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author | Masahiro Yamada <masahiroy@kernel.org> | 2021-05-12 15:52:01 +0900 |
---|---|---|
committer | Masahiro Yamada <masahiroy@kernel.org> | 2021-05-24 12:06:51 +0900 |
commit | 0d989ac2c90b5f51fe12102d3cddf54b959f2014 (patch) | |
tree | 2288248dd0b997c298aa8bf7659b14e423cb9241 | |
parent | 1bb0b18a06dceee1fdc32161a72e28eab6f011c4 (diff) | |
download | linux-0d989ac2c90b5f51fe12102d3cddf54b959f2014.tar.bz2 |
kbuild: remove libelf checks from top Makefile
I do not see a good reason why only the libelf development package must
be so carefully checked.
Kbuild generally does not check host tools or libraries.
For example, x86_64 defconfig fails to build with no libssl development
package installed.
scripts/extract-cert.c:21:10: fatal error: openssl/bio.h: No such file or directory
21 | #include <openssl/bio.h>
| ^~~~~~~~~~~~~~~
To solve the build error, you need to install libssl-dev or openssl-devel
package, depending on your distribution.
'apt-file search', 'dnf provides', etc. is your frined to find a proper
package to install.
This commit removes all the libelf checks from the top Makefile.
If libelf is missing, objtool will fail to build in a similar pattern:
.../linux/tools/objtool/include/objtool/elf.h:10:10: fatal error: gelf.h: No such file or directory
10 | #include <gelf.h>
You need to install libelf-dev, libelf-devel, or elfutils-libelf-devel
to proceed.
Another remarkable change is, CONFIG_STACK_VALIDATION (without
CONFIG_UNWINDER_ORC) previously continued to build with a warning,
but now it will treat missing libelf as an error.
This is just a one-time installation, so it should not hurt to break
a build and make a user install the package.
BTW, the traditional way to handle such checks is autotool, but according
to [1], I do not expect the kernel build would have similar scripting
like './configure' does.
[1]: https://lore.kernel.org/lkml/CA+55aFzr2HTZVOuzpHYDwmtRJLsVzE-yqg2DHpHi_9ePsYp5ug@mail.gmail.com/
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
-rw-r--r-- | Makefile | 78 | ||||
-rw-r--r-- | scripts/Makefile.build | 2 | ||||
-rw-r--r-- | scripts/Makefile.modfinal | 2 |
3 files changed, 22 insertions, 60 deletions
@@ -1081,41 +1081,6 @@ export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE) MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE) export MODLIB -HOST_LIBELF_LIBS = $(shell pkg-config libelf --libs 2>/dev/null || echo -lelf) - -has_libelf = $(call try-run,\ - echo "int main() {}" | $(HOSTCC) $(KBUILD_HOSTLDFLAGS) -xc -o /dev/null $(HOST_LIBELF_LIBS) -,1,0) - -ifdef CONFIG_STACK_VALIDATION - ifeq ($(has_libelf),1) - objtool_target := tools/objtool FORCE - else - SKIP_STACK_VALIDATION := 1 - export SKIP_STACK_VALIDATION - endif -endif - -PHONY += resolve_btfids_clean - -resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids - -# tools/bpf/resolve_btfids directory might not exist -# in output directory, skip its clean in that case -resolve_btfids_clean: -ifneq ($(wildcard $(resolve_btfids_O)),) - $(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean -endif - -ifdef CONFIG_BPF -ifdef CONFIG_DEBUG_INFO_BTF - ifeq ($(has_libelf),1) - resolve_btfids_target := tools/bpf/resolve_btfids FORCE - else - ERROR_RESOLVE_BTFIDS := 1 - endif -endif # CONFIG_DEBUG_INFO_BTF -endif # CONFIG_BPF - PHONY += prepare0 export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/) @@ -1227,7 +1192,7 @@ prepare0: archprepare $(Q)$(MAKE) $(build)=. # All the preparing.. -prepare: prepare0 prepare-objtool prepare-resolve_btfids +prepare: prepare0 PHONY += remove-stale-files remove-stale-files: @@ -1244,26 +1209,6 @@ uapi-asm-generic: $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \ generic=include/uapi/asm-generic -PHONY += prepare-objtool prepare-resolve_btfids -prepare-objtool: $(objtool_target) -ifeq ($(SKIP_STACK_VALIDATION),1) -ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL - @echo "error: Cannot generate __mcount_loc for CONFIG_DYNAMIC_FTRACE=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2 - @false -endif -ifdef CONFIG_UNWINDER_ORC - @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2 - @false -else - @echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2 -endif -endif - -prepare-resolve_btfids: $(resolve_btfids_target) -ifeq ($(ERROR_RESOLVE_BTFIDS),1) - @echo "error: Cannot resolve BTF IDs for CONFIG_DEBUG_INFO_BTF, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2 - @false -endif # Generate some files # --------------------------------------------------------------------------- @@ -1354,6 +1299,27 @@ scripts_unifdef: scripts_basic # --------------------------------------------------------------------------- # Tools +ifdef CONFIG_STACK_VALIDATION +prepare: tools/objtool +endif + +ifdef CONFIG_BPF +ifdef CONFIG_DEBUG_INFO_BTF +prepare: tools/bpf/resolve_btfids +endif +endif + +PHONY += resolve_btfids_clean + +resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids + +# tools/bpf/resolve_btfids directory might not exist +# in output directory, skip its clean in that case +resolve_btfids_clean: +ifneq ($(wildcard $(resolve_btfids_O)),) + $(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean +endif + # Clear a bunch of variables before executing the submake ifeq ($(quiet),silent_) tools_silent=s diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 949f723efe53..7adc3a2c3c31 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -219,7 +219,6 @@ endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT ifdef CONFIG_STACK_VALIDATION ifndef CONFIG_LTO_CLANG -ifneq ($(SKIP_STACK_VALIDATION),1) __objtool_obj := $(objtree)/tools/objtool/objtool @@ -233,7 +232,6 @@ objtool_obj = $(if $(patsubst y%,, \ $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \ $(__objtool_obj)) -endif # SKIP_STACK_VALIDATION endif # CONFIG_LTO_CLANG endif # CONFIG_STACK_VALIDATION diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal index dd87cea9fba7..bdee3babc5cf 100644 --- a/scripts/Makefile.modfinal +++ b/scripts/Makefile.modfinal @@ -39,12 +39,10 @@ prelink-ext := .lto # so let's now process the prelinked binary before we link the module. ifdef CONFIG_STACK_VALIDATION -ifneq ($(SKIP_STACK_VALIDATION),1) cmd_ld_ko_o += \ $(objtree)/tools/objtool/objtool $(objtool_args) \ $(@:.ko=$(prelink-ext).o); -endif # SKIP_STACK_VALIDATION endif # CONFIG_STACK_VALIDATION endif # CONFIG_LTO_CLANG |