From 0d13bfce023ac7cef4d0a50b83750254ce31c479 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andriin@fb.com>
Date: Fri, 13 Dec 2019 17:43:25 -0800
Subject: libbpf: Don't require root for bpf_object__open()

Reorganize bpf_object__open and bpf_object__load steps such that
bpf_object__open doesn't need root access. This was previously done for
feature probing and BTF sanitization. This doesn't have to happen on open,
though, so move all those steps into the load phase.

This is important, because it makes it possible for tools like bpftool, to
just open BPF object file and inspect their contents: programs, maps, BTF,
etc. For such operations it is prohibitive to require root access. On the
other hand, there is a lot of custom libbpf logic in those steps, so its best
avoided for tools to reimplement all that on their own.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-2-andriin@fb.com
---
 tools/lib/bpf/libbpf.c | 83 +++++++++++++++++++++++++-------------------------
 1 file changed, 41 insertions(+), 42 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 27d5f7ecba32..dc993112b40b 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -101,13 +101,6 @@ void libbpf_print(enum libbpf_print_level level, const char *format, ...)
 
 #define STRERR_BUFSIZE  128
 
-#define CHECK_ERR(action, err, out) do {	\
-	err = action;			\
-	if (err)			\
-		goto out;		\
-} while (0)
-
-
 /* Copied from tools/perf/util/util.h */
 #ifndef zfree
 # define zfree(ptr) ({ free(*ptr); *ptr = NULL; })
@@ -864,8 +857,7 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
 	def->value_size = data->d_size;
 	def->max_entries = 1;
 	def->map_flags = type == LIBBPF_MAP_RODATA ? BPF_F_RDONLY_PROG : 0;
-	if (obj->caps.array_mmap)
-		def->map_flags |= BPF_F_MMAPABLE;
+	def->map_flags |= BPF_F_MMAPABLE;
 
 	pr_debug("map '%s' (global data): at sec_idx %d, offset %zu, flags %x.\n",
 		 map_name, map->sec_idx, map->sec_offset, def->map_flags);
@@ -888,8 +880,6 @@ static int bpf_object__init_global_data_maps(struct bpf_object *obj)
 {
 	int err;
 
-	if (!obj->caps.global_data)
-		return 0;
 	/*
 	 * Populate obj->maps with libbpf internal maps.
 	 */
@@ -1393,10 +1383,11 @@ static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict,
 	return 0;
 }
 
-static int bpf_object__init_maps(struct bpf_object *obj, bool relaxed_maps,
-				 const char *pin_root_path)
+static int bpf_object__init_maps(struct bpf_object *obj,
+				 struct bpf_object_open_opts *opts)
 {
-	bool strict = !relaxed_maps;
+	const char *pin_root_path = OPTS_GET(opts, pin_root_path, NULL);
+	bool strict = !OPTS_GET(opts, relaxed_maps, false);
 	int err;
 
 	err = bpf_object__init_user_maps(obj, strict);
@@ -1592,8 +1583,7 @@ static int bpf_object__sanitize_and_load_btf(struct bpf_object *obj)
 	return 0;
 }
 
-static int bpf_object__elf_collect(struct bpf_object *obj, bool relaxed_maps,
-				   const char *pin_root_path)
+static int bpf_object__elf_collect(struct bpf_object *obj)
 {
 	Elf *elf = obj->efile.elf;
 	GElf_Ehdr *ep = &obj->efile.ehdr;
@@ -1728,14 +1718,7 @@ static int bpf_object__elf_collect(struct bpf_object *obj, bool relaxed_maps,
 		pr_warn("Corrupted ELF file: index of strtab invalid\n");
 		return -LIBBPF_ERRNO__FORMAT;
 	}
-	err = bpf_object__init_btf(obj, btf_data, btf_ext_data);
-	if (!err)
-		err = bpf_object__init_maps(obj, relaxed_maps, pin_root_path);
-	if (!err)
-		err = bpf_object__sanitize_and_load_btf(obj);
-	if (!err)
-		err = bpf_object__init_prog_names(obj);
-	return err;
+	return bpf_object__init_btf(obj, btf_data, btf_ext_data);
 }
 
 static struct bpf_program *
@@ -1876,11 +1859,6 @@ static int bpf_program__record_reloc(struct bpf_program *prog,
 		pr_warn("bad data relo against section %u\n", shdr_idx);
 		return -LIBBPF_ERRNO__RELOC;
 	}
-	if (!obj->caps.global_data) {
-		pr_warn("relocation: kernel does not support global \'%s\' variable access in insns[%d]\n",
-			name, insn_idx);
-		return -LIBBPF_ERRNO__RELOC;
-	}
 	for (map_idx = 0; map_idx < nr_maps; map_idx++) {
 		map = &obj->maps[map_idx];
 		if (map->libbpf_type != type)
@@ -3918,12 +3896,10 @@ static struct bpf_object *
 __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz,
 		   struct bpf_object_open_opts *opts)
 {
-	const char *pin_root_path;
 	struct bpf_program *prog;
 	struct bpf_object *obj;
 	const char *obj_name;
 	char tmp_name[64];
-	bool relaxed_maps;
 	__u32 attach_prog_fd;
 	int err;
 
@@ -3953,16 +3929,16 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz,
 		return obj;
 
 	obj->relaxed_core_relocs = OPTS_GET(opts, relaxed_core_relocs, false);
-	relaxed_maps = OPTS_GET(opts, relaxed_maps, false);
-	pin_root_path = OPTS_GET(opts, pin_root_path, NULL);
 	attach_prog_fd = OPTS_GET(opts, attach_prog_fd, 0);
 
-	CHECK_ERR(bpf_object__elf_init(obj), err, out);
-	CHECK_ERR(bpf_object__check_endianness(obj), err, out);
-	CHECK_ERR(bpf_object__probe_caps(obj), err, out);
-	CHECK_ERR(bpf_object__elf_collect(obj, relaxed_maps, pin_root_path),
-		  err, out);
-	CHECK_ERR(bpf_object__collect_reloc(obj), err, out);
+	err = bpf_object__elf_init(obj);
+	err = err ? : bpf_object__check_endianness(obj);
+	err = err ? : bpf_object__elf_collect(obj);
+	err = err ? : bpf_object__init_maps(obj, opts);
+	err = err ? : bpf_object__init_prog_names(obj);
+	err = err ? : bpf_object__collect_reloc(obj);
+	if (err)
+		goto out;
 	bpf_object__elf_finish(obj);
 
 	bpf_object__for_each_program(prog, obj) {
@@ -4080,6 +4056,24 @@ int bpf_object__unload(struct bpf_object *obj)
 	return 0;
 }
 
+static int bpf_object__sanitize_maps(struct bpf_object *obj)
+{
+	struct bpf_map *m;
+
+	bpf_object__for_each_map(m, obj) {
+		if (!bpf_map__is_internal(m))
+			continue;
+		if (!obj->caps.global_data) {
+			pr_warn("kernel doesn't support global data\n");
+			return -ENOTSUP;
+		}
+		if (!obj->caps.array_mmap)
+			m->def.map_flags ^= BPF_F_MMAPABLE;
+	}
+
+	return 0;
+}
+
 int bpf_object__load_xattr(struct bpf_object_load_attr *attr)
 {
 	struct bpf_object *obj;
@@ -4098,9 +4092,14 @@ int bpf_object__load_xattr(struct bpf_object_load_attr *attr)
 
 	obj->loaded = true;
 
-	CHECK_ERR(bpf_object__create_maps(obj), err, out);
-	CHECK_ERR(bpf_object__relocate(obj, attr->target_btf_path), err, out);
-	CHECK_ERR(bpf_object__load_progs(obj, attr->log_level), err, out);
+	err = bpf_object__probe_caps(obj);
+	err = err ? : bpf_object__sanitize_and_load_btf(obj);
+	err = err ? : bpf_object__sanitize_maps(obj);
+	err = err ? : bpf_object__create_maps(obj);
+	err = err ? : bpf_object__relocate(obj, attr->target_btf_path);
+	err = err ? : bpf_object__load_progs(obj, attr->log_level);
+	if (err)
+		goto out;
 
 	return 0;
 out:
-- 
cgit v1.2.3


From d7a18ea7e8b612669acd0131fd075e5c735c1ce5 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andriin@fb.com>
Date: Fri, 13 Dec 2019 17:43:26 -0800
Subject: libbpf: Add generic bpf_program__attach()

Generalize BPF program attaching and allow libbpf to auto-detect type (and
extra parameters, where applicable) and attach supported BPF program types
based on program sections. Currently this is supported for:
- kprobe/kretprobe;
- tracepoint;
- raw tracepoint;
- tracing programs (typed raw TP/fentry/fexit).

