_test dedup_tests[] = {
 				BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 8),
 			BTF_FUNC_ENC(NAME_TBD, 12),					/* [13] func */
 			BTF_TYPE_FLOAT_ENC(NAME_TBD, 2),				/* [14] float */
-			BTF_TAG_ENC(NAME_TBD, 13, -1),					/* [15] tag */
-			BTF_TAG_ENC(NAME_TBD, 13, 1),					/* [16] tag */
+			BTF_DECL_TAG_ENC(NAME_TBD, 13, -1),				/* [15] tag */
+			BTF_DECL_TAG_ENC(NAME_TBD, 13, 1),				/* [16] tag */
 			BTF_END_RAW,
 		},
 		BTF_STR_SEC("\0A\0B\0C\0D\0E\0F\0G\0H\0I\0J\0K\0L\0M\0N\0O\0P"),
@@ -6869,8 +6869,8 @@ const struct btf_dedup_test dedup_tests[] = {
 				BTF_FUNC_PROTO_ARG_ENC(NAME_TBD, 8),
 			BTF_FUNC_ENC(NAME_TBD, 12),					/* [13] func */
 			BTF_TYPE_FLOAT_ENC(NAME_TBD, 2),				/* [14] float */
-			BTF_TAG_ENC(NAME_TBD, 13, -1),					/* [15] tag */
-			BTF_TAG_ENC(NAME_TBD, 13, 1),					/* [16] tag */
+			BTF_DECL_TAG_ENC(NAME_TBD, 13, -1),				/* [15] tag */
+			BTF_DECL_TAG_ENC(NAME_TBD, 13, 1),				/* [16] tag */
 			BTF_END_RAW,
 		},
 		BTF_STR_SEC("\0A\0B\0C\0D\0E\0F\0G\0H\0I\0J\0K\0L\0M\0N\0O\0P"),
@@ -7036,14 +7036,14 @@ const struct btf_dedup_test dedup_tests[] = {
 				BTF_FUNC_PROTO_ARG_ENC(NAME_NTH(3), 1),
 			BTF_FUNC_ENC(NAME_NTH(4), 2),			/* [4] */
 			/* tag -> t */
-			BTF_TAG_ENC(NAME_NTH(5), 2, -1),		/* [5] */
-			BTF_TAG_ENC(NAME_NTH(5), 2, -1),		/* [6] */
+			BTF_DECL_TAG_ENC(NAME_NTH(5), 2, -1),		/* [5] */
+			BTF_DECL_TAG_ENC(NAME_NTH(5), 2, -1),		/* [6] */
 			/* tag -> func */
-			BTF_TAG_ENC(NAME_NTH(5), 4, -1),		/* [7] */
-			BTF_TAG_ENC(NAME_NTH(5), 4, -1),		/* [8] */
+			BTF_DECL_TAG_ENC(NAME_NTH(5), 4, -1),		/* [7] */
+			BTF_DECL_TAG_ENC(NAME_NTH(5), 4, -1),		/* [8] */
 			/* tag -> func arg a1 */
-			BTF_TAG_ENC(NAME_NTH(5), 4, 1),			/* [9] */
-			BTF_TAG_ENC(NAME_NTH(5), 4, 1),			/* [10] */
+			BTF_DECL_TAG_ENC(NAME_NTH(5), 4, 1),		/* [9] */
+			BTF_DECL_TAG_ENC(NAME_NTH(5), 4, 1),		/* [10] */
 			BTF_END_RAW,
 		},
 		BTF_STR_SEC("\0t\0a1\0a2\0f\0tag"),
@@ -7056,9 +7056,9 @@ const struct btf_dedup_test dedup_tests[] = {
 				BTF_FUNC_PROTO_ARG_ENC(NAME_NTH(2), 1),
 				BTF_FUNC_PROTO_ARG_ENC(NAME_NTH(3), 1),
 			BTF_FUNC_ENC(NAME_NTH(4), 2),			/* [4] */
-			BTF_TAG_ENC(NAME_NTH(5), 2, -1),		/* [5] */
-			BTF_TAG_ENC(NAME_NTH(5), 4, -1),		/* [6] */
-			BTF_TAG_ENC(NAME_NTH(5), 4, 1),			/* [7] */
+			BTF_DECL_TAG_ENC(NAME_NTH(5), 2, -1),		/* [5] */
+			BTF_DECL_TAG_ENC(NAME_NTH(5), 4, -1),		/* [6] */
+			BTF_DECL_TAG_ENC(NAME_NTH(5), 4, 1),		/* [7] */
 			BTF_END_RAW,
 		},
 		BTF_STR_SEC("\0t\0a1\0a2\0f\0tag"),
@@ -7084,17 +7084,17 @@ const struct btf_dedup_test dedup_tests[] = {
 				BTF_FUNC_PROTO_ARG_ENC(NAME_NTH(2), 1),
 			BTF_FUNC_ENC(NAME_NTH(3), 4),			/* [5] */
 			/* tag -> f: tag1, tag2 */
-			BTF_TAG_ENC(NAME_NTH(4), 3, -1),		/* [6] */
-			BTF_TAG_ENC(NAME_NTH(5), 3, -1),		/* [7] */
+			BTF_DECL_TAG_ENC(NAME_NTH(4), 3, -1),		/* [6] */
+			BTF_DECL_TAG_ENC(NAME_NTH(5), 3, -1),		/* [7] */
 			/* tag -> f/a2: tag1, tag2 */
-			BTF_TAG_ENC(NAME_NTH(4), 3, 1),			/* [8] */
-			BTF_TAG_ENC(NAME_NTH(5), 3, 1),			/* [9] */
+			BTF_DECL_TAG_ENC(NAME_NTH(4), 3, 1),		/* [8] */
+			BTF_DECL_TAG_ENC(NAME_NTH(5), 3, 1),		/* [9] */
 			/* tag -> f: tag1, tag3 */
-			BTF_TAG_ENC(NAME_NTH(4), 5, -1),		/* [10] */
-			BTF_TAG_ENC(NAME_NTH(6), 5, -1),		/* [11] */
+			BTF_DECL_TAG_ENC(NAME_NTH(4), 5, -1),		/* [10] */
+			BTF_DECL_TAG_ENC(NAME_NTH(6), 5, -1),		/* [11] */
 			/* tag -> f/a2: tag1, tag3 */
-			BTF_TAG_ENC(NAME_NTH(4), 5, 1),			/* [12] */
-			BTF_TAG_ENC(NAME_NTH(6), 5, 1),			/* [13] */
+			BTF_DECL_TAG_ENC(NAME_NTH(4), 5, 1),		/* [12] */
+			BTF_DECL_TAG_ENC(NAME_NTH(6), 5, 1),		/* [13] */
 			BTF_END_RAW,
 		},
 		BTF_STR_SEC("\0a1\0a2\0f\0tag1\0tag2\0tag3"),
@@ -7106,12 +7106,12 @@ const struct btf_dedup_test dedup_tests[] = {
 				BTF_FUNC_PROTO_ARG_ENC(NAME_NTH(1), 1),
 				BTF_FUNC_PROTO_ARG_ENC(NAME_NTH(2), 1),
 			BTF_FUNC_ENC(NAME_NTH(3), 2),			/* [3] */
-			BTF_TAG_ENC(NAME_NTH(4), 3, -1),		/* [4] */
-			BTF_TAG_ENC(NAME_NTH(5), 3, -1),		/* [5] */
-			BTF_TAG_ENC(NAME_NTH(6), 3, -1),		/* [6] */
-			BTF_TAG_ENC(NAME_NTH(4), 3, 1),			/* [7] */
-			BTF_TAG_ENC(NAME_NTH(5), 3, 1),			/* [8] */
-			BTF_TAG_ENC(NAME_NTH(6), 3, 1),			/* [9] */
+			BTF_DECL_TAG_ENC(NAME_NTH(4), 3, -1),		/* [4] */
+			BTF_DECL_TAG_ENC(NAME_NTH(5), 3, -1),		/* [5] */
+			BTF_DECL_TAG_ENC(NAME_NTH(6), 3, -1),		/* [6] */
+			BTF_DECL_TAG_ENC(NAME_NTH(4), 3, 1),		/* [7] */
+			BTF_DECL_TAG_ENC(NAME_NTH(5), 3, 1),		/* [8] */
+			BTF_DECL_TAG_ENC(NAME_NTH(6), 3, 1),		/* [9] */
 			BTF_END_RAW,
 		},
 		BTF_STR_SEC("\0a1\0a2\0f\0tag1\0tag2\0tag3"),
@@ -7133,17 +7133,17 @@ const struct btf_dedup_test dedup_tests[] = {
 				BTF_MEMBER_ENC(NAME_NTH(2), 1, 0),
 				BTF_MEMBER_ENC(NAME_NTH(3), 1, 32),
 			/* tag -> t: tag1, tag2 */
-			BTF_TAG_ENC(NAME_NTH(4), 2, -1),		/* [4] */
-			BTF_TAG_ENC(NAME_NTH(5), 2, -1),		/* [5] */
+			BTF_DECL_TAG_ENC(NAME_NTH(4), 2, -1),		/* [4] */
+			BTF_DECL_TAG_ENC(NAME_NTH(5), 2, -1),		/* [5] */
 			/* tag -> t/m2: tag1, tag2 */
-			BTF_TAG_ENC(NAME_NTH(4), 2, 1),			/* [6] */
-			BTF_TAG_ENC(NAME_NTH(5), 2, 1),			/* [7] */
+			BTF_DECL_TAG_ENC(NAME_NTH(4), 2, 1),		/* [6] */
+			BTF_DECL_TAG_ENC(NAME_NTH(5), 2, 1),		/* [7] */
 			/* tag -> t: tag1, tag3 */
-			BTF_TAG_ENC(NAME_NTH(4), 3, -1),		/* [8] */
-			BTF_TAG_ENC(NAME_NTH(6), 3, -1),		/* [9] */
+			BTF_DECL_TAG_ENC(NAME_NTH(4), 3, -1),		/* [8] */
+			BTF_DECL_TAG_ENC(NAME_NTH(6), 3, -1),		/* [9] */
 			/* tag -> t/m2: tag1, tag3 */
-			BTF_TAG_ENC(NAME_NTH(4), 3, 1),			/* [10] */
-			BTF_TAG_ENC(NAME_NTH(6), 3, 1),			/* [11] */
+			BTF_DECL_TAG_ENC(NAME_NTH(4), 3, 1),		/* [10] */
+			BTF_DECL_TAG_ENC(NAME_NTH(6), 3, 1),		/* [11] */
 			BTF_END_RAW,
 		},
 		BTF_STR_SEC("\0t\0m1\0m2\0tag1\0tag2\0tag3"),
@@ -7154,12 +7154,12 @@ const struct btf_dedup_test dedup_tests[] = {
 			BTF_STRUCT_ENC(NAME_NTH(1), 2, 8),		/* [2] */
 				BTF_MEMBER_ENC(NAME_NTH(2), 1, 0),
 				BTF_MEMBER_ENC(NAME_NTH(3), 1, 32),
-			BTF_TAG_ENC(NAME_NTH(4), 2, -1),		/* [3] */
-			BTF_TAG_ENC(NAME_NTH(5), 2, -1),		/* [4] */
-			BTF_TAG_ENC(NAME_NTH(6), 2, -1),		/* [5] */
-			BTF_TAG_ENC(NAME_NTH(4), 2, 1),			/* [6] */
-			BTF_TAG_ENC(NAME_NTH(5), 2, 1),			/* [7] */
-			BTF_TAG_ENC(NAME_NTH(6), 2, 1),			/* [8] */
+			BTF_DECL_TAG_ENC(NAME_NTH(4), 2, -1),		/* [3] */
+			BTF_DECL_TAG_ENC(NAME_NTH(5), 2, -1),		/* [4] */
+			BTF_DECL_TAG_ENC(NAME_NTH(6), 2, -1),		/* [5] */
+			BTF_DECL_TAG_ENC(NAME_NTH(4), 2, 1),		/* [6] */
+			BTF_DECL_TAG_ENC(NAME_NTH(5), 2, 1),		/* [7] */
+			BTF_DECL_TAG_ENC(NAME_NTH(6), 2, 1),		/* [8] */
 			BTF_END_RAW,
 		},
 		BTF_STR_SEC("\0t\0m1\0m2\0tag1\0tag2\0tag3"),
@@ -7202,8 +7202,8 @@ static int btf_type_size(const struct btf_type *t)
 		return base_size + sizeof(struct btf_var);
 	case BTF_KIND_DATASEC:
 		return base_size + vlen * sizeof(struct btf_var_secinfo);
-	case BTF_KIND_TAG:
-		return base_size + sizeof(struct btf_tag);
+	case BTF_KIND_DECL_TAG:
+		return base_size + sizeof(struct btf_decl_tag);
 	default:
 		fprintf(stderr, "Unsupported BTF_KIND:%u\n", kind);
 		return -EINVAL;
diff --git a/tools/testing/selftests/bpf/prog_tests/btf_write.c b/tools/testing/selftests/bpf/prog_tests/btf_write.c
index 886e0fc1efb1..b912eeb0b6b4 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf_write.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf_write.c
@@ -277,26 +277,26 @@ static void gen_btf(struct btf *btf)
 		     "[17] DATASEC 'datasec1' size=12 vlen=1\n"
 		     "\ttype_id=1 offset=4 size=8", "raw_dump");
 
-	/* TAG */
-	id = btf__add_tag(btf, "tag1", 16, -1);
+	/* DECL_TAG */
+	id = btf__add_decl_tag(btf, "tag1", 16, -1);
 	ASSERT_EQ(id, 18, "tag_id");
 	t = btf__type_by_id(btf, 18);
 	ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "tag1", "tag_value");
-	ASSERT_EQ(btf_kind(t), BTF_KIND_TAG, "tag_kind");
+	ASSERT_EQ(btf_kind(t), BTF_KIND_DECL_TAG, "tag_kind");
 	ASSERT_EQ(t->type, 16, "tag_type");
-	ASSERT_EQ(btf_tag(t)->component_idx, -1, "tag_component_idx");
+	ASSERT_EQ(btf_decl_tag(t)->component_idx, -1, "tag_component_idx");
 	ASSERT_STREQ(btf_type_raw_dump(btf, 18),
-		     "[18] TAG 'tag1' type_id=16 component_idx=-1", "raw_dump");
+		     "[18] DECL_TAG 'tag1' type_id=16 component_idx=-1", "raw_dump");
 
-	id = btf__add_tag(btf, "tag2", 14, 1);
+	id = btf__add_decl_tag(btf, "tag2", 14, 1);
 	ASSERT_EQ(id, 19, "tag_id");
 	t = btf__type_by_id(btf, 19);
 	ASSERT_STREQ(btf__str_by_offset(btf, t->name_off), "tag2", "tag_value");
-	ASSERT_EQ(btf_kind(t), BTF_KIND_TAG, "tag_kind");
+	ASSERT_EQ(btf_kind(t), BTF_KIND_DECL_TAG, "tag_kind");
 	ASSERT_EQ(t->type, 14, "tag_type");
-	ASSERT_EQ(btf_tag(t)->component_idx, 1, "tag_component_idx");
+	ASSERT_EQ(btf_decl_tag(t)->component_idx, 1, "tag_component_idx");
 	ASSERT_STREQ(btf_type_raw_dump(btf, 19),
-		     "[19] TAG 'tag2' type_id=14 component_idx=1", "raw_dump");
+		     "[19] DECL_TAG 'tag2' type_id=14 component_idx=1", "raw_dump");
 }
 
 static void test_btf_add()
@@ -336,8 +336,8 @@ static void test_btf_add()
 		"[16] VAR 'var1' type_id=1, linkage=global-alloc",
 		"[17] DATASEC 'datasec1' size=12 vlen=1\n"
 		"\ttype_id=1 offset=4 size=8",
-		"[18] TAG 'tag1' type_id=16 component_idx=-1",
-		"[19] TAG 'tag2' type_id=14 component_idx=1");
+		"[18] DECL_TAG 'tag1' type_id=16 component_idx=-1",
+		"[19] DECL_TAG 'tag2' type_id=14 component_idx=1");
 
 	btf__free(btf);
 }
@@ -389,8 +389,8 @@ static void test_btf_add_btf()
 		"[16] VAR 'var1' type_id=1, linkage=global-alloc",
 		"[17] DATASEC 'datasec1' size=12 vlen=1\n"
 		"\ttype_id=1 offset=4 size=8",
-		"[18] TAG 'tag1' type_id=16 component_idx=-1",
-		"[19] TAG 'tag2' type_id=14 component_idx=1",
+		"[18] DECL_TAG 'tag1' type_id=16 component_idx=-1",
+		"[19] DECL_TAG 'tag2' type_id=14 component_idx=1",
 
 		/* types appended from the second BTF */
 		"[20] INT 'int' size=4 bits_offset=0 nr_bits=32 encoding=SIGNED",
@@ -418,8 +418,8 @@ static void test_btf_add_btf()
 		"[35] VAR 'var1' type_id=20, linkage=global-alloc",
 		"[36] DATASEC 'datasec1' size=12 vlen=1\n"
 		"\ttype_id=20 offset=4 size=8",
-		"[37] TAG 'tag1' type_id=35 component_idx=-1",
-		"[38] TAG 'tag2' type_id=33 component_idx=1");
+		"[37] DECL_TAG 'tag1' type_id=35 component_idx=-1",
+		"[38] DECL_TAG 'tag2' type_id=33 component_idx=1");
 
 cleanup:
 	btf__free(btf1);
diff --git a/tools/testing/selftests/bpf/progs/tag.c b/tools/testing/selftests/bpf/progs/tag.c
index b46b1bfac7da..672d19e7b120 100644
--- a/tools/testing/selftests/bpf/progs/tag.c
+++ b/tools/testing/selftests/bpf/progs/tag.c
@@ -8,9 +8,9 @@
 #define __has_attribute(x) 0
 #endif
 
-#if __has_attribute(btf_tag)
-#define __tag1 __attribute__((btf_tag("tag1")))
-#define __tag2 __attribute__((btf_tag("tag2")))
+#if __has_attribute(btf_decl_tag)
+#define __tag1 __attribute__((btf_decl_tag("tag1")))
+#define __tag2 __attribute__((btf_decl_tag("tag2")))
 volatile const bool skip_tests __tag1 __tag2 = false;
 #else
 #define __tag1
diff --git a/tools/testing/selftests/bpf/test_btf.h b/tools/testing/selftests/bpf/test_btf.h
index 0619e06d745e..32c7a57867da 100644
--- a/tools/testing/selftests/bpf/test_btf.h
+++ b/tools/testing/selftests/bpf/test_btf.h
@@ -69,7 +69,7 @@
 #define BTF_TYPE_FLOAT_ENC(name, sz) \
 	BTF_TYPE_ENC(name, BTF_INFO_ENC(BTF_KIND_FLOAT, 0, 0), sz)
 
-#define BTF_TAG_ENC(value, type, component_idx)	\
-	BTF_TYPE_ENC(value, BTF_INFO_ENC(BTF_KIND_TAG, 0, 0), type), (component_idx)
+#define BTF_DECL_TAG_ENC(value, type, component_idx)	\
+	BTF_TYPE_ENC(value, BTF_INFO_ENC(BTF_KIND_DECL_TAG, 0, 0), type), (component_idx)
 
 #endif /* _TEST_BTF_H */
-- 
cgit v1.2.3


From d51b6b2287ae0c5432f03457a1dbc844e1968d12 Mon Sep 17 00:00:00 2001
From: Quentin Monnet <quentin@isovalent.com>
Date: Sun, 10 Oct 2021 01:25:28 +0100
Subject: libbpf: Remove Makefile warnings on out-of-sync netlink.h/if_link.h

Although relying on some definitions from the netlink.h and if_link.h
headers copied into tools/include/uapi/linux/, libbpf does not need
those headers to stay entirely up-to-date with their original versions,
and the warnings emitted by the Makefile when it detects a difference
are usually just noise. Let's remove those warnings.

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211010002528.9772-1-quentin@isovalent.com
---
 tools/lib/bpf/Makefile | 6 ------
 1 file changed, 6 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index 9c6804ca5b45..b393b5e82380 100644
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -146,12 +146,6 @@ $(BPF_IN_SHARED): force $(BPF_GENERATED)
 	@(test -f ../../include/uapi/linux/bpf_common.h -a -f ../../../include/uapi/linux/bpf_common.h && ( \
 	(diff -B ../../include/uapi/linux/bpf_common.h ../../../include/uapi/linux/bpf_common.h >/dev/null) || \
 	echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/bpf_common.h' differs from latest version at 'include/uapi/linux/bpf_common.h'" >&2 )) || true
-	@(test -f ../../include/uapi/linux/netlink.h -a -f ../../../include/uapi/linux/netlink.h && ( \
-	(diff -B ../../include/uapi/linux/netlink.h ../../../include/uapi/linux/netlink.h >/dev/null) || \
-	echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/netlink.h' differs from latest version at 'include/uapi/linux/netlink.h'" >&2 )) || true
-	@(test -f ../../include/uapi/linux/if_link.h -a -f ../../../include/uapi/linux/if_link.h && ( \
-	(diff -B ../../include/uapi/linux/if_link.h ../../../include/uapi/linux/if_link.h >/dev/null) || \
-	echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/if_link.h' differs from latest version at 'include/uapi/linux/if_link.h'" >&2 )) || true
 	@(test -f ../../include/uapi/linux/if_xdp.h -a -f ../../../include/uapi/linux/if_xdp.h && ( \
 	(diff -B ../../include/uapi/linux/if_xdp.h ../../../include/uapi/linux/if_xdp.h >/dev/null) || \
 	echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/if_xdp.h' differs from latest version at 'include/uapi/linux/if_xdp.h'" >&2 )) || true
-- 
cgit v1.2.3


From ebc7b50a3849d73665013573cf3c09f27fb14fde Mon Sep 17 00:00:00 2001
From: Dave Marchevsky <davemarchevsky@fb.com>
Date: Mon, 11 Oct 2021 01:20:28 -0700
Subject: libbpf: Migrate internal use of bpf_program__get_prog_info_linear

In preparation for bpf_program__get_prog_info_linear deprecation, move
the single use in libbpf to call bpf_obj_get_info_by_fd directly.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211011082031.4148337-2-davemarchevsky@fb.com
---
 tools/lib/bpf/libbpf.c | 22 ++++++++++------------
 1 file changed, 10 insertions(+), 12 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 63d738654ff6..760c7e346603 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -8461,28 +8461,27 @@ int libbpf_find_vmlinux_btf_id(const char *name,
 
 static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd)
 {
-	struct bpf_prog_info_linear *info_linear;
-	struct bpf_prog_info *info;
+	struct bpf_prog_info info = {};
+	__u32 info_len = sizeof(info);
 	struct btf *btf;
 	int err;
 
-	info_linear = bpf_program__get_prog_info_linear(attach_prog_fd, 0);
-	err = libbpf_get_error(info_linear);
+	err = bpf_obj_get_info_by_fd(attach_prog_fd, &info, &info_len);
 	if (err) {
-		pr_warn("failed get_prog_info_linear for FD %d\n",
-			attach_prog_fd);
+		pr_warn("failed bpf_obj_get_info_by_fd for FD %d: %d\n",
+			attach_prog_fd, err);
 		return err;
 	}
 
 	err = -EINVAL;
-	info = &info_linear->info;
-	if (!info->btf_id) {
+	if (!info.btf_id) {
 		pr_warn("The target program doesn't have BTF\n");
 		goto out;
 	}
-	btf = btf__load_from_kernel_by_id(info->btf_id);
-	if (libbpf_get_error(btf)) {
-		pr_warn("Failed to get BTF of the program\n");
+	btf = btf__load_from_kernel_by_id(info.btf_id);
+	err = libbpf_get_error(btf);
+	if (err) {
+		pr_warn("Failed to get BTF %d of the program: %d\n", info.btf_id, err);
 		goto out;
 	}
 	err = btf__find_by_name_kind(btf, name, BTF_KIND_FUNC);
@@ -8492,7 +8491,6 @@ static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd)
 		goto out;
 	}
 out:
-	free(info_linear);
 	return err;
 }
 
-- 
cgit v1.2.3


From c9e982b879465ca74e3593ce82808aa259265a71 Mon Sep 17 00:00:00 2001
From: Ilya Leoshkevich <iii@linux.ibm.com>
Date: Wed, 13 Oct 2021 18:09:00 +0200
Subject: libbpf: Fix dumping big-endian bitfields

On big-endian arches not only bytes, but also bits are numbered in
reverse order (see e.g. S/390 ELF ABI Supplement, but this is also true
for other big-endian arches as well).

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211013160902.428340-3-iii@linux.ibm.com
---
 tools/lib/bpf/btf_dump.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index 5ef42f0abed1..679bf34e3f47 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -1562,29 +1562,28 @@ static int btf_dump_get_bitfield_value(struct btf_dump *d,
 				       __u64 *value)
 {
 	__u16 left_shift_bits, right_shift_bits;
-	__u8 nr_copy_bits, nr_copy_bytes;
 	const __u8 *bytes = data;
-	int sz = t->size;
+	__u8 nr_copy_bits;
 	__u64 num = 0;
 	int i;
 
 	/* Maximum supported bitfield size is 64 bits */
-	if (sz > 8) {
-		pr_warn("unexpected bitfield size %d\n", sz);
+	if (t->size > 8) {
+		pr_warn("unexpected bitfield size %d\n", t->size);
 		return -EINVAL;
 	}
 
 	/* Bitfield value retrieval is done in two steps; first relevant bytes are
 	 * stored in num, then we left/right shift num to eliminate irrelevant bits.
 	 */
-	nr_copy_bits = bit_sz + bits_offset;
-	nr_copy_bytes = t->size;
 #if __BYTE_ORDER == __LITTLE_ENDIAN
-	for (i = nr_copy_bytes - 1; i >= 0; i--)
+	for (i = t->size - 1; i >= 0; i--)
 		num = num * 256 + bytes[i];
+	nr_copy_bits = bit_sz + bits_offset;
 #elif __BYTE_ORDER == __BIG_ENDIAN
-	for (i = 0; i < nr_copy_bytes; i++)
+	for (i = 0; i < t->size; i++)
 		num = num * 256 + bytes[i];
+	nr_copy_bits = t->size * 8 - bits_offset;
 #else
 # error "Unrecognized __BYTE_ORDER__"
 #endif
-- 
cgit v1.2.3


From 961632d5416389a6f2e7478b674ac645c7e3ff01 Mon Sep 17 00:00:00 2001
From: Ilya Leoshkevich <iii@linux.ibm.com>
Date: Wed, 13 Oct 2021 18:09:01 +0200
Subject: libbpf: Fix dumping non-aligned __int128

Non-aligned integers are dumped as bitfields, which is supported for at
most 64-bit integers. Fix by using the same trick as
btf_dump_float_data(): copy non-aligned values to the local buffer.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211013160902.428340-4-iii@linux.ibm.com
---
 tools/lib/bpf/btf_dump.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index 679bf34e3f47..e98c201f29b5 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -1670,9 +1670,10 @@ static int btf_dump_int_data(struct btf_dump *d,
 {
 	__u8 encoding = btf_int_encoding(t);
 	bool sign = encoding & BTF_INT_SIGNED;
+	char buf[16] __aligned(16);
 	int sz = t->size;
 
-	if (sz == 0) {
+	if (sz == 0 || sz > sizeof(buf)) {
 		pr_warn("unexpected size %d for id [%u]\n", sz, type_id);
 		return -EINVAL;
 	}
@@ -1680,8 +1681,10 @@ static int btf_dump_int_data(struct btf_dump *d,
 	/* handle packed int data - accesses of integers not aligned on
 	 * int boundaries can cause problems on some platforms.
 	 */
-	if (!ptr_is_aligned(data, sz))
-		return btf_dump_bitfield_data(d, t, data, 0, 0);
+	if (!ptr_is_aligned(data, sz)) {
+		memcpy(buf, data, sz);
+		data = buf;
+	}
 
 	switch (sz) {
 	case 16: {
-- 
cgit v1.2.3


From 632f96d2652e0d4188de837f88a977eedb55aee1 Mon Sep 17 00:00:00 2001
From: Ilya Leoshkevich <iii@linux.ibm.com>
Date: Thu, 21 Oct 2021 12:46:58 +0200
Subject: libbpf: Fix ptr_is_aligned() usages

Currently ptr_is_aligned() takes size, and not alignment, as a
parameter, which may be overly pessimistic e.g. for __i128 on s390,
which must be only 8-byte aligned. Fix by using btf__align_of().

