From 01af3bf06755dc5cda7050fe5d898998e5775e63 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Fri, 13 Dec 2019 17:43:32 -0800 Subject: [PATCH] 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 Signed-off-by: Alexei Starovoitov Acked-by: Martin KaFai Lau 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 ++ .../selftests/bpf/prog_tests/rdonly_maps.c | 11 +++----- 4 files changed, 36 insertions(+), 14 deletions(-) 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; -- 2.25.1