More types support can be trivially added within this framework.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-3-andriin@fb.com
---
 tools/lib/bpf/libbpf.c                             | 181 +++++++++++++++++----
 tools/lib/bpf/libbpf.h                             |   2 +
 tools/lib/bpf/libbpf.map                           |   2 +
 .../testing/selftests/bpf/prog_tests/probe_user.c  |   6 +-
 4 files changed, 153 insertions(+), 38 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index dc993112b40b..61b8cdf78332 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -4972,7 +4972,28 @@ void bpf_program__set_expected_attach_type(struct bpf_program *prog,
  */
 #define BPF_APROG_COMPAT(string, ptype) BPF_PROG_SEC(string, ptype)
 
-static const struct {
+#define SEC_DEF(sec_pfx, ptype, ...) {					    \
+	.sec = sec_pfx,							    \
+	.len = sizeof(sec_pfx) - 1,					    \
+	.prog_type = BPF_PROG_TYPE_##ptype,				    \
+	__VA_ARGS__							    \
+}
+
+struct bpf_sec_def;
+
+typedef struct bpf_link *(*attach_fn_t)(const struct bpf_sec_def *sec,
+					struct bpf_program *prog);
+
+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);
+
+struct bpf_sec_def {
 	const char *sec;
 	size_t len;
 	enum bpf_prog_type prog_type;
@@ -4980,25 +5001,40 @@ static const struct {
 	bool is_attachable;
 	bool is_attach_btf;
 	enum bpf_attach_type attach_type;
-} section_names[] = {
+	attach_fn_t attach_fn;
+};
+
+static const struct bpf_sec_def section_defs[] = {
 	BPF_PROG_SEC("socket",			BPF_PROG_TYPE_SOCKET_FILTER),
 	BPF_PROG_SEC("sk_reuseport",		BPF_PROG_TYPE_SK_REUSEPORT),
-	BPF_PROG_SEC("kprobe/",			BPF_PROG_TYPE_KPROBE),
+	SEC_DEF("kprobe/", KPROBE,
+		.attach_fn = attach_kprobe),
 	BPF_PROG_SEC("uprobe/",			BPF_PROG_TYPE_KPROBE),
-	BPF_PROG_SEC("kretprobe/",		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("action",			BPF_PROG_TYPE_SCHED_ACT),
-	BPF_PROG_SEC("tracepoint/",		BPF_PROG_TYPE_TRACEPOINT),
-	BPF_PROG_SEC("tp/",			BPF_PROG_TYPE_TRACEPOINT),
-	BPF_PROG_SEC("raw_tracepoint/",		BPF_PROG_TYPE_RAW_TRACEPOINT),
-	BPF_PROG_SEC("raw_tp/",			BPF_PROG_TYPE_RAW_TRACEPOINT),
-	BPF_PROG_BTF("tp_btf/",			BPF_PROG_TYPE_TRACING,
-						BPF_TRACE_RAW_TP),
-	BPF_PROG_BTF("fentry/",			BPF_PROG_TYPE_TRACING,
-						BPF_TRACE_FENTRY),
-	BPF_PROG_BTF("fexit/",			BPF_PROG_TYPE_TRACING,
-						BPF_TRACE_FEXIT),
+	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("fexit/", TRACING,
+		.expected_attach_type = BPF_TRACE_FEXIT,
+		.is_attach_btf = true,
+		.attach_fn = attach_trace),
 	BPF_PROG_SEC("xdp",			BPF_PROG_TYPE_XDP),
 	BPF_PROG_SEC("perf_event",		BPF_PROG_TYPE_PERF_EVENT),
 	BPF_PROG_SEC("lwt_in",			BPF_PROG_TYPE_LWT_IN),
@@ -5060,12 +5096,26 @@ static const struct {
 #undef BPF_APROG_SEC
 #undef BPF_EAPROG_SEC
 #undef BPF_APROG_COMPAT
+#undef SEC_DEF
 
 #define MAX_TYPE_NAME_SIZE 32
 
+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];
+	}
+	return NULL;
+}
+
 static char *libbpf_get_type_names(bool attach_type)
 {
-	int i, len = ARRAY_SIZE(section_names) * MAX_TYPE_NAME_SIZE;
+	int i, len = ARRAY_SIZE(section_defs) * MAX_TYPE_NAME_SIZE;
 	char *buf;
 
 	buf = malloc(len);
@@ -5074,16 +5124,16 @@ 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_names); i++) {
-		if (attach_type && !section_names[i].is_attachable)
+	for (i = 0; i < ARRAY_SIZE(section_defs); i++) {
+		if (attach_type && !section_defs[i].is_attachable)
 			continue;
 
-		if (strlen(buf) + strlen(section_names[i].sec) + 2 > len) {
+		if (strlen(buf) + strlen(section_defs[i].sec) + 2 > len) {
 			free(buf);
 			return NULL;
 		}
 		strcat(buf, " ");
-		strcat(buf, section_names[i].sec);
+		strcat(buf, section_defs[i].sec);
 	}
 
 	return buf;
@@ -5092,19 +5142,19 @@ static char *libbpf_get_type_names(bool attach_type)
 int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
 			     enum bpf_attach_type *expected_attach_type)
 {
+	const struct bpf_sec_def *sec_def;
 	char *type_names;
-	int i;
 
 	if (!name)
 		return -EINVAL;
 
-	for (i = 0; i < ARRAY_SIZE(section_names); i++) {
-		if (strncmp(name, section_names[i].sec, section_names[i].len))
-			continue;
-		*prog_type = section_names[i].prog_type;
-		*expected_attach_type = section_names[i].expected_attach_type;
+	sec_def = find_sec_def(name);
+	if (sec_def) {
+		*prog_type = sec_def->prog_type;
+		*expected_attach_type = sec_def->expected_attach_type;
 		return 0;
 	}
+
 	pr_warn("failed to guess program type from ELF section '%s'\n", name);
 	type_names = libbpf_get_type_names(false);
 	if (type_names != NULL) {
@@ -5187,16 +5237,16 @@ static int libbpf_find_attach_btf_id(const char *name,
 	if (!name)
 		return -EINVAL;
 
-	for (i = 0; i < ARRAY_SIZE(section_names); i++) {
-		if (!section_names[i].is_attach_btf)
+	for (i = 0; i < ARRAY_SIZE(section_defs); i++) {
+		if (!section_defs[i].is_attach_btf)
 			continue;
-		if (strncmp(name, section_names[i].sec, section_names[i].len))
+		if (strncmp(name, section_defs[i].sec, section_defs[i].len))
 			continue;
 		if (attach_prog_fd)
-			err = libbpf_find_prog_btf_id(name + section_names[i].len,
+			err = libbpf_find_prog_btf_id(name + section_defs[i].len,
 						      attach_prog_fd);
 		else
-			err = libbpf_find_vmlinux_btf_id(name + section_names[i].len,
+			err = libbpf_find_vmlinux_btf_id(name + section_defs[i].len,
 							 attach_type);
 		if (err <= 0)
 			pr_warn("%s is not found in vmlinux BTF\n", name);
@@ -5215,12 +5265,12 @@ int libbpf_attach_type_by_name(const char *name,
 	if (!name)
 		return -EINVAL;
 
-	for (i = 0; i < ARRAY_SIZE(section_names); i++) {
-		if (strncmp(name, section_names[i].sec, section_names[i].len))
+	for (i = 0; i < ARRAY_SIZE(section_defs); i++) {
+		if (strncmp(name, section_defs[i].sec, section_defs[i].len))
 			continue;
-		if (!section_names[i].is_attachable)
+		if (!section_defs[i].is_attachable)
 			return -EINVAL;
-		*attach_type = section_names[i].attach_type;
+		*attach_type = section_defs[i].attach_type;
 		return 0;
 	}
 	pr_warn("failed to guess attach type based on ELF section name '%s'\n", name);
@@ -5680,6 +5730,18 @@ struct bpf_link *bpf_program__attach_kprobe(struct bpf_program *prog,
 	return link;
 }
 
+static struct bpf_link *attach_kprobe(const struct bpf_sec_def *sec,
+				      struct bpf_program *prog)
+{
+	const char *func_name;
+	bool retprobe;
+
+	func_name = bpf_program__title(prog, false) + sec->len;
+	retprobe = strcmp(sec->sec, "kretprobe/") == 0;
+
+	return bpf_program__attach_kprobe(prog, retprobe, func_name);
+}
+
 struct bpf_link *bpf_program__attach_uprobe(struct bpf_program *prog,
 					    bool retprobe, pid_t pid,
 					    const char *binary_path,
@@ -5792,6 +5854,32 @@ struct bpf_link *bpf_program__attach_tracepoint(struct bpf_program *prog,
 	return link;
 }
 
+static struct bpf_link *attach_tp(const struct bpf_sec_def *sec,
+				  struct bpf_program *prog)
+{
+	char *sec_name, *tp_cat, *tp_name;
+	struct bpf_link *link;
+
+	sec_name = strdup(bpf_program__title(prog, false));
+	if (!sec_name)
+		return ERR_PTR(-ENOMEM);
+
+	/* extract "tp/<category>/<name>" */
+	tp_cat = sec_name + sec->len;
+	tp_name = strchr(tp_cat, '/');
+	if (!tp_name) {
+		link = ERR_PTR(-EINVAL);
+		goto out;
+	}
+	*tp_name = '\0';
+	tp_name++;
+
+	link = bpf_program__attach_tracepoint(prog, tp_cat, tp_name);
+out:
+	free(sec_name);
+	return link;
+}
+
 static int bpf_link__destroy_fd(struct bpf_link *link)
 {
 	struct bpf_link_fd *l = (void *)link;
@@ -5831,6 +5919,14 @@ struct bpf_link *bpf_program__attach_raw_tracepoint(struct bpf_program *prog,
 	return (struct bpf_link *)link;
 }
 
+static struct bpf_link *attach_raw_tp(const struct bpf_sec_def *sec,
+				      struct bpf_program *prog)
+{
+	const char *tp_name = bpf_program__title(prog, false) + sec->len;
+
+	return bpf_program__attach_raw_tracepoint(prog, tp_name);
+}
+
 struct bpf_link *bpf_program__attach_trace(struct bpf_program *prog)
 {
 	char errmsg[STRERR_BUFSIZE];
@@ -5862,6 +5958,23 @@ struct bpf_link *bpf_program__attach_trace(struct bpf_program *prog)
 	return (struct bpf_link *)link;
 }
 
+static struct bpf_link *attach_trace(const struct bpf_sec_def *sec,
+				     struct bpf_program *prog)
+{
+	return bpf_program__attach_trace(prog);
+}
+
+struct bpf_link *bpf_program__attach(struct bpf_program *prog)
+{
+	const struct bpf_sec_def *sec_def;
+
+	sec_def = find_sec_def(bpf_program__title(prog, false));
+	if (!sec_def || !sec_def->attach_fn)
+		return ERR_PTR(-ESRCH);
+
+	return sec_def->attach_fn(sec_def, prog);
+}
+
 enum bpf_perf_event_ret
 bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size,
 			   void **copy_mem, size_t *copy_size,
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 0dbf4bfba0c4..804f445c9957 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -237,6 +237,8 @@ struct bpf_link;
 