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211021104658.624944-2-iii@linux.ibm.com
---
 tools/lib/bpf/btf_dump.c | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index e98c201f29b5..e9e5801ece4c 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -1657,9 +1657,15 @@ static int btf_dump_base_type_check_zero(struct btf_dump *d,
 	return 0;
 }
 
-static bool ptr_is_aligned(const void *data, int data_sz)
+static bool ptr_is_aligned(const struct btf *btf, __u32 type_id,
+			   const void *data)
 {
-	return ((uintptr_t)data) % data_sz == 0;
+	int alignment = btf__align_of(btf, type_id);
+
+	if (alignment == 0)
+		return false;
+
+	return ((uintptr_t)data) % alignment == 0;
 }
 
 static int btf_dump_int_data(struct btf_dump *d,
@@ -1681,7 +1687,7 @@ static int btf_dump_int_data(struct btf_dump *d,
 	/* handle packed int data - accesses of integers not aligned on
 	 * int boundaries can cause problems on some platforms.
 	 */
-	if (!ptr_is_aligned(data, sz)) {
+	if (!ptr_is_aligned(d->btf, type_id, data)) {
 		memcpy(buf, data, sz);
 		data = buf;
 	}
@@ -1770,7 +1776,7 @@ static int btf_dump_float_data(struct btf_dump *d,
 	int sz = t->size;
 
 	/* handle unaligned data; copy to local union */
-	if (!ptr_is_aligned(data, sz)) {
+	if (!ptr_is_aligned(d->btf, type_id, data)) {
 		memcpy(&fl, data, sz);
 		flp = &fl;
 	}
@@ -1933,7 +1939,7 @@ static int btf_dump_ptr_data(struct btf_dump *d,
 			      __u32 id,
 			      const void *data)
 {
-	if (ptr_is_aligned(data, d->ptr_sz) && d->ptr_sz == sizeof(void *)) {
+	if (ptr_is_aligned(d->btf, id, data) && d->ptr_sz == sizeof(void *)) {
 		btf_dump_type_values(d, "%p", *(void **)data);
 	} else {
 		union ptr_data pt;
@@ -1953,10 +1959,8 @@ static int btf_dump_get_enum_value(struct btf_dump *d,
 				   __u32 id,
 				   __s64 *value)
 {
-	int sz = t->size;
-
 	/* handle unaligned enum value */
-	if (!ptr_is_aligned(data, sz)) {
+	if (!ptr_is_aligned(d->btf, id, data)) {
 		__u64 val;
 		int err;
 
-- 
cgit v1.2.3


From b96c07f3b5ae6944eb52fd96a322340aa80aef5d Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Wed, 20 Oct 2021 18:43:55 -0700
Subject: libbpf: Deprecate btf__finalize_data() and move it into libbpf.c

There isn't a good use case where anyone but libbpf itself needs to call
btf__finalize_data(). It was implemented for internal use and it's not
clear why it was made into public API in the first place. To function, it
requires active ELF data, which is stored inside bpf_object for the
duration of opening phase only. But the only BTF that needs bpf_object's
ELF is that bpf_object's BTF itself, which libbpf fixes up automatically
during bpf_object__open() operation anyways. There is no need for any
additional fix up and no reasonable scenario where it's useful and
appropriate.

Thus, btf__finalize_data() is just an API atavism and is better removed.
So this patch marks it as deprecated immediately (v0.6+) and moves the
code from btf.c into libbpf.c where it's used in the context of
bpf_object opening phase. Such code co-location allows to make code
structure more straightforward and remove bpf_object__section_size() and
bpf_object__variable_offset() internal helpers from libbpf_internal.h,
making them static. Their naming is also adjusted to not create
a wrong illusion that they are some sort of method of bpf_object. They
are internal helpers and are called appropriately.

This is part of libbpf 1.0 effort ([0]).

  [0] Closes: https://github.com/libbpf/libbpf/issues/276

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211021014404.2635234-2-andrii@kernel.org
---
 tools/lib/bpf/btf.c             |  93 -----------------------------------
 tools/lib/bpf/btf.h             |   1 +
 tools/lib/bpf/libbpf.c          | 106 ++++++++++++++++++++++++++++++++++++++--
 tools/lib/bpf/libbpf_internal.h |   4 --
 4 files changed, 102 insertions(+), 102 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 1f6dea11f600..3a01c4b7f36a 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -1107,99 +1107,6 @@ struct btf *btf__parse_split(const char *path, struct btf *base_btf)
 	return libbpf_ptr(btf_parse(path, base_btf, NULL));
 }
 
-static int compare_vsi_off(const void *_a, const void *_b)
-{
-	const struct btf_var_secinfo *a = _a;
-	const struct btf_var_secinfo *b = _b;
-
-	return a->offset - b->offset;
-}
-
-static int btf_fixup_datasec(struct bpf_object *obj, struct btf *btf,
-			     struct btf_type *t)
-{
-	__u32 size = 0, off = 0, i, vars = btf_vlen(t);
-	const char *name = btf__name_by_offset(btf, t->name_off);
-	const struct btf_type *t_var;
-	struct btf_var_secinfo *vsi;
-	const struct btf_var *var;
-	int ret;
-
-	if (!name) {
-		pr_debug("No name found in string section for DATASEC kind.\n");
-		return -ENOENT;
-	}
-
-	/* .extern datasec size and var offsets were set correctly during
-	 * extern collection step, so just skip straight to sorting variables
-	 */
-	if (t->size)
-		goto sort_vars;
-
-	ret = bpf_object__section_size(obj, name, &size);
-	if (ret || !size || (t->size && t->size != size)) {
-		pr_debug("Invalid size for section %s: %u bytes\n", name, size);
-		return -ENOENT;
-	}
-
-	t->size = size;
-
-	for (i = 0, vsi = btf_var_secinfos(t); i < vars; i++, vsi++) {
-		t_var = btf__type_by_id(btf, vsi->type);
-		var = btf_var(t_var);
-
-		if (!btf_is_var(t_var)) {
-			pr_debug("Non-VAR type seen in section %s\n", name);
-			return -EINVAL;
-		}
-
-		if (var->linkage == BTF_VAR_STATIC)
-			continue;
-
-		name = btf__name_by_offset(btf, t_var->name_off);
-		if (!name) {
-			pr_debug("No name found in string section for VAR kind\n");
-			return -ENOENT;
-		}
-
-		ret = bpf_object__variable_offset(obj, name, &off);
-		if (ret) {
-			pr_debug("No offset found in symbol table for VAR %s\n",
-				 name);
-			return -ENOENT;
-		}
-
-		vsi->offset = off;
-	}
-
-sort_vars:
-	qsort(btf_var_secinfos(t), vars, sizeof(*vsi), compare_vsi_off);
-	return 0;
-}
-
-int btf__finalize_data(struct bpf_object *obj, struct btf *btf)
-{
-	int err = 0;
-	__u32 i;
-
-	for (i = 1; i <= btf->nr_types; i++) {
-		struct btf_type *t = btf_type_by_id(btf, i);
-
-		/* Loader needs to fix up some of the things compiler
-		 * couldn't get its hands on while emitting BTF. This
-		 * is section size and global variable offset. We use
-		 * the info from the ELF itself for this purpose.
-		 */
-		if (btf_is_datasec(t)) {
-			err = btf_fixup_datasec(obj, btf, t);
-			if (err)
-				break;
-		}
-	}
-
-	return libbpf_err(err);
-}
-
 static void *btf_get_raw_data(const struct btf *btf, __u32 *size, bool swap_endian);
 
 int btf__load_into_kernel(struct btf *btf)
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 4011e206e6f7..c9364be42035 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -123,6 +123,7 @@ LIBBPF_API struct btf *btf__load_from_kernel_by_id_split(__u32 id, struct btf *b
 LIBBPF_DEPRECATED_SINCE(0, 6, "use btf__load_from_kernel_by_id instead")
 LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
 
+LIBBPF_DEPRECATED_SINCE(0, 6, "intended for internal libbpf use only")
 LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf);
 LIBBPF_DEPRECATED_SINCE(0, 6, "use btf__load_into_kernel instead")
 LIBBPF_API int btf__load(struct btf *btf);
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 760c7e346603..fdc25a112150 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1324,8 +1324,7 @@ static bool bpf_map_type__is_map_in_map(enum bpf_map_type type)
 	return false;
 }
 
-int bpf_object__section_size(const struct bpf_object *obj, const char *name,
-			     __u32 *size)
+static int find_elf_sec_sz(const struct bpf_object *obj, const char *name, __u32 *size)
 {
 	int ret = -ENOENT;
 
@@ -1357,8 +1356,7 @@ int bpf_object__section_size(const struct bpf_object *obj, const char *name,
 	return *size ? 0 : ret;
 }
 
-int bpf_object__variable_offset(const struct bpf_object *obj, const char *name,
-				__u32 *off)
+static int find_elf_var_offset(const struct bpf_object *obj, const char *name, __u32 *off)
 {
 	Elf_Data *symbols = obj->efile.symbols;
 	const char *sname;
@@ -2650,6 +2648,104 @@ out:
 	return 0;
 }
 
+static int compare_vsi_off(const void *_a, const void *_b)
+{
+	const struct btf_var_secinfo *a = _a;
+	const struct btf_var_secinfo *b = _b;
+
+	return a->offset - b->offset;
+}
+
+static int btf_fixup_datasec(struct bpf_object *obj, struct btf *btf,
+			     struct btf_type *t)
+{
+	__u32 size = 0, off = 0, i, vars = btf_vlen(t);
+	const char *name = btf__name_by_offset(btf, t->name_off);
+	const struct btf_type *t_var;
+	struct btf_var_secinfo *vsi;
+	const struct btf_var *var;
+	int ret;
+
+	if (!name) {
+		pr_debug("No name found in string section for DATASEC kind.\n");
+		return -ENOENT;
+	}
+
+	/* .extern datasec size and var offsets were set correctly during
+	 * extern collection step, so just skip straight to sorting variables
+	 */
+	if (t->size)
+		goto sort_vars;
+
+	ret = find_elf_sec_sz(obj, name, &size);
+	if (ret || !size || (t->size && t->size != size)) {
+		pr_debug("Invalid size for section %s: %u bytes\n", name, size);
+		return -ENOENT;
+	}
+
+	t->size = size;
+
+	for (i = 0, vsi = btf_var_secinfos(t); i < vars; i++, vsi++) {
+		t_var = btf__type_by_id(btf, vsi->type);
+		var = btf_var(t_var);
+
+		if (!btf_is_var(t_var)) {
+			pr_debug("Non-VAR type seen in section %s\n", name);
+			return -EINVAL;
+		}
+
+		if (var->linkage == BTF_VAR_STATIC)
+			continue;
+
+		name = btf__name_by_offset(btf, t_var->name_off);
+		if (!name) {
+			pr_debug("No name found in string section for VAR kind\n");
+			return -ENOENT;
+		}
+
+		ret = find_elf_var_offset(obj, name, &off);
+		if (ret) {
+			pr_debug("No offset found in symbol table for VAR %s\n",
+				 name);
+			return -ENOENT;
+		}
+
+		vsi->offset = off;
+	}
+
+sort_vars:
+	qsort(btf_var_secinfos(t), vars, sizeof(*vsi), compare_vsi_off);
+	return 0;
+}
+
+static int btf_finalize_data(struct bpf_object *obj, struct btf *btf)
+{
+	int err = 0;
+	__u32 i, n = btf__get_nr_types(btf);
+
+	for (i = 1; i <= n; i++) {
+		struct btf_type *t = btf_type_by_id(btf, i);
+
+		/* Loader needs to fix up some of the things compiler
+		 * couldn't get its hands on while emitting BTF. This
+		 * is section size and global variable offset. We use
+		 * the info from the ELF itself for this purpose.
+		 */
+		if (btf_is_datasec(t)) {
+			err = btf_fixup_datasec(obj, btf, t);
+			if (err)
+				break;
+		}
+	}
+
+	return libbpf_err(err);
+}
+
+int btf__finalize_data(struct bpf_object *obj, struct btf *btf)
+{
+	return btf_finalize_data(obj, btf);
+}
+
 static int bpf_object__finalize_btf(struct bpf_object *obj)
 {
 	int err;
@@ -2657,7 +2753,7 @@ static int bpf_object__finalize_btf(struct bpf_object *obj)
 	if (!obj->btf)
 		return 0;
 
-	err = btf__finalize_data(obj, obj->btf);
+	err = btf_finalize_data(obj, obj->btf);
 	if (err) {
 		pr_warn("Error finalizing %s: %d.\n", BTF_ELF_SEC, err);
 		return err;
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index f6a5748dd318..4bbd327a4ce9 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -303,10 +303,6 @@ struct bpf_prog_load_params {
 
 int libbpf__bpf_prog_load(const struct bpf_prog_load_params *load_attr);
 
-int bpf_object__section_size(const struct bpf_object *obj, const char *name,
-			     __u32 *size);
-int bpf_object__variable_offset(const struct bpf_object *obj, const char *name,
-				__u32 *off);
 struct btf *btf_get_from_fd(int btf_fd, struct btf *base_btf);
 void btf_get_kernel_prefix_kind(enum bpf_attach_type attach_type,
 				const char **prefix, int *kind);
-- 
cgit v1.2.3


From 29a30ff501518a49282754909543cef1ef49e4bc Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Wed, 20 Oct 2021 18:43:56 -0700
Subject: libbpf: Extract ELF processing state into separate struct

Name currently anonymous internal struct that keeps ELF-related state
for bpf_object. Just a bit of clean up, no functional changes.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211021014404.2635234-3-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c | 70 ++++++++++++++++++++++++--------------------------
 1 file changed, 34 insertions(+), 36 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index fdc25a112150..84a0683d214b 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -462,6 +462,35 @@ struct module_btf {
 	int fd_array_idx;
 };
 
+struct elf_state {
+	int fd;
+	const void *obj_buf;
+	size_t obj_buf_sz;
+	Elf *elf;
+	GElf_Ehdr ehdr;
+	Elf_Data *symbols;
+	Elf_Data *data;
+	Elf_Data *rodata;
+	Elf_Data *bss;
+	Elf_Data *st_ops_data;
+	size_t shstrndx; /* section index for section name strings */
+	size_t strtabidx;
+	struct {
+		GElf_Shdr shdr;
+		Elf_Data *data;
+	} *reloc_sects;
+	int nr_reloc_sects;
+	int maps_shndx;
+	int btf_maps_shndx;
+	__u32 btf_maps_sec_btf_id;
+	int text_shndx;
+	int symbols_shndx;
+	int data_shndx;
+	int rodata_shndx;
+	int bss_shndx;
+	int st_ops_shndx;
+};
+
 struct bpf_object {
 	char name[BPF_OBJ_NAME_LEN];
 	char license[64];
@@ -484,40 +513,10 @@ struct bpf_object {
 
 	struct bpf_gen *gen_loader;
 
+	/* Information when doing ELF related work. Only valid if efile.elf is not NULL */
+	struct elf_state efile;
 	/*
-	 * Information when doing elf related work. Only valid if fd
-	 * is valid.
-	 */
-	struct {
-		int fd;
-		const void *obj_buf;
-		size_t obj_buf_sz;
-		Elf *elf;
-		GElf_Ehdr ehdr;
-		Elf_Data *symbols;
-		Elf_Data *data;
-		Elf_Data *rodata;
-		Elf_Data *bss;
-		Elf_Data *st_ops_data;
-		size_t shstrndx; /* section index for section name strings */
-		size_t strtabidx;
-		struct {
-			GElf_Shdr shdr;
-			Elf_Data *data;
-		} *reloc_sects;
-		int nr_reloc_sects;
-		int maps_shndx;
-		int btf_maps_shndx;
-		__u32 btf_maps_sec_btf_id;
-		int text_shndx;
-		int symbols_shndx;
-		int data_shndx;
-		int rodata_shndx;
-		int bss_shndx;
-		int st_ops_shndx;
-	} efile;
-	/*
-	 * All loaded bpf_object is linked in a list, which is
+	 * All loaded bpf_object are linked in a list, which is
 	 * hidden to caller. bpf_objects__<func> handlers deal with
 	 * all objects.
 	 */
@@ -551,7 +550,6 @@ struct bpf_object {
 
 	char path[];
 };
-#define obj_elf_valid(o)	((o)->efile.elf)
 
 static const char *elf_sym_str(const struct bpf_object *obj, size_t off);
 static const char *elf_sec_str(const struct bpf_object *obj, size_t off);
@@ -1185,7 +1183,7 @@ static struct bpf_object *bpf_object__new(const char *path,
 
 static void bpf_object__elf_finish(struct bpf_object *obj)
 {
-	if (!obj_elf_valid(obj))
+	if (!obj->efile.elf)
 		return;
 
 	if (obj->efile.elf) {
@@ -1210,7 +1208,7 @@ static int bpf_object__elf_init(struct bpf_object *obj)
 	int err = 0;
 	GElf_Ehdr *ep;
 
-	if (obj_elf_valid(obj)) {
+	if (obj->efile.elf) {
 		pr_warn("elf: init internal error\n");
 		return -LIBBPF_ERRNO__LIBELF;
 	}
-- 
cgit v1.2.3


From ad23b7238474c6319bf692ae6ce037d9696df1d1 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Wed, 20 Oct 2021 18:43:57 -0700
Subject: libbpf: Use Elf64-specific types explicitly for dealing with ELF

Minimize the usage of class-agnostic gelf_xxx() APIs from libelf. These
APIs require copying ELF data structures into local GElf_xxx structs and
have a more cumbersome API. BPF ELF file is defined to be always 64-bit
ELF object, even when intended to be run on 32-bit host architectures,
so there is no need to do class-agnostic conversions everywhere. BPF
static linker implementation within libbpf has been using Elf64-specific
types since initial implementation.

Add two simple helpers, elf_sym_by_idx() and elf_rel_by_idx(), for more
succinct direct access to ELF symbol and relocation records within ELF
data itself and switch all the GElf_xxx usage into Elf64_xxx
equivalents. The only remaining place within libbpf.c that's still using
gelf API is gelf_getclass(), as there doesn't seem to be a direct way to
get underlying ELF bitness.

No functional changes intended.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211021014404.2635234-4-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c          | 353 ++++++++++++++++++++++------------------
 tools/lib/bpf/libbpf_internal.h |   4 +-
 tools/lib/bpf/linker.c          |   1 -
 3 files changed, 196 insertions(+), 162 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 84a0683d214b..74f7d9252d13 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -467,7 +467,7 @@ struct elf_state {
 	const void *obj_buf;
 	size_t obj_buf_sz;
 	Elf *elf;
-	GElf_Ehdr ehdr;
+	Elf64_Ehdr *ehdr;
 	Elf_Data *symbols;
 	Elf_Data *data;
 	Elf_Data *rodata;
@@ -476,7 +476,7 @@ struct elf_state {
 	size_t shstrndx; /* section index for section name strings */
 	size_t strtabidx;
 	struct {
-		GElf_Shdr shdr;
+		Elf64_Shdr *shdr;
 		Elf_Data *data;
 	} *reloc_sects;
 	int nr_reloc_sects;
@@ -555,9 +555,11 @@ static const char *elf_sym_str(const struct bpf_object *obj, size_t off);
 static const char *elf_sec_str(const struct bpf_object *obj, size_t off);
 static Elf_Scn *elf_sec_by_idx(const struct bpf_object *obj, size_t idx);
 static Elf_Scn *elf_sec_by_name(const struct bpf_object *obj, const char *name);
-static int elf_sec_hdr(const struct bpf_object *obj, Elf_Scn *scn, GElf_Shdr *hdr);
+static Elf64_Shdr *elf_sec_hdr(const struct bpf_object *obj, Elf_Scn *scn);
 static const char *elf_sec_name(const struct bpf_object *obj, Elf_Scn *scn);
 static Elf_Data *elf_sec_data(const struct bpf_object *obj, Elf_Scn *scn);
+static Elf64_Sym *elf_sym_by_idx(const struct bpf_object *obj, size_t idx);
+static Elf64_Rel *elf_rel_by_idx(Elf_Data *data, size_t idx);
 
 void bpf_program__unload(struct bpf_program *prog)
 {
@@ -699,25 +701,25 @@ bpf_object__add_programs(struct bpf_object *obj, Elf_Data *sec_data,
 	size_t sec_sz = sec_data->d_size, sec_off, prog_sz, nr_syms;
 	int nr_progs, err, i;
 	const char *name;
-	GElf_Sym sym;
+	Elf64_Sym *sym;
 
 	progs = obj->programs;
 	nr_progs = obj->nr_programs;
-	nr_syms = symbols->d_size / sizeof(GElf_Sym);
+	nr_syms = symbols->d_size / sizeof(Elf64_Sym);
 	sec_off = 0;
 
 	for (i = 0; i < nr_syms; i++) {
-		if (!gelf_getsym(symbols, i, &sym))
-			continue;
-		if (sym.st_shndx != sec_idx)
+		sym = elf_sym_by_idx(obj, i);
+
+		if (sym->st_shndx != sec_idx)
 			continue;
-		if (GELF_ST_TYPE(sym.st_info) != STT_FUNC)
+		if (ELF64_ST_TYPE(sym->st_info) != STT_FUNC)
 			continue;
 
-		prog_sz = sym.st_size;
-		sec_off = sym.st_value;
+		prog_sz = sym->st_size;
+		sec_off = sym->st_value;
 
-		name = elf_sym_str(obj, sym.st_name);
+		name = elf_sym_str(obj, sym->st_name);
 		if (!name) {
 			pr_warn("sec '%s': failed to get symbol name for offset %zu\n",
 				sec_name, sec_off);
@@ -730,7 +732,7 @@ bpf_object__add_programs(struct bpf_object *obj, Elf_Data *sec_data,
 			return -LIBBPF_ERRNO__FORMAT;
 		}
 
-		if (sec_idx != obj->efile.text_shndx && GELF_ST_BIND(sym.st_info) == STB_LOCAL) {
+		if (sec_idx != obj->efile.text_shndx && ELF64_ST_BIND(sym->st_info) == STB_LOCAL) {
 			pr_warn("sec '%s': program '%s' is static and not supported\n", sec_name, name);
 			return -ENOTSUP;
 		}
@@ -763,9 +765,9 @@ bpf_object__add_programs(struct bpf_object *obj, Elf_Data *sec_data,
 		 * as static to enable more permissive BPF verification mode
 		 * with more outside context available to BPF verifier
 		 */
-		if (GELF_ST_BIND(sym.st_info) != STB_LOCAL
-		    && (GELF_ST_VISIBILITY(sym.st_other) == STV_HIDDEN
-			|| GELF_ST_VISIBILITY(sym.st_other) == STV_INTERNAL))
+		if (ELF64_ST_BIND(sym->st_info) != STB_LOCAL
+		    && (ELF64_ST_VISIBILITY(sym->st_other) == STV_HIDDEN
+			|| ELF64_ST_VISIBILITY(sym->st_other) == STV_INTERNAL))
 			prog->mark_btf_static = true;
 
 		nr_progs++;
@@ -1205,8 +1207,9 @@ static void bpf_object__elf_finish(struct bpf_object *obj)
 
 static int bpf_object__elf_init(struct bpf_object *obj)
 {
+	Elf64_Ehdr *ehdr;
 	int err = 0;
-	GElf_Ehdr *ep;
+	Elf *elf;
 
 	if (obj->efile.elf) {
 		pr_warn("elf: init internal error\n");
@@ -1218,8 +1221,7 @@ static int bpf_object__elf_init(struct bpf_object *obj)
 		 * obj_buf should have been validated by
 		 * bpf_object__open_buffer().
 		 */
-		obj->efile.elf = elf_memory((char *)obj->efile.obj_buf,
-					    obj->efile.obj_buf_sz);
+		elf = elf_memory((char *)obj->efile.obj_buf, obj->efile.obj_buf_sz);
 	} else {
 		obj->efile.fd = open(obj->path, O_RDONLY);
 		if (obj->efile.fd < 0) {
@@ -1231,23 +1233,37 @@ static int bpf_object__elf_init(struct bpf_object *obj)
 			return err;
 		}
 
-		obj->efile.elf = elf_begin(obj->efile.fd, ELF_C_READ_MMAP, NULL);
+		elf = elf_begin(obj->efile.fd, ELF_C_READ_MMAP, NULL);
 	}
 
-	if (!obj->efile.elf) {
+	if (!elf) {
 		pr_warn("elf: failed to open %s as ELF file: %s\n", obj->path, elf_errmsg(-1));
 		err = -LIBBPF_ERRNO__LIBELF;
 		goto errout;
 	}
 
-	if (!gelf_getehdr(obj->efile.elf, &obj->efile.ehdr)) {
+	obj->efile.elf = elf;
+
+	if (elf_kind(elf) != ELF_K_ELF) {
+		err = -LIBBPF_ERRNO__FORMAT;
+		pr_warn("elf: '%s' is not a proper ELF object\n", obj->path);
+		goto errout;
+	}
+
+	if (gelf_getclass(elf) != ELFCLASS64) {
+		err = -LIBBPF_ERRNO__FORMAT;
+		pr_warn("elf: '%s' is not a 64-bit ELF object\n", obj->path);
+		goto errout;
+	}
+
+	obj->efile.ehdr = ehdr = elf64_getehdr(elf);
+	if (!obj->efile.ehdr) {
 		pr_warn("elf: failed to get ELF header from %s: %s\n", obj->path, elf_errmsg(-1));
 		err = -LIBBPF_ERRNO__FORMAT;
 		goto errout;
 	}
-	ep = &obj->efile.ehdr;
 
-	if (elf_getshdrstrndx(obj->efile.elf, &obj->efile.shstrndx)) {
+	if (elf_getshdrstrndx(elf, &obj->efile.shstrndx)) {
 		pr_warn("elf: failed to get section names section index for %s: %s\n",
 			obj->path, elf_errmsg(-1));
 		err = -LIBBPF_ERRNO__FORMAT;
@@ -1255,7 +1271,7 @@ static int bpf_object__elf_init(struct bpf_object *obj)
 	}
 
 	/* Elf is corrupted/truncated, avoid calling elf_strptr. */
-	if (!elf_rawdata(elf_getscn(obj->efile.elf, obj->efile.shstrndx), NULL)) {
+	if (!elf_rawdata(elf_getscn(elf, obj->efile.shstrndx), NULL)) {
 		pr_warn("elf: failed to get section names strings from %s: %s\n",
 			obj->path, elf_errmsg(-1));
 		err = -LIBBPF_ERRNO__FORMAT;
@@ -1263,8 +1279,7 @@ static int bpf_object__elf_init(struct bpf_object *obj)
 	}
 
 	/* Old LLVM set e_machine to EM_NONE */
-	if (ep->e_type != ET_REL ||
-	    (ep->e_machine && ep->e_machine != EM_BPF)) {
+	if (ehdr->e_type != ET_REL || (ehdr->e_machine && ehdr->e_machine != EM_BPF)) {
 		pr_warn("elf: %s is not a valid eBPF object file\n", obj->path);
 		err = -LIBBPF_ERRNO__FORMAT;
 		goto errout;
@@ -1279,10 +1294,10 @@ errout:
 static int bpf_object__check_endianness(struct bpf_object *obj)
 {
 #if __BYTE_ORDER == __LITTLE_ENDIAN
-	if (obj->efile.ehdr.e_ident[EI_DATA] == ELFDATA2LSB)
+	if (obj->efile.ehdr->e_ident[EI_DATA] == ELFDATA2LSB)
 		return 0;
 #elif __BYTE_ORDER == __BIG_ENDIAN
-	if (obj->efile.ehdr.e_ident[EI_DATA] == ELFDATA2MSB)
+	if (obj->efile.ehdr->e_ident[EI_DATA] == ELFDATA2MSB)
 		return 0;
 #else
 # error "Unrecognized __BYTE_ORDER__"
@@ -1363,23 +1378,20 @@ static int find_elf_var_offset(const struct bpf_object *obj, const char *name, _
 	if (!name || !off)
 		return -EINVAL;
 
-	for (si = 0; si < symbols->d_size / sizeof(GElf_Sym); si++) {
-		GElf_Sym sym;
+	for (si = 0; si < symbols->d_size / sizeof(Elf64_Sym); si++) {
+		Elf64_Sym *sym = elf_sym_by_idx(obj, si);
 
-		if (!gelf_getsym(symbols, si, &sym))
-			continue;
-		if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL ||
-		    GELF_ST_TYPE(sym.st_info) != STT_OBJECT)
+		if (ELF64_ST_BIND(sym->st_info) != STB_GLOBAL ||
+		    ELF64_ST_TYPE(sym->st_info) != STT_OBJECT)
 			continue;
 
-		sname = elf_sym_str(obj, sym.st_name);
+		sname = elf_sym_str(obj, sym->st_name);
 		if (!sname) {
-			pr_warn("failed to get sym name string for var %s\n",
-				name);
+			pr_warn("failed to get sym name string for var %s\n", name);
 			return -EIO;
 		}
 		if (strcmp(name, sname) == 0) {
-			*off = sym.st_value;
+			*off = sym->st_value;
 			return 0;
 		}
 	}
@@ -1866,15 +1878,13 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
 	 *
 	 * TODO: Detect array of map and report error.
 	 */
-	nr_syms = symbols->d_size / sizeof(GElf_Sym);
+	nr_syms = symbols->d_size / sizeof(Elf64_Sym);
 	for (i = 0; i < nr_syms; i++) {
-		GElf_Sym sym;
+		Elf64_Sym *sym = elf_sym_by_idx(obj, i);
 
-		if (!gelf_getsym(symbols, i, &sym))
+		if (sym->st_shndx != obj->efile.maps_shndx)
 			continue;
-		if (sym.st_shndx != obj->efile.maps_shndx)
-			continue;
-		if (GELF_ST_TYPE(sym.st_info) == STT_SECTION)
+		if (ELF64_ST_TYPE(sym->st_info) == STT_SECTION)
 			continue;
 		nr_maps++;
 	}
@@ -1891,40 +1901,38 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
 
 	/* Fill obj->maps using data in "maps" section.  */
 	for (i = 0; i < nr_syms; i++) {
-		GElf_Sym sym;
+		Elf64_Sym *sym = elf_sym_by_idx(obj, i);
 		const char *map_name;
 		struct bpf_map_def *def;
 		struct bpf_map *map;
 
-		if (!gelf_getsym(symbols, i, &sym))
-			continue;
-		if (sym.st_shndx != obj->efile.maps_shndx)
+		if (sym->st_shndx != obj->efile.maps_shndx)
 			continue;
-		if (GELF_ST_TYPE(sym.st_info) == STT_SECTION)
+		if (ELF64_ST_TYPE(sym->st_info) == STT_SECTION)
 			continue;
 
 		map = bpf_object__add_map(obj);
 		if (IS_ERR(map))
 			return PTR_ERR(map);
 
-		map_name = elf_sym_str(obj, sym.st_name);
+		map_name = elf_sym_str(obj, sym->st_name);
 		if (!map_name) {
 			pr_warn("failed to get map #%d name sym string for obj %s\n",
 				i, obj->path);
 			return -LIBBPF_ERRNO__FORMAT;
 		}
 
-		if (GELF_ST_BIND(sym.st_info) == STB_LOCAL) {
+		if (ELF64_ST_BIND(sym->st_info) == STB_LOCAL) {
 			pr_warn("map '%s' (legacy): static maps are not supported\n", map_name);
 			return -ENOTSUP;
 		}
 
 		map->libbpf_type = LIBBPF_MAP_UNSPEC;
-		map->sec_idx = sym.st_shndx;
-		map->sec_offset = sym.st_value;
+		map->sec_idx = sym->st_shndx;
+		map->sec_offset = sym->st_value;
 		pr_debug("map '%s' (legacy): at sec_idx %d, offset %zu.\n",
 			 map_name, map->sec_idx, map->sec_offset);
-		if (sym.st_value + map_def_sz > data->d_size) {
+		if (sym->st_value + map_def_sz > data->d_size) {
 			pr_warn("corrupted maps section in %s: last map \"%s\" too small\n",
 				obj->path, map_name);
 			return -EINVAL;
@@ -1936,7 +1944,7 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
 			return -ENOMEM;
 		}
 		pr_debug("map %d is \"%s\"\n", i, map->name);
-		def = (struct bpf_map_def *)(data->d_buf + sym.st_value);
+		def = (struct bpf_map_def *)(data->d_buf + sym->st_value);
 		/*
 		 * If the definition of the map in the object file fits in
 		 * bpf_map_def, copy it.  Any extra fields in our version
@@ -2506,12 +2514,13 @@ static int bpf_object__init_maps(struct bpf_object *obj,
 
 static bool section_have_execinstr(struct bpf_object *obj, int idx)
 {
-	GElf_Shdr sh;
+	Elf64_Shdr *sh;
 
-	if (elf_sec_hdr(obj, elf_sec_by_idx(obj, idx), &sh))
+	sh = elf_sec_hdr(obj, elf_sec_by_idx(obj, idx));
+	if (!sh)
 		return false;
 
-	return sh.sh_flags & SHF_EXECINSTR;
+	return sh->sh_flags & SHF_EXECINSTR;
 }
 
 static bool btf_needs_sanitization(struct bpf_object *obj)
@@ -2987,32 +2996,36 @@ static Elf_Scn *elf_sec_by_name(const struct bpf_object *obj, const char *name)
 	return NULL;
 }
 
-static int elf_sec_hdr(const struct bpf_object *obj, Elf_Scn *scn, GElf_Shdr *hdr)
+static Elf64_Shdr *elf_sec_hdr(const struct bpf_object *obj, Elf_Scn *scn)
 {
+	Elf64_Shdr *shdr;
+
 	if (!scn)
-		return -EINVAL;
+		return NULL;
 
-	if (gelf_getshdr(scn, hdr) != hdr) {
+	shdr = elf64_getshdr(scn);
+	if (!shdr) {
 		pr_warn("elf: failed to get section(%zu) header from %s: %s\n",
 			elf_ndxscn(scn), obj->path, elf_errmsg(-1));
-		return -EINVAL;
+		return NULL;
 	}
 
-	return 0;
+	return shdr;
 }
 
 static const char *elf_sec_name(const struct bpf_object *obj, Elf_Scn *scn)
 {
 	const char *name;
-	GElf_Shdr sh;
+	Elf64_Shdr *sh;
 
 	if (!scn)
 		return NULL;
 
-	if (elf_sec_hdr(obj, scn, &sh))
+	sh = elf_sec_hdr(obj, scn);
+	if (!sh)
 		return NULL;
 
-	name = elf_sec_str(obj, sh.sh_name);
+	name = elf_sec_str(obj, sh->sh_name);
 	if (!name) {
 		pr_warn("elf: failed to get section(%zu) name from %s: %s\n",
 			elf_ndxscn(scn), obj->path, elf_errmsg(-1));
@@ -3040,13 +3053,29 @@ static Elf_Data *elf_sec_data(const struct bpf_object *obj, Elf_Scn *scn)
 	return data;
 }
 
+static Elf64_Sym *elf_sym_by_idx(const struct bpf_object *obj, size_t idx)
+{
+	if (idx >= obj->efile.symbols->d_size / sizeof(Elf64_Sym))
+		return NULL;
+
+	return (Elf64_Sym *)obj->efile.symbols->d_buf + idx;
+}
+
+static Elf64_Rel *elf_rel_by_idx(Elf_Data *data, size_t idx)
+{
+	if (idx >= data->d_size / sizeof(Elf64_Rel))
+		return NULL;
+
+	return (Elf64_Rel *)data->d_buf + idx;
+}
+
 static bool is_sec_name_dwarf(const char *name)
 {
 	/* approximation, but the actual list is too long */
 	return str_has_pfx(name, ".debug_");
 }
 
-static bool ignore_elf_section(GElf_Shdr *hdr, const char *name)
+static bool ignore_elf_section(Elf64_Shdr *hdr, const char *name)
 {
 	/* no special handling of .strtab */
 	if (hdr->sh_type == SHT_STRTAB)
@@ -3101,17 +3130,18 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 	const char *name;
 	Elf_Data *data;
 	Elf_Scn *scn;
-	GElf_Shdr sh;
+	Elf64_Shdr *sh;
 
 	/* a bunch of ELF parsing functionality depends on processing symbols,
 	 * so do the first pass and find the symbol table
 	 */
 	scn = NULL;
 	while ((scn = elf_nextscn(elf, scn)) != NULL) {
-		if (elf_sec_hdr(obj, scn, &sh))
+		sh = elf_sec_hdr(obj, scn);
+		if (!sh)
 			return -LIBBPF_ERRNO__FORMAT;
 
-		if (sh.sh_type == SHT_SYMTAB) {
+		if (sh->sh_type == SHT_SYMTAB) {
 			if (obj->efile.symbols) {
 				pr_warn("elf: multiple symbol tables in %s\n", obj->path);
 				return -LIBBPF_ERRNO__FORMAT;
@@ -3123,7 +3153,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 
 			obj->efile.symbols = data;
 			obj->efile.symbols_shndx = elf_ndxscn(scn);
-			obj->efile.strtabidx = sh.sh_link;
+			obj->efile.strtabidx = sh->sh_link;
 		}
 	}
 
@@ -3137,14 +3167,15 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 	while ((scn = elf_nextscn(elf, scn)) != NULL) {
 		idx++;
 
-		if (elf_sec_hdr(obj, scn, &sh))
+		sh = elf_sec_hdr(obj, scn);
+		if (!sh)
 			return -LIBBPF_ERRNO__FORMAT;
 
-		name = elf_sec_str(obj, sh.sh_name);
+		name = elf_sec_str(obj, sh->sh_name);
 		if (!name)
 			return -LIBBPF_ERRNO__FORMAT;
 
-		if (ignore_elf_section(&sh, name))
+		if (ignore_elf_section(sh, name))
 			continue;
 
 		data = elf_sec_data(obj, scn);
@@ -3153,8 +3184,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 
 		pr_debug("elf: section(%d) %s, size %ld, link %d, flags %lx, type=%d\n",
 			 idx, name, (unsigned long)data->d_size,
-			 (int)sh.sh_link, (unsigned long)sh.sh_flags,
-			 (int)sh.sh_type);
+			 (int)sh->sh_link, (unsigned long)sh->sh_flags,
+			 (int)sh->sh_type);
 
 		if (strcmp(name, "license") == 0) {
 			err = bpf_object__init_license(obj, data->d_buf, data->d_size);
@@ -3172,10 +3203,10 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 			btf_data = data;
 		} else if (strcmp(name, BTF_EXT_ELF_SEC) == 0) {
 			btf_ext_data = data;
-		} else if (sh.sh_type == SHT_SYMTAB) {
+		} else if (sh->sh_type == SHT_SYMTAB) {
 			/* already processed during the first pass above */
-		} else if (sh.sh_type == SHT_PROGBITS && data->d_size > 0) {
-			if (sh.sh_flags & SHF_EXECINSTR) {
+		} else if (sh->sh_type == SHT_PROGBITS && data->d_size > 0) {
+			if (sh->sh_flags & SHF_EXECINSTR) {
 				if (strcmp(name, ".text") == 0)
 					obj->efile.text_shndx = idx;
 				err = bpf_object__add_programs(obj, data, name, idx);
@@ -3194,10 +3225,10 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 				pr_info("elf: skipping unrecognized data section(%d) %s\n",
 					idx, name);
 			}
-		} else if (sh.sh_type == SHT_REL) {
+		} else if (sh->sh_type == SHT_REL) {
 			int nr_sects = obj->efile.nr_reloc_sects;
 			void *sects = obj->efile.reloc_sects;
-			int sec = sh.sh_info; /* points to other section */
+			int sec = sh->sh_info; /* points to other section */
 
 			/* Only do relo for section with exec instructions */
 			if (!section_have_execinstr(obj, sec) &&
@@ -3219,12 +3250,12 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 
 			obj->efile.reloc_sects[nr_sects].shdr = sh;
 			obj->efile.reloc_sects[nr_sects].data = data;
-		} else if (sh.sh_type == SHT_NOBITS && strcmp(name, BSS_SEC) == 0) {
+		} else if (sh->sh_type == SHT_NOBITS && strcmp(name, BSS_SEC) == 0) {
 			obj->efile.bss = data;
 			obj->efile.bss_shndx = idx;
 		} else {
 			pr_info("elf: skipping section(%d) %s (size %zu)\n", idx, name,
-				(size_t)sh.sh_size);
+				(size_t)sh->sh_size);
 		}
 	}
 
@@ -3240,19 +3271,19 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 	return bpf_object__init_btf(obj, btf_data, btf_ext_data);
 }
 
-static bool sym_is_extern(const GElf_Sym *sym)
+static bool sym_is_extern(const Elf64_Sym *sym)
 {
-	int bind = GELF_ST_BIND(sym->st_info);
+	int bind = ELF64_ST_BIND(sym->st_info);
 	/* externs are symbols w/ type=NOTYPE, bind=GLOBAL|WEAK, section=UND */
 	return sym->st_shndx == SHN_UNDEF &&
 	       (bind == STB_GLOBAL || bind == STB_WEAK) &&
-	       GELF_ST_TYPE(sym->st_info) == STT_NOTYPE;
+	       ELF64_ST_TYPE(sym->st_info) == STT_NOTYPE;
 }
 
-static bool sym_is_subprog(const GElf_Sym *sym, int text_shndx)
+static bool sym_is_subprog(const Elf64_Sym *sym, int text_shndx)
 {
-	int bind = GELF_ST_BIND(sym->st_info);
-	int type = GELF_ST_TYPE(sym->st_info);
+	int bind = ELF64_ST_BIND(sym->st_info);
+	int type = ELF64_ST_TYPE(sym->st_info);
 
 	/* in .text section */
 	if (sym->st_shndx != text_shndx)
@@ -3450,30 +3481,31 @@ static int bpf_object__collect_externs(struct bpf_object *obj)
 	int i, n, off, dummy_var_btf_id;
 	const char *ext_name, *sec_name;
 	Elf_Scn *scn;
-	GElf_Shdr sh;
+	Elf64_Shdr *sh;
 
 	if (!obj->efile.symbols)
 		return 0;
 
 	scn = elf_sec_by_idx(obj, obj->efile.symbols_shndx);
-	if (elf_sec_hdr(obj, scn, &sh))
+	sh = elf_sec_hdr(obj, scn);
+	if (!sh)
 		return -LIBBPF_ERRNO__FORMAT;
 
 	dummy_var_btf_id = add_dummy_ksym_var(obj->btf);
 	if (dummy_var_btf_id < 0)
 		return dummy_var_btf_id;
 
-	n = sh.sh_size / sh.sh_entsize;
+	n = sh->sh_size / sh->sh_entsize;
 	pr_debug("looking for externs among %d symbols...\n", n);
 
 	for (i = 0; i < n; i++) {
-		GElf_Sym sym;
+		Elf64_Sym *sym = elf_sym_by_idx(obj, i);
 
-		if (!gelf_getsym(obj->efile.symbols, i, &sym))
+		if (!sym)
 			return -LIBBPF_ERRNO__FORMAT;
-		if (!sym_is_extern(&sym))
+		if (!sym_is_extern(sym))
 			continue;
-		ext_name = elf_sym_str(obj, sym.st_name);
+		ext_name = elf_sym_str(obj, sym->st_name);
 		if (!ext_name || !ext_name[0])
 			continue;
 
@@ -3495,7 +3527,7 @@ static int bpf_object__collect_externs(struct bpf_object *obj)
 		t = btf__type_by_id(obj->btf, ext->btf_id);
 		ext->name = btf__name_by_offset(obj->btf, t->name_off);
 		ext->sym_idx = i;
-		ext->is_weak = GELF_ST_BIND(sym.st_info) == STB_WEAK;
+		ext->is_weak = ELF64_ST_BIND(sym->st_info) == STB_WEAK;
 
 		ext->sec_btf_id = find_extern_sec_btf_id(obj->btf, ext->btf_id);
 		if (ext->sec_btf_id <= 0) {
@@ -3730,7 +3762,7 @@ bpf_object__section_to_libbpf_map_type(const struct bpf_object *obj, int shndx)
 static int bpf_program__record_reloc(struct bpf_program *prog,
 				     struct reloc_desc *reloc_desc,
 				     __u32 insn_idx, const char *sym_name,
-				     const GElf_Sym *sym, const GElf_Rel *rel)
+				     const Elf64_Sym *sym, const Elf64_Rel *rel)
 {
 	struct bpf_insn *insn = &prog->insns[insn_idx];
 	size_t map_idx, nr_maps = prog->obj->nr_maps;
@@ -3747,7 +3779,7 @@ static int bpf_program__record_reloc(struct bpf_program *prog,
 	}
 
 	if (sym_is_extern(sym)) {
-		int sym_idx = GELF_R_SYM(rel->r_info);
+		int sym_idx = ELF64_R_SYM(rel->r_info);
 		int i, n = obj->nr_extern;
 		struct extern_desc *ext;
 
@@ -3912,9 +3944,8 @@ static struct bpf_program *find_prog_by_sec_insn(const struct bpf_object *obj,
 }
 
 static int
-bpf_object__collect_prog_relos(struct bpf_object *obj, GElf_Shdr *shdr, Elf_Data *data)
+bpf_object__collect_prog_relos(struct bpf_object *obj, Elf64_Shdr *shdr, Elf_Data *data)
 {
-	Elf_Data *symbols = obj->efile.symbols;
 	const char *relo_sec_name, *sec_name;
 	size_t sec_idx = shdr->sh_info;
 	struct bpf_program *prog;
@@ -3924,8 +3955,8 @@ bpf_object__collect_prog_relos(struct bpf_object *obj, GElf_Shdr *shdr, Elf_Data
 	__u32 insn_idx;
 	Elf_Scn *scn;
 	Elf_Data *scn_data;
-	GElf_Sym sym;
-	GElf_Rel rel;
+	Elf64_Sym *sym;
+	Elf64_Rel *rel;
 
 	scn = elf_sec_by_idx(obj, sec_idx);
 	scn_data = elf_sec_data(obj, scn);
@@ -3940,33 +3971,36 @@ bpf_object__collect_prog_relos(struct bpf_object *obj, GElf_Shdr *shdr, Elf_Data
 	nrels = shdr->sh_size / shdr->sh_entsize;
 
 	for (i = 0; i < nrels; i++) {
-		if (!gelf_getrel(data, i, &rel)) {
+		rel = elf_rel_by_idx(data, i);
+		if (!rel) {
 			pr_warn("sec '%s': failed to get relo #%d\n", relo_sec_name, i);
 			return -LIBBPF_ERRNO__FORMAT;
 		}
-		if (!gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym)) {
+
+		sym = elf_sym_by_idx(obj, ELF64_R_SYM(rel->r_info));
+		if (!sym) {
 			pr_warn("sec '%s': symbol 0x%zx not found for relo #%d\n",
-				relo_sec_name, (size_t)GELF_R_SYM(rel.r_info), i);
+				relo_sec_name, (size_t)ELF64_R_SYM(rel->r_info), i);
 			return -LIBBPF_ERRNO__FORMAT;
 		}
 
-		if (rel.r_offset % BPF_INSN_SZ || rel.r_offset >= scn_data->d_size) {
+		if (rel->r_offset % BPF_INSN_SZ || rel->r_offset >= scn_data->d_size) {
 			pr_warn("sec '%s': invalid offset 0x%zx for relo #%d\n",
-				relo_sec_name, (size_t)GELF_R_SYM(rel.r_info), i);
+				relo_sec_name, (size_t)ELF64_R_SYM(rel->r_info), i);
 			return -LIBBPF_ERRNO__FORMAT;
 		}
 
-		insn_idx = rel.r_offset / BPF_INSN_SZ;
+		insn_idx = rel->r_offset / BPF_INSN_SZ;
 		/* relocations against static functions are recorded as
 		 * relocations against the section that contains a function;
 		 * in such case, symbol will be STT_SECTION and sym.st_name
 		 * will point to empty string (0), so fetch section name
 		 * instead
 		 */
-		if (GELF_ST_TYPE(sym.st_info) == STT_SECTION && sym.st_name == 0)
-			sym_name = elf_sec_name(obj, elf_sec_by_idx(obj, sym.st_shndx));
+		if (ELF64_ST_TYPE(sym->st_info) == STT_SECTION && sym->st_name == 0)
+			sym_name = elf_sec_name(obj, elf_sec_by_idx(obj, sym->st_shndx));
 		else
-			sym_name = elf_sym_str(obj, sym.st_name);
+			sym_name = elf_sym_str(obj, sym->st_name);
 		sym_name = sym_name ?: "<?";
 
 		pr_debug("sec '%s': relo #%d: insn #%u against '%s'\n",
@@ -3988,7 +4022,7 @@ bpf_object__collect_prog_relos(struct bpf_object *obj, GElf_Shdr *shdr, Elf_Data
 		/* adjust insn_idx to local BPF program frame of reference */
 		insn_idx -= prog->sec_insn_off;
 		err = bpf_program__record_reloc(prog, &relos[prog->nr_reloc],
-						insn_idx, sym_name, &sym, &rel);
+						insn_idx, sym_name, sym, rel);
 		if (err)
 			return err;
 
@@ -6036,10 +6070,10 @@ bpf_object__relocate(struct bpf_object *obj, const char *targ_btf_path)
 }
 
 static int bpf_object__collect_st_ops_relos(struct bpf_object *obj,
-					    GElf_Shdr *shdr, Elf_Data *data);
+					    Elf64_Shdr *shdr, Elf_Data *data);
 
 static int bpf_object__collect_map_relos(struct bpf_object *obj,
-					 GElf_Shdr *shdr, Elf_Data *data)
+					 Elf64_Shdr *shdr, Elf_Data *data)
 {
 	const int bpf_ptr_sz = 8, host_ptr_sz = sizeof(void *);
 	int i, j, nrels, new_sz;
@@ -6048,10 +6082,9 @@ static int bpf_object__collect_map_relos(struct bpf_object *obj,
 	struct bpf_map *map = NULL, *targ_map;
 	const struct btf_member *member;
 	const char *name, *mname;
-	Elf_Data *symbols;
 	unsigned int moff;
-	GElf_Sym sym;
-	GElf_Rel rel;
+	Elf64_Sym *sym;
+	Elf64_Rel *rel;
 	void *tmp;
 
 	if (!obj->efile.btf_maps_sec_btf_id || !obj->btf)
@@ -6060,28 +6093,30 @@ static int bpf_object__collect_map_relos(struct bpf_object *obj,
 	if (!sec)
 		return -EINVAL;
 
-	symbols = obj->efile.symbols;
 	nrels = shdr->sh_size / shdr->sh_entsize;
 	for (i = 0; i < nrels; i++) {
-		if (!gelf_getrel(data, i, &rel)) {
+		rel = elf_rel_by_idx(data, i);
+		if (!rel) {
 			pr_warn(".maps relo #%d: failed to get ELF relo\n", i);
 			return -LIBBPF_ERRNO__FORMAT;
 		}
-		if (!gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym)) {
+
+		sym = elf_sym_by_idx(obj, ELF64_R_SYM(rel->r_info));
+		if (!sym) {
 			pr_warn(".maps relo #%d: symbol %zx not found\n",
-				i, (size_t)GELF_R_SYM(rel.r_info));
+				i, (size_t)ELF64_R_SYM(rel->r_info));
 			return -LIBBPF_ERRNO__FORMAT;
 		}
-		name = elf_sym_str(obj, sym.st_name) ?: "<?>";
-		if (sym.st_shndx != obj->efile.btf_maps_shndx) {
+		name = elf_sym_str(obj, sym->st_name) ?: "<?>";
+		if (sym->st_shndx != obj->efile.btf_maps_shndx) {
 			pr_warn(".maps relo #%d: '%s' isn't a BTF-defined map\n",
 				i, name);
 			return -LIBBPF_ERRNO__RELOC;
 		}
 
-		pr_debug(".maps relo #%d: for %zd value %zd rel.r_offset %zu name %d ('%s')\n",
-			 i, (ssize_t)(rel.r_info >> 32), (size_t)sym.st_value,
-			 (size_t)rel.r_offset, sym.st_name, name);
+		pr_debug(".maps relo #%d: for %zd value %zd rel->r_offset %zu name %d ('%s')\n",
+			 i, (ssize_t)(rel->r_info >> 32), (size_t)sym->st_value,
+			 (size_t)rel->r_offset, sym->st_name, name);
 
 		for (j = 0; j < obj->nr_maps; j++) {
 			map = &obj->maps[j];
@@ -6089,13 +6124,13 @@ static int bpf_object__collect_map_relos(struct bpf_object *obj,
 				continue;
 
 			vi = btf_var_secinfos(sec) + map->btf_var_idx;
-			if (vi->offset <= rel.r_offset &&
-			    rel.r_offset + bpf_ptr_sz <= vi->offset + vi->size)
+			if (vi->offset <= rel->r_offset &&
+			    rel->r_offset + bpf_ptr_sz <= vi->offset + vi->size)
 				break;
 		}
 		if (j == obj->nr_maps) {
-			pr_warn(".maps relo #%d: cannot find map '%s' at rel.r_offset %zu\n",
-				i, name, (size_t)rel.r_offset);
+			pr_warn(".maps relo #%d: cannot find map '%s' at rel->r_offset %zu\n",
+				i, name, (size_t)rel->r_offset);
 			return -EINVAL;
 		}
 
@@ -6122,10 +6157,10 @@ static int bpf_object__collect_map_relos(struct bpf_object *obj,
 			return -EINVAL;
 
 		moff = btf_member_bit_offset(def, btf_vlen(def) - 1) / 8;
-		if (rel.r_offset - vi->offset < moff)
+		if (rel->r_offset - vi->offset < moff)
 			return -EINVAL;
 
-		moff = rel.r_offset - vi->offset - moff;
+		moff = rel->r_offset - vi->offset - moff;
 		/* here we use BPF pointer size, which is always 64 bit, as we
 		 * are parsing ELF that was built for BPF target
 		 */
@@ -6171,7 +6206,7 @@ static int bpf_object__collect_relos(struct bpf_object *obj)
 	int i, err;
 
 	for (i = 0; i < obj->efile.nr_reloc_sects; i++) {
-		GElf_Shdr *shdr = &obj->efile.reloc_sects[i].shdr;
+		Elf64_Shdr *shdr = obj->efile.reloc_sects[i].shdr;
 		Elf_Data *data = obj->efile.reloc_sects[i].data;
 		int idx = shdr->sh_info;
 
@@ -8362,7 +8397,7 @@ static struct bpf_map *find_struct_ops_map_by_offset(struct bpf_object *obj,
 
 /* Collect the reloc from ELF and populate the st_ops->progs[] */
 static int bpf_object__collect_st_ops_relos(struct bpf_object *obj,
-					    GElf_Shdr *shdr, Elf_Data *data)
+					    Elf64_Shdr *shdr, Elf_Data *data)
 {
 	const struct btf_member *member;
 	struct bpf_struct_ops *st_ops;
@@ -8370,58 +8405,58 @@ static int bpf_object__collect_st_ops_relos(struct bpf_object *obj,
 	unsigned int shdr_idx;
 	const struct btf *btf;
 	struct bpf_map *map;
-	Elf_Data *symbols;
 	unsigned int moff, insn_idx;
 	const char *name;
 	__u32 member_idx;
-	GElf_Sym sym;
-	GElf_Rel rel;
+	Elf64_Sym *sym;
+	Elf64_Rel *rel;
 	int i, nrels;
 
-	symbols = obj->efile.symbols;
 	btf = obj->btf;
 	nrels = shdr->sh_size / shdr->sh_entsize;
 	for (i = 0; i < nrels; i++) {
-		if (!gelf_getrel(data, i, &rel)) {
+		rel = elf_rel_by_idx(data, i);
+		if (!rel) {
 			pr_warn("struct_ops reloc: failed to get %d reloc\n", i);
 			return -LIBBPF_ERRNO__FORMAT;
 		}
 
-		if (!gelf_getsym(symbols, GELF_R_SYM(rel.r_info), &sym)) {
+		sym = elf_sym_by_idx(obj, ELF64_R_SYM(rel->r_info));
+		if (!sym) {
 			pr_warn("struct_ops reloc: symbol %zx not found\n",
-				(size_t)GELF_R_SYM(rel.r_info));
+				(size_t)ELF64_R_SYM(rel->r_info));
 			return -LIBBPF_ERRNO__FORMAT;
 		}
 
-		name = elf_sym_str(obj, sym.st_name) ?: "<?>";
-		map = find_struct_ops_map_by_offset(obj, rel.r_offset);
+		name = elf_sym_str(obj, sym->st_name) ?: "<?>";
+		map = find_struct_ops_map_by_offset(obj, rel->r_offset);
 		if (!map) {
-			pr_warn("struct_ops reloc: cannot find map at rel.r_offset %zu\n",
-				(size_t)rel.r_offset);
+			pr_warn("struct_ops reloc: cannot find map at rel->r_offset %zu\n",
+				(size_t)rel->r_offset);
 			return -EINVAL;
 		}
 
-		moff = rel.r_offset - map->sec_offset;
-		shdr_idx = sym.st_shndx;
+		moff = rel->r_offset - map->sec_offset;
+		shdr_idx = sym->st_shndx;
 		st_ops = map->st_ops;
-		pr_debug("struct_ops reloc %s: for %lld value %lld shdr_idx %u rel.r_offset %zu map->sec_offset %zu name %d (\'%s\')\n",
+		pr_debug("struct_ops reloc %s: for %lld value %lld shdr_idx %u rel->r_offset %zu map->sec_offset %zu name %d (\'%s\')\n",
 			 map->name,
-			 (long long)(rel.r_info >> 32),
-			 (long long)sym.st_value,
-			 shdr_idx, (size_t)rel.r_offset,
-			 map->sec_offset, sym.st_name, name);
+			 (long long)(rel->r_info >> 32),
+			 (long long)sym->st_value,
+			 shdr_idx, (size_t)rel->r_offset,
+			 map->sec_offset, sym->st_name, name);
 
 		if (shdr_idx >= SHN_LORESERVE) {
-			pr_warn("struct_ops reloc %s: rel.r_offset %zu shdr_idx %u unsupported non-static function\n",
-				map->name, (size_t)rel.r_offset, shdr_idx);
+			pr_warn("struct_ops reloc %s: rel->r_offset %zu shdr_idx %u unsupported non-static function\n",
+				map->name, (size_t)rel->r_offset, shdr_idx);
 			return -LIBBPF_ERRNO__RELOC;
 		}
-		if (sym.st_value % BPF_INSN_SZ) {
+		if (sym->st_value % BPF_INSN_SZ) {
 			pr_warn("struct_ops reloc %s: invalid target program offset %llu\n",
-				map->name, (unsigned long long)sym.st_value);
+				map->name, (unsigned long long)sym->st_value);
 			return -LIBBPF_ERRNO__FORMAT;
 		}
-		insn_idx = sym.st_value / BPF_INSN_SZ;
+		insn_idx = sym->st_value / BPF_INSN_SZ;
 
 		member = find_member_by_offset(st_ops->type, moff * 8);
 		if (!member) {
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index 4bbd327a4ce9..13bc7950e304 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -52,8 +52,8 @@
 #endif
 
 /* Older libelf all end up in this expression, for both 32 and 64 bit */
-#ifndef GELF_ST_VISIBILITY
-#define GELF_ST_VISIBILITY(o) ((o) & 0x03)
+#ifndef ELF64_ST_VISIBILITY
+#define ELF64_ST_VISIBILITY(o) ((o) & 0x03)
 #endif
 
 #define BTF_INFO_ENC(kind, kind_flag, vlen) \
diff --git a/tools/lib/bpf/linker.c b/tools/lib/bpf/linker.c
index 2df880cefdae..13e6fdc7d8cb 100644
--- a/tools/lib/bpf/linker.c
+++ b/tools/lib/bpf/linker.c
@@ -15,7 +15,6 @@
 #include <linux/btf.h>
 #include <elf.h>
 #include <libelf.h>
-#include <gelf.h>
 #include <fcntl.h>
 #include "libbpf.h"
 #include "btf.h"
-- 
cgit v1.2.3


From 25bbbd7a444b1624000389830d46ffdc5b809ee8 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Wed, 20 Oct 2021 18:43:58 -0700
Subject: libbpf: Remove assumptions about uniqueness of .rodata/.data/.bss
 maps

Remove internal libbpf assumption that there can be only one .rodata,
.data, and .bss map per BPF object. To achieve that, extend and
generalize the scheme that was used for keeping track of relocation ELF
sections. Now each ELF section has a temporary extra index that keeps
track of logical type of ELF section (relocations, data, read-only data,
BSS). Switch relocation to this scheme, as well as .rodata/.data/.bss
handling.