 LIBBPF_API int bpf_link__destroy(struct bpf_link *link);
 
+LIBBPF_API struct bpf_link *
+bpf_program__attach(struct bpf_program *prog);
 LIBBPF_API struct bpf_link *
 bpf_program__attach_perf_event(struct bpf_program *prog, int pfd);
 LIBBPF_API struct bpf_link *
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 495df575f87f..757a88f64b5a 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -210,4 +210,6 @@ LIBBPF_0.0.6 {
 } LIBBPF_0.0.5;
 
 LIBBPF_0.0.7 {
+	global:
+		bpf_program__attach;
 } LIBBPF_0.0.6;
diff --git a/tools/testing/selftests/bpf/prog_tests/probe_user.c b/tools/testing/selftests/bpf/prog_tests/probe_user.c
index 8a3187dec048..7aecfd9e87d1 100644
--- a/tools/testing/selftests/bpf/prog_tests/probe_user.c
+++ b/tools/testing/selftests/bpf/prog_tests/probe_user.c
@@ -3,8 +3,7 @@
 
 void test_probe_user(void)
 {
-#define kprobe_name "__sys_connect"
-	const char *prog_name = "kprobe/" kprobe_name;
+	const char *prog_name = "kprobe/__sys_connect";
 	const char *obj_file = "./test_probe_user.o";
 	DECLARE_LIBBPF_OPTS(bpf_object_open_opts, opts, );
 	int err, results_map_fd, sock_fd, duration = 0;
@@ -33,8 +32,7 @@ void test_probe_user(void)
 		  "err %d\n", results_map_fd))
 		goto cleanup;
 
-	kprobe_link = bpf_program__attach_kprobe(kprobe_prog, false,
-						 kprobe_name);
+	kprobe_link = bpf_program__attach(kprobe_prog);
 	if (CHECK(IS_ERR(kprobe_link), "attach_kprobe",
 		  "err %ld\n", PTR_ERR(kprobe_link))) {
 		kprobe_link = NULL;
-- 
cgit v1.2.3


From 612d05be250aa8804d3baba7a12445a267a580d3 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andriin@fb.com>
Date: Fri, 13 Dec 2019 17:43:27 -0800
Subject: libbpf: Move non-public APIs from libbpf.h to libbpf_internal.h

Few libbpf APIs are not public but currently exposed through libbpf.h to be
used by bpftool. Move them to libbpf_internal.h, where intent of being
non-stable and non-public is much more obvious.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-4-andriin@fb.com
---
 tools/bpf/bpftool/net.c         |  1 +
 tools/lib/bpf/libbpf.h          | 17 -----------------
 tools/lib/bpf/libbpf_internal.h | 17 +++++++++++++++++
 3 files changed, 18 insertions(+), 17 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/bpf/bpftool/net.c b/tools/bpf/bpftool/net.c
index 4f52d3151616..d93bee298e54 100644
--- a/tools/bpf/bpftool/net.c
+++ b/tools/bpf/bpftool/net.c
@@ -18,6 +18,7 @@
 
 #include <bpf.h>
 #include <nlattr.h>
+#include "libbpf_internal.h"
 #include "main.h"
 #include "netlink_dumper.h"
 
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 804f445c9957..2698fbcb0c79 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -126,11 +126,6 @@ bpf_object__open_buffer(const void *obj_buf, size_t obj_buf_sz,
 LIBBPF_API struct bpf_object *
 bpf_object__open_xattr(struct bpf_object_open_attr *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);
-
 enum libbpf_pin_type {
 	LIBBPF_PIN_NONE,
 	/* PIN_BY_NAME: pin maps by name (in /sys/fs/bpf by default) */
@@ -514,18 +509,6 @@ bpf_perf_event_read_simple(void *mmap_mem, size_t mmap_size, size_t page_size,
 			   void **copy_mem, size_t *copy_size,
 			   bpf_perf_event_print_t fn, void *private_data);
 
-struct nlattr;
-typedef int (*libbpf_dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb);
-int libbpf_netlink_open(unsigned int *nl_pid);
-int libbpf_nl_get_link(int sock, unsigned int nl_pid,
-		       libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie);
-int libbpf_nl_get_class(int sock, unsigned int nl_pid, int ifindex,
-			libbpf_dump_nlmsg_t dump_class_nlmsg, void *cookie);
-int libbpf_nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex,
-			libbpf_dump_nlmsg_t dump_qdisc_nlmsg, void *cookie);
-int libbpf_nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,
-			 libbpf_dump_nlmsg_t dump_filter_nlmsg, void *cookie);
-
 struct bpf_prog_linfo;
 struct bpf_prog_info;
 
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
index f4f10715db40..7d71621bb7e8 100644
--- a/tools/lib/bpf/libbpf_internal.h
+++ b/tools/lib/bpf/libbpf_internal.h
@@ -100,6 +100,23 @@ int parse_cpu_mask_file(const char *fcpu, bool **mask, int *mask_sz);
 int libbpf__load_raw_btf(const char *raw_types, size_t types_len,
 			 const char *str_sec, size_t str_len);
 
+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 nlattr;
+typedef int (*libbpf_dump_nlmsg_t)(void *cookie, void *msg, struct nlattr **tb);
+int libbpf_netlink_open(unsigned int *nl_pid);
+int libbpf_nl_get_link(int sock, unsigned int nl_pid,
+		       libbpf_dump_nlmsg_t dump_link_nlmsg, void *cookie);
+int libbpf_nl_get_class(int sock, unsigned int nl_pid, int ifindex,
+			libbpf_dump_nlmsg_t dump_class_nlmsg, void *cookie);
+int libbpf_nl_get_qdisc(int sock, unsigned int nl_pid, int ifindex,
+			libbpf_dump_nlmsg_t dump_qdisc_nlmsg, void *cookie);
+int libbpf_nl_get_filter(int sock, unsigned int nl_pid, int ifindex, int handle,
+			 libbpf_dump_nlmsg_t dump_filter_nlmsg, void *cookie);
+
 struct btf_ext_info {
 	/*
 	 * info points to the individual info section (e.g. func_info and
-- 
cgit v1.2.3


From 917f6b7b07a46e53fa73e112d23c97d1b201a877 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andriin@fb.com>
Date: Fri, 13 Dec 2019 17:43:28 -0800
Subject: libbpf: Add BPF_EMBED_OBJ macro for embedding BPF .o files

Add a convenience macro BPF_EMBED_OBJ, which allows to embed other files
(typically used to embed BPF .o files) into a hosting userspace programs. To
C program it is exposed as struct bpf_embed_data, containing a pointer to
raw data and its size in bytes.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-5-andriin@fb.com
---
 tools/lib/bpf/libbpf.h                             | 35 ++++++++++++++++++++++
 .../selftests/bpf/prog_tests/attach_probe.c        | 23 ++------------
 2 files changed, 38 insertions(+), 20 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 2698fbcb0c79..fa803dde1f46 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -615,6 +615,41 @@ bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear);
  */
 LIBBPF_API int libbpf_num_possible_cpus(void);
 
+struct bpf_embed_data {
+	void *data;
+	size_t size;
+};
+
+#define BPF_EMBED_OBJ_DECLARE(NAME)					\
+extern struct bpf_embed_data NAME##_embed;				\
+extern char NAME##_data[];						\
+extern char NAME##_data_end[];
+
+#define __BPF_EMBED_OBJ(NAME, PATH, SZ, ASM_TYPE)			\
+asm (									\
+"	.pushsection \".rodata\", \"a\", @progbits		\n"	\
+"	.global "#NAME"_data					\n"	\
+#NAME"_data:							\n"	\
+"	.incbin \"" PATH "\"					\n"	\
+"	.global "#NAME"_data_end				\n"	\
+#NAME"_data_end:						\n"	\
+"	.global "#NAME"_embed					\n"	\
+"	.type "#NAME"_embed, @object				\n"	\
+"	.size "#NAME"_size, "#SZ"				\n"	\
+"	.align 8,						\n"	\
+#NAME"_embed:							\n"	\
+"	"ASM_TYPE" "#NAME"_data					\n"	\
+"	"ASM_TYPE" "#NAME"_data_end - "#NAME"_data 		\n"	\
+"	.popsection						\n"	\
+);									\
+BPF_EMBED_OBJ_DECLARE(NAME)
+
+#if __SIZEOF_POINTER__ == 4
+#define BPF_EMBED_OBJ(NAME, PATH) __BPF_EMBED_OBJ(NAME, PATH, 8, ".long")
+#else
+#define BPF_EMBED_OBJ(NAME, PATH) __BPF_EMBED_OBJ(NAME, PATH, 16, ".quad")
+#endif
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif
diff --git a/tools/testing/selftests/bpf/prog_tests/attach_probe.c b/tools/testing/selftests/bpf/prog_tests/attach_probe.c
index a83111a32d4a..b2e7c1424b07 100644
--- a/tools/testing/selftests/bpf/prog_tests/attach_probe.c
+++ b/tools/testing/selftests/bpf/prog_tests/attach_probe.c
@@ -1,24 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <test_progs.h>
 