We don't yet allow multiple .rodata, .data, and .bss sections, but no
libbpf internal code makes an assumption that there can be only one of
each and thus they can be explicitly referenced by a single index. Next
patches will actually allow multiple .rodata and .data sections.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211021014404.2635234-5-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c | 260 ++++++++++++++++++++++++++-----------------------
 1 file changed, 140 insertions(+), 120 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 74f7d9252d13..a7320d272b34 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -462,6 +462,20 @@ struct module_btf {
 	int fd_array_idx;
 };
 
+enum sec_type {
+	SEC_UNUSED = 0,
+	SEC_RELO,
+	SEC_BSS,
+	SEC_DATA,
+	SEC_RODATA,
+};
+
+struct elf_sec_desc {
+	enum sec_type sec_type;
+	Elf64_Shdr *shdr;
+	Elf_Data *data;
+};
+
 struct elf_state {
 	int fd;
 	const void *obj_buf;
@@ -469,25 +483,16 @@ struct elf_state {
 	Elf *elf;
 	Elf64_Ehdr *ehdr;
 	Elf_Data *symbols;
-	Elf_Data *data;
-	Elf_Data *rodata;
-	Elf_Data *bss;
 	Elf_Data *st_ops_data;
 	size_t shstrndx; /* section index for section name strings */
 	size_t strtabidx;
-	struct {
-		Elf64_Shdr *shdr;
-		Elf_Data *data;
-	} *reloc_sects;
-	int nr_reloc_sects;
+	struct elf_sec_desc *secs;
+	int sec_cnt;
 	int maps_shndx;
 	int btf_maps_shndx;
 	__u32 btf_maps_sec_btf_id;
 	int text_shndx;
 	int symbols_shndx;
-	int data_shndx;
-	int rodata_shndx;
-	int bss_shndx;
 	int st_ops_shndx;
 };
 
@@ -506,10 +511,10 @@ struct bpf_object {
 	struct extern_desc *externs;
 	int nr_extern;
 	int kconfig_map_idx;
-	int rodata_map_idx;
 
 	bool loaded;
 	bool has_subcalls;
+	bool has_rodata;
 
 	struct bpf_gen *gen_loader;
 
@@ -1168,12 +1173,8 @@ static struct bpf_object *bpf_object__new(const char *path,
 	obj->efile.obj_buf_sz = obj_buf_sz;
 	obj->efile.maps_shndx = -1;
 	obj->efile.btf_maps_shndx = -1;
-	obj->efile.data_shndx = -1;
-	obj->efile.rodata_shndx = -1;
-	obj->efile.bss_shndx = -1;
 	obj->efile.st_ops_shndx = -1;
 	obj->kconfig_map_idx = -1;
-	obj->rodata_map_idx = -1;
 
 	obj->kern_version = get_kernel_version();
 	obj->loaded = false;
@@ -1193,13 +1194,10 @@ static void bpf_object__elf_finish(struct bpf_object *obj)
 		obj->efile.elf = NULL;
 	}
 	obj->efile.symbols = NULL;
-	obj->efile.data = NULL;
-	obj->efile.rodata = NULL;
-	obj->efile.bss = NULL;
 	obj->efile.st_ops_data = NULL;
 
-	zfree(&obj->efile.reloc_sects);
-	obj->efile.nr_reloc_sects = 0;
+	zfree(&obj->efile.secs);
+	obj->efile.sec_cnt = 0;
 	zclose(obj->efile.fd);
 	obj->efile.obj_buf = NULL;
 	obj->efile.obj_buf_sz = 0;
@@ -1340,30 +1338,18 @@ static bool bpf_map_type__is_map_in_map(enum bpf_map_type type)
 static int find_elf_sec_sz(const struct bpf_object *obj, const char *name, __u32 *size)
 {
 	int ret = -ENOENT;
+	Elf_Data *data;
+	Elf_Scn *scn;
 
 	*size = 0;
-	if (!name) {
+	if (!name)
 		return -EINVAL;
-	} else if (!strcmp(name, DATA_SEC)) {
-		if (obj->efile.data)
-			*size = obj->efile.data->d_size;
-	} else if (!strcmp(name, BSS_SEC)) {
-		if (obj->efile.bss)
-			*size = obj->efile.bss->d_size;
-	} else if (!strcmp(name, RODATA_SEC)) {
-		if (obj->efile.rodata)
-			*size = obj->efile.rodata->d_size;
-	} else if (!strcmp(name, STRUCT_OPS_SEC)) {
-		if (obj->efile.st_ops_data)
-			*size = obj->efile.st_ops_data->d_size;
-	} else {
-		Elf_Scn *scn = elf_sec_by_name(obj, name);
-		Elf_Data *data = elf_sec_data(obj, scn);
 
-		if (data) {
-			ret = 0; /* found it */
-			*size = data->d_size;
-		}
+	scn = elf_sec_by_name(obj, name);
+	data = elf_sec_data(obj, scn);
+	if (data) {
+		ret = 0; /* found it */
+		*size = data->d_size;
 	}
 
 	return *size ? 0 : ret;
@@ -1516,34 +1502,39 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
 
 static int bpf_object__init_global_data_maps(struct bpf_object *obj)
 {
-	int err;
+	struct elf_sec_desc *sec_desc;
+	int err = 0, sec_idx;
 
 	/*
 	 * Populate obj->maps with libbpf internal maps.
 	 */
-	if (obj->efile.data_shndx >= 0) {
-		err = bpf_object__init_internal_map(obj, LIBBPF_MAP_DATA,
-						    obj->efile.data_shndx,
-						    obj->efile.data->d_buf,
-						    obj->efile.data->d_size);
-		if (err)
-			return err;
-	}
-	if (obj->efile.rodata_shndx >= 0) {
-		err = bpf_object__init_internal_map(obj, LIBBPF_MAP_RODATA,
-						    obj->efile.rodata_shndx,
-						    obj->efile.rodata->d_buf,
-						    obj->efile.rodata->d_size);
-		if (err)
-			return err;
-
-		obj->rodata_map_idx = obj->nr_maps - 1;
-	}
-	if (obj->efile.bss_shndx >= 0) {
-		err = bpf_object__init_internal_map(obj, LIBBPF_MAP_BSS,
-						    obj->efile.bss_shndx,
-						    NULL,
-						    obj->efile.bss->d_size);
+	for (sec_idx = 1; sec_idx < obj->efile.sec_cnt; sec_idx++) {
+		sec_desc = &obj->efile.secs[sec_idx];
+
+		switch (sec_desc->sec_type) {
+		case SEC_DATA:
+			err = bpf_object__init_internal_map(obj, LIBBPF_MAP_DATA,
+							    sec_idx,
+							    sec_desc->data->d_buf,
+							    sec_desc->data->d_size);
+			break;
+		case SEC_RODATA:
+			obj->has_rodata = true;
+			err = bpf_object__init_internal_map(obj, LIBBPF_MAP_RODATA,
+							    sec_idx,
+							    sec_desc->data->d_buf,
+							    sec_desc->data->d_size);
+			break;
+		case SEC_BSS:
+			err = bpf_object__init_internal_map(obj, LIBBPF_MAP_BSS,
+							    sec_idx,
+							    NULL,
+							    sec_desc->data->d_size);
+			break;
+		default:
+			/* skip */
+			break;
+		}
 		if (err)
 			return err;
 	}
@@ -3123,6 +3114,7 @@ static int cmp_progs(const void *_a, const void *_b)
 
 static int bpf_object__elf_collect(struct bpf_object *obj)
 {
+	struct elf_sec_desc *sec_desc;
 	Elf *elf = obj->efile.elf;
 	Elf_Data *btf_ext_data = NULL;
 	Elf_Data *btf_data = NULL;
@@ -3132,6 +3124,15 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 	Elf_Scn *scn;
 	Elf64_Shdr *sh;
 
+	/* ELF section indices are 1-based, so allocate +1 element to keep
+	 * indexing simple. Also include 0th invalid section into sec_cnt for
+	 * simpler and more traditional iteration logic.
+	 */
+	obj->efile.sec_cnt = 1 + obj->efile.ehdr->e_shnum;
+	obj->efile.secs = calloc(obj->efile.sec_cnt, sizeof(*obj->efile.secs));
+	if (!obj->efile.secs)
+		return -ENOMEM;
+
 	/* a bunch of ELF parsing functionality depends on processing symbols,
 	 * so do the first pass and find the symbol table
 	 */
@@ -3151,8 +3152,10 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 			if (!data)
 				return -LIBBPF_ERRNO__FORMAT;
 
+			idx = elf_ndxscn(scn);
+
 			obj->efile.symbols = data;
-			obj->efile.symbols_shndx = elf_ndxscn(scn);
+			obj->efile.symbols_shndx = idx;
 			obj->efile.strtabidx = sh->sh_link;
 		}
 	}
@@ -3165,7 +3168,8 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 
 	scn = NULL;
 	while ((scn = elf_nextscn(elf, scn)) != NULL) {
-		idx++;
+		idx = elf_ndxscn(scn);
+		sec_desc = &obj->efile.secs[idx];
 
 		sh = elf_sec_hdr(obj, scn);
 		if (!sh)
@@ -3213,11 +3217,13 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 				if (err)
 					return err;
 			} else if (strcmp(name, DATA_SEC) == 0) {
-				obj->efile.data = data;
-				obj->efile.data_shndx = idx;
+				sec_desc->sec_type = SEC_DATA;
+				sec_desc->shdr = sh;
+				sec_desc->data = data;
 			} else if (strcmp(name, RODATA_SEC) == 0) {
-				obj->efile.rodata = data;
-				obj->efile.rodata_shndx = idx;
+				sec_desc->sec_type = SEC_RODATA;
+				sec_desc->shdr = sh;
+				sec_desc->data = data;
 			} else if (strcmp(name, STRUCT_OPS_SEC) == 0) {
 				obj->efile.st_ops_data = data;
 				obj->efile.st_ops_shndx = idx;
@@ -3226,33 +3232,25 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 					idx, name);
 			}
 		} else if (sh->sh_type == SHT_REL) {
-			int nr_sects = obj->efile.nr_reloc_sects;
-			void *sects = obj->efile.reloc_sects;
-			int sec = sh->sh_info; /* points to other section */
+			int targ_sec_idx = sh->sh_info; /* points to other section */
 
 			/* Only do relo for section with exec instructions */
-			if (!section_have_execinstr(obj, sec) &&
+			if (!section_have_execinstr(obj, targ_sec_idx) &&
 			    strcmp(name, ".rel" STRUCT_OPS_SEC) &&
 			    strcmp(name, ".rel" MAPS_ELF_SEC)) {
 				pr_info("elf: skipping relo section(%d) %s for section(%d) %s\n",
-					idx, name, sec,
-					elf_sec_name(obj, elf_sec_by_idx(obj, sec)) ?: "<?>");
+					idx, name, targ_sec_idx,
+					elf_sec_name(obj, elf_sec_by_idx(obj, targ_sec_idx)) ?: "<?>");
 				continue;
 			}
 
-			sects = libbpf_reallocarray(sects, nr_sects + 1,
-						    sizeof(*obj->efile.reloc_sects));
-			if (!sects)
-				return -ENOMEM;
-
-			obj->efile.reloc_sects = sects;
-			obj->efile.nr_reloc_sects++;
-
-			obj->efile.reloc_sects[nr_sects].shdr = sh;
-			obj->efile.reloc_sects[nr_sects].data = data;
+			sec_desc->sec_type = SEC_RELO;
+			sec_desc->shdr = sh;
+			sec_desc->data = data;
 		} else if (sh->sh_type == SHT_NOBITS && strcmp(name, BSS_SEC) == 0) {
-			obj->efile.bss = data;
-			obj->efile.bss_shndx = idx;
+			sec_desc->sec_type = SEC_BSS;
+			sec_desc->shdr = sh;
+			sec_desc->data = data;
 		} else {
 			pr_info("elf: skipping section(%d) %s (size %zu)\n", idx, name,
 				(size_t)sh->sh_size);
@@ -3732,9 +3730,14 @@ bpf_object__find_program_by_name(const struct bpf_object *obj,
 static bool bpf_object__shndx_is_data(const struct bpf_object *obj,
 				      int shndx)
 {
-	return shndx == obj->efile.data_shndx ||
-	       shndx == obj->efile.bss_shndx ||
-	       shndx == obj->efile.rodata_shndx;
+	switch (obj->efile.secs[shndx].sec_type) {
+	case SEC_BSS:
+	case SEC_DATA:
+	case SEC_RODATA:
+		return true;
+	default:
+		return false;
+	}
 }
 
 static bool bpf_object__shndx_is_maps(const struct bpf_object *obj,
@@ -3747,16 +3750,19 @@ static bool bpf_object__shndx_is_maps(const struct bpf_object *obj,
 static enum libbpf_map_type
 bpf_object__section_to_libbpf_map_type(const struct bpf_object *obj, int shndx)
 {
-	if (shndx == obj->efile.data_shndx)
-		return LIBBPF_MAP_DATA;
-	else if (shndx == obj->efile.bss_shndx)
+	if (shndx == obj->efile.symbols_shndx)
+		return LIBBPF_MAP_KCONFIG;
+
+	switch (obj->efile.secs[shndx].sec_type) {
+	case SEC_BSS:
 		return LIBBPF_MAP_BSS;
-	else if (shndx == obj->efile.rodata_shndx)
+	case SEC_DATA:
+		return LIBBPF_MAP_DATA;
+	case SEC_RODATA:
 		return LIBBPF_MAP_RODATA;
-	else if (shndx == obj->efile.symbols_shndx)
-		return LIBBPF_MAP_KCONFIG;
-	else
+	default:
 		return LIBBPF_MAP_UNSPEC;
+	}
 }
 
 static int bpf_program__record_reloc(struct bpf_program *prog,
@@ -3892,7 +3898,7 @@ static int bpf_program__record_reloc(struct bpf_program *prog,
 	}
 	for (map_idx = 0; map_idx < nr_maps; map_idx++) {
 		map = &obj->maps[map_idx];
-		if (map->libbpf_type != type)
+		if (map->libbpf_type != type || map->sec_idx != sym->st_shndx)
 			continue;
 		pr_debug("prog '%s': found data map %zd (%s, sec %d, off %zu) for insn %u\n",
 			 prog->name, map_idx, map->name, map->sec_idx,
@@ -6205,10 +6211,18 @@ static int bpf_object__collect_relos(struct bpf_object *obj)
 {
 	int i, err;
 
-	for (i = 0; i < obj->efile.nr_reloc_sects; i++) {
-		Elf64_Shdr *shdr = obj->efile.reloc_sects[i].shdr;
-		Elf_Data *data = obj->efile.reloc_sects[i].data;
-		int idx = shdr->sh_info;
+	for (i = 0; i < obj->efile.sec_cnt; i++) {
+		struct elf_sec_desc *sec_desc = &obj->efile.secs[i];
+		Elf64_Shdr *shdr;
+		Elf_Data *data;
+		int idx;
+
+		if (sec_desc->sec_type != SEC_RELO)
+			continue;
+
+		shdr = sec_desc->shdr;
+		data = sec_desc->data;
+		idx = shdr->sh_info;
 
 		if (shdr->sh_type != SHT_REL) {
 			pr_warn("internal error at %d\n", __LINE__);
@@ -6331,6 +6345,7 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
 	     char *license, __u32 kern_version, int *pfd)
 {
 	struct bpf_prog_load_params load_attr = {};
+	struct bpf_object *obj = prog->obj;
 	char *cp, errmsg[STRERR_BUFSIZE];
 	size_t log_buf_size = 0;
 	char *log_buf = NULL;
@@ -6351,7 +6366,7 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
 
 	load_attr.prog_type = prog->type;
 	load_attr.expected_attach_type = prog->expected_attach_type;
-	if (kernel_supports(prog->obj, FEAT_PROG_NAME))
+	if (kernel_supports(obj, FEAT_PROG_NAME))
 		load_attr.name = prog->name;
 	load_attr.insns = insns;
 	load_attr.insn_cnt = insns_cnt;
@@ -6364,8 +6379,8 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
 	load_attr.prog_ifindex = prog->prog_ifindex;
 
 	/* specify func_info/line_info only if kernel supports them */
-	btf_fd = bpf_object__btf_fd(prog->obj);
-	if (btf_fd >= 0 && kernel_supports(prog->obj, FEAT_BTF_FUNC)) {
+	btf_fd = bpf_object__btf_fd(obj);
+	if (btf_fd >= 0 && kernel_supports(obj, FEAT_BTF_FUNC)) {
 		load_attr.prog_btf_fd = btf_fd;
 		load_attr.func_info = prog->func_info;
 		load_attr.func_info_rec_size = prog->func_info_rec_size;
@@ -6376,7 +6391,7 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
 	}
 	load_attr.log_level = prog->log_level;
 	load_attr.prog_flags = prog->prog_flags;
-	load_attr.fd_array = prog->obj->fd_array;
+	load_attr.fd_array = obj->fd_array;
 
 	/* adjust load_attr if sec_def provides custom preload callback */
 	if (prog->sec_def && prog->sec_def->preload_fn) {
@@ -6388,9 +6403,9 @@ load_program(struct bpf_program *prog, struct bpf_insn *insns, int insns_cnt,
 		}
 	}
 
-	if (prog->obj->gen_loader) {
-		bpf_gen__prog_load(prog->obj->gen_loader, &load_attr,
-				   prog - prog->obj->programs);
+	if (obj->gen_loader) {
+		bpf_gen__prog_load(obj->gen_loader, &load_attr,
+				   prog - obj->programs);
 		*pfd = -1;
 		return 0;
 	}
@@ -6411,16 +6426,21 @@ retry_load:
 		if (log_buf && load_attr.log_level)
 			pr_debug("verifier log:\n%s", log_buf);
 
-		if (prog->obj->rodata_map_idx >= 0 &&
-		    kernel_supports(prog->obj, FEAT_PROG_BIND_MAP)) {
-			struct bpf_map *rodata_map =
-				&prog->obj->maps[prog->obj->rodata_map_idx];
+		if (obj->has_rodata && kernel_supports(obj, FEAT_PROG_BIND_MAP)) {
+			struct bpf_map *map;
+			int i;
+
+			for (i = 0; i < obj->nr_maps; i++) {
+				map = &prog->obj->maps[i];
+				if (map->libbpf_type != LIBBPF_MAP_RODATA)
+					continue;
 
-			if (bpf_prog_bind_map(ret, bpf_map__fd(rodata_map), NULL)) {
-				cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
-				pr_warn("prog '%s': failed to bind .rodata map: %s\n",
-					prog->name, cp);
-				/* Don't fail hard if can't bind rodata. */
+				if (bpf_prog_bind_map(ret, bpf_map__fd(map), NULL)) {
+					cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
+					pr_warn("prog '%s': failed to bind .rodata map: %s\n",
+						prog->name, cp);
+					/* Don't fail hard if can't bind rodata. */
+				}
 			}
 		}
 
-- 
cgit v1.2.3


From aed659170a3171e425913ae259d46396fb9c10ef Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Wed, 20 Oct 2021 18:44:01 -0700
Subject: libbpf: Support multiple .rodata.* and .data.* BPF maps

Add support for having multiple .rodata and .data data sections ([0]).
.rodata/.data are supported like the usual, but now also
.rodata.<whatever> and .data.<whatever> are also supported. Each such
section will get its own backing BPF_MAP_TYPE_ARRAY, just like
.rodata and .data.

Multiple .bss maps are not supported, as the whole '.bss' name is
confusing and might be deprecated soon, as well as user would need to
specify custom ELF section with SEC() attribute anyway, so might as well
stick to just .data.* and .rodata.* convention.

User-visible map name for such new maps is going to be just their ELF
section names.

  [0] https://github.com/libbpf/libbpf/issues/274

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211021014404.2635234-8-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c | 130 ++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 101 insertions(+), 29 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index a7320d272b34..031f4611e0ff 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -370,15 +370,14 @@ enum libbpf_map_type {
 	LIBBPF_MAP_KCONFIG,
 };
 
-static const char * const libbpf_type_to_btf_name[] = {
-	[LIBBPF_MAP_DATA]	= DATA_SEC,
-	[LIBBPF_MAP_BSS]	= BSS_SEC,
-	[LIBBPF_MAP_RODATA]	= RODATA_SEC,
-	[LIBBPF_MAP_KCONFIG]	= KCONFIG_SEC,
-};
-
 struct bpf_map {
 	char *name;
+	/* real_name is defined for special internal maps (.rodata*,
+	 * .data*, .bss, .kconfig) and preserves their original ELF section
+	 * name. This is important to be be able to find corresponding BTF
+	 * DATASEC information.
+	 */
+	char *real_name;
 	int fd;
 	int sec_idx;
 	size_t sec_offset;
@@ -1429,17 +1428,55 @@ static size_t bpf_map_mmap_sz(const struct bpf_map *map)
 	return map_sz;
 }
 
-static char *internal_map_name(struct bpf_object *obj,
-			       enum libbpf_map_type type)
+static char *internal_map_name(struct bpf_object *obj, const char *real_name)
 {
 	char map_name[BPF_OBJ_NAME_LEN], *p;
-	const char *sfx = libbpf_type_to_btf_name[type];
-	int sfx_len = max((size_t)7, strlen(sfx));
-	int pfx_len = min((size_t)BPF_OBJ_NAME_LEN - sfx_len - 1,
-			  strlen(obj->name));
+	int pfx_len, sfx_len = max((size_t)7, strlen(real_name));
+
+	/* This is one of the more confusing parts of libbpf for various
+	 * reasons, some of which are historical. The original idea for naming
+	 * internal names was to include as much of BPF object name prefix as
+	 * possible, so that it can be distinguished from similar internal
+	 * maps of a different BPF object.
+	 * As an example, let's say we have bpf_object named 'my_object_name'
+	 * and internal map corresponding to '.rodata' ELF section. The final
+	 * map name advertised to user and to the kernel will be
+	 * 'my_objec.rodata', taking first 8 characters of object name and
+	 * entire 7 characters of '.rodata'.
+	 * Somewhat confusingly, if internal map ELF section name is shorter
+	 * than 7 characters, e.g., '.bss', we still reserve 7 characters
+	 * for the suffix, even though we only have 4 actual characters, and
+	 * resulting map will be called 'my_objec.bss', not even using all 15
+	 * characters allowed by the kernel. Oh well, at least the truncated
+	 * object name is somewhat consistent in this case. But if the map
+	 * name is '.kconfig', we'll still have entirety of '.kconfig' added
+	 * (8 chars) and thus will be left with only first 7 characters of the
+	 * object name ('my_obje'). Happy guessing, user, that the final map
+	 * name will be "my_obje.kconfig".
+	 * Now, with libbpf starting to support arbitrarily named .rodata.*
+	 * and .data.* data sections, it's possible that ELF section name is
+	 * longer than allowed 15 chars, so we now need to be careful to take
+	 * only up to 15 first characters of ELF name, taking no BPF object
+	 * name characters at all. So '.rodata.abracadabra' will result in
+	 * '.rodata.abracad' kernel and user-visible name.
+	 * We need to keep this convoluted logic intact for .data, .bss and
+	 * .rodata maps, but for new custom .data.custom and .rodata.custom
+	 * maps we use their ELF names as is, not prepending bpf_object name
+	 * in front. We still need to truncate them to 15 characters for the
+	 * kernel. Full name can be recovered for such maps by using DATASEC
+	 * BTF type associated with such map's value type, though.
+	 */
+	if (sfx_len >= BPF_OBJ_NAME_LEN)
+		sfx_len = BPF_OBJ_NAME_LEN - 1;
+
+	/* if there are two or more dots in map name, it's a custom dot map */
+	if (strchr(real_name + 1, '.') != NULL)
+		pfx_len = 0;
+	else
+		pfx_len = min((size_t)BPF_OBJ_NAME_LEN - sfx_len - 1, strlen(obj->name));
 
 	snprintf(map_name, sizeof(map_name), "%.*s%.*s", pfx_len, obj->name,
-		 sfx_len, libbpf_type_to_btf_name[type]);
+		 sfx_len, real_name);
 
 	/* sanitise map name to characters allowed by kernel */
 	for (p = map_name; *p && p < map_name + sizeof(map_name); p++)
@@ -1451,7 +1488,7 @@ static char *internal_map_name(struct bpf_object *obj,
 
 static int
 bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
-			      int sec_idx, void *data, size_t data_sz)
+			      const char *real_name, int sec_idx, void *data, size_t data_sz)
 {
 	struct bpf_map_def *def;
 	struct bpf_map *map;
@@ -1464,9 +1501,11 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
 	map->libbpf_type = type;
 	map->sec_idx = sec_idx;
 	map->sec_offset = 0;
-	map->name = internal_map_name(obj, type);
-	if (!map->name) {
-		pr_warn("failed to alloc map name\n");
+	map->real_name = strdup(real_name);
+	map->name = internal_map_name(obj, real_name);
+	if (!map->real_name || !map->name) {
+		zfree(&map->real_name);
+		zfree(&map->name);
 		return -ENOMEM;
 	}
 
@@ -1489,6 +1528,7 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
 		map->mmaped = NULL;
 		pr_warn("failed to alloc map '%s' content buffer: %d\n",
 			map->name, err);
+		zfree(&map->real_name);
 		zfree(&map->name);
 		return err;
 	}
@@ -1503,6 +1543,7 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
 static int bpf_object__init_global_data_maps(struct bpf_object *obj)
 {
 	struct elf_sec_desc *sec_desc;
+	const char *sec_name;
 	int err = 0, sec_idx;
 
 	/*
@@ -1513,21 +1554,24 @@ static int bpf_object__init_global_data_maps(struct bpf_object *obj)
 
 		switch (sec_desc->sec_type) {
 		case SEC_DATA:
+			sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, sec_idx));
 			err = bpf_object__init_internal_map(obj, LIBBPF_MAP_DATA,
-							    sec_idx,
+							    sec_name, sec_idx,
 							    sec_desc->data->d_buf,
 							    sec_desc->data->d_size);
 			break;
 		case SEC_RODATA:
 			obj->has_rodata = true;
+			sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, sec_idx));
 			err = bpf_object__init_internal_map(obj, LIBBPF_MAP_RODATA,
-							    sec_idx,
+							    sec_name, sec_idx,
 							    sec_desc->data->d_buf,
 							    sec_desc->data->d_size);
 			break;
 		case SEC_BSS:
+			sec_name = elf_sec_name(obj, elf_sec_by_idx(obj, sec_idx));
 			err = bpf_object__init_internal_map(obj, LIBBPF_MAP_BSS,
-							    sec_idx,
+							    sec_name, sec_idx,
 							    NULL,
 							    sec_desc->data->d_size);
 			break;
@@ -1831,7 +1875,7 @@ static int bpf_object__init_kconfig_map(struct bpf_object *obj)
 
 	map_sz = last_ext->kcfg.data_off + last_ext->kcfg.sz;
 	err = bpf_object__init_internal_map(obj, LIBBPF_MAP_KCONFIG,
-					    obj->efile.symbols_shndx,
+					    ".kconfig", obj->efile.symbols_shndx,
 					    NULL, map_sz);
 	if (err)
 		return err;
@@ -1931,7 +1975,7 @@ static int bpf_object__init_user_maps(struct bpf_object *obj, bool strict)
 
 		map->name = strdup(map_name);
 		if (!map->name) {
-			pr_warn("failed to alloc map name\n");
+			pr_warn("map '%s': failed to alloc map name\n", map_name);
 			return -ENOMEM;
 		}
 		pr_debug("map %d is \"%s\"\n", i, map->name);
@@ -3216,11 +3260,13 @@ static int bpf_object__elf_collect(struct bpf_object *obj)
 				err = bpf_object__add_programs(obj, data, name, idx);
 				if (err)
 					return err;
-			} else if (strcmp(name, DATA_SEC) == 0) {
+			} else if (strcmp(name, DATA_SEC) == 0 ||
+				   str_has_pfx(name, DATA_SEC ".")) {
 				sec_desc->sec_type = SEC_DATA;
 				sec_desc->shdr = sh;
 				sec_desc->data = data;
-			} else if (strcmp(name, RODATA_SEC) == 0) {
+			} else if (strcmp(name, RODATA_SEC) == 0 ||
+				   str_has_pfx(name, RODATA_SEC ".")) {
 				sec_desc->sec_type = SEC_RODATA;
 				sec_desc->shdr = sh;
 				sec_desc->data = data;
@@ -4060,8 +4106,7 @@ static int bpf_map_find_btf_info(struct bpf_object *obj, struct bpf_map *map)
 		 * LLVM annotates global data differently in BTF, that is,
 		 * only as '.data', '.bss' or '.rodata'.
 		 */
-		ret = btf__find_by_name(obj->btf,
-				libbpf_type_to_btf_name[map->libbpf_type]);
+		ret = btf__find_by_name(obj->btf, map->real_name);
 	}
 	if (ret < 0)
 		return ret;
@@ -7831,6 +7876,7 @@ static void bpf_map__destroy(struct bpf_map *map)
 	}
 
 	zfree(&map->name);
+	zfree(&map->real_name);
 	zfree(&map->pin_path);
 
 	if (map->fd >= 0)
@@ -8755,9 +8801,30 @@ const struct bpf_map_def *bpf_map__def(const struct bpf_map *map)
 	return map ? &map->def : libbpf_err_ptr(-EINVAL);
 }
 
+static bool map_uses_real_name(const struct bpf_map *map)
+{
+	/* Since libbpf started to support custom .data.* and .rodata.* maps,
+	 * their user-visible name differs from kernel-visible name. Users see
+	 * such map's corresponding ELF section name as a map name.
+	 * This check distinguishes .data/.rodata from .data.* and .rodata.*
+	 * maps to know which name has to be returned to the user.
+	 */
+	if (map->libbpf_type == LIBBPF_MAP_DATA && strcmp(map->real_name, DATA_SEC) != 0)
+		return true;
+	if (map->libbpf_type == LIBBPF_MAP_RODATA && strcmp(map->real_name, RODATA_SEC) != 0)
+		return true;
+	return false;
+}
+
 const char *bpf_map__name(const struct bpf_map *map)
 {
-	return map ? map->name : NULL;
+	if (!map)
+		return NULL;
+
+	if (map_uses_real_name(map))
+		return map->real_name;
+
+	return map->name;
 }
 
 enum bpf_map_type bpf_map__type(const struct bpf_map *map)
@@ -8976,7 +9043,12 @@ bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name)
 	struct bpf_map *pos;
 
 	bpf_object__for_each_map(pos, obj) {
-		if (pos->name && !strcmp(pos->name, name))
+		if (map_uses_real_name(pos)) {
+			if (strcmp(pos->real_name, name) == 0)
+				return pos;
+			continue;
+		}
+		if (strcmp(pos->name, name) == 0)
 			return pos;
 	}
 	return errno = ENOENT, NULL;
-- 
cgit v1.2.3


From 26071635ac5ecd8276bf3bdfc3ea1128c93ac722 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Wed, 20 Oct 2021 18:44:03 -0700
Subject: libbpf: Simplify look up by name of internal maps

Map name that's assigned to internal maps (.rodata, .data, .bss, etc)
consist of a small prefix of bpf_object's name and ELF section name as
a suffix. This makes it hard for users to "guess" the name to use for
looking up by name with bpf_object__find_map_by_name() API.

One proposal was to drop object name prefix from the map name and just
use ".rodata", ".data", etc, names. One downside called out was that
when multiple BPF applications are active on the host, it will be hard
to distinguish between multiple instances of .rodata and know which BPF
object (app) they belong to. Having few first characters, while quite
limiting, still can give a bit of a clue, in general.

Note, though, that btf_value_type_id for such global data maps (ARRAY)
points to DATASEC type, which encodes full ELF name, so tools like
bpftool can take advantage of this fact to "recover" full original name
of the map. This is also the reason why for custom .data.* and .rodata.*
maps libbpf uses only their ELF names and doesn't prepend object name at
all.

Another downside of such approach is that it is not backwards compatible
and, among direct use of bpf_object__find_map_by_name() API, will break
any BPF skeleton generated using bpftool that was compiled with older
libbpf version.

Instead of causing all this pain, libbpf will still generate map name
using a combination of object name and ELF section name, but it will
allow looking such maps up by their natural names, which correspond to
their respective ELF section names. This means non-truncated ELF section
names longer than 15 characters are going to be expected and supported.

With such set up, we get the best of both worlds: leave small bits of
a clue about BPF application that instantiated such maps, as well as
making it easy for user apps to lookup such maps at runtime. In this
sense it closes corresponding libbpf 1.0 issue ([0]).

BPF skeletons will continue using full names for lookups.

  [0] Closes: https://github.com/libbpf/libbpf/issues/275

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20211021014404.2635234-10-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 031f4611e0ff..db6e48014839 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -9043,6 +9043,16 @@ bpf_object__find_map_by_name(const struct bpf_object *obj, const char *name)
 	struct bpf_map *pos;
 
 	bpf_object__for_each_map(pos, obj) {
+		/* if it's a special internal map name (which always starts
+		 * with dot) then check if that special name matches the
+		 * real map name (ELF section name)
+		 */
+		if (name[0] == '.') {
+			if (pos->real_name && strcmp(pos->real_name, name) == 0)
+				return pos;
+			continue;
+		}
+		/* otherwise map name has to be an exact match */
 		if (map_uses_real_name(pos)) {
 			if (strcmp(pos->real_name, name) == 0)
 				return pos;
-- 
cgit v1.2.3


From fae1b05e6f0acf116f6450535b0e1c13051102d3 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Fri, 22 Oct 2021 12:25:02 -0700
Subject: libbpf: Fix the use of aligned attribute

Building libbpf sources out of kernel tree (in Github repo) we run into
compilation error due to unknown __aligned attribute. It must be coming
from some kernel header, which is not available to Github sources. Use
explicit __attribute__((aligned(16))) instead.

Fixes: 961632d54163 ("libbpf: Fix dumping non-aligned __int128")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211022192502.2975553-1-andrii@kernel.org
---
 tools/lib/bpf/btf_dump.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index e9e5801ece4c..3c19644b5fad 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -1676,7 +1676,7 @@ static int btf_dump_int_data(struct btf_dump *d,
 {
 	__u8 encoding = btf_int_encoding(t);
 	bool sign = encoding & BTF_INT_SIGNED;
-	char buf[16] __aligned(16);
+	char buf[16] __attribute__((aligned(16)));
 	int sz = t->size;
 
 	if (sz == 0 || sz > sizeof(buf)) {
-- 
cgit v1.2.3


From 1000298c76830bc291358e98e8fa5baa3baa9b3a Mon Sep 17 00:00:00 2001
From: Mauricio Vásquez <mauricio@kinvolk.io>
Date: Fri, 22 Oct 2021 15:20:35 -0500
Subject: libbpf: Fix memory leak in btf__dedup()
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Free btf_dedup if btf_ensure_modifiable() returns error.

Fixes: 919d2b1dbb07 ("libbpf: Allow modification of BTF and add btf__add_str API")
Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211022202035.48868-1-mauricio@kinvolk.io
---
 tools/lib/bpf/btf.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 3a01c4b7f36a..85705c10f7b2 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -2991,8 +2991,10 @@ int btf__dedup(struct btf *btf, struct btf_ext *btf_ext,
 		return libbpf_err(-EINVAL);
 	}
 
-	if (btf_ensure_modifiable(btf))
-		return libbpf_err(-ENOMEM);
+	if (btf_ensure_modifiable(btf)) {
+		err = -ENOMEM;
+		goto done;
+	}
 
 	err = btf_dedup_prep(d);
 	if (err) {
-- 
cgit v1.2.3


From 6a886de070fad850d6cb74a787c9ed017303d9ac Mon Sep 17 00:00:00 2001
From: Hengqi Chen <hengqi.chen@gmail.com>
Date: Fri, 22 Oct 2021 21:06:19 +0800
Subject: libbpf: Add btf__type_cnt() and btf__raw_data() APIs

Add btf__type_cnt() and btf__raw_data() APIs and deprecate
btf__get_nr_type() and btf__get_raw_data() since the old APIs
don't follow the libbpf naming convention for getters which
omit 'get' in the name (see [0]). btf__raw_data() is just an
alias to the existing btf__get_raw_data(). btf__type_cnt()
now returns the number of all types of the BTF object
including 'void'.

  [0] Closes: https://github.com/libbpf/libbpf/issues/279

Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211022130623.1548429-2-hengqi.chen@gmail.com
---
 tools/lib/bpf/btf.c      | 36 ++++++++++++++++++++++--------------
 tools/lib/bpf/btf.h      |  4 ++++
 tools/lib/bpf/btf_dump.c |  8 ++++----
 tools/lib/bpf/libbpf.c   | 36 ++++++++++++++++++------------------
 tools/lib/bpf/libbpf.map |  2 ++
 tools/lib/bpf/linker.c   | 28 ++++++++++++++--------------
 6 files changed, 64 insertions(+), 50 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 85705c10f7b2..66997d985ff8 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -57,7 +57,7 @@ struct btf {
 	 * representation is broken up into three independently allocated
 	 * memory regions to be able to modify them independently.
 	 * raw_data is nulled out at that point, but can be later allocated
-	 * and cached again if user calls btf__get_raw_data(), at which point
+	 * and cached again if user calls btf__raw_data(), at which point
 	 * raw_data will contain a contiguous copy of header, types, and
 	 * strings:
 	 *
@@ -435,6 +435,11 @@ __u32 btf__get_nr_types(const struct btf *btf)
 	return btf->start_id + btf->nr_types - 1;
 }
 
+__u32 btf__type_cnt(const struct btf *btf)
+{
+	return btf->start_id + btf->nr_types;
+}
+
 const struct btf *btf__base_btf(const struct btf *btf)
 {
 	return btf->base_btf;
@@ -466,8 +471,8 @@ static int determine_ptr_size(const struct btf *btf)
 	if (btf->base_btf && btf->base_btf->ptr_sz > 0)
 		return btf->base_btf->ptr_sz;
 
-	n = btf__get_nr_types(btf);
-	for (i = 1; i <= n; i++) {
+	n = btf__type_cnt(btf);
+	for (i = 1; i < n; i++) {
 		t = btf__type_by_id(btf, i);
 		if (!btf_is_int(t))
 			continue;
@@ -684,12 +689,12 @@ int btf__resolve_type(const struct btf *btf, __u32 type_id)
 
 __s32 btf__find_by_name(const struct btf *btf, const char *type_name)
 {
-	__u32 i, nr_types = btf__get_nr_types(btf);
+	__u32 i, nr_types = btf__type_cnt(btf);
 
 	if (!strcmp(type_name, "void"))
 		return 0;
 
-	for (i = 1; i <= nr_types; i++) {
+	for (i = 1; i < nr_types; i++) {
 		const struct btf_type *t = btf__type_by_id(btf, i);
 		const char *name = btf__name_by_offset(btf, t->name_off);
 
@@ -703,12 +708,12 @@ __s32 btf__find_by_name(const struct btf *btf, const char *type_name)
 static __s32 btf_find_by_name_kind(const struct btf *btf, int start_id,
 				   const char *type_name, __u32 kind)
 {
-	__u32 i, nr_types = btf__get_nr_types(btf);
+	__u32 i, nr_types = btf__type_cnt(btf);
 
 	if (kind == BTF_KIND_UNKN || !strcmp(type_name, "void"))
 		return 0;
 
-	for (i = start_id; i <= nr_types; i++) {
+	for (i = start_id; i < nr_types; i++) {
 		const struct btf_type *t = btf__type_by_id(btf, i);
 		const char *name;
 
@@ -781,7 +786,7 @@ static struct btf *btf_new_empty(struct btf *base_btf)
 
 	if (base_btf) {
 		btf->base_btf = base_btf;
-		btf->start_id = btf__get_nr_types(base_btf) + 1;
+		btf->start_id = btf__type_cnt(base_btf);
 		btf->start_str_off = base_btf->hdr->str_len;
 	}
 
@@ -831,7 +836,7 @@ static struct btf *btf_new(const void *data, __u32 size, struct btf *base_btf)
 
 	if (base_btf) {
 		btf->base_btf = base_btf;
-		btf->start_id = btf__get_nr_types(base_btf) + 1;
+		btf->start_id = btf__type_cnt(base_btf);
 		btf->start_str_off = base_btf->hdr->str_len;
 	}
 
@@ -1224,7 +1229,7 @@ err_out:
 	return NULL;
 }
 
-const void *btf__get_raw_data(const struct btf *btf_ro, __u32 *size)
+const void *btf__raw_data(const struct btf *btf_ro, __u32 *size)
 {
 	struct btf *btf = (struct btf *)btf_ro;
 	__u32 data_sz;
@@ -1232,7 +1237,7 @@ const void *btf__get_raw_data(const struct btf *btf_ro, __u32 *size)
 
 	data = btf_get_raw_data(btf, &data_sz, btf->swapped_endian);
 	if (!data)
-		return errno = -ENOMEM, NULL;
+		return errno = ENOMEM, NULL;
 
 	btf->raw_size = data_sz;
 	if (btf->swapped_endian)
@@ -1243,6 +1248,9 @@ const void *btf__get_raw_data(const struct btf *btf_ro, __u32 *size)
 	return data;
 }
 
+__attribute__((alias("btf__raw_data")))
+const void *btf__get_raw_data(const struct btf *btf, __u32 *size);
+
 const char *btf__str_by_offset(const struct btf *btf, __u32 offset)
 {
 	if (offset < btf->start_str_off)
@@ -1651,7 +1659,7 @@ int btf__add_btf(struct btf *btf, const struct btf *src_btf)
 	old_strs_len = btf->hdr->str_len;
 
 	data_sz = src_btf->hdr->type_len;
-	cnt = btf__get_nr_types(src_btf);
+	cnt = btf__type_cnt(src_btf) - 1;
 
 	/* pre-allocate enough memory for new types */
 	t = btf_add_type_mem(btf, data_sz);
@@ -1968,7 +1976,7 @@ int btf__add_union(struct btf *btf, const char *name, __u32 byte_sz)
 
 static struct btf_type *btf_last_type(struct btf *btf)
 {
-	return btf_type_by_id(btf, btf__get_nr_types(btf));
+	return btf_type_by_id(btf, btf__type_cnt(btf) - 1);
 }
 
 /*
@@ -3174,7 +3182,7 @@ static struct btf_dedup *btf_dedup_new(struct btf *btf, struct btf_ext *btf_ext,
 		goto done;
 	}
 
-	type_cnt = btf__get_nr_types(btf) + 1;
+	type_cnt = btf__type_cnt(btf);
 	d->map = malloc(sizeof(__u32) * type_cnt);
 	if (!d->map) {
 		err = -ENOMEM;
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index c9364be42035..bc005ba3ceec 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -132,7 +132,9 @@ LIBBPF_API __s32 btf__find_by_name(const struct btf *btf,
 				   const char *type_name);
 LIBBPF_API __s32 btf__find_by_name_kind(const struct btf *btf,
 					const char *type_name, __u32 kind);
+LIBBPF_DEPRECATED_SINCE(0, 7, "use btf__type_cnt() instead; note that btf__get_nr_types() == btf__type_cnt() - 1")
 LIBBPF_API __u32 btf__get_nr_types(const struct btf *btf);
+LIBBPF_API __u32 btf__type_cnt(const struct btf *btf);
 LIBBPF_API const struct btf *btf__base_btf(const struct btf *btf);
 LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf,
 						  __u32 id);
@@ -145,7 +147,9 @@ LIBBPF_API int btf__resolve_type(const struct btf *btf, __u32 type_id);
 LIBBPF_API int btf__align_of(const struct btf *btf, __u32 id);
 LIBBPF_API int btf__fd(const struct btf *btf);
 LIBBPF_API void btf__set_fd(struct btf *btf, int fd);
+LIBBPF_DEPRECATED_SINCE(0, 7, "use btf__raw_data() instead")
 LIBBPF_API const void *btf__get_raw_data(const struct btf *btf, __u32 *size);
+LIBBPF_API const void *btf__raw_data(const struct btf *btf, __u32 *size);
 LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
 LIBBPF_API const char *btf__str_by_offset(const struct btf *btf, __u32 offset);
 LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,
diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index 3c19644b5fad..8e05ab44c22a 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -188,7 +188,7 @@ err:
 
 static int btf_dump_resize(struct btf_dump *d)
 {
-	int err, last_id = btf__get_nr_types(d->btf);
+	int err, last_id = btf__type_cnt(d->btf) - 1;
 
 	if (last_id <= d->last_id)
 		return 0;
@@ -262,7 +262,7 @@ int btf_dump__dump_type(struct btf_dump *d, __u32 id)
 {
 	int err, i;
 
-	if (id > btf__get_nr_types(d->btf))
+	if (id >= btf__type_cnt(d->btf))
 		return libbpf_err(-EINVAL);
 
 	err = btf_dump_resize(d);
@@ -294,11 +294,11 @@ int btf_dump__dump_type(struct btf_dump *d, __u32 id)
  */
 static int btf_dump_mark_referenced(struct btf_dump *d)
 {
-	int i, j, n = btf__get_nr_types(d->btf);
+	int i, j, n = btf__type_cnt(d->btf);
 	const struct btf_type *t;
 	__u16 vlen;
 
-	for (i = d->last_id + 1; i <= n; i++) {
+	for (i = d->last_id + 1; i < n; i++) {
 		t = btf__type_by_id(d->btf, i);
 		vlen = btf_vlen(t);
 
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index db6e48014839..eb102440a28a 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -2497,8 +2497,8 @@ static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict,
 		return -EINVAL;
 	}
 
-	nr_types = btf__get_nr_types(obj->btf);
-	for (i = 1; i <= nr_types; i++) {
+	nr_types = btf__type_cnt(obj->btf);
+	for (i = 1; i < nr_types; i++) {
 		t = btf__type_by_id(obj->btf, i);
 		if (!btf_is_datasec(t))
 			continue;
@@ -2579,7 +2579,7 @@ static void bpf_object__sanitize_btf(struct bpf_object *obj, struct btf *btf)
 	struct btf_type *t;
 	int i, j, vlen;
 
-	for (i = 1; i <= btf__get_nr_types(btf); i++) {
+	for (i = 1; i < btf__type_cnt(btf); i++) {
 		t = (struct btf_type *)btf__type_by_id(btf, i);
 
 		if ((!has_datasec && btf_is_var(t)) || (!has_decl_tag && btf_is_decl_tag(t))) {
@@ -2763,9 +2763,9 @@ sort_vars:
 static int btf_finalize_data(struct bpf_object *obj, struct btf *btf)
 {
 	int err = 0;
-	__u32 i, n = btf__get_nr_types(btf);
+	__u32 i, n = btf__type_cnt(btf);
 
-	for (i = 1; i <= n; i++) {
+	for (i = 1; i < n; i++) {
 		struct btf_type *t = btf_type_by_id(btf, i);
 
 		/* Loader needs to fix up some of the things compiler
@@ -2905,8 +2905,8 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj)
 		if (!prog->mark_btf_static || !prog_is_subprog(obj, prog))
 			continue;
 
-		n = btf__get_nr_types(obj->btf);
-		for (j = 1; j <= n; j++) {
+		n = btf__type_cnt(obj->btf);
+		for (j = 1; j < n; j++) {
 			t = btf_type_by_id(obj->btf, j);
 			if (!btf_is_func(t) || btf_func_linkage(t) != BTF_FUNC_GLOBAL)
 				continue;
@@ -2926,7 +2926,7 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj)
 		__u32 sz;
 
 		/* clone BTF to sanitize a copy and leave the original intact */
-		raw_data = btf__get_raw_data(obj->btf, &sz);
+		raw_data = btf__raw_data(obj->btf, &sz);
 		kern_btf = btf__new(raw_data, sz);
 		err = libbpf_get_error(kern_btf);
 		if (err)
@@ -2939,7 +2939,7 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj)
 
 	if (obj->gen_loader) {
 		__u32 raw_size = 0;
-		const void *raw_data = btf__get_raw_data(kern_btf, &raw_size);
+		const void *raw_data = btf__raw_data(kern_btf, &raw_size);
 
 		if (!raw_data)
 			return -ENOMEM;
@@ -3350,8 +3350,8 @@ static int find_extern_btf_id(const struct btf *btf, const char *ext_name)
 	if (!btf)
 		return -ESRCH;
 
-	n = btf__get_nr_types(btf);
-	for (i = 1; i <= n; i++) {
+	n = btf__type_cnt(btf);
+	for (i = 1; i < n; i++) {
 		t = btf__type_by_id(btf, i);
 
 		if (!btf_is_var(t) && !btf_is_func(t))
@@ -3382,8 +3382,8 @@ static int find_extern_sec_btf_id(struct btf *btf, int ext_btf_id) {
 	if (!btf)
 		return -ESRCH;
 
-	n = btf__get_nr_types(btf);
-	for (i = 1; i <= n; i++) {
+	n = btf__type_cnt(btf);
+	for (i = 1; i < n; i++) {
 		t = btf__type_by_id(btf, i);
 
 		if (!btf_is_datasec(t))
@@ -3467,8 +3467,8 @@ static int find_int_btf_id(const struct btf *btf)
 	const struct btf_type *t;
 	int i, n;
 
-	n = btf__get_nr_types(btf);
-	for (i = 1; i <= n; i++) {
+	n = btf__type_cnt(btf);
+	for (i = 1; i < n; i++) {
 		t = btf__type_by_id(btf, i);
 
 		if (btf_is_int(t) && btf_int_bits(t) == 32)
@@ -5076,8 +5076,8 @@ static int bpf_core_add_cands(struct bpf_core_cand *local_cand,
 	size_t targ_essent_len;
 	int n, i;
 
-	n = btf__get_nr_types(targ_btf);
-	for (i = targ_start_id; i <= n; i++) {
+	n = btf__type_cnt(targ_btf);
+	for (i = targ_start_id; i < n; i++) {
 		t = btf__type_by_id(targ_btf, i);
 		if (btf_kind(t) != btf_kind(local_cand->t))
 			continue;
@@ -5252,7 +5252,7 @@ bpf_core_find_cands(struct bpf_object *obj, const struct btf *local_btf, __u32 l
 		err = bpf_core_add_cands(&local_cand, local_essent_len,
 					 obj->btf_modules[i].btf,
 					 obj->btf_modules[i].name,
-					 btf__get_nr_types(obj->btf_vmlinux) + 1,
+					 btf__type_cnt(obj->btf_vmlinux),
 					 cands);
 		if (err)
 			goto err_out;
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index e6fb1ba49369..116964a29e44 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -395,4 +395,6 @@ LIBBPF_0.6.0 {
 		bpf_object__prev_program;
 		btf__add_btf;
 		btf__add_decl_tag;
+		btf__raw_data;
+		btf__type_cnt;
 } LIBBPF_0.5.0;
diff --git a/tools/lib/bpf/linker.c b/tools/lib/bpf/linker.c
index 13e6fdc7d8cb..7bf658fbda80 100644
--- a/tools/lib/bpf/linker.c
+++ b/tools/lib/bpf/linker.c
@@ -920,7 +920,7 @@ static int check_btf_type_id(__u32 *type_id, void *ctx)
 {
 	struct btf *btf = ctx;
 
-	if (*type_id > btf__get_nr_types(btf))
+	if (*type_id >= btf__type_cnt(btf))
 		return -EINVAL;
 
 	return 0;
@@ -947,8 +947,8 @@ static int linker_sanity_check_btf(struct src_obj *obj)
 	if (!obj->btf)
 		return 0;
 
-	n = btf__get_nr_types(obj->btf);
-	for (i = 1; i <= n; i++) {
+	n = btf__type_cnt(obj->btf);
+	for (i = 1; i < n; i++) {
 		t = btf_type_by_id(obj->btf, i);
 
 		err = err ?: btf_type_visit_type_ids(t, check_btf_type_id, obj->btf);
@@ -1658,8 +1658,8 @@ static int find_glob_sym_btf(struct src_obj *obj, Elf64_Sym *sym, const char *sy
 		return -EINVAL;
 	}
 
-	n = btf__get_nr_types(obj->btf);
-	for (i = 1; i <= n; i++) {
+	n = btf__type_cnt(obj->btf);
+	for (i = 1; i < n; i++) {
 		t = btf__type_by_id(obj->btf, i);
 
 		/* some global and extern FUNCs and VARs might not be associated with any
@@ -2130,8 +2130,8 @@ static int linker_fixup_btf(struct src_obj *obj)
 	if (!obj->btf)
 		return 0;
 
-	n = btf__get_nr_types(obj->btf);
-	for (i = 1; i <= n; i++) {
+	n = btf__type_cnt(obj->btf);
+	for (i = 1; i < n; i++) {
 		struct btf_var_secinfo *vi;
 		struct btf_type *t;
 
@@ -2234,14 +2234,14 @@ static int linker_append_btf(struct bpf_linker *linker, struct src_obj *obj)
 	if (!obj->btf)
 		return 0;
 
-	start_id = btf__get_nr_types(linker->btf) + 1;
-	n = btf__get_nr_types(obj->btf);
+	start_id = btf__type_cnt(linker->btf);
+	n = btf__type_cnt(obj->btf);
 
 	obj->btf_type_map = calloc(n + 1, sizeof(int));
 	if (!obj->btf_type_map)
 		return -ENOMEM;
 
-	for (i = 1; i <= n; i++) {
+	for (i = 1; i < n; i++) {
 		struct glob_sym *glob_sym = NULL;
 
 		t = btf__type_by_id(obj->btf, i);
@@ -2296,8 +2296,8 @@ static int linker_append_btf(struct bpf_linker *linker, struct src_obj *obj)
 	}
 
 	/* remap all the types except DATASECs */
-	n = btf__get_nr_types(linker->btf);
-	for (i = start_id; i <= n; i++) {
+	n = btf__type_cnt(linker->btf);
+	for (i = start_id; i < n; i++) {
 		struct btf_type *dst_t = btf_type_by_id(linker->btf, i);
 
 		if (btf_type_visit_type_ids(dst_t, remap_type_id, obj->btf_type_map))
@@ -2656,7 +2656,7 @@ static int finalize_btf(struct bpf_linker *linker)
 	__u32 raw_sz;
 
 	/* bail out if no BTF data was produced */
-	if (btf__get_nr_types(linker->btf) == 0)
+	if (btf__type_cnt(linker->btf) == 1)
 		return 0;
 
 	for (i = 1; i < linker->sec_cnt; i++) {
@@ -2693,7 +2693,7 @@ static int finalize_btf(struct bpf_linker *linker)
 	}
 
 	/* Emit .BTF section */
-	raw_data = btf__get_raw_data(linker->btf, &raw_sz);
+	raw_data = btf__raw_data(linker->btf, &raw_sz);
 	if (!raw_data)
 		return -ENOMEM;
 
-- 
cgit v1.2.3


From a77f879ba1178437e5df87090165e5a45a91ba7f Mon Sep 17 00:00:00 2001
From: Stanislav Fomichev <sdf@google.com>
Date: Thu, 21 Oct 2021 14:48:12 -0700
Subject: libbpf: Use func name when pinning programs with
 LIBBPF_STRICT_SEC_NAME

We can't use section name anymore because they are not unique
and pinning objects with multiple programs with the same
progtype/secname will fail.