-#define EMBED_FILE(NAME, PATH)						    \
-asm (									    \
-"      .pushsection \".rodata\", \"a\", @progbits              \n"	    \
-"      .global "#NAME"_data                                    \n"	    \
-#NAME"_data:                                                   \n"	    \
-"      .incbin \"" PATH "\"                                    \n"	    \
-#NAME"_data_end:                                               \n"	    \
-"      .global "#NAME"_size                                    \n"	    \
-"      .type "#NAME"_size, @object                             \n"	    \
-"      .size "#NAME"_size, 4                                   \n"	    \
-"      .align 4,                                               \n"	    \
-#NAME"_size:                                                   \n"	    \
-"      .int "#NAME"_data_end - "#NAME"_data                    \n"	    \
-"      .popsection                                             \n"	    \
-);									    \
-extern char NAME##_data[];						    \
-extern int NAME##_size;
-
 ssize_t get_base_addr() {
 	size_t start;
 	char buf[256];
@@ -39,7 +21,7 @@ ssize_t get_base_addr() {
 	return -EINVAL;
 }
 
-EMBED_FILE(probe, "test_attach_probe.o");
+BPF_EMBED_OBJ(probe, "test_attach_probe.o");
 
 void test_attach_probe(void)
 {
@@ -73,7 +55,8 @@ void test_attach_probe(void)
 	uprobe_offset = (size_t)&get_base_addr - base_addr;
 
 	/* open object */
-	obj = bpf_object__open_mem(probe_data, probe_size, &open_opts);
+	obj = bpf_object__open_mem(probe_embed.data, probe_embed.size,
+				   &open_opts);
 	if (CHECK(IS_ERR(obj), "obj_open_mem", "err %ld\n", PTR_ERR(obj)))
 		return;
 
-- 
cgit v1.2.3


From 544402d4b49332a4a9b2b8fff20f9d9f5ef86559 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andriin@fb.com>
Date: Fri, 13 Dec 2019 17:43:29 -0800
Subject: libbpf: Extract common user-facing helpers

LIBBPF_API and DECLARE_LIBBPF_OPTS are needed in many public libbpf API
headers. Extract them into libbpf_common.h to avoid unnecessary
interdependency between btf.h, libbpf.h, and bpf.h or code duplication.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-6-andriin@fb.com
---
 tools/lib/bpf/bpf.h           |  6 ++----
 tools/lib/bpf/btf.h           |  6 ++----
 tools/lib/bpf/libbpf.h        | 28 ++--------------------------
 tools/lib/bpf/libbpf_common.h | 38 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 44 insertions(+), 34 deletions(-)
 create mode 100644 tools/lib/bpf/libbpf_common.h

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
index 3c791fa8e68e..269807ce9ef5 100644
--- a/tools/lib/bpf/bpf.h
+++ b/tools/lib/bpf/bpf.h
@@ -28,14 +28,12 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#include "libbpf_common.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-#ifndef LIBBPF_API
-#define LIBBPF_API __attribute__((visibility("default")))
-#endif
-
 struct bpf_create_map_attr {
 	const char *name;
 	enum bpf_map_type map_type;
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index d9ac73a02cde..5fc23b988deb 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -8,14 +8,12 @@
 #include <linux/btf.h>
 #include <linux/types.h>
 
+#include "libbpf_common.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-#ifndef LIBBPF_API
-#define LIBBPF_API __attribute__((visibility("default")))
-#endif
-
 #define BTF_ELF_SEC ".BTF"
 #define BTF_EXT_ELF_SEC ".BTF.ext"
 #define MAPS_ELF_SEC ".maps"
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index fa803dde1f46..49e6fa01024b 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -17,14 +17,12 @@
 #include <sys/types.h>  // for size_t
 #include <linux/bpf.h>
 
+#include "libbpf_common.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-#ifndef LIBBPF_API
-#define LIBBPF_API __attribute__((visibility("default")))
-#endif
-
 enum libbpf_errno {
 	__LIBBPF_ERRNO__START = 4000,
 
@@ -67,28 +65,6 @@ struct bpf_object_open_attr {
 	enum bpf_prog_type prog_type;
 };
 
-/* Helper macro to declare and initialize libbpf options struct
- *
- * This dance with uninitialized declaration, followed by memset to zero,
- * followed by assignment using compound literal syntax is done to preserve
- * ability to use a nice struct field initialization syntax and **hopefully**
- * have all the padding bytes initialized to zero. It's not guaranteed though,
- * when copying literal, that compiler won't copy garbage in literal's padding
- * bytes, but that's the best way I've found and it seems to work in practice.
- *
- * Macro declares opts struct of given type and name, zero-initializes,
- * including any extra padding, it with memset() and then assigns initial
- * values provided by users in struct initializer-syntax as varargs.
- */
-#define DECLARE_LIBBPF_OPTS(TYPE, NAME, ...)				    \
-	struct TYPE NAME = ({ 						    \
-		memset(&NAME, 0, sizeof(struct TYPE));			    \
-		(struct TYPE) {						    \
-			.sz = sizeof(struct TYPE),			    \
-			__VA_ARGS__					    \
-		};							    \
-	})
-
 struct bpf_object_open_opts {
 	/* size of this struct, for forward/backward compatiblity */
 	size_t sz;
diff --git a/tools/lib/bpf/libbpf_common.h b/tools/lib/bpf/libbpf_common.h
new file mode 100644
index 000000000000..4fb833840961
--- /dev/null
+++ b/tools/lib/bpf/libbpf_common.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
+
+/*
+ * Common user-facing libbpf helpers.
+ *
+ * Copyright (c) 2019 Facebook
+ */
+
+#ifndef __LIBBPF_LIBBPF_COMMON_H
+#define __LIBBPF_LIBBPF_COMMON_H
+
+#ifndef LIBBPF_API
+#define LIBBPF_API __attribute__((visibility("default")))
+#endif
+
+/* Helper macro to declare and initialize libbpf options struct
+ *
+ * This dance with uninitialized declaration, followed by memset to zero,
+ * followed by assignment using compound literal syntax is done to preserve
+ * ability to use a nice struct field initialization syntax and **hopefully**
+ * have all the padding bytes initialized to zero. It's not guaranteed though,
+ * when copying literal, that compiler won't copy garbage in literal's padding
+ * bytes, but that's the best way I've found and it seems to work in practice.
+ *
+ * Macro declares opts struct of given type and name, zero-initializes,
+ * including any extra padding, it with memset() and then assigns initial
+ * values provided by users in struct initializer-syntax as varargs.
+ */
+#define DECLARE_LIBBPF_OPTS(TYPE, NAME, ...)				    \
+	struct TYPE NAME = ({ 						    \
+		memset(&NAME, 0, sizeof(struct TYPE));			    \
+		(struct TYPE) {						    \
+			.sz = sizeof(struct TYPE),			    \
+			__VA_ARGS__					    \
+		};							    \
+	})
+
+#endif /* __LIBBPF_LIBBPF_COMMON_H */
-- 
cgit v1.2.3


From 3d208f4ca111a614903f49d5a77b93ddc6de294e Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andriin@fb.com>
Date: Fri, 13 Dec 2019 17:43:30 -0800
Subject: libbpf: Expose btf__align_of() API

Expose BTF API that calculates type alignment requirements.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-7-andriin@fb.com
---
 tools/lib/bpf/btf.c      | 39 +++++++++++++++++++++++++++++++++++++++
 tools/lib/bpf/btf.h      |  1 +
 tools/lib/bpf/btf_dump.c | 47 ++++++-----------------------------------------
 tools/lib/bpf/libbpf.map |  1 +
 4 files changed, 47 insertions(+), 41 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 88efa2bb7137..84fe82f27bef 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -278,6 +278,45 @@ done:
 	return nelems * size;
 }
 
+int btf__align_of(const struct btf *btf, __u32 id)
+{
+	const struct btf_type *t = btf__type_by_id(btf, id);
+	__u16 kind = btf_kind(t);
+
+	switch (kind) {
+	case BTF_KIND_INT:
+	case BTF_KIND_ENUM:
+		return min(sizeof(void *), t->size);
+	case BTF_KIND_PTR:
+		return sizeof(void *);
+	case BTF_KIND_TYPEDEF:
+	case BTF_KIND_VOLATILE:
+	case BTF_KIND_CONST:
+	case BTF_KIND_RESTRICT:
+		return btf__align_of(btf, t->type);
+	case BTF_KIND_ARRAY:
+		return btf__align_of(btf, btf_array(t)->type);
+	case BTF_KIND_STRUCT:
+	case BTF_KIND_UNION: {
+		const struct btf_member *m = btf_members(t);
+		__u16 vlen = btf_vlen(t);
+		int i, align = 1, t;
+
+		for (i = 0; i < vlen; i++, m++) {
+			t = btf__align_of(btf, m->type);
+			if (t <= 0)
+				return t;
+			align = max(align, t);
+		}
+
+		return align;
+	}
+	default:
+		pr_warn("unsupported BTF_KIND:%u\n", btf_kind(t));
+		return 0;
+	}
+}
+
 int btf__resolve_type(const struct btf *btf, __u32 type_id)
 {
 	const struct btf_type *t;
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 5fc23b988deb..a114c8ef4f08 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -77,6 +77,7 @@ LIBBPF_API const struct btf_type *btf__type_by_id(const struct btf *btf,
 						  __u32 id);
 LIBBPF_API __s64 btf__resolve_size(const struct btf *btf, __u32 type_id);
 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 const void *btf__get_raw_data(const struct btf *btf, __u32 *size);
 LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset);
diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index cb126d8fcf75..53393026d085 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -752,41 +752,6 @@ static void btf_dump_emit_type(struct btf_dump *d, __u32 id, __u32 cont_id)
 	}
 }
 
-static int btf_align_of(const struct btf *btf, __u32 id)
-{
-	const struct btf_type *t = btf__type_by_id(btf, id);
-	__u16 kind = btf_kind(t);
-
-	switch (kind) {
-	case BTF_KIND_INT:
-	case BTF_KIND_ENUM:
-		return min(sizeof(void *), t->size);
-	case BTF_KIND_PTR:
-		return sizeof(void *);
-	case BTF_KIND_TYPEDEF:
-	case BTF_KIND_VOLATILE:
-	case BTF_KIND_CONST:
-	case BTF_KIND_RESTRICT:
-		return btf_align_of(btf, t->type);
-	case BTF_KIND_ARRAY:
-		return btf_align_of(btf, btf_array(t)->type);
-	case BTF_KIND_STRUCT:
-	case BTF_KIND_UNION: {
-		const struct btf_member *m = btf_members(t);
-		__u16 vlen = btf_vlen(t);
-		int i, align = 1;
-
-		for (i = 0; i < vlen; i++, m++)
-			align = max(align, btf_align_of(btf, m->type));
-
-		return align;
-	}
-	default:
-		pr_warn("unsupported BTF_KIND:%u\n", btf_kind(t));
-		return 1;
-	}
-}
-
 static bool btf_is_struct_packed(const struct btf *btf, __u32 id,
 				 const struct btf_type *t)
 {
@@ -794,18 +759,18 @@ static bool btf_is_struct_packed(const struct btf *btf, __u32 id,
 	int align, i, bit_sz;
 	__u16 vlen;
 
-	align = btf_align_of(btf, id);
+	align = btf__align_of(btf, id);
 	/* size of a non-packed struct has to be a multiple of its alignment*/
-	if (t->size % align)
+	if (align && t->size % align)
 		return true;
 
 	m = btf_members(t);
 	vlen = btf_vlen(t);
 	/* all non-bitfield fields have to be naturally aligned */
 	for (i = 0; i < vlen; i++, m++) {
-		align = btf_align_of(btf, m->type);
+		align = btf__align_of(btf, m->type);
 		bit_sz = btf_member_bitfield_size(t, i);
-		if (bit_sz == 0 && m->offset % (8 * align) != 0)
+		if (align && bit_sz == 0 && m->offset % (8 * align) != 0)
 			return true;
 	}
 
@@ -889,7 +854,7 @@ static void btf_dump_emit_struct_def(struct btf_dump *d,
 		fname = btf_name_of(d, m->name_off);
 		m_sz = btf_member_bitfield_size(t, i);
 		m_off = btf_member_bit_offset(t, i);
-		align = packed ? 1 : btf_align_of(d->btf, m->type);
+		align = packed ? 1 : btf__align_of(d->btf, m->type);
 
 		btf_dump_emit_bit_padding(d, off, m_off, m_sz, align, lvl + 1);
 		btf_dump_printf(d, "\n%s", pfx(lvl + 1));
@@ -907,7 +872,7 @@ static void btf_dump_emit_struct_def(struct btf_dump *d,
 
 	/* pad at the end, if necessary */
 	if (is_struct) {
-		align = packed ? 1 : btf_align_of(d->btf, id);
+		align = packed ? 1 : btf__align_of(d->btf, id);
 		btf_dump_emit_bit_padding(d, off, t->size * 8, 0, align,
 					  lvl + 1);
 	}
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 757a88f64b5a..e7fcca36f186 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -212,4 +212,5 @@ LIBBPF_0.0.6 {
 LIBBPF_0.0.7 {
 	global:
 		bpf_program__attach;
+		btf__align_of;
 } LIBBPF_0.0.6;
-- 
cgit v1.2.3


From 9f81654eebe8de7e0db15534816d8f6c84b2e1e5 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andriin@fb.com>
Date: Fri, 13 Dec 2019 17:43:31 -0800
Subject: libbpf: Expose BTF-to-C type declaration emitting API

Expose API that allows to emit type declaration and field/variable definition
(if optional field name is specified) in valid C syntax for any provided BTF
type. This is going to be used by bpftool when emitting data section layout as
a struct. As part of making this API useful in a stand-alone fashion, move
initialization of some of the internal btf_dump state to earlier phase.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-8-andriin@fb.com
---
 tools/lib/bpf/btf.h      | 22 ++++++++++++++++
 tools/lib/bpf/btf_dump.c | 68 ++++++++++++++++++++++++++++++------------------
 tools/lib/bpf/libbpf.map |  1 +
 3 files changed, 65 insertions(+), 26 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index a114c8ef4f08..8d73f7f5551f 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -126,6 +126,28 @@ LIBBPF_API void btf_dump__free(struct btf_dump *d);
 
 LIBBPF_API int btf_dump__dump_type(struct btf_dump *d, __u32 id);
 
+struct btf_dump_emit_type_decl_opts {
+	/* size of this struct, for forward/backward compatiblity */
+	size_t sz;
+	/* optional field name for type declaration, e.g.:
+	 * - struct my_struct <FNAME>
+	 * - void (*<FNAME>)(int)
+	 * - char (*<FNAME>)[123]
+	 */
+	const char *field_name;
+	/* extra indentation level (in number of tabs) to emit for multi-line
+	 * type declarations (e.g., anonymous struct); applies for lines
+	 * starting from the second one (first line is assumed to have
+	 * necessary indentation already
+	 */
+	int indent_level;
+};
+#define btf_dump_emit_type_decl_opts__last_field indent_level
+
+LIBBPF_API int
+btf_dump__emit_type_decl(struct btf_dump *d, __u32 id,
+			 const struct btf_dump_emit_type_decl_opts *opts);
+
 /*
  * A set of helpers for easier BTF types handling
  */
diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index 53393026d085..e95f7710f210 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -116,6 +116,8 @@ static void btf_dump_printf(const struct btf_dump *d, const char *fmt, ...)
 	va_end(args);
 }
 
+static int btf_dump_mark_referenced(struct btf_dump *d);
+
 struct btf_dump *btf_dump__new(const struct btf *btf,
 			       const struct btf_ext *btf_ext,
 			       const struct btf_dump_opts *opts,
@@ -137,18 +139,39 @@ struct btf_dump *btf_dump__new(const struct btf *btf,
 	if (IS_ERR(d->type_names)) {
 		err = PTR_ERR(d->type_names);
 		d->type_names = NULL;
-		btf_dump__free(d);
-		return ERR_PTR(err);
 	}
 	d->ident_names = hashmap__new(str_hash_fn, str_equal_fn, NULL);
 	if (IS_ERR(d->ident_names)) {
 		err = PTR_ERR(d->ident_names);
 		d->ident_names = NULL;
-		btf_dump__free(d);
-		return ERR_PTR(err);
+		goto err;
+	}
+	d->type_states = calloc(1 + btf__get_nr_types(d->btf),
+				sizeof(d->type_states[0]));
+	if (!d->type_states) {
+		err = -ENOMEM;
+		goto err;
+	}
+	d->cached_names = calloc(1 + btf__get_nr_types(d->btf),
+				 sizeof(d->cached_names[0]));
+	if (!d->cached_names) {
+		err = -ENOMEM;
+		goto err;
 	}
 
+	/* VOID is special */
+	d->type_states[0].order_state = ORDERED;
+	d->type_states[0].emit_state = EMITTED;
+
+	/* eagerly determine referenced types for anon enums */
+	err = btf_dump_mark_referenced(d);
+	if (err)
+		goto err;
+
 	return d;
+err:
+	btf_dump__free(d);
+	return ERR_PTR(err);
 }
 
 void btf_dump__free(struct btf_dump *d)
@@ -175,7 +198,6 @@ void btf_dump__free(struct btf_dump *d)
 	free(d);
 }
 
-static int btf_dump_mark_referenced(struct btf_dump *d);
 static int btf_dump_order_type(struct btf_dump *d, __u32 id, bool through_ptr);
 static void btf_dump_emit_type(struct btf_dump *d, __u32 id, __u32 cont_id);
 
@@ -202,27 +224,6 @@ int btf_dump__dump_type(struct btf_dump *d, __u32 id)
 	if (id > btf__get_nr_types(d->btf))
 		return -EINVAL;
 
-	/* type states are lazily allocated, as they might not be needed */
-	if (!d->type_states) {
-		d->type_states = calloc(1 + btf__get_nr_types(d->btf),
-					sizeof(d->type_states[0]));
-		if (!d->type_states)
-			return -ENOMEM;
-		d->cached_names = calloc(1 + btf__get_nr_types(d->btf),
-					 sizeof(d->cached_names[0]));
-		if (!d->cached_names)
-			return -ENOMEM;
-
-		/* VOID is special */
-		d->type_states[0].order_state = ORDERED;
-		d->type_states[0].emit_state = EMITTED;
-
-		/* eagerly determine referenced types for anon enums */
-		err = btf_dump_mark_referenced(d);
-		if (err)
-			return err;
-	}
-
 	d->emit_queue_cnt = 0;
 	err = btf_dump_order_type(d, id, false);
 	if (err < 0)
@@ -1016,6 +1017,21 @@ static int btf_dump_push_decl_stack_id(struct btf_dump *d, __u32 id)
  * of a stack frame. Some care is required to "pop" stack frames after
  * processing type declaration chain.
  */
+int btf_dump__emit_type_decl(struct btf_dump *d, __u32 id,
+			     const struct btf_dump_emit_type_decl_opts *opts)
+{
+	const char *fname;
+	int lvl;
+
+	if (!OPTS_VALID(opts, btf_dump_emit_type_decl_opts))
+		return -EINVAL;
+
+	fname = OPTS_GET(opts, field_name, NULL);
+	lvl = OPTS_GET(opts, indent_level, 0);
+	btf_dump_emit_type_decl(d, id, fname, lvl);
+	return 0;
+}
+
 static void btf_dump_emit_type_decl(struct btf_dump *d, __u32 id,
 				    const char *fname, int lvl)
 {
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index e7fcca36f186..990c7c0e2d9f 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -211,6 +211,7 @@ LIBBPF_0.0.6 {
 
 LIBBPF_0.0.7 {
 	global:
+		btf_dump__emit_type_decl;
 		bpf_program__attach;
 		btf__align_of;
 } LIBBPF_0.0.6;
-- 
cgit v1.2.3


From 01af3bf06755dc5cda7050fe5d898998e5775e63 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andriin@fb.com>
Date: Fri, 13 Dec 2019 17:43:32 -0800
Subject: libbpf: Expose BPF program's function name

Add APIs to get BPF program function name, as opposed to bpf_program__title(),
which returns BPF program function's section name. Function name has a benefit
of being a valid C identifier and uniquely identifies a specific BPF program,
while section name can be duplicated across multiple independent BPF programs.