  [0] Closes: https://github.com/libbpf/libbpf/issues/273

Fixes: 33a2c75c55e2 ("libbpf: add internal pin_name")
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20211021214814.1236114-2-sdf@google.com
---
 tools/lib/bpf/libbpf.c        | 13 +++++++++++--
 tools/lib/bpf/libbpf_legacy.h |  3 +++
 2 files changed, 14 insertions(+), 2 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index eb102440a28a..604abe00785f 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -285,7 +285,7 @@ struct bpf_program {
 	size_t sub_insn_off;
 
 	char *name;
-	/* sec_name with / replaced by _; makes recursive pinning
+	/* name with / replaced by _; makes recursive pinning
 	 * in bpf_object__pin_programs easier
 	 */
 	char *pin_name;
@@ -618,7 +618,16 @@ static char *__bpf_program__pin_name(struct bpf_program *prog)
 {
 	char *name, *p;
 
-	name = p = strdup(prog->sec_name);
+	if (libbpf_mode & LIBBPF_STRICT_SEC_NAME)
+		name = strdup(prog->name);
+	else
+		name = strdup(prog->sec_name);
+
+	if (!name)
+		return NULL;
+
+	p = name;
+
 	while ((p = strchr(p, '/')))
 		*p = '_';
 
diff --git a/tools/lib/bpf/libbpf_legacy.h b/tools/lib/bpf/libbpf_legacy.h
index 74e6f860f703..29ccafab11a8 100644
--- a/tools/lib/bpf/libbpf_legacy.h
+++ b/tools/lib/bpf/libbpf_legacy.h
@@ -52,6 +52,9 @@ enum libbpf_strict_mode {
 	 * allowed, with LIBBPF_STRICT_SEC_PREFIX this will become
 	 * unrecognized by libbpf and would have to be just SEC("xdp") and
 	 * SEC("xdp") and SEC("perf_event").
+	 *
+	 * Note, in this mode the program pin path will be based on the
+	 * function name instead of section name.
 	 */
 	LIBBPF_STRICT_SEC_NAME = 0x04,
 
-- 
cgit v1.2.3


From 5245dafe3d49efba4d3285cf27ee1cc1eeafafc6 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Fri, 22 Oct 2021 17:31:56 -0700
Subject: libbpf: Fix overflow in BTF sanity checks

btf_header's str_off+str_len or type_off+type_len can overflow as they
are u32s. This will lead to bypassing the sanity checks during BTF
parsing, resulting in crashes afterwards. Fix by using 64-bit signed
integers for comparison.

Fixes: d8123624506c ("libbpf: Fix BTF data layout checks and allow empty BTF")
Reported-by: Evgeny Vereshchagin <evvers@ya.ru>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211023003157.726961-1-andrii@kernel.org
---
 tools/lib/bpf/btf.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 66997d985ff8..05b945208815 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -241,12 +241,12 @@ static int btf_parse_hdr(struct btf *btf)
 	}
 
 	meta_left = btf->raw_size - sizeof(*hdr);
-	if (meta_left < hdr->str_off + hdr->str_len) {
+	if (meta_left < (long long)hdr->str_off + hdr->str_len) {
 		pr_debug("Invalid BTF total size:%u\n", btf->raw_size);
 		return -EINVAL;
 	}
 
-	if (hdr->type_off + hdr->type_len > hdr->str_off) {
+	if ((long long)hdr->type_off + hdr->type_len > hdr->str_off) {
 		pr_debug("Invalid BTF data sections layout: type data at %u + %u, strings data at %u + %u\n",
 			 hdr->type_off, hdr->type_len, hdr->str_off, hdr->str_len);
 		return -EINVAL;
-- 
cgit v1.2.3


From c825f5fee19caf301d9821cd79abaa734322de26 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Fri, 22 Oct 2021 17:31:57 -0700
Subject: libbpf: Fix BTF header parsing checks

Original code assumed fixed and correct BTF header length. That's not
always the case, though, so fix this bug with a proper additional check.
And use actual header length instead of sizeof(struct btf_header) in
sanity checks.

Fixes: 8a138aed4a80 ("bpf: btf: Add BTF support to libbpf")
Reported-by: Evgeny Vereshchagin <evvers@ya.ru>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211023003157.726961-2-andrii@kernel.org
---
 tools/lib/bpf/btf.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 05b945208815..ef924fc2c911 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -236,13 +236,19 @@ static int btf_parse_hdr(struct btf *btf)
 		}
 		btf_bswap_hdr(hdr);
 	} else if (hdr->magic != BTF_MAGIC) {
-		pr_debug("Invalid BTF magic:%x\n", hdr->magic);
+		pr_debug("Invalid BTF magic: %x\n", hdr->magic);
 		return -EINVAL;
 	}
 
-	meta_left = btf->raw_size - sizeof(*hdr);
+	if (btf->raw_size < hdr->hdr_len) {
+		pr_debug("BTF header len %u larger than data size %u\n",
+			 hdr->hdr_len, btf->raw_size);
+		return -EINVAL;
+	}
+
+	meta_left = btf->raw_size - hdr->hdr_len;
 	if (meta_left < (long long)hdr->str_off + hdr->str_len) {
-		pr_debug("Invalid BTF total size:%u\n", btf->raw_size);
+		pr_debug("Invalid BTF total size: %u\n", btf->raw_size);
 		return -EINVAL;
 	}
 
-- 
cgit v1.2.3


From de5d0dcef602de39070c31c7e56c58249c56ba37 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Mon, 25 Oct 2021 15:45:28 -0700
Subject: libbpf: Fix off-by-one bug in bpf_core_apply_relo()

Fix instruction index validity check which has off-by-one error.

Fixes: 3ee4f5335511 ("libbpf: Split bpf_core_apply_relo() into bpf_program independent helper.")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211025224531.1088894-2-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 604abe00785f..e27a249d46fb 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -5405,7 +5405,7 @@ static int bpf_core_apply_relo(struct bpf_program *prog,
 	 * relocated, so it's enough to just subtract in-section offset
 	 */
 	insn_idx = insn_idx - prog->sec_insn_off;
-	if (insn_idx > prog->insns_cnt)
+	if (insn_idx >= prog->insns_cnt)
 		return -EINVAL;
 	insn = &prog->insns[insn_idx];
 
-- 
cgit v1.2.3


From 65a7fa2e4e5381d205d3b0098da0fc8471fbbfb6 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Mon, 25 Oct 2021 15:45:29 -0700
Subject: libbpf: Add ability to fetch bpf_program's underlying instructions

Add APIs providing read-only access to bpf_program BPF instructions ([0]).
This is useful for diagnostics purposes, but it also allows a cleaner
support for cloning BPF programs after libbpf did all the FD resolution
and CO-RE relocations, subprog instructions appending, etc. Currently,
cloning BPF program is possible only through hijacking a half-broken
bpf_program__set_prep() API, which doesn't really work well for anything
but most primitive programs. For instance, set_prep() API doesn't allow
adjusting BPF program load parameters which are necessary for loading
fentry/fexit BPF programs (the case where BPF program cloning is
a necessity if doing some sort of mass-attachment functionality).

Given bpf_program__set_prep() API is set to be deprecated, having
a cleaner alternative is a must. libbpf internally already keeps track
of linear array of struct bpf_insn, so it's not hard to expose it. The
only gotcha is that libbpf previously freed instructions array during
bpf_object load time, which would make this API much less useful overall,
because in between bpf_object__open() and bpf_object__load() a lot of
changes to instructions are done by libbpf.

So this patch makes libbpf hold onto prog->insns array even after BPF
program loading. I think this is a small price for added functionality
and improved introspection of BPF program code.

See retsnoop PR ([1]) for how it can be used in practice and code
savings compared to relying on bpf_program__set_prep().

  [0] Closes: https://github.com/libbpf/libbpf/issues/298
  [1] https://github.com/anakryiko/retsnoop/pull/1

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211025224531.1088894-3-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c   | 12 ++++++++++--
 tools/lib/bpf/libbpf.h   | 36 ++++++++++++++++++++++++++++++++++--
 tools/lib/bpf/libbpf.map |  2 ++
 3 files changed, 46 insertions(+), 4 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index e27a249d46fb..dc86ad24dfcb 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -6653,8 +6653,6 @@ int bpf_program__load(struct bpf_program *prog, char *license, __u32 kern_ver)
 out:
 	if (err)
 		pr_warn("failed to load program '%s'\n", prog->name);
-	zfree(&prog->insns);
-	prog->insns_cnt = 0;
 	return libbpf_err(err);
 }
 
@@ -8143,6 +8141,16 @@ size_t bpf_program__size(const struct bpf_program *prog)
 	return prog->insns_cnt * BPF_INSN_SZ;
 }
 
+const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog)
+{
+	return prog->insns;
+}
+
+size_t bpf_program__insn_cnt(const struct bpf_program *prog)
+{
+	return prog->insns_cnt;
+}
+
 int bpf_program__set_prep(struct bpf_program *prog, int nr_instances,
 			  bpf_program_prep_t prep)
 {
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 89ca9c83ed4e..c6bcc5b98906 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -226,6 +226,40 @@ LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload
 /* returns program size in bytes */
 LIBBPF_API size_t bpf_program__size(const struct bpf_program *prog);
 
+struct bpf_insn;
+
+/**
+ * @brief **bpf_program__insns()** gives read-only access to BPF program's
+ * underlying BPF instructions.
+ * @param prog BPF program for which to return instructions
+ * @return a pointer to an array of BPF instructions that belong to the
+ * specified BPF program
+ *
+ * Returned pointer is always valid and not NULL. Number of `struct bpf_insn`
+ * pointed to can be fetched using **bpf_program__insn_cnt()** API.
+ *
+ * Keep in mind, libbpf can modify and append/delete BPF program's
+ * instructions as it processes BPF object file and prepares everything for
+ * uploading into the kernel. So depending on the point in BPF object
+ * lifetime, **bpf_program__insns()** can return different sets of
+ * instructions. As an example, during BPF object load phase BPF program
+ * instructions will be CO-RE-relocated, BPF subprograms instructions will be
+ * appended, ldimm64 instructions will have FDs embedded, etc. So instructions
+ * returned before **bpf_object__load()** and after it might be quite
+ * different.
+ */
+LIBBPF_API const struct bpf_insn *bpf_program__insns(const struct bpf_program *prog);
+/**
+ * @brief **bpf_program__insn_cnt()** returns number of `struct bpf_insn`'s
+ * that form specified BPF program.
+ * @param prog BPF program for which to return number of BPF instructions
+ *
+ * See **bpf_program__insns()** documentation for notes on how libbpf can
+ * change instructions and their count during different phases of
+ * **bpf_object** lifetime.
+ */
+LIBBPF_API size_t bpf_program__insn_cnt(const struct bpf_program *prog);
+
 LIBBPF_API int bpf_program__load(struct bpf_program *prog, char *license,
 				 __u32 kern_version);
 LIBBPF_API int bpf_program__fd(const struct bpf_program *prog);
@@ -365,8 +399,6 @@ LIBBPF_API struct bpf_link *
 bpf_program__attach_iter(const struct bpf_program *prog,
 			 const struct bpf_iter_attach_opts *opts);
 
-struct bpf_insn;
-
 /*
  * Libbpf allows callers to adjust BPF programs before being loaded
  * into kernel. One program in an object file can be transformed into
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 116964a29e44..15239c05659c 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -393,6 +393,8 @@ LIBBPF_0.6.0 {
 		bpf_object__next_program;
 		bpf_object__prev_map;
 		bpf_object__prev_program;
+		bpf_program__insn_cnt;
+		bpf_program__insns;
 		btf__add_btf;
 		btf__add_decl_tag;
 		btf__raw_data;
-- 
cgit v1.2.3


From e21d585cb3db65a207cd338c74b9886090ef1ceb Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Mon, 25 Oct 2021 15:45:30 -0700
Subject: libbpf: Deprecate multi-instance bpf_program APIs

Schedule deprecation of a set of APIs that are related to multi-instance
bpf_programs:
  - bpf_program__set_prep() ([0]);
  - bpf_program__{set,unset}_instance() ([1]);
  - bpf_program__nth_fd().

These APIs are obscure, very niche, and don't seem to be used much in
practice. bpf_program__set_prep() is pretty useless for anything but the
simplest BPF programs, as it doesn't allow to adjust BPF program load
attributes, among other things. In short, it already bitrotted and will
bitrot some more if not removed.

With bpf_program__insns() API, which gives access to post-processed BPF
program instructions of any given entry-point BPF program, it's now
possible to do whatever necessary adjustments were possible with
set_prep() API before, but also more. Given any such use case is
automatically an advanced use case, requiring users to stick to
low-level bpf_prog_load() APIs and managing their own prog FDs is
reasonable.

  [0] Closes: https://github.com/libbpf/libbpf/issues/299
  [1] Closes: https://github.com/libbpf/libbpf/issues/300

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211025224531.1088894-4-andrii@kernel.org
---
 tools/lib/bpf/libbpf.c | 22 +++++++++++++---------
 tools/lib/bpf/libbpf.h |  6 +++++-
 2 files changed, 18 insertions(+), 10 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index dc86ad24dfcb..4b2158657507 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -7358,8 +7358,7 @@ static int check_path(const char *path)
 	return err;
 }
 
-int bpf_program__pin_instance(struct bpf_program *prog, const char *path,
-			      int instance)
+static int bpf_program_pin_instance(struct bpf_program *prog, const char *path, int instance)
 {
 	char *cp, errmsg[STRERR_BUFSIZE];
 	int err;
@@ -7394,8 +7393,7 @@ int bpf_program__pin_instance(struct bpf_program *prog, const char *path,
 	return 0;
 }
 
-int bpf_program__unpin_instance(struct bpf_program *prog, const char *path,
-				int instance)
+static int bpf_program_unpin_instance(struct bpf_program *prog, const char *path, int instance)
 {
 	int err;
 
@@ -7423,6 +7421,12 @@ int bpf_program__unpin_instance(struct bpf_program *prog, const char *path,
 	return 0;
 }
 
+__attribute__((alias("bpf_program_pin_instance")))
+int bpf_object__pin_instance(struct bpf_program *prog, const char *path, int instance);
+
+__attribute__((alias("bpf_program_unpin_instance")))
+int bpf_program__unpin_instance(struct bpf_program *prog, const char *path, int instance);
+
 int bpf_program__pin(struct bpf_program *prog, const char *path)
 {
 	int i, err;
@@ -7447,7 +7451,7 @@ int bpf_program__pin(struct bpf_program *prog, const char *path)
 
 	if (prog->instances.nr == 1) {
 		/* don't create subdirs when pinning single instance */
-		return bpf_program__pin_instance(prog, path, 0);
+		return bpf_program_pin_instance(prog, path, 0);
 	}
 
 	for (i = 0; i < prog->instances.nr; i++) {
@@ -7463,7 +7467,7 @@ int bpf_program__pin(struct bpf_program *prog, const char *path)
 			goto err_unpin;
 		}
 
-		err = bpf_program__pin_instance(prog, buf, i);
+		err = bpf_program_pin_instance(prog, buf, i);
 		if (err)
 			goto err_unpin;
 	}
@@ -7481,7 +7485,7 @@ err_unpin:
 		else if (len >= PATH_MAX)
 			continue;
 
-		bpf_program__unpin_instance(prog, buf, i);
+		bpf_program_unpin_instance(prog, buf, i);
 	}
 
 	rmdir(path);
@@ -7509,7 +7513,7 @@ int bpf_program__unpin(struct bpf_program *prog, const char *path)
 
 	if (prog->instances.nr == 1) {
 		/* don't create subdirs when pinning single instance */
-		return bpf_program__unpin_instance(prog, path, 0);
+		return bpf_program_unpin_instance(prog, path, 0);
 	}
 
 	for (i = 0; i < prog->instances.nr; i++) {
@@ -7522,7 +7526,7 @@ int bpf_program__unpin(struct bpf_program *prog, const char *path)
 		else if (len >= PATH_MAX)
 			return libbpf_err(-ENAMETOOLONG);
 
-		err = bpf_program__unpin_instance(prog, buf, i);
+		err = bpf_program_unpin_instance(prog, buf, i);
 		if (err)
 			return err;
 	}
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index c6bcc5b98906..449eeed80be6 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -263,9 +263,11 @@ LIBBPF_API size_t bpf_program__insn_cnt(const struct bpf_program *prog);
 LIBBPF_API int bpf_program__load(struct bpf_program *prog, char *license,
 				 __u32 kern_version);
 LIBBPF_API int bpf_program__fd(const struct bpf_program *prog);
+LIBBPF_DEPRECATED_SINCE(0, 7, "multi-instance bpf_program support is deprecated")
 LIBBPF_API int bpf_program__pin_instance(struct bpf_program *prog,
 					 const char *path,
 					 int instance);
+LIBBPF_DEPRECATED_SINCE(0, 7, "multi-instance bpf_program support is deprecated")
 LIBBPF_API int bpf_program__unpin_instance(struct bpf_program *prog,
 					   const char *path,
 					   int instance);
@@ -427,7 +429,7 @@ bpf_program__attach_iter(const struct bpf_program *prog,
  * one instance. In this case bpf_program__fd(prog) is equal to
  * bpf_program__nth_fd(prog, 0).
  */
-
+LIBBPF_DEPRECATED_SINCE(0, 7, "use bpf_program__insns() for getting bpf_program instructions")
 struct bpf_prog_prep_result {
 	/*
 	 * If not NULL, load new instruction array.
@@ -456,9 +458,11 @@ typedef int (*bpf_program_prep_t)(struct bpf_program *prog, int n,
 				  struct bpf_insn *insns, int insns_cnt,
 				  struct bpf_prog_prep_result *res);
 
+LIBBPF_DEPRECATED_SINCE(0, 7, "use bpf_program__insns() for getting bpf_program instructions")
 LIBBPF_API int bpf_program__set_prep(struct bpf_program *prog, int nr_instance,
 				     bpf_program_prep_t prep);
 
+LIBBPF_DEPRECATED_SINCE(0, 7, "multi-instance bpf_program support is deprecated")
 LIBBPF_API int bpf_program__nth_fd(const struct bpf_program *prog, int n);
 
 /*
-- 
cgit v1.2.3


From c4813e969ac471af730902377a2656b6b1b92c4d Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andrii@kernel.org>
Date: Mon, 25 Oct 2021 15:45:31 -0700
Subject: libbpf: Deprecate ambiguously-named bpf_program__size() API

The name of the API doesn't convey clearly that this size is in number
of bytes (there needed to be a separate comment to make this clear in
libbpf.h). Further, measuring the size of BPF program in bytes is not
exactly the best fit, because BPF programs always consist of 8-byte
instructions. As such, bpf_program__insn_cnt() is a better alternative
in pretty much any imaginable case.

So schedule bpf_program__size() deprecation starting from v0.7 and it
will be removed in libbpf 1.0.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211025224531.1088894-5-andrii@kernel.org
---
 tools/lib/bpf/libbpf.h | 1 +
 1 file changed, 1 insertion(+)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 449eeed80be6..e1900819bfab 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -224,6 +224,7 @@ LIBBPF_API bool bpf_program__autoload(const struct bpf_program *prog);
 LIBBPF_API int bpf_program__set_autoload(struct bpf_program *prog, bool autoload);
 
 /* returns program size in bytes */
+LIBBPF_DEPRECATED_SINCE(0, 7, "use bpf_program__insn_cnt() instead")
 LIBBPF_API size_t bpf_program__size(const struct bpf_program *prog);
 
 struct bpf_insn;
-- 
cgit v1.2.3


From 45f2bebc8079788f62f22d9e8b2819afb1789d7b Mon Sep 17 00:00:00 2001
From: Ilya Leoshkevich <iii@linux.ibm.com>
Date: Tue, 26 Oct 2021 03:08:26 +0200
Subject: libbpf: Fix endianness detection in BPF_CORE_READ_BITFIELD_PROBED()

__BYTE_ORDER is supposed to be defined by a libc, and __BYTE_ORDER__ -
by a compiler. bpf_core_read.h checks __BYTE_ORDER == __LITTLE_ENDIAN,
which is true if neither are defined, leading to incorrect behavior on
big-endian hosts if libc headers are not included, which is often the
case.

Fixes: ee26dade0e3b ("libbpf: Add support for relocatable bitfields")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211026010831.748682-2-iii@linux.ibm.com
---
 tools/lib/bpf/bpf_core_read.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/bpf_core_read.h b/tools/lib/bpf/bpf_core_read.h
index 09ebe3db5f2f..e4aa9996a550 100644
--- a/tools/lib/bpf/bpf_core_read.h
+++ b/tools/lib/bpf/bpf_core_read.h
@@ -40,7 +40,7 @@ enum bpf_enum_value_kind {
 #define __CORE_RELO(src, field, info)					      \
 	__builtin_preserve_field_info((src)->field, BPF_FIELD_##info)
 
-#if __BYTE_ORDER == __LITTLE_ENDIAN
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 #define __CORE_BITFIELD_PROBE_READ(dst, src, fld)			      \
 	bpf_probe_read_kernel(						      \
 			(void *)dst,				      \
-- 
cgit v1.2.3


From 3930198dc9a0720a2b6561c67e55859ec51b73f9 Mon Sep 17 00:00:00 2001
From: Ilya Leoshkevich <iii@linux.ibm.com>
Date: Tue, 26 Oct 2021 03:08:27 +0200
Subject: libbpf: Use __BYTE_ORDER__

Use the compiler-defined __BYTE_ORDER__ instead of the libc-defined
__BYTE_ORDER for consistency.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211026010831.748682-3-iii@linux.ibm.com
---
 tools/lib/bpf/btf.c       |  4 ++--
 tools/lib/bpf/btf_dump.c  |  8 ++++----
 tools/lib/bpf/libbpf.c    |  4 ++--
 tools/lib/bpf/linker.c    | 12 ++++++------
 tools/lib/bpf/relo_core.c |  2 +-
 5 files changed, 15 insertions(+), 15 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index ef924fc2c911..0c628c33e23b 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -538,9 +538,9 @@ int btf__set_pointer_size(struct btf *btf, size_t ptr_sz)
 
 static bool is_host_big_endian(void)
 {
-#if __BYTE_ORDER == __LITTLE_ENDIAN
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 	return false;
-#elif __BYTE_ORDER == __BIG_ENDIAN
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 	return true;
 #else
 # error "Unrecognized __BYTE_ORDER__"
diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index 8e05ab44c22a..17db62b5002e 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -1576,11 +1576,11 @@ static int btf_dump_get_bitfield_value(struct btf_dump *d,
 	/* Bitfield value retrieval is done in two steps; first relevant bytes are
 	 * stored in num, then we left/right shift num to eliminate irrelevant bits.
 	 */
-#if __BYTE_ORDER == __LITTLE_ENDIAN
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 	for (i = t->size - 1; i >= 0; i--)
 		num = num * 256 + bytes[i];
 	nr_copy_bits = bit_sz + bits_offset;
-#elif __BYTE_ORDER == __BIG_ENDIAN
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 	for (i = 0; i < t->size; i++)
 		num = num * 256 + bytes[i];
 	nr_copy_bits = t->size * 8 - bits_offset;
@@ -1700,10 +1700,10 @@ static int btf_dump_int_data(struct btf_dump *d,
 		/* avoid use of __int128 as some 32-bit platforms do not
 		 * support it.
 		 */
-#if __BYTE_ORDER == __LITTLE_ENDIAN
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 		lsi = ints[0];
 		msi = ints[1];
-#elif __BYTE_ORDER == __BIG_ENDIAN
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 		lsi = ints[1];
 		msi = ints[0];
 #else
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 4b2158657507..2fbed2d4a645 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1299,10 +1299,10 @@ errout:
 
 static int bpf_object__check_endianness(struct bpf_object *obj)
 {
-#if __BYTE_ORDER == __LITTLE_ENDIAN
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 	if (obj->efile.ehdr->e_ident[EI_DATA] == ELFDATA2LSB)
 		return 0;
-#elif __BYTE_ORDER == __BIG_ENDIAN
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 	if (obj->efile.ehdr->e_ident[EI_DATA] == ELFDATA2MSB)
 		return 0;
 #else
diff --git a/tools/lib/bpf/linker.c b/tools/lib/bpf/linker.c
index 7bf658fbda80..ce0800e61dc7 100644
--- a/tools/lib/bpf/linker.c
+++ b/tools/lib/bpf/linker.c
@@ -323,12 +323,12 @@ static int init_output_elf(struct bpf_linker *linker, const char *file)
 
 	linker->elf_hdr->e_machine = EM_BPF;
 	linker->elf_hdr->e_type = ET_REL;
-#if __BYTE_ORDER == __LITTLE_ENDIAN
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 	linker->elf_hdr->e_ident[EI_DATA] = ELFDATA2LSB;
-#elif __BYTE_ORDER == __BIG_ENDIAN
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 	linker->elf_hdr->e_ident[EI_DATA] = ELFDATA2MSB;
 #else
-#error "Unknown __BYTE_ORDER"
+#error "Unknown __BYTE_ORDER__"
 #endif
 
 	/* STRTAB */
@@ -538,12 +538,12 @@ static int linker_load_obj_file(struct bpf_linker *linker, const char *filename,
 				const struct bpf_linker_file_opts *opts,
 				struct src_obj *obj)
 {
-#if __BYTE_ORDER == __LITTLE_ENDIAN
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 	const int host_endianness = ELFDATA2LSB;
-#elif __BYTE_ORDER == __BIG_ENDIAN
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 	const int host_endianness = ELFDATA2MSB;
 #else
-#error "Unknown __BYTE_ORDER"
+#error "Unknown __BYTE_ORDER__"
 #endif
 	int err = 0;
 	Elf_Scn *scn;
diff --git a/tools/lib/bpf/relo_core.c b/tools/lib/bpf/relo_core.c
index 4016ed492d0c..b5b8956a1be8 100644
--- a/tools/lib/bpf/relo_core.c
+++ b/tools/lib/bpf/relo_core.c
@@ -662,7 +662,7 @@ static int bpf_core_calc_field_relo(const char *prog_name,
 			*validate = true; /* signedness is never ambiguous */
 		break;
 	case BPF_FIELD_LSHIFT_U64:
-#if __BYTE_ORDER == __LITTLE_ENDIAN
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 		*val = 64 - (bit_off + bit_sz - byte_off  * 8);
 #else
 		*val = (8 - byte_sz) * 8 + (bit_off - byte_off * 8);
-- 
cgit v1.2.3


From 689624f037ce219d42312534eff4dc470b54dec4 Mon Sep 17 00:00:00 2001
From: Joe Burton <jevburton@google.com>
Date: Tue, 26 Oct 2021 22:35:28 +0000
Subject: libbpf: Deprecate bpf_objects_list

Add a flag to `enum libbpf_strict_mode' to disable the global
`bpf_objects_list', preventing race conditions when concurrent threads
call bpf_object__open() or bpf_object__close().

bpf_object__next() will return NULL if this option is set.

Callers may achieve the same workflow by tracking bpf_objects in
application code.