Add also bpf_object__find_program_by_name(), similar to
bpf_object__find_program_by_title(), to facilitate looking up BPF programs by
their C function names.

Convert one of selftests to new API for look up.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-9-andriin@fb.com
---
 tools/lib/bpf/libbpf.c                             | 28 ++++++++++++++++++----
 tools/lib/bpf/libbpf.h                             |  9 +++++--
 tools/lib/bpf/libbpf.map                           |  2 ++
 .../testing/selftests/bpf/prog_tests/rdonly_maps.c | 11 ++++-----
 4 files changed, 36 insertions(+), 14 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 61b8cdf78332..e7a6b57d849c 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -209,8 +209,8 @@ static const char * const libbpf_type_to_btf_name[] = {
 };
 
 struct bpf_map {
-	int fd;
 	char *name;
+	int fd;
 	int sec_idx;
 	size_t sec_offset;
 	int map_ifindex;
@@ -1384,7 +1384,7 @@ static int bpf_object__init_user_btf_maps(struct bpf_object *obj, bool strict,
 }
 
 static int bpf_object__init_maps(struct bpf_object *obj,
-				 struct bpf_object_open_opts *opts)
+				 const struct bpf_object_open_opts *opts)
 {
 	const char *pin_root_path = OPTS_GET(opts, pin_root_path, NULL);
 	bool strict = !OPTS_GET(opts, relaxed_maps, false);
@@ -1748,6 +1748,19 @@ bpf_object__find_program_by_title(const struct bpf_object *obj,
 	return NULL;
 }
 
+struct bpf_program *
+bpf_object__find_program_by_name(const struct bpf_object *obj,
+				 const char *name)
+{
+	struct bpf_program *prog;
+
+	bpf_object__for_each_program(prog, obj) {
+		if (!strcmp(prog->name, name))
+			return prog;
+	}
+	return NULL;
+}
+
 static bool bpf_object__shndx_is_data(const struct bpf_object *obj,
 				      int shndx)
 {
@@ -3894,7 +3907,7 @@ static int libbpf_find_attach_btf_id(const char *name,
 				     __u32 attach_prog_fd);
 static struct bpf_object *
 __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz,
-		   struct bpf_object_open_opts *opts)
+		   const struct bpf_object_open_opts *opts)
 {
 	struct bpf_program *prog;
 	struct bpf_object *obj;
@@ -4003,7 +4016,7 @@ struct bpf_object *bpf_object__open(const char *path)
 }
 
 struct bpf_object *
-bpf_object__open_file(const char *path, struct bpf_object_open_opts *opts)
+bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts)
 {
 	if (!path)
 		return ERR_PTR(-EINVAL);
@@ -4015,7 +4028,7 @@ bpf_object__open_file(const char *path, struct bpf_object_open_opts *opts)
 
 struct bpf_object *
 bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz,
-		     struct bpf_object_open_opts *opts)
+		     const struct bpf_object_open_opts *opts)
 {
 	if (!obj_buf || obj_buf_sz == 0)
 		return ERR_PTR(-EINVAL);
@@ -4820,6 +4833,11 @@ void bpf_program__set_ifindex(struct bpf_program *prog, __u32 ifindex)
 	prog->prog_ifindex = ifindex;
 }
 
+const char *bpf_program__name(const struct bpf_program *prog)
+{
+	return prog->name;
+}
+
 const char *bpf_program__title(const struct bpf_program *prog, bool needs_copy)
 {
 	const char *title;
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index 49e6fa01024b..f37bd4a3e14b 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -90,10 +90,10 @@ struct bpf_object_open_opts {
 
 LIBBPF_API struct bpf_object *bpf_object__open(const char *path);
 LIBBPF_API struct bpf_object *
-bpf_object__open_file(const char *path, struct bpf_object_open_opts *opts);
+bpf_object__open_file(const char *path, const struct bpf_object_open_opts *opts);
 LIBBPF_API struct bpf_object *
 bpf_object__open_mem(const void *obj_buf, size_t obj_buf_sz,
-		     struct bpf_object_open_opts *opts);
+		     const struct bpf_object_open_opts *opts);
 
 /* deprecated bpf_object__open variants */
 LIBBPF_API struct bpf_object *
@@ -132,6 +132,7 @@ struct bpf_object_load_attr {
 LIBBPF_API int bpf_object__load(struct bpf_object *obj);
 LIBBPF_API int bpf_object__load_xattr(struct bpf_object_load_attr *attr);
 LIBBPF_API int bpf_object__unload(struct bpf_object *obj);
+
 LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj);
 LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj);
 
@@ -142,6 +143,9 @@ LIBBPF_API int bpf_object__btf_fd(const struct bpf_object *obj);
 LIBBPF_API struct bpf_program *
 bpf_object__find_program_by_title(const struct bpf_object *obj,
 				  const char *title);
+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);
 #define bpf_object__for_each_safe(pos, tmp)			\
@@ -185,6 +189,7 @@ LIBBPF_API void *bpf_program__priv(const struct bpf_program *prog);
 LIBBPF_API void bpf_program__set_ifindex(struct bpf_program *prog,
 					 __u32 ifindex);
 
+LIBBPF_API const char *bpf_program__name(const struct bpf_program *prog);
 LIBBPF_API const char *bpf_program__title(const struct bpf_program *prog,
 					  bool needs_copy);
 
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 990c7c0e2d9f..5a7630748eeb 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -212,6 +212,8 @@ LIBBPF_0.0.6 {
 LIBBPF_0.0.7 {
 	global:
 		btf_dump__emit_type_decl;
+		bpf_object__find_program_by_name;
 		bpf_program__attach;
+		bpf_program__name;
 		btf__align_of;
 } LIBBPF_0.0.6;
diff --git a/tools/testing/selftests/bpf/prog_tests/rdonly_maps.c b/tools/testing/selftests/bpf/prog_tests/rdonly_maps.c
index d90acc13d1ec..563e12120e77 100644
--- a/tools/testing/selftests/bpf/prog_tests/rdonly_maps.c
+++ b/tools/testing/selftests/bpf/prog_tests/rdonly_maps.c
@@ -16,14 +16,11 @@ struct rdonly_map_subtest {
 
 void test_rdonly_maps(void)
 {
-	const char *prog_name_skip_loop = "raw_tracepoint/sys_enter:skip_loop";
-	const char *prog_name_part_loop = "raw_tracepoint/sys_enter:part_loop";
-	const char *prog_name_full_loop = "raw_tracepoint/sys_enter:full_loop";
 	const char *file = "test_rdonly_maps.o";
 	struct rdonly_map_subtest subtests[] = {
-		{ "skip loop", prog_name_skip_loop, 0, 0 },
-		{ "part loop", prog_name_part_loop, 3, 2 + 3 + 4 },
-		{ "full loop", prog_name_full_loop, 4, 2 + 3 + 4 + 5 },
+		{ "skip loop", "skip_loop", 0, 0 },
+		{ "part loop", "part_loop", 3, 2 + 3 + 4 },
+		{ "full loop", "full_loop", 4, 2 + 3 + 4 + 5 },
 	};
 	int i, err, zero = 0, duration = 0;
 	struct bpf_link *link = NULL;
@@ -50,7 +47,7 @@ void test_rdonly_maps(void)
 		if (!test__start_subtest(t->subtest_name))
 			continue;
 
-		prog = bpf_object__find_program_by_title(obj, t->prog_name);
+		prog = bpf_object__find_program_by_name(obj, t->prog_name);
 		if (CHECK(!prog, "find_prog", "prog '%s' not found\n",
 			  t->prog_name))
 			goto cleanup;
-- 
cgit v1.2.3


From eba9c5f498a11a8558e099d14692c24f2fea27e3 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andriin@fb.com>
Date: Fri, 13 Dec 2019 17:43:33 -0800
Subject: libbpf: Refactor global data map initialization

Refactor global data map initialization to use anonymous mmap()-ed memory
instead of malloc()-ed one. This allows to do a transparent re-mmap()-ing of
already existing memory address to point to BPF map's memory after
bpf_object__load() step (done in follow up patch). This choreographed setup
allows to have a nice and unsurprising way to pre-initialize read-only (and
r/w as well) maps by user and after BPF map creation keep working with
mmap()-ed contents of this map. All in a way that doesn't require user code to
update any pointers: the illusion of working with memory contents is preserved
before and after actual BPF map instantiation.