  [0] Closes: https://github.com/libbpf/libbpf/issues/293

Signed-off-by: Joe Burton <jevburton@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211026223528.413950-1-jevburton.kernel@gmail.com
---
 tools/lib/bpf/libbpf.c        | 8 +++++++-
 tools/lib/bpf/libbpf.h        | 3 ++-
 tools/lib/bpf/libbpf_legacy.h | 6 ++++++
 3 files changed, 15 insertions(+), 2 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 2fbed2d4a645..59d39ce9f375 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1148,6 +1148,7 @@ static struct bpf_object *bpf_object__new(const char *path,
 					  size_t obj_buf_sz,
 					  const char *obj_name)
 {
+	bool strict = (libbpf_mode & LIBBPF_STRICT_NO_OBJECT_LIST);
 	struct bpf_object *obj;
 	char *end;
 
@@ -1188,7 +1189,8 @@ static struct bpf_object *bpf_object__new(const char *path,
 	obj->loaded = false;
 
 	INIT_LIST_HEAD(&obj->list);
-	list_add(&obj->list, &bpf_objects_list);
+	if (!strict)
+		list_add(&obj->list, &bpf_objects_list);
 	return obj;
 }
 
@@ -7935,6 +7937,10 @@ struct bpf_object *
 bpf_object__next(struct bpf_object *prev)
 {
 	struct bpf_object *next;
+	bool strict = (libbpf_mode & LIBBPF_STRICT_NO_OBJECT_LIST);
+
+	if (strict)
+		return NULL;
 
 	if (!prev)
 		next = list_first_entry(&bpf_objects_list,
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index e1900819bfab..defabdbe7760 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -168,7 +168,8 @@ LIBBPF_API struct bpf_program *
 bpf_object__find_program_by_name(const struct bpf_object *obj,
 				 const char *name);
 
-LIBBPF_API struct bpf_object *bpf_object__next(struct bpf_object *prev);
+LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "track bpf_objects in application code instead")
+struct bpf_object *bpf_object__next(struct bpf_object *prev);
 #define bpf_object__for_each_safe(pos, tmp)			\
 	for ((pos) = bpf_object__next(NULL),		\
 		(tmp) = bpf_object__next(pos);		\
diff --git a/tools/lib/bpf/libbpf_legacy.h b/tools/lib/bpf/libbpf_legacy.h
index 29ccafab11a8..5ba5c9beccfa 100644
--- a/tools/lib/bpf/libbpf_legacy.h
+++ b/tools/lib/bpf/libbpf_legacy.h
@@ -57,6 +57,12 @@ enum libbpf_strict_mode {
 	 * function name instead of section name.
 	 */
 	LIBBPF_STRICT_SEC_NAME = 0x04,
+	/*
+	 * Disable the global 'bpf_objects_list'. Maintaining this list adds
+	 * a race condition to bpf_object__open() and bpf_object__close().
+	 * Clients can maintain it on their own if it is valuable for them.
+	 */
+	LIBBPF_STRICT_NO_OBJECT_LIST = 0x08,
 
 	__LIBBPF_STRICT_LAST,
 };
-- 
cgit v1.2.3


From 47512102cde2d252d7b984d9675cfd3420b48ad9 Mon Sep 17 00:00:00 2001
From: Joanne Koong <joannekoong@fb.com>
Date: Wed, 27 Oct 2021 16:45:01 -0700
Subject: libbpf: Add "map_extra" as a per-map-type extra flag

This patch adds the libbpf infrastructure for supporting a
per-map-type "map_extra" field, whose definition will be
idiosyncratic depending on map type.

For example, for the bloom filter map, the lower 4 bits of
map_extra is used to denote the number of hash functions.

Please note that until libbpf 1.0 is here, the
"bpf_create_map_params" struct is used as a temporary
means for propagating the map_extra field to the kernel.

Signed-off-by: Joanne Koong <joannekoong@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211027234504.30744-3-joannekoong@fb.com
---
 tools/lib/bpf/bpf.c              | 27 ++++++++++++++++++++++++++-
 tools/lib/bpf/bpf_gen_internal.h |  2 +-
 tools/lib/bpf/gen_loader.c       |  3 ++-
 tools/lib/bpf/libbpf.c           | 38 +++++++++++++++++++++++++++++++++-----
 tools/lib/bpf/libbpf.h           |  3 +++
 tools/lib/bpf/libbpf.map         |  2 ++
 tools/lib/bpf/libbpf_internal.h  | 25 ++++++++++++++++++++++++-
 7 files changed, 91 insertions(+), 9 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index 7d1741ceaa32..fe4b6ebc9b8f 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -77,7 +77,7 @@ static inline int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size)
 	return fd;
 }
 
-int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr)
+int libbpf__bpf_create_map_xattr(const struct bpf_create_map_params *create_attr)
 {
 	union bpf_attr attr;
 	int fd;
@@ -102,11 +102,36 @@ int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr)
 			create_attr->btf_vmlinux_value_type_id;
 	else
 		attr.inner_map_fd = create_attr->inner_map_fd;
+	attr.map_extra = create_attr->map_extra;
 
 	fd = sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
 	return libbpf_err_errno(fd);
 }
 
+int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr)
+{
+	struct bpf_create_map_params p = {};
+
+	p.map_type = create_attr->map_type;
+	p.key_size = create_attr->key_size;
+	p.value_size = create_attr->value_size;
+	p.max_entries = create_attr->max_entries;
+	p.map_flags = create_attr->map_flags;
+	p.name = create_attr->name;
+	p.numa_node = create_attr->numa_node;
+	p.btf_fd = create_attr->btf_fd;
+	p.btf_key_type_id = create_attr->btf_key_type_id;
+	p.btf_value_type_id = create_attr->btf_value_type_id;
+	p.map_ifindex = create_attr->map_ifindex;
+	if (p.map_type == BPF_MAP_TYPE_STRUCT_OPS)
+		p.btf_vmlinux_value_type_id =
+			create_attr->btf_vmlinux_value_type_id;
+	else
+		p.inner_map_fd = create_attr->inner_map_fd;
+
+	return libbpf__bpf_create_map_xattr(&p);
+}
+
 int bpf_create_map_node(enum bpf_map_type map_type, const char *name,
 			int key_size, int value_size, int max_entries,
 			__u32 map_flags, int node)
diff --git a/tools/lib/bpf/bpf_gen_internal.h b/tools/lib/bpf/bpf_gen_internal.h
index 70eccbffefb1..b8d41d6fbc40 100644
--- a/tools/lib/bpf/bpf_gen_internal.h
+++ b/tools/lib/bpf/bpf_gen_internal.h
@@ -43,7 +43,7 @@ void bpf_gen__init(struct bpf_gen *gen, int log_level);
 int bpf_gen__finish(struct bpf_gen *gen);
 void bpf_gen__free(struct bpf_gen *gen);
 void bpf_gen__load_btf(struct bpf_gen *gen, const void *raw_data, __u32 raw_size);
-void bpf_gen__map_create(struct bpf_gen *gen, struct bpf_create_map_attr *map_attr, int map_idx);
+void bpf_gen__map_create(struct bpf_gen *gen, struct bpf_create_map_params *map_attr, int map_idx);
 struct bpf_prog_load_params;
 void bpf_gen__prog_load(struct bpf_gen *gen, struct bpf_prog_load_params *load_attr, int prog_idx);
 void bpf_gen__map_update_elem(struct bpf_gen *gen, int map_idx, void *value, __u32 value_size);
diff --git a/tools/lib/bpf/gen_loader.c b/tools/lib/bpf/gen_loader.c
index 937bfc7db41e..e552484ae4a4 100644
--- a/tools/lib/bpf/gen_loader.c
+++ b/tools/lib/bpf/gen_loader.c
@@ -431,7 +431,7 @@ void bpf_gen__load_btf(struct bpf_gen *gen, const void *btf_raw_data,
 }
 
 void bpf_gen__map_create(struct bpf_gen *gen,
-			 struct bpf_create_map_attr *map_attr, int map_idx)
+			 struct bpf_create_map_params *map_attr, int map_idx)
 {
 	int attr_size = offsetofend(union bpf_attr, btf_vmlinux_value_type_id);
 	bool close_inner_map_fd = false;
@@ -443,6 +443,7 @@ void bpf_gen__map_create(struct bpf_gen *gen,
 	attr.key_size = map_attr->key_size;
 	attr.value_size = map_attr->value_size;
 	attr.map_flags = map_attr->map_flags;
+	attr.map_extra = map_attr->map_extra;
 	memcpy(attr.map_name, map_attr->name,
 	       min((unsigned)strlen(map_attr->name), BPF_OBJ_NAME_LEN - 1));
 	attr.numa_node = map_attr->numa_node;
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 59d39ce9f375..232e4efe82e9 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -400,6 +400,7 @@ struct bpf_map {
 	char *pin_path;
 	bool pinned;
 	bool reused;
+	__u64 map_extra;
 };
 
 enum extern_type {
@@ -2324,6 +2325,13 @@ int parse_btf_map_def(const char *map_name, struct btf *btf,
 			}
 			map_def->pinning = val;
 			map_def->parts |= MAP_DEF_PINNING;
+		} else if (strcmp(name, "map_extra") == 0) {
+			__u32 map_extra;
+
+			if (!get_map_field_int(map_name, btf, m, &map_extra))
+				return -EINVAL;
+			map_def->map_extra = map_extra;
+			map_def->parts |= MAP_DEF_MAP_EXTRA;
 		} else {
 			if (strict) {
 				pr_warn("map '%s': unknown field '%s'.\n", map_name, name);
@@ -2348,6 +2356,7 @@ static void fill_map_from_def(struct bpf_map *map, const struct btf_map_def *def
 	map->def.value_size = def->value_size;
 	map->def.max_entries = def->max_entries;
 	map->def.map_flags = def->map_flags;
+	map->map_extra = def->map_extra;
 
 	map->numa_node = def->numa_node;
 	map->btf_key_type_id = def->key_type_id;
@@ -2371,7 +2380,10 @@ static void fill_map_from_def(struct bpf_map *map, const struct btf_map_def *def
 	if (def->parts & MAP_DEF_MAX_ENTRIES)
 		pr_debug("map '%s': found max_entries = %u.\n", map->name, def->max_entries);
 	if (def->parts & MAP_DEF_MAP_FLAGS)
-		pr_debug("map '%s': found map_flags = %u.\n", map->name, def->map_flags);
+		pr_debug("map '%s': found map_flags = 0x%x.\n", map->name, def->map_flags);
+	if (def->parts & MAP_DEF_MAP_EXTRA)
+		pr_debug("map '%s': found map_extra = 0x%llx.\n", map->name,
+			 (unsigned long long)def->map_extra);
 	if (def->parts & MAP_DEF_PINNING)
 		pr_debug("map '%s': found pinning = %u.\n", map->name, def->pinning);
 	if (def->parts & MAP_DEF_NUMA_NODE)
@@ -4210,6 +4222,7 @@ int bpf_map__reuse_fd(struct bpf_map *map, int fd)
 	map->btf_key_type_id = info.btf_key_type_id;
 	map->btf_value_type_id = info.btf_value_type_id;
 	map->reused = true;
+	map->map_extra = info.map_extra;
 
 	return 0;
 
@@ -4724,7 +4737,8 @@ static bool map_is_reuse_compat(const struct bpf_map *map, int map_fd)
 		map_info.key_size == map->def.key_size &&
 		map_info.value_size == map->def.value_size &&
 		map_info.max_entries == map->def.max_entries &&
-		map_info.map_flags == map->def.map_flags);
+		map_info.map_flags == map->def.map_flags &&
+		map_info.map_extra == map->map_extra);
 }
 
 static int
@@ -4807,7 +4821,7 @@ static void bpf_map__destroy(struct bpf_map *map);
 
 static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, bool is_inner)
 {
-	struct bpf_create_map_attr create_attr;
+	struct bpf_create_map_params create_attr;
 	struct bpf_map_def *def = &map->def;
 	int err = 0;
 
@@ -4821,6 +4835,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b
 	create_attr.key_size = def->key_size;
 	create_attr.value_size = def->value_size;
 	create_attr.numa_node = map->numa_node;
+	create_attr.map_extra = map->map_extra;
 
 	if (def->type == BPF_MAP_TYPE_PERF_EVENT_ARRAY && !def->max_entries) {
 		int nr_cpus;
@@ -4895,7 +4910,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b
 		 */
 		map->fd = 0;
 	} else {
-		map->fd = bpf_create_map_xattr(&create_attr);
+		map->fd = libbpf__bpf_create_map_xattr(&create_attr);
 	}
 	if (map->fd < 0 && (create_attr.btf_key_type_id ||
 			    create_attr.btf_value_type_id)) {
@@ -4910,7 +4925,7 @@ static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, b
 		create_attr.btf_value_type_id = 0;
 		map->btf_key_type_id = 0;
 		map->btf_value_type_id = 0;
-		map->fd = bpf_create_map_xattr(&create_attr);
+		map->fd = libbpf__bpf_create_map_xattr(&create_attr);
 	}
 
 	err = map->fd < 0 ? -errno : 0;
@@ -8880,6 +8895,19 @@ int bpf_map__set_map_flags(struct bpf_map *map, __u32 flags)
 	return 0;
 }
 
+__u64 bpf_map__map_extra(const struct bpf_map *map)
+{
+	return map->map_extra;
+}
+
+int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra)
+{
+	if (map->fd >= 0)
+		return libbpf_err(-EBUSY);
+	map->map_extra = map_extra;
+	return 0;
+}
+
 __u32 bpf_map__numa_node(const struct bpf_map *map)
 {
 	return map->numa_node;
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index defabdbe7760..9de0f299706b 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -600,6 +600,9 @@ LIBBPF_API __u32 bpf_map__btf_value_type_id(const struct bpf_map *map);
 /* get/set map if_index */
 LIBBPF_API __u32 bpf_map__ifindex(const struct bpf_map *map);
 LIBBPF_API int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
+/* get/set map map_extra flags */
+LIBBPF_API __u64 bpf_map__map_extra(const struct bpf_map *map);
+LIBBPF_API int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra);
 
 typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
 LIBBPF_API int bpf_map__set_priv(struct bpf_map *map, void *priv,
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 15239c05659c..43580eb47740 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -389,6 +389,8 @@ LIBBPF_0.5.0 {
 
 LIBBPF_0.6.0 {
 	global:
+		bpf_map__map_extra;
+		bpf_map__set_map_extra;
 		bpf_object__next_map;
 		bpf_object__next_program;
 		bpf_object__prev_map;
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index 13bc7950e304..a6dd7e25747f 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -193,8 +193,9 @@ enum map_def_parts {
 	MAP_DEF_NUMA_NODE	= 0x080,
 	MAP_DEF_PINNING		= 0x100,
 	MAP_DEF_INNER_MAP	= 0x200,
+	MAP_DEF_MAP_EXTRA	= 0x400,
 
-	MAP_DEF_ALL		= 0x3ff, /* combination of all above */
+	MAP_DEF_ALL		= 0x7ff, /* combination of all above */
 };
 
 struct btf_map_def {
@@ -208,6 +209,7 @@ struct btf_map_def {
 	__u32 map_flags;
 	__u32 numa_node;
 	__u32 pinning;
+	__u64 map_extra;
 };
 
 int parse_btf_map_def(const char *map_name, struct btf *btf,
@@ -303,6 +305,27 @@ struct bpf_prog_load_params {
 
 int libbpf__bpf_prog_load(const struct bpf_prog_load_params *load_attr);
 
+struct bpf_create_map_params {
+	const char *name;
+	enum bpf_map_type map_type;
+	__u32 map_flags;
+	__u32 key_size;
+	__u32 value_size;
+	__u32 max_entries;
+	__u32 numa_node;
+	__u32 btf_fd;
+	__u32 btf_key_type_id;
+	__u32 btf_value_type_id;
+	__u32 map_ifindex;
+	union {
+		__u32 inner_map_fd;
+		__u32 btf_vmlinux_value_type_id;
+	};
+	__u64 map_extra;
+};
+
+int libbpf__bpf_create_map_xattr(const struct bpf_create_map_params *create_attr);
+
 struct btf *btf_get_from_fd(int btf_fd, struct btf *base_btf);
 void btf_get_kernel_prefix_kind(enum bpf_attach_type attach_type,
 				const char **prefix, int *kind);
-- 
cgit v1.2.3


From c24941cd3766b6de682dbe6809bd6af12271ab5b Mon Sep 17 00:00:00 2001
From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: Thu, 28 Oct 2021 12:04:55 +0530
Subject: libbpf: Add typeless ksym support to gen_loader

This uses the bpf_kallsyms_lookup_name helper added in previous patches
to relocate typeless ksyms. The return value ENOENT can be ignored, and
the value written to 'res' can be directly stored to the insn, as it is
overwritten to 0 on lookup failure. For repeating symbols, we can simply
copy the previously populated bpf_insn.

Also, we need to take care to not close fds for typeless ksym_desc, so
reuse the 'off' member's space to add a marker for typeless ksym and use
that to skip them in cleanup_relos.

We add a emit_ksym_relo_log helper that avoids duplicating common
logging instructions between typeless and weak ksym (for future commit).

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211028063501.2239335-3-memxor@gmail.com
---
 tools/lib/bpf/bpf_gen_internal.h | 12 +++--
 tools/lib/bpf/gen_loader.c       | 97 +++++++++++++++++++++++++++++++++++-----
 tools/lib/bpf/libbpf.c           | 13 +++---
 3 files changed, 99 insertions(+), 23 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/bpf_gen_internal.h b/tools/lib/bpf/bpf_gen_internal.h
index b8d41d6fbc40..d26e5472fe50 100644
--- a/tools/lib/bpf/bpf_gen_internal.h
+++ b/tools/lib/bpf/bpf_gen_internal.h
@@ -8,13 +8,19 @@ struct ksym_relo_desc {
 	int kind;
 	int insn_idx;
 	bool is_weak;
+	bool is_typeless;
 };
 
 struct ksym_desc {
 	const char *name;
 	int ref;
 	int kind;
-	int off;
+	union {
+		/* used for kfunc */
+		int off;
+		/* used for typeless ksym */
+		bool typeless;
+	};
 	int insn;
 };
 
@@ -49,7 +55,7 @@ void bpf_gen__prog_load(struct bpf_gen *gen, struct bpf_prog_load_params *load_a
 void bpf_gen__map_update_elem(struct bpf_gen *gen, int map_idx, void *value, __u32 value_size);
 void bpf_gen__map_freeze(struct bpf_gen *gen, int map_idx);
 void bpf_gen__record_attach_target(struct bpf_gen *gen, const char *name, enum bpf_attach_type type);
-void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, bool is_weak, int kind,
-			    int insn_idx);
+void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, bool is_weak,
+			    bool is_typeless, int kind, int insn_idx);
 
 #endif
diff --git a/tools/lib/bpf/gen_loader.c b/tools/lib/bpf/gen_loader.c
index e552484ae4a4..bae065a9dbec 100644
--- a/tools/lib/bpf/gen_loader.c
+++ b/tools/lib/bpf/gen_loader.c
@@ -560,7 +560,7 @@ static void emit_find_attach_target(struct bpf_gen *gen)
 }
 
 void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, bool is_weak,
-			    int kind, int insn_idx)
+			    bool is_typeless, int kind, int insn_idx)
 {
 	struct ksym_relo_desc *relo;
 
@@ -573,6 +573,7 @@ void bpf_gen__record_extern(struct bpf_gen *gen, const char *name, bool is_weak,
 	relo += gen->relo_cnt;
 	relo->name = name;
 	relo->is_weak = is_weak;
+	relo->is_typeless = is_typeless;
 	relo->kind = kind;
 	relo->insn_idx = insn_idx;
 	gen->relo_cnt++;
@@ -622,6 +623,29 @@ static void emit_bpf_find_by_name_kind(struct bpf_gen *gen, struct ksym_relo_des
 	debug_ret(gen, "find_by_name_kind(%s,%d)", relo->name, relo->kind);
 }
 
+/* Overwrites BPF_REG_{0, 1, 2, 3, 4, 7}
+ * Returns result in BPF_REG_7
+ * Returns u64 symbol addr in BPF_REG_9
+ */
+static void emit_bpf_kallsyms_lookup_name(struct bpf_gen *gen, struct ksym_relo_desc *relo)
+{
+	int name_off, len = strlen(relo->name) + 1, res_off;
+
+	name_off = add_data(gen, relo->name, len);
+	res_off = add_data(gen, NULL, 8); /* res is u64 */
+	emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_1, BPF_PSEUDO_MAP_IDX_VALUE,
+					 0, 0, 0, name_off));
+	emit(gen, BPF_MOV64_IMM(BPF_REG_2, len));
+	emit(gen, BPF_MOV64_IMM(BPF_REG_3, 0));
+	emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_4, BPF_PSEUDO_MAP_IDX_VALUE,
+					 0, 0, 0, res_off));
+	emit(gen, BPF_MOV64_REG(BPF_REG_7, BPF_REG_4));
+	emit(gen, BPF_EMIT_CALL(BPF_FUNC_kallsyms_lookup_name));
+	emit(gen, BPF_LDX_MEM(BPF_DW, BPF_REG_9, BPF_REG_7, 0));
+	emit(gen, BPF_MOV64_REG(BPF_REG_7, BPF_REG_0));
+	debug_ret(gen, "kallsyms_lookup_name(%s,%d)", relo->name, relo->kind);
+}
+
 /* Expects:
  * BPF_REG_8 - pointer to instruction
  *
@@ -701,6 +725,58 @@ log:
 		   relo->name, kdesc->ref);
 }
 
+static void emit_ksym_relo_log(struct bpf_gen *gen, struct ksym_relo_desc *relo,
+			       int ref)
+{
+	if (!gen->log_level)
+		return;
+	emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_8,
+			      offsetof(struct bpf_insn, imm)));
+	emit(gen, BPF_LDX_MEM(BPF_H, BPF_REG_9, BPF_REG_8, sizeof(struct bpf_insn) +
+			      offsetof(struct bpf_insn, imm)));
+	debug_regs(gen, BPF_REG_7, BPF_REG_9, " var t=%d w=%d (%s:count=%d): imm[0]: %%d, imm[1]: %%d",
+		   relo->is_typeless, relo->is_weak, relo->name, ref);
+	emit(gen, BPF_LDX_MEM(BPF_B, BPF_REG_9, BPF_REG_8, offsetofend(struct bpf_insn, code)));
+	debug_regs(gen, BPF_REG_9, -1, " var t=%d w=%d (%s:count=%d): insn.reg",
+		   relo->is_typeless, relo->is_weak, relo->name, ref);
+}
+
+/* Expects:
+ * BPF_REG_8 - pointer to instruction
+ */
+static void emit_relo_ksym_typeless(struct bpf_gen *gen,
+				    struct ksym_relo_desc *relo, int insn)
+{
+	struct ksym_desc *kdesc;
+
+	kdesc = get_ksym_desc(gen, relo);
+	if (!kdesc)
+		return;
+	/* try to copy from existing ldimm64 insn */
+	if (kdesc->ref > 1) {
+		move_blob2blob(gen, insn + offsetof(struct bpf_insn, imm), 4,
+			       kdesc->insn + offsetof(struct bpf_insn, imm));
+		move_blob2blob(gen, insn + sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm), 4,
+			       kdesc->insn + sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm));
+		goto log;
+	}
+	/* remember insn offset, so we can copy ksym addr later */
+	kdesc->insn = insn;
+	/* skip typeless ksym_desc in fd closing loop in cleanup_relos */
+	kdesc->typeless = true;
+	emit_bpf_kallsyms_lookup_name(gen, relo);
+	emit(gen, BPF_JMP_IMM(BPF_JEQ, BPF_REG_7, -ENOENT, 1));
+	emit_check_err(gen);
+	/* store lower half of addr into insn[insn_idx].imm */
+	emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_8, BPF_REG_9, offsetof(struct bpf_insn, imm)));
+	/* store upper half of addr into insn[insn_idx + 1].imm */
+	emit(gen, BPF_ALU64_IMM(BPF_RSH, BPF_REG_9, 32));
+	emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_8, BPF_REG_9,
+		      sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm)));
+log:
+	emit_ksym_relo_log(gen, relo, kdesc->ref);
+}
+
 /* Expects:
  * BPF_REG_8 - pointer to instruction
  */
@@ -730,14 +806,7 @@ static void emit_relo_ksym_btf(struct bpf_gen *gen, struct ksym_relo_desc *relo,
 	emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_8, BPF_REG_7,
 			      sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm)));
 log:
-	if (!gen->log_level)
-		return;
-	emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_7, BPF_REG_8,
-			      offsetof(struct bpf_insn, imm)));
-	emit(gen, BPF_LDX_MEM(BPF_H, BPF_REG_9, BPF_REG_8, sizeof(struct bpf_insn) +
-			      offsetof(struct bpf_insn, imm)));
-	debug_regs(gen, BPF_REG_7, BPF_REG_9, " var (%s:count=%d): imm: %%d, fd: %%d",
-		   relo->name, kdesc->ref);
+	emit_ksym_relo_log(gen, relo, kdesc->ref);
 }
 
 static void emit_relo(struct bpf_gen *gen, struct ksym_relo_desc *relo, int insns)
@@ -749,7 +818,10 @@ static void emit_relo(struct bpf_gen *gen, struct ksym_relo_desc *relo, int insn
 	emit2(gen, BPF_LD_IMM64_RAW_FULL(BPF_REG_8, BPF_PSEUDO_MAP_IDX_VALUE, 0, 0, 0, insn));
 	switch (relo->kind) {
 	case BTF_KIND_VAR:
-		emit_relo_ksym_btf(gen, relo, insn);
+		if (relo->is_typeless)
+			emit_relo_ksym_typeless(gen, relo, insn);
+		else
+			emit_relo_ksym_btf(gen, relo, insn);
 		break;
 	case BTF_KIND_FUNC:
 		emit_relo_kfunc_btf(gen, relo, insn);
@@ -774,12 +846,13 @@ static void cleanup_relos(struct bpf_gen *gen, int insns)
 	int i, insn;
 
 	for (i = 0; i < gen->nr_ksyms; i++) {
-		if (gen->ksyms[i].kind == BTF_KIND_VAR) {
+		/* only close fds for typed ksyms and kfuncs */
+		if (gen->ksyms[i].kind == BTF_KIND_VAR && !gen->ksyms[i].typeless) {
 			/* close fd recorded in insn[insn_idx + 1].imm */
 			insn = gen->ksyms[i].insn;
 			insn += sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm);
 			emit_sys_close_blob(gen, insn);
-		} else { /* BTF_KIND_FUNC */
+		} else if (gen->ksyms[i].kind == BTF_KIND_FUNC) {
 			emit_sys_close_blob(gen, blob_fd_array_off(gen, gen->ksyms[i].off));
 			if (gen->ksyms[i].off < MAX_FD_ARRAY_SZ)
 				gen->nr_fd_array--;
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 232e4efe82e9..73e1e70a722f 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -6575,17 +6575,14 @@ static int bpf_program__record_externs(struct bpf_program *prog)
 		case RELO_EXTERN_VAR:
 			if (ext->type != EXT_KSYM)
 				continue;
-			if (!ext->ksym.type_id) {
-				pr_warn("typeless ksym %s is not supported yet\n",
-					ext->name);
-				return -ENOTSUP;
-			}
-			bpf_gen__record_extern(obj->gen_loader, ext->name, ext->is_weak,
+			bpf_gen__record_extern(obj->gen_loader, ext->name,
+					       ext->is_weak, !ext->ksym.type_id,
 					       BTF_KIND_VAR, relo->insn_idx);
 			break;
 		case RELO_EXTERN_FUNC:
-			bpf_gen__record_extern(obj->gen_loader, ext->name, ext->is_weak,
-					       BTF_KIND_FUNC, relo->insn_idx);
+			bpf_gen__record_extern(obj->gen_loader, ext->name,
+					       ext->is_weak, false, BTF_KIND_FUNC,
+					       relo->insn_idx);
 			break;
 		default:
 			continue;
-- 
cgit v1.2.3


From 585a3571981d8a93e2211e1ac835d31a63e68cd8 Mon Sep 17 00:00:00 2001
From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: Thu, 28 Oct 2021 12:04:56 +0530
Subject: libbpf: Add weak ksym support to gen_loader

This extends existing ksym relocation code to also support relocating
weak ksyms. Care needs to be taken to zero out the src_reg (currently
BPF_PSEUOD_BTF_ID, always set for gen_loader by bpf_object__relocate_data)
when the BTF ID lookup fails at runtime.  This is not a problem for
libbpf as it only sets ext->is_set when BTF ID lookup succeeds (and only
proceeds in case of failure if ext->is_weak, leading to src_reg
remaining as 0 for weak unresolved ksym).

A pattern similar to emit_relo_kfunc_btf is followed of first storing
the default values and then jumping over actual stores in case of an
error. For src_reg adjustment, we also need to perform it when copying
the populated instruction, so depending on if copied insn[0].imm is 0 or
not, we decide to jump over the adjustment.

We cannot reach that point unless the ksym was weak and resolved and
zeroed out, as the emit_check_err will cause us to jump to cleanup
label, so we do not need to recheck whether the ksym is weak before
doing the adjustment after copying BTF ID and BTF FD.