Selftests and runqslower example demonstrate this feature in follow up patches.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-10-andriin@fb.com
---
 tools/lib/bpf/libbpf.c | 97 ++++++++++++++++++++++++++++++--------------------
 1 file changed, 59 insertions(+), 38 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index e7a6b57d849c..06dfa36ed0bb 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -221,16 +221,12 @@ struct bpf_map {
 	void *priv;
 	bpf_map_clear_priv_t clear_priv;
 	enum libbpf_map_type libbpf_type;
+	void *mmaped;
 	char *pin_path;
 	bool pinned;
 	bool reused;
 };
 
-struct bpf_secdata {
-	void *rodata;
-	void *data;
-};
-
 static LIST_HEAD(bpf_objects_list);
 
 struct bpf_object {
@@ -243,7 +239,6 @@ struct bpf_object {
 	struct bpf_map *maps;
 	size_t nr_maps;
 	size_t maps_cap;
-	struct bpf_secdata sections;
 
 	bool loaded;
 	bool has_pseudo_calls;
@@ -828,13 +823,24 @@ static struct bpf_map *bpf_object__add_map(struct bpf_object *obj)
 	return &obj->maps[obj->nr_maps++];
 }
 
+static size_t bpf_map_mmap_sz(const struct bpf_map *map)
+{
+	long page_sz = sysconf(_SC_PAGE_SIZE);
+	size_t map_sz;
+
+	map_sz = roundup(map->def.value_size, 8) * map->def.max_entries;
+	map_sz = roundup(map_sz, page_sz);
+	return map_sz;
+}
+
 static int
 bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
-			      int sec_idx, Elf_Data *data, void **data_buff)
+			      int sec_idx, void *data, size_t data_sz)
 {
 	char map_name[BPF_OBJ_NAME_LEN];
 	struct bpf_map_def *def;
 	struct bpf_map *map;
+	int err;
 
 	map = bpf_object__add_map(obj);
 	if (IS_ERR(map))
@@ -854,7 +860,7 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
 	def = &map->def;
 	def->type = BPF_MAP_TYPE_ARRAY;
 	def->key_size = sizeof(int);
-	def->value_size = data->d_size;
+	def->value_size = data_sz;
 	def->max_entries = 1;
 	def->map_flags = type == LIBBPF_MAP_RODATA ? BPF_F_RDONLY_PROG : 0;
 	def->map_flags |= BPF_F_MMAPABLE;
@@ -862,16 +868,20 @@ bpf_object__init_internal_map(struct bpf_object *obj, enum libbpf_map_type type,
 	pr_debug("map '%s' (global data): at sec_idx %d, offset %zu, flags %x.\n",
 		 map_name, map->sec_idx, map->sec_offset, def->map_flags);
 
-	if (data_buff) {
-		*data_buff = malloc(data->d_size);
-		if (!*data_buff) {
-			zfree(&map->name);
-			pr_warn("failed to alloc map content buffer\n");
-			return -ENOMEM;
-		}
-		memcpy(*data_buff, data->d_buf, data->d_size);
+	map->mmaped = mmap(NULL, bpf_map_mmap_sz(map), PROT_READ | PROT_WRITE,
+			   MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+	if (map->mmaped == MAP_FAILED) {
+		err = -errno;
+		map->mmaped = NULL;
+		pr_warn("failed to alloc map '%s' content buffer: %d\n",
+			map->name, err);
+		zfree(&map->name);
+		return err;
 	}
 
+	if (type != LIBBPF_MAP_BSS)
+		memcpy(map->mmaped, data, data_sz);
+
 	pr_debug("map %td is \"%s\"\n", map - obj->maps, map->name);
 	return 0;
 }
@@ -886,23 +896,24 @@ static int bpf_object__init_global_data_maps(struct bpf_object *obj)
 	if (obj->efile.data_shndx >= 0) {
 		err = bpf_object__init_internal_map(obj, LIBBPF_MAP_DATA,
 						    obj->efile.data_shndx,
-						    obj->efile.data,
-						    &obj->sections.data);
+						    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,
-						    &obj->sections.rodata);
+						    obj->efile.rodata->d_buf,
+						    obj->efile.rodata->d_size);
 		if (err)
 			return err;
 	}
 	if (obj->efile.bss_shndx >= 0) {
 		err = bpf_object__init_internal_map(obj, LIBBPF_MAP_BSS,
 						    obj->efile.bss_shndx,
-						    obj->efile.bss, NULL);
+						    NULL,
+						    obj->efile.bss->d_size);
 		if (err)
 			return err;
 	}
@@ -2292,27 +2303,32 @@ bpf_object__populate_internal_map(struct bpf_object *obj, struct bpf_map *map)
 {
 	char *cp, errmsg[STRERR_BUFSIZE];
 	int err, zero = 0;
-	__u8 *data;
 
 	/* Nothing to do here since kernel already zero-initializes .bss map. */
 	if (map->libbpf_type == LIBBPF_MAP_BSS)
 		return 0;
 
-	data = map->libbpf_type == LIBBPF_MAP_DATA ?
-	       obj->sections.data : obj->sections.rodata;
+	err = bpf_map_update_elem(map->fd, &zero, map->mmaped, 0);
+	if (err) {
+		err = -errno;
+		cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
+		pr_warn("Error setting initial map(%s) contents: %s\n",
+			map->name, cp);
+		return err;
+	}
 
-	err = bpf_map_update_elem(map->fd, &zero, data, 0);
 	/* Freeze .rodata map as read-only from syscall side. */
-	if (!err && map->libbpf_type == LIBBPF_MAP_RODATA) {
+	if (map->libbpf_type == LIBBPF_MAP_RODATA) {
 		err = bpf_map_freeze(map->fd);
 		if (err) {
-			cp = libbpf_strerror_r(errno, errmsg, sizeof(errmsg));
+			err = -errno;
+			cp = libbpf_strerror_r(err, errmsg, sizeof(errmsg));
 			pr_warn("Error freezing map(%s) as read-only: %s\n",
 				map->name, cp);
-			err = 0;
+			return err;
 		}
 	}
-	return err;
+	return 0;
 }
 
 static int
@@ -4683,17 +4699,22 @@ void bpf_object__close(struct bpf_object *obj)
 	btf_ext__free(obj->btf_ext);
 
 	for (i = 0; i < obj->nr_maps; i++) {
-		zfree(&obj->maps[i].name);
-		zfree(&obj->maps[i].pin_path);
-		if (obj->maps[i].clear_priv)
-			obj->maps[i].clear_priv(&obj->maps[i],
-						obj->maps[i].priv);
-		obj->maps[i].priv = NULL;
-		obj->maps[i].clear_priv = NULL;
+		struct bpf_map *map = &obj->maps[i];
+
+		if (map->clear_priv)
+			map->clear_priv(map, map->priv);
+		map->priv = NULL;
+		map->clear_priv = NULL;
+
+		if (map->mmaped) {
+			munmap(map->mmaped, bpf_map_mmap_sz(map));
+			map->mmaped = NULL;
+		}
+
+		zfree(&map->name);
+		zfree(&map->pin_path);
 	}
 
-	zfree(&obj->sections.rodata);
-	zfree(&obj->sections.data);
 	zfree(&obj->maps);
 	obj->nr_maps = 0;
 
-- 
cgit v1.2.3


From 13acb508ae203075134327551a6705e6e8f23d48 Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andriin@fb.com>
Date: Fri, 13 Dec 2019 17:43:34 -0800
Subject: libbpf: Postpone BTF ID finding for TRACING programs to load phase

Move BTF ID determination for BPF_PROG_TYPE_TRACING programs to a load phase.
Performing it at open step is inconvenient, because it prevents BPF skeleton
generation on older host kernel, which doesn't contain BTF_KIND_FUNCs
information in vmlinux BTF. This is a common set up, though, when, e.g.,
selftests are compiled on older host kernel, but the test program itself is
executed in qemu VM with bleeding edge kernel. Having this BTF searching
performed at load time allows to successfully use bpf_object__open() for
codegen and inspection of BPF object file.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-11-andriin@fb.com
---
 tools/lib/bpf/libbpf.c | 37 ++++++++++++++++++-------------------
 1 file changed, 18 insertions(+), 19 deletions(-)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 06dfa36ed0bb..3488ac4f7015 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -3815,11 +3815,22 @@ out:
 	return ret;
 }
 
-int
-bpf_program__load(struct bpf_program *prog,
-		  char *license, __u32 kern_version)
+static int libbpf_find_attach_btf_id(const char *name,
+				     enum bpf_attach_type attach_type,
+				     __u32 attach_prog_fd);
+
+int bpf_program__load(struct bpf_program *prog, char *license, __u32 kern_ver)
 {
-	int err = 0, fd, i;
+	int err = 0, fd, i, btf_id;
+
+	if (prog->type == BPF_PROG_TYPE_TRACING) {
+		btf_id = libbpf_find_attach_btf_id(prog->section_name,
+						   prog->expected_attach_type,
+						   prog->attach_prog_fd);
+		if (btf_id <= 0)
+			return btf_id;
+		prog->attach_btf_id = btf_id;
+	}
 
 	if (prog->instances.nr < 0 || !prog->instances.fds) {
 		if (prog->preprocessor) {
@@ -3843,7 +3854,7 @@ bpf_program__load(struct bpf_program *prog,
 				prog->section_name, prog->instances.nr);
 		}
 		err = load_program(prog, prog->insns, prog->insns_cnt,
-				   license, kern_version, &fd);
+				   license, kern_ver, &fd);
 		if (!err)
 			prog->instances.fds[0] = fd;
 		goto out;
@@ -3872,9 +3883,7 @@ bpf_program__load(struct bpf_program *prog,
 		}
 
 		err = load_program(prog, result.new_insn_ptr,
-				   result.new_insn_cnt,
-				   license, kern_version, &fd);
-
+				   result.new_insn_cnt, license, kern_ver, &fd);
 		if (err) {
 			pr_warn("Loading the %dth instance of program '%s' failed\n",
 				i, prog->section_name);
@@ -3918,9 +3927,6 @@ bpf_object__load_progs(struct bpf_object *obj, int log_level)
 	return 0;
 }
 
-static int libbpf_find_attach_btf_id(const char *name,
-				     enum bpf_attach_type attach_type,
-				     __u32 attach_prog_fd);
 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)
@@ -3984,15 +3990,8 @@ __bpf_object__open(const char *path, const void *obj_buf, size_t obj_buf_sz,
 
 		bpf_program__set_type(prog, prog_type);
 		bpf_program__set_expected_attach_type(prog, attach_type);
-		if (prog_type == BPF_PROG_TYPE_TRACING) {
-			err = libbpf_find_attach_btf_id(prog->section_name,
-							attach_type,
-							attach_prog_fd);
-			if (err <= 0)
-				goto out;
-			prog->attach_btf_id = err;
+		if (prog_type == BPF_PROG_TYPE_TRACING)
 			prog->attach_prog_fd = attach_prog_fd;
-		}
 	}
 
 	return obj;
-- 
cgit v1.2.3


From 3f51935314b8c0e0f45f28bed2e7a023b2c7627c Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andriin@fb.com>
Date: Fri, 13 Dec 2019 17:43:35 -0800
Subject: libbpf: Reduce log level of supported section names dump