This is consistent with how libbpf relocates weak ksym. Logging
statements are added to show the relocation result and aid debugging.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211028063501.2239335-4-memxor@gmail.com
---
 tools/lib/bpf/gen_loader.c | 35 ++++++++++++++++++++++++++++++++---
 1 file changed, 32 insertions(+), 3 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/gen_loader.c b/tools/lib/bpf/gen_loader.c
index bae065a9dbec..502dea53a742 100644
--- a/tools/lib/bpf/gen_loader.c
+++ b/tools/lib/bpf/gen_loader.c
@@ -13,6 +13,7 @@
 #include "hashmap.h"
 #include "bpf_gen_internal.h"
 #include "skel_internal.h"
+#include <asm/byteorder.h>
 
 #define MAX_USED_MAPS	64
 #define MAX_USED_PROGS	32
@@ -777,12 +778,24 @@ log:
 	emit_ksym_relo_log(gen, relo, kdesc->ref);
 }
 
+static __u32 src_reg_mask(void)
+{
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+	return 0x0f; /* src_reg,dst_reg,... */
+#elif defined(__BIG_ENDIAN_BITFIELD)
+	return 0xf0; /* dst_reg,src_reg,... */
+#else
+#error "Unsupported bit endianness, cannot proceed"
+#endif
+}
+
 /* Expects:
  * BPF_REG_8 - pointer to instruction
  */
 static void emit_relo_ksym_btf(struct bpf_gen *gen, struct ksym_relo_desc *relo, int insn)
 {
 	struct ksym_desc *kdesc;
+	__u32 reg_mask;
 
 	kdesc = get_ksym_desc(gen, relo);
 	if (!kdesc)
@@ -793,19 +806,35 @@ static void emit_relo_ksym_btf(struct bpf_gen *gen, struct ksym_relo_desc *relo,
 			       kdesc->insn + offsetof(struct bpf_insn, imm));
 		move_blob2blob(gen, insn + sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm), 4,
 			       kdesc->insn + sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm));
-		goto log;
+		emit(gen, BPF_LDX_MEM(BPF_W, BPF_REG_9, BPF_REG_8, offsetof(struct bpf_insn, imm)));
+		/* jump over src_reg adjustment if imm is not 0 */
+		emit(gen, BPF_JMP_IMM(BPF_JNE, BPF_REG_9, 0, 3));
+		goto clear_src_reg;
 	}
 	/* remember insn offset, so we can copy BTF ID and FD later */
 	kdesc->insn = insn;
 	emit_bpf_find_by_name_kind(gen, relo);
-	emit_check_err(gen);
+	if (!relo->is_weak)
+		emit_check_err(gen);
+	/* set default values as 0 */
+	emit(gen, BPF_ST_MEM(BPF_W, BPF_REG_8, offsetof(struct bpf_insn, imm), 0));
+	emit(gen, BPF_ST_MEM(BPF_W, BPF_REG_8, sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm), 0));
+	/* skip success case stores if ret < 0 */
+	emit(gen, BPF_JMP_IMM(BPF_JSLT, BPF_REG_7, 0, 4));
 	/* store btf_id into insn[insn_idx].imm */
 	emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_8, BPF_REG_7, offsetof(struct bpf_insn, imm)));
 	/* store btf_obj_fd into insn[insn_idx + 1].imm */
 	emit(gen, BPF_ALU64_IMM(BPF_RSH, BPF_REG_7, 32));
 	emit(gen, BPF_STX_MEM(BPF_W, BPF_REG_8, BPF_REG_7,
 			      sizeof(struct bpf_insn) + offsetof(struct bpf_insn, imm)));
-log:
+	emit(gen, BPF_JMP_IMM(BPF_JSGE, BPF_REG_7, 0, 3));
+clear_src_reg:
+	/* clear bpf_object__relocate_data's src_reg assignment, otherwise we get a verifier failure */
+	reg_mask = src_reg_mask();
+	emit(gen, BPF_LDX_MEM(BPF_B, BPF_REG_9, BPF_REG_8, offsetofend(struct bpf_insn, code)));
+	emit(gen, BPF_ALU32_IMM(BPF_AND, BPF_REG_9, reg_mask));
+	emit(gen, BPF_STX_MEM(BPF_B, BPF_REG_8, BPF_REG_9, offsetofend(struct bpf_insn, code)));
+
 	emit_ksym_relo_log(gen, relo, kdesc->ref);
 }
 
-- 
cgit v1.2.3


From 549a63238603103fa33cecd49487cf6c0f52e503 Mon Sep 17 00:00:00 2001
From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: Thu, 28 Oct 2021 12:04:57 +0530
Subject: libbpf: Ensure that BPF syscall fds are never 0, 1, or 2

Add a simple wrapper for passing an fd and getting a new one >= 3 if it
is one of 0, 1, or 2. There are two primary reasons to make this change:
First, libbpf relies on the assumption a certain BPF fd is never 0 (e.g.
most recently noticed in [0]). Second, Alexei pointed out in [1] that
some environments reset stdin, stdout, and stderr if they notice an
invalid fd at these numbers. To protect against both these cases, switch
all internal BPF syscall wrappers in libbpf to always return an fd >= 3.
We only need to modify the syscall wrappers and not other code that
assumes a valid fd by doing >= 0, to avoid pointless churn, and because
it is still a valid assumption. The cost paid is two additional syscalls
if fd is in range [0, 2].

  [0]: e31eec77e4ab ("bpf: selftests: Fix fd cleanup in get_branch_snapshot")
  [1]: https://lore.kernel.org/bpf/CAADnVQKVKY8o_3aU8Gzke443+uHa-eGoM0h7W4srChMXU1S4Bg@mail.gmail.com

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211028063501.2239335-5-memxor@gmail.com
---
 tools/lib/bpf/bpf.c             | 35 ++++++++++++++++++++++-------------
 tools/lib/bpf/libbpf_internal.h | 24 ++++++++++++++++++++++++
 2 files changed, 46 insertions(+), 13 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index fe4b6ebc9b8f..c09cbb868c9f 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -65,13 +65,22 @@ static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
 	return syscall(__NR_bpf, cmd, attr, size);
 }
 
+static inline int sys_bpf_fd(enum bpf_cmd cmd, union bpf_attr *attr,
+			     unsigned int size)
+{
+	int fd;
+
+	fd = sys_bpf(cmd, attr, size);
+	return ensure_good_fd(fd);
+}
+
 static inline int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size)
 {
 	int retries = 5;
 	int fd;
 
 	do {
-		fd = sys_bpf(BPF_PROG_LOAD, attr, size);
+		fd = sys_bpf_fd(BPF_PROG_LOAD, attr, size);
 	} while (fd < 0 && errno == EAGAIN && retries-- > 0);
 
 	return fd;
@@ -104,7 +113,7 @@ int libbpf__bpf_create_map_xattr(const struct bpf_create_map_params *create_attr
 		attr.inner_map_fd = create_attr->inner_map_fd;
 	attr.map_extra = create_attr->map_extra;
 
-	fd = sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
+	fd = sys_bpf_fd(BPF_MAP_CREATE, &attr, sizeof(attr));
 	return libbpf_err_errno(fd);
 }
 
@@ -206,7 +215,7 @@ int bpf_create_map_in_map_node(enum bpf_map_type map_type, const char *name,
 		attr.numa_node = node;
 	}
 
-	fd = sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
+	fd = sys_bpf_fd(BPF_MAP_CREATE, &attr, sizeof(attr));
 	return libbpf_err_errno(fd);
 }
 
@@ -634,7 +643,7 @@ int bpf_obj_get(const char *pathname)
 	memset(&attr, 0, sizeof(attr));
 	attr.pathname = ptr_to_u64((void *)pathname);
 
-	fd = sys_bpf(BPF_OBJ_GET, &attr, sizeof(attr));
+	fd = sys_bpf_fd(BPF_OBJ_GET, &attr, sizeof(attr));
 	return libbpf_err_errno(fd);
 }
 
@@ -745,7 +754,7 @@ int bpf_link_create(int prog_fd, int target_fd,
 		break;
 	}
 proceed:
-	fd = sys_bpf(BPF_LINK_CREATE, &attr, sizeof(attr));
+	fd = sys_bpf_fd(BPF_LINK_CREATE, &attr, sizeof(attr));
 	return libbpf_err_errno(fd);
 }
 
@@ -788,7 +797,7 @@ int bpf_iter_create(int link_fd)
 	memset(&attr, 0, sizeof(attr));
 	attr.iter_create.link_fd = link_fd;
 
-	fd = sys_bpf(BPF_ITER_CREATE, &attr, sizeof(attr));
+	fd = sys_bpf_fd(BPF_ITER_CREATE, &attr, sizeof(attr));
 	return libbpf_err_errno(fd);
 }
 
@@ -946,7 +955,7 @@ int bpf_prog_get_fd_by_id(__u32 id)
 	memset(&attr, 0, sizeof(attr));
 	attr.prog_id = id;
 
-	fd = sys_bpf(BPF_PROG_GET_FD_BY_ID, &attr, sizeof(attr));
+	fd = sys_bpf_fd(BPF_PROG_GET_FD_BY_ID, &attr, sizeof(attr));
 	return libbpf_err_errno(fd);
 }
 
@@ -958,7 +967,7 @@ int bpf_map_get_fd_by_id(__u32 id)
 	memset(&attr, 0, sizeof(attr));
 	attr.map_id = id;
 
-	fd = sys_bpf(BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr));
+	fd = sys_bpf_fd(BPF_MAP_GET_FD_BY_ID, &attr, sizeof(attr));
 	return libbpf_err_errno(fd);
 }
 
@@ -970,7 +979,7 @@ int bpf_btf_get_fd_by_id(__u32 id)
 	memset(&attr, 0, sizeof(attr));
 	attr.btf_id = id;
 
-	fd = sys_bpf(BPF_BTF_GET_FD_BY_ID, &attr, sizeof(attr));
+	fd = sys_bpf_fd(BPF_BTF_GET_FD_BY_ID, &attr, sizeof(attr));
 	return libbpf_err_errno(fd);
 }
 
@@ -982,7 +991,7 @@ int bpf_link_get_fd_by_id(__u32 id)
 	memset(&attr, 0, sizeof(attr));
 	attr.link_id = id;
 
-	fd = sys_bpf(BPF_LINK_GET_FD_BY_ID, &attr, sizeof(attr));
+	fd = sys_bpf_fd(BPF_LINK_GET_FD_BY_ID, &attr, sizeof(attr));
 	return libbpf_err_errno(fd);
 }
 
@@ -1013,7 +1022,7 @@ int bpf_raw_tracepoint_open(const char *name, int prog_fd)
 	attr.raw_tracepoint.name = ptr_to_u64(name);
 	attr.raw_tracepoint.prog_fd = prog_fd;
 
-	fd = sys_bpf(BPF_RAW_TRACEPOINT_OPEN, &attr, sizeof(attr));
+	fd = sys_bpf_fd(BPF_RAW_TRACEPOINT_OPEN, &attr, sizeof(attr));
 	return libbpf_err_errno(fd);
 }
 
@@ -1033,7 +1042,7 @@ retry:
 		attr.btf_log_buf = ptr_to_u64(log_buf);
 	}
 
-	fd = sys_bpf(BPF_BTF_LOAD, &attr, sizeof(attr));
+	fd = sys_bpf_fd(BPF_BTF_LOAD, &attr, sizeof(attr));
 
 	if (fd < 0 && !do_log && log_buf && log_buf_size) {
 		do_log = true;
@@ -1075,7 +1084,7 @@ int bpf_enable_stats(enum bpf_stats_type type)
 	memset(&attr, 0, sizeof(attr));
 	attr.enable_stats.type = type;
 
-	fd = sys_bpf(BPF_ENABLE_STATS, &attr, sizeof(attr));
+	fd = sys_bpf_fd(BPF_ENABLE_STATS, &attr, sizeof(attr));
 	return libbpf_err_errno(fd);
 }
 
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index a6dd7e25747f..aeb79e3a8ff9 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -13,6 +13,8 @@
 #include <limits.h>
 #include <errno.h>
 #include <linux/err.h>
+#include <fcntl.h>
+#include <unistd.h>
 #include "libbpf_legacy.h"
 #include "relo_core.h"
 
@@ -491,4 +493,26 @@ static inline bool is_ldimm64_insn(struct bpf_insn *insn)
 	return insn->code == (BPF_LD | BPF_IMM | BPF_DW);
 }
 
+/* if fd is stdin, stdout, or stderr, dup to a fd greater than 2
+ * Takes ownership of the fd passed in, and closes it if calling
+ * fcntl(fd, F_DUPFD_CLOEXEC, 3).
+ */
+static inline int ensure_good_fd(int fd)
+{
+	int old_fd = fd, saved_errno;
+
+	if (fd < 0)
+		return fd;
+	if (fd < 3) {
+		fd = fcntl(fd, F_DUPFD_CLOEXEC, 3);
+		saved_errno = errno;
+		close(old_fd);
+		if (fd < 0) {
+			pr_warn("failed to dup FD %d to FD > 2: %d\n", old_fd, -saved_errno);
+			errno = saved_errno;
+		}
+	}
+	return fd;
+}
+
 #endif /* __LIBBPF_LIBBPF_INTERNAL_H */
-- 
cgit v1.2.3


From 92274e24b01b331ef7a4227135933e6163fe94aa Mon Sep 17 00:00:00 2001
From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Date: Thu, 28 Oct 2021 12:04:58 +0530
Subject: libbpf: Use O_CLOEXEC uniformly when opening fds

There are some instances where we don't use O_CLOEXEC when opening an
fd, fix these up. Otherwise, it is possible that a parallel fork causes
these fds to leak into a child process on execve.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211028063501.2239335-6-memxor@gmail.com
---
 tools/lib/bpf/btf.c           | 2 +-
 tools/lib/bpf/libbpf.c        | 6 +++---
 tools/lib/bpf/libbpf_probes.c | 2 +-
 tools/lib/bpf/linker.c        | 4 ++--
 tools/lib/bpf/xsk.c           | 6 +++---
 5 files changed, 10 insertions(+), 10 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 0c628c33e23b..7e4c5586bd87 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -897,7 +897,7 @@ static struct btf *btf_parse_elf(const char *path, struct btf *base_btf,
 		return ERR_PTR(-LIBBPF_ERRNO__LIBELF);
 	}
 
-	fd = open(path, O_RDONLY);
+	fd = open(path, O_RDONLY | O_CLOEXEC);
 	if (fd < 0) {
 		err = -errno;
 		pr_warn("failed to open %s: %s\n", path, strerror(errno));
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 73e1e70a722f..742d1a388179 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -1232,7 +1232,7 @@ static int bpf_object__elf_init(struct bpf_object *obj)
 		 */
 		elf = elf_memory((char *)obj->efile.obj_buf, obj->efile.obj_buf_sz);
 	} else {
-		obj->efile.fd = open(obj->path, O_RDONLY);
+		obj->efile.fd = open(obj->path, O_RDONLY | O_CLOEXEC);
 		if (obj->efile.fd < 0) {
 			char errmsg[STRERR_BUFSIZE], *cp;
 
@@ -9615,7 +9615,7 @@ static int append_to_file(const char *file, const char *fmt, ...)
 	int fd, n, err = 0;
 	va_list ap;
 
-	fd = open(file, O_WRONLY | O_APPEND, 0);
+	fd = open(file, O_WRONLY | O_APPEND | O_CLOEXEC, 0);
 	if (fd < 0)
 		return -errno;
 
@@ -11260,7 +11260,7 @@ int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz)
 	int fd, err = 0, len;
 	char buf[128];
 
-	fd = open(fcpu, O_RDONLY);
+	fd = open(fcpu, O_RDONLY | O_CLOEXEC);
 	if (fd < 0) {
 		err = -errno;
 		pr_warn("Failed to open cpu mask file %s: %d\n", fcpu, err);
diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c
index cd8c703dde71..68f2dbf364aa 100644
--- a/tools/lib/bpf/libbpf_probes.c
+++ b/tools/lib/bpf/libbpf_probes.c
@@ -33,7 +33,7 @@ static int get_vendor_id(int ifindex)
 
 	snprintf(path, sizeof(path), "/sys/class/net/%s/device/vendor", ifname);
 
-	fd = open(path, O_RDONLY);
+	fd = open(path, O_RDONLY | O_CLOEXEC);
 	if (fd < 0)
 		return -1;
 
diff --git a/tools/lib/bpf/linker.c b/tools/lib/bpf/linker.c
index ce0800e61dc7..f677dccdeae4 100644
--- a/tools/lib/bpf/linker.c
+++ b/tools/lib/bpf/linker.c
@@ -301,7 +301,7 @@ static int init_output_elf(struct bpf_linker *linker, const char *file)
 	if (!linker->filename)
 		return -ENOMEM;
 
-	linker->fd = open(file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+	linker->fd = open(file, O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC, 0644);
 	if (linker->fd < 0) {
 		err = -errno;
 		pr_warn("failed to create '%s': %d\n", file, err);
@@ -556,7 +556,7 @@ static int linker_load_obj_file(struct bpf_linker *linker, const char *filename,
 
 	obj->filename = filename;
 
-	obj->fd = open(filename, O_RDONLY);
+	obj->fd = open(filename, O_RDONLY | O_CLOEXEC);
 	if (obj->fd < 0) {
 		err = -errno;
 		pr_warn("failed to open file '%s': %d\n", filename, err);
diff --git a/tools/lib/bpf/xsk.c b/tools/lib/bpf/xsk.c
index a2111696ba91..81f8fbc85e70 100644
--- a/tools/lib/bpf/xsk.c
+++ b/tools/lib/bpf/xsk.c
@@ -300,7 +300,7 @@ int xsk_umem__create_v0_0_4(struct xsk_umem **umem_ptr, void *umem_area,
 	if (!umem)
 		return -ENOMEM;
 
-	umem->fd = socket(AF_XDP, SOCK_RAW, 0);
+	umem->fd = socket(AF_XDP, SOCK_RAW | SOCK_CLOEXEC, 0);
 	if (umem->fd < 0) {
 		err = -errno;
 		goto out_umem_alloc;
@@ -549,7 +549,7 @@ static int xsk_get_max_queues(struct xsk_socket *xsk)
 	struct ifreq ifr = {};
 	int fd, err, ret;
 
-	fd = socket(AF_LOCAL, SOCK_DGRAM, 0);
+	fd = socket(AF_LOCAL, SOCK_DGRAM | SOCK_CLOEXEC, 0);
 	if (fd < 0)
 		return -errno;
 
@@ -1046,7 +1046,7 @@ int xsk_socket__create_shared(struct xsk_socket **xsk_ptr,
 	}
 
 	if (umem->refcount++ > 0) {
-		xsk->fd = socket(AF_XDP, SOCK_RAW, 0);
+		xsk->fd = socket(AF_XDP, SOCK_RAW | SOCK_CLOEXEC, 0);
 		if (xsk->fd < 0) {
 			err = -errno;
 			goto out_xsk_alloc;
-- 
cgit v1.2.3


From 589fed479ba1e93f94d9772aa6162cd81f7e491c Mon Sep 17 00:00:00 2001
From: Björn Töpel <bjorn@kernel.org>
Date: Thu, 28 Oct 2021 18:10:56 +0200
Subject: riscv, libbpf: Add RISC-V (RV64) support to bpf_tracing.h
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Add macros for 64-bit RISC-V PT_REGS to bpf_tracing.h.

Signed-off-by: Björn Töpel <bjorn@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211028161057.520552-4-bjorn@kernel.org
---
 tools/lib/bpf/bpf_tracing.h | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/bpf_tracing.h b/tools/lib/bpf/bpf_tracing.h
index d6bfbe009296..db05a5937105 100644
--- a/tools/lib/bpf/bpf_tracing.h
+++ b/tools/lib/bpf/bpf_tracing.h
@@ -24,6 +24,9 @@
 #elif defined(__TARGET_ARCH_sparc)
 	#define bpf_target_sparc
 	#define bpf_target_defined
+#elif defined(__TARGET_ARCH_riscv)
+	#define bpf_target_riscv
+	#define bpf_target_defined
 #else
 
 /* Fall back to what the compiler says */
@@ -48,6 +51,9 @@
 #elif defined(__sparc__)
 	#define bpf_target_sparc
 	#define bpf_target_defined
+#elif defined(__riscv) && __riscv_xlen == 64
+	#define bpf_target_riscv
+	#define bpf_target_defined
 #endif /* no compiler target */
 
 #endif
@@ -288,6 +294,32 @@ struct pt_regs;
 #define PT_REGS_IP_CORE(x) BPF_CORE_READ((x), pc)
 #endif
 
+#elif defined(bpf_target_riscv)
+
+struct pt_regs;
+#define PT_REGS_RV const volatile struct user_regs_struct
+#define PT_REGS_PARM1(x) (((PT_REGS_RV *)(x))->a0)
+#define PT_REGS_PARM2(x) (((PT_REGS_RV *)(x))->a1)
+#define PT_REGS_PARM3(x) (((PT_REGS_RV *)(x))->a2)
+#define PT_REGS_PARM4(x) (((PT_REGS_RV *)(x))->a3)
+#define PT_REGS_PARM5(x) (((PT_REGS_RV *)(x))->a4)
+#define PT_REGS_RET(x) (((PT_REGS_RV *)(x))->ra)
+#define PT_REGS_FP(x) (((PT_REGS_RV *)(x))->s5)
+#define PT_REGS_RC(x) (((PT_REGS_RV *)(x))->a5)
+#define PT_REGS_SP(x) (((PT_REGS_RV *)(x))->sp)
+#define PT_REGS_IP(x) (((PT_REGS_RV *)(x))->epc)
+
+#define PT_REGS_PARM1_CORE(x) BPF_CORE_READ((PT_REGS_RV *)(x), a0)
+#define PT_REGS_PARM2_CORE(x) BPF_CORE_READ((PT_REGS_RV *)(x), a1)
+#define PT_REGS_PARM3_CORE(x) BPF_CORE_READ((PT_REGS_RV *)(x), a2)
+#define PT_REGS_PARM4_CORE(x) BPF_CORE_READ((PT_REGS_RV *)(x), a3)
+#define PT_REGS_PARM5_CORE(x) BPF_CORE_READ((PT_REGS_RV *)(x), a4)
+#define PT_REGS_RET_CORE(x) BPF_CORE_READ((PT_REGS_RV *)(x), ra)
+#define PT_REGS_FP_CORE(x) BPF_CORE_READ((PT_REGS_RV *)(x), fp)
+#define PT_REGS_RC_CORE(x) BPF_CORE_READ((PT_REGS_RV *)(x), a5)
+#define PT_REGS_SP_CORE(x) BPF_CORE_READ((PT_REGS_RV *)(x), sp)
+#define PT_REGS_IP_CORE(x) BPF_CORE_READ((PT_REGS_RV *)(x), epc)
+
 #endif
 
 #if defined(bpf_target_powerpc)
-- 
cgit v1.2.3


From 0b170456e0dda92b8925d40e217461fcc4e1efc9 Mon Sep 17 00:00:00 2001
From: Magnus Karlsson <magnus.karlsson@intel.com>
Date: Fri, 29 Oct 2021 11:01:11 +0200
Subject: libbpf: Deprecate AF_XDP support
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Deprecate AF_XDP support in libbpf ([0]). This has been moved to
libxdp as it is a better fit for that library. The AF_XDP support only
uses the public libbpf functions and can therefore just use libbpf as
a library from libxdp. The libxdp APIs are exactly the same so it
should just be linking with libxdp instead of libbpf for the AF_XDP
functionality. If not, please submit a bug report. Linking with both
libraries is supported but make sure you link in the correct order so
that the new functions in libxdp are used instead of the deprecated
ones in libbpf.

Libxdp can be found at https://github.com/xdp-project/xdp-tools.

  [0] Closes: https://github.com/libbpf/libbpf/issues/270

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20211029090111.4733-1-magnus.karlsson@gmail.com
---
 tools/lib/bpf/xsk.h | 90 +++++++++++++++++++++++++++++++----------------------
 1 file changed, 52 insertions(+), 38 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/xsk.h b/tools/lib/bpf/xsk.h
index 01c12dca9c10..64e9c57fd792 100644
--- a/tools/lib/bpf/xsk.h
+++ b/tools/lib/bpf/xsk.h
@@ -23,6 +23,12 @@
 extern "C" {
 #endif
 
+/* This whole API has been deprecated and moved to libxdp that can be found at
+ * https://github.com/xdp-project/xdp-tools. The APIs are exactly the same so
+ * it should just be linking with libxdp instead of libbpf for this set of
+ * functionality. If not, please submit a bug report on the aforementioned page.
+ */
+
 /* Load-Acquire Store-Release barriers used by the XDP socket
  * library. The following macros should *NOT* be considered part of
  * the xsk.h API, and is subject to change anytime.
@@ -245,8 +251,10 @@ static inline __u64 xsk_umem__add_offset_to_addr(__u64 addr)
 	return xsk_umem__extract_addr(addr) + xsk_umem__extract_offset(addr);
 }
 
-LIBBPF_API int xsk_umem__fd(const struct xsk_umem *umem);
-LIBBPF_API int xsk_socket__fd(const struct xsk_socket *xsk);
+LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
+int xsk_umem__fd(const struct xsk_umem *umem);
+LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
+int xsk_socket__fd(const struct xsk_socket *xsk);
 
 #define XSK_RING_CONS__DEFAULT_NUM_DESCS      2048
 #define XSK_RING_PROD__DEFAULT_NUM_DESCS      2048
@@ -263,10 +271,10 @@ struct xsk_umem_config {
 	__u32 flags;
 };
 
-LIBBPF_API int xsk_setup_xdp_prog(int ifindex,
-				  int *xsks_map_fd);
-LIBBPF_API int xsk_socket__update_xskmap(struct xsk_socket *xsk,
-					 int xsks_map_fd);
+LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
+int xsk_setup_xdp_prog(int ifindex, int *xsks_map_fd);
+LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
+int xsk_socket__update_xskmap(struct xsk_socket *xsk, int xsks_map_fd);
 
 /* Flags for the libbpf_flags field. */
 #define XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD (1 << 0)
@@ -280,40 +288,46 @@ struct xsk_socket_config {
 };
 
 /* Set config to NULL to get the default configuration. */
-LIBBPF_API int xsk_umem__create(struct xsk_umem **umem,
-				void *umem_area, __u64 size,
-				struct xsk_ring_prod *fill,
-				struct xsk_ring_cons *comp,
-				const struct xsk_umem_config *config);
-LIBBPF_API int xsk_umem__create_v0_0_2(struct xsk_umem **umem,
-				       void *umem_area, __u64 size,
-				       struct xsk_ring_prod *fill,
-				       struct xsk_ring_cons *comp,
-				       const struct xsk_umem_config *config);
-LIBBPF_API int xsk_umem__create_v0_0_4(struct xsk_umem **umem,
-				       void *umem_area, __u64 size,
-				       struct xsk_ring_prod *fill,
-				       struct xsk_ring_cons *comp,
-				       const struct xsk_umem_config *config);
-LIBBPF_API int xsk_socket__create(struct xsk_socket **xsk,
-				  const char *ifname, __u32 queue_id,
-				  struct xsk_umem *umem,
-				  struct xsk_ring_cons *rx,
-				  struct xsk_ring_prod *tx,
-				  const struct xsk_socket_config *config);
-LIBBPF_API int
-xsk_socket__create_shared(struct xsk_socket **xsk_ptr,
-			  const char *ifname,
-			  __u32 queue_id, struct xsk_umem *umem,
-			  struct xsk_ring_cons *rx,
-			  struct xsk_ring_prod *tx,
-			  struct xsk_ring_prod *fill,
-			  struct xsk_ring_cons *comp,
-			  const struct xsk_socket_config *config);
+LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
+int xsk_umem__create(struct xsk_umem **umem,
+		     void *umem_area, __u64 size,
+		     struct xsk_ring_prod *fill,
+		     struct xsk_ring_cons *comp,
+		     const struct xsk_umem_config *config);
+LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
+int xsk_umem__create_v0_0_2(struct xsk_umem **umem,
+			    void *umem_area, __u64 size,
+			    struct xsk_ring_prod *fill,
+			    struct xsk_ring_cons *comp,
+			    const struct xsk_umem_config *config);
+LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
+int xsk_umem__create_v0_0_4(struct xsk_umem **umem,
+			    void *umem_area, __u64 size,
+			    struct xsk_ring_prod *fill,
+			    struct xsk_ring_cons *comp,
+			    const struct xsk_umem_config *config);
+LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
+int xsk_socket__create(struct xsk_socket **xsk,
+		       const char *ifname, __u32 queue_id,
+		       struct xsk_umem *umem,
+		       struct xsk_ring_cons *rx,
+		       struct xsk_ring_prod *tx,
+		       const struct xsk_socket_config *config);
+LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
+int xsk_socket__create_shared(struct xsk_socket **xsk_ptr,
+			      const char *ifname,
+			      __u32 queue_id, struct xsk_umem *umem,
+			      struct xsk_ring_cons *rx,
+			      struct xsk_ring_prod *tx,
+			      struct xsk_ring_prod *fill,
+			      struct xsk_ring_cons *comp,
+			      const struct xsk_socket_config *config);
 
 /* Returns 0 for success and -EBUSY if the umem is still in use. */
-LIBBPF_API int xsk_umem__delete(struct xsk_umem *umem);
-LIBBPF_API void xsk_socket__delete(struct xsk_socket *xsk);
+LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
+int xsk_umem__delete(struct xsk_umem *umem);
+LIBBPF_API LIBBPF_DEPRECATED_SINCE(0, 7, "AF_XDP support deprecated and moved to libxdp")
+void xsk_socket__delete(struct xsk_socket *xsk);
 
 #ifdef __cplusplus
 } /* extern "C" */
-- 
cgit v1.2.3