It's quite spammy. And now that bpf_object__open() is trying to determine
program type from its section name, we are getting these verbose messages all
the time. Reduce their log level to DEBUG.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-12-andriin@fb.com
---
 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 3488ac4f7015..b6bd6c47c919 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -5196,7 +5196,7 @@ int libbpf_prog_type_by_name(const char *name, enum bpf_prog_type *prog_type,
 	pr_warn("failed to guess program type from ELF section '%s'\n", name);
 	type_names = libbpf_get_type_names(false);
 	if (type_names != NULL) {
-		pr_info("supported section(type) names are:%s\n", type_names);
+		pr_debug("supported section(type) names are:%s\n", type_names);
 		free(type_names);
 	}
 
-- 
cgit v1.2.3


From d66562fba1ce66975bd61b0786fb8b1810f33caa Mon Sep 17 00:00:00 2001
From: Andrii Nakryiko <andriin@fb.com>
Date: Fri, 13 Dec 2019 17:43:36 -0800
Subject: libbpf: Add BPF object skeleton support

Add new set of APIs, allowing to open/load/attach BPF object through BPF
object skeleton, generated by bpftool for a specific BPF object file. All the
xxx_skeleton() APIs wrap up corresponding bpf_object_xxx() APIs, but
additionally also automate map/program lookups by name, global data
initialization and mmap()-ing, etc.  All this greatly improves and simplifies
userspace usability of working with BPF programs. See follow up patches for
examples.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-13-andriin@fb.com
---
 tools/lib/bpf/libbpf.c   | 162 +++++++++++++++++++++++++++++++++++++++++++++++
 tools/lib/bpf/libbpf.h   |  38 +++++++++++
 tools/lib/bpf/libbpf.map |   5 ++
 3 files changed, 205 insertions(+)

(limited to 'tools/lib')

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index b6bd6c47c919..a1a902fa6e0c 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -6793,3 +6793,165 @@ int libbpf_num_possible_cpus(void)
 	WRITE_ONCE(cpus, tmp_cpus);
 	return tmp_cpus;
 }
+
+int bpf_object__open_skeleton(struct bpf_object_skeleton *s,
+			      const struct bpf_object_open_opts *opts)
+{
+	DECLARE_LIBBPF_OPTS(bpf_object_open_opts, skel_opts,
+		.object_name = s->name,
+	);
+	struct bpf_object *obj;
+	int i;
+
+	/* Attempt to preserve opts->object_name, unless overriden by user
+	 * explicitly. Overwriting object name for skeletons is discouraged,
+	 * as it breaks global data maps, because they contain object name
+	 * prefix as their own map name prefix. When skeleton is generated,
+	 * bpftool is making an assumption that this name will stay the same.
+	 */
+	if (opts) {
+		memcpy(&skel_opts, opts, sizeof(*opts));
+		if (!opts->object_name)
+			skel_opts.object_name = s->name;
+	}
+
+	obj = bpf_object__open_mem(s->data, s->data_sz, &skel_opts);
+	if (IS_ERR(obj)) {
+		pr_warn("failed to initialize skeleton BPF object '%s': %ld\n",
+			s->name, PTR_ERR(obj));
+		return PTR_ERR(obj);
+	}
+
+	*s->obj = obj;
+
+	for (i = 0; i < s->map_cnt; i++) {
+		struct bpf_map **map = s->maps[i].map;
+		const char *name = s->maps[i].name;
+		void **mmaped = s->maps[i].mmaped;
+
+		*map = bpf_object__find_map_by_name(obj, name);
+		if (!*map) {
+			pr_warn("failed to find skeleton map '%s'\n", name);
+			return -ESRCH;
+		}
+
+		if (mmaped)
+			*mmaped = (*map)->mmaped;
+	}
+
+	for (i = 0; i < s->prog_cnt; i++) {
+		struct bpf_program **prog = s->progs[i].prog;
+		const char *name = s->progs[i].name;
+
+		*prog = bpf_object__find_program_by_name(obj, name);
+		if (!*prog) {
+			pr_warn("failed to find skeleton program '%s'\n", name);
+			return -ESRCH;
+		}
+	}
+
+	return 0;
+}
+
+int bpf_object__load_skeleton(struct bpf_object_skeleton *s)
+{
+	int i, err;
+
+	err = bpf_object__load(*s->obj);
+	if (err) {
+		pr_warn("failed to load BPF skeleton '%s': %d\n", s->name, err);
+		return err;
+	}
+
+	for (i = 0; i < s->map_cnt; i++) {
+		struct bpf_map *map = *s->maps[i].map;
+		size_t mmap_sz = bpf_map_mmap_sz(map);
+		int prot, map_fd = bpf_map__fd(map);
+		void **mmaped = s->maps[i].mmaped;
+		void *remapped;
+
+		if (!mmaped)
+			continue;
+
+		if (!(map->def.map_flags & BPF_F_MMAPABLE)) {
+			*mmaped = NULL;
+			continue;
+		}
+
+		if (map->def.map_flags & BPF_F_RDONLY_PROG)
+			prot = PROT_READ;
+		else
+			prot = PROT_READ | PROT_WRITE;
+
+		/* Remap anonymous mmap()-ed "map initialization image" as
+		 * a BPF map-backed mmap()-ed memory, but preserving the same
+		 * memory address. This will cause kernel to change process'
+		 * page table to point to a different piece of kernel memory,
+		 * but from userspace point of view memory address (and its
+		 * contents, being identical at this point) will stay the
+		 * same. This mapping will be released by bpf_object__close()
+		 * as per normal clean up procedure, so we don't need to worry
+		 * about it from skeleton's clean up perspective.
+		 */
+		remapped = mmap(*mmaped, mmap_sz, prot, MAP_SHARED | MAP_FIXED,
+				map_fd, 0);
+		if (remapped == MAP_FAILED) {
+			err = -errno;
+			*mmaped = NULL;
+			pr_warn("failed to re-mmap() map '%s': %d\n",
+				 bpf_map__name(map), err);
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+int bpf_object__attach_skeleton(struct bpf_object_skeleton *s)
+{
+	int i;
+
+	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;
+		const char *sec_name = bpf_program__title(prog, false);
+
+		sec_def = find_sec_def(sec_name);
+		if (!sec_def || !sec_def->attach_fn)
+			continue;
+
+		*link = sec_def->attach_fn(sec_def, prog);
+		if (IS_ERR(*link)) {
+			pr_warn("failed to auto-attach program '%s': %ld\n",
+				bpf_program__name(prog), PTR_ERR(*link));
+			return PTR_ERR(*link);
+		}
+	}
+
+	return 0;
+}
+
+void bpf_object__detach_skeleton(struct bpf_object_skeleton *s)
+{
+	int i;
+
+	for (i = 0; i < s->prog_cnt; i++) {
+		struct bpf_link **link = s->progs[i].link;
+
+		if (!IS_ERR_OR_NULL(*link))
+			bpf_link__destroy(*link);
+		*link = NULL;
+	}
+}
+
+void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s)
+{
+	if (s->progs)
+		bpf_object__detach_skeleton(s);
+	if (s->obj)
+		bpf_object__close(*s->obj);
+	free(s->maps);
+	free(s->progs);
+	free(s);
+}
diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h
index f37bd4a3e14b..623191e71415 100644
--- a/tools/lib/bpf/libbpf.h
+++ b/tools/lib/bpf/libbpf.h
@@ -631,6 +631,44 @@ BPF_EMBED_OBJ_DECLARE(NAME)
 #define BPF_EMBED_OBJ(NAME, PATH) __BPF_EMBED_OBJ(NAME, PATH, 16, ".quad")
 #endif
 
+struct bpf_map_skeleton {
+	const char *name;
+	struct bpf_map **map;
+	void **mmaped;
+};
+
+struct bpf_prog_skeleton {
+	const char *name;
+	struct bpf_program **prog;
+	struct bpf_link **link;
+};
+
+struct bpf_object_skeleton {
+	size_t sz; /* size of this struct, for forward/backward compatibility */
+
+	const char *name;
+	void *data;
+	size_t data_sz;
+
+	struct bpf_object **obj;
+
+	int map_cnt;
+	int map_skel_sz; /* sizeof(struct bpf_skeleton_map) */
+	struct bpf_map_skeleton *maps;
+
+	int prog_cnt;
+	int prog_skel_sz; /* sizeof(struct bpf_skeleton_prog) */
+	struct bpf_prog_skeleton *progs;
+};
+
+LIBBPF_API int
+bpf_object__open_skeleton(struct bpf_object_skeleton *s,
+			  const struct bpf_object_open_opts *opts);
+LIBBPF_API int bpf_object__load_skeleton(struct bpf_object_skeleton *s);
+LIBBPF_API int bpf_object__attach_skeleton(struct bpf_object_skeleton *s);
+LIBBPF_API void bpf_object__detach_skeleton(struct bpf_object_skeleton *s);
+LIBBPF_API void bpf_object__destroy_skeleton(struct bpf_object_skeleton *s);
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 5a7630748eeb..1376d992a703 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -213,6 +213,11 @@ LIBBPF_0.0.7 {
 	global:
 		btf_dump__emit_type_decl;
 		bpf_object__find_program_by_name;
+		bpf_object__attach_skeleton;
+		bpf_object__destroy_skeleton;
+		bpf_object__detach_skeleton;
+		bpf_object__load_skeleton;
+		bpf_object__open_skeleton;
 		bpf_program__attach;
 		bpf_program__name;
 		btf__align_of;
-- 
cgit v1.2.3