diff options
author | Jiri Olsa <jolsa@kernel.org> | 2023-08-09 10:34:24 +0200 |
---|---|---|
committer | Alexei Starovoitov <ast@kernel.org> | 2023-08-22 00:51:26 +0200 |
commit | e613d1d0f7d4f6ee9b458c62f85c577872dce9a6 (patch) | |
tree | a21abb94cf79c2bcd054142ddce89773e2d4c899 /tools/lib | |
parent | libbpf: Add elf_resolve_syms_offsets function (diff) | |
download | linux-e613d1d0f7d4f6ee9b458c62f85c577872dce9a6.tar.xz linux-e613d1d0f7d4f6ee9b458c62f85c577872dce9a6.zip |
libbpf: Add elf_resolve_pattern_offsets function
Adding elf_resolve_pattern_offsets function that looks up
offsets for symbols specified by pattern argument.
The 'pattern' argument allows wildcards (*?' supported).
Offsets are returned in allocated array together with its
size and needs to be released by the caller.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230809083440.3209381-13-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/lib')
-rw-r--r-- | tools/lib/bpf/elf.c | 61 | ||||
-rw-r--r-- | tools/lib/bpf/libbpf.c | 2 | ||||
-rw-r--r-- | tools/lib/bpf/libbpf_internal.h | 5 |
3 files changed, 67 insertions, 1 deletions
diff --git a/tools/lib/bpf/elf.c b/tools/lib/bpf/elf.c index 8c512641c1d7..9d0296c1726a 100644 --- a/tools/lib/bpf/elf.c +++ b/tools/lib/bpf/elf.c @@ -377,3 +377,64 @@ out: elf_close(&elf_fd); return err; } + +/* + * Return offsets in @poffsets for symbols specified by @pattern argument. + * On success returns 0 and offsets are returned in allocated @poffsets + * array with the @pctn size, that needs to be released by the caller. + */ +int elf_resolve_pattern_offsets(const char *binary_path, const char *pattern, + unsigned long **poffsets, size_t *pcnt) +{ + int sh_types[2] = { SHT_SYMTAB, SHT_DYNSYM }; + unsigned long *offsets = NULL; + size_t cap = 0, cnt = 0; + struct elf_fd elf_fd; + int err = 0, i; + + err = elf_open(binary_path, &elf_fd); + if (err) + return err; + + for (i = 0; i < ARRAY_SIZE(sh_types); i++) { + struct elf_sym_iter iter; + struct elf_sym *sym; + + err = elf_sym_iter_new(&iter, elf_fd.elf, binary_path, sh_types[i], STT_FUNC); + if (err == -ENOENT) + continue; + if (err) + goto out; + + while ((sym = elf_sym_iter_next(&iter))) { + if (!glob_match(sym->name, pattern)) + continue; + + err = libbpf_ensure_mem((void **) &offsets, &cap, sizeof(*offsets), + cnt + 1); + if (err) + goto out; + + offsets[cnt++] = elf_sym_offset(sym); + } + + /* If we found anything in the first symbol section, + * do not search others to avoid duplicates. + */ + if (cnt) + break; + } + + if (cnt) { + *poffsets = offsets; + *pcnt = cnt; + } else { + err = -ENOENT; + } + +out: + if (err) + free(offsets); + elf_close(&elf_fd); + return err; +} diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index c05dd32910e0..88a38e607959 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -10569,7 +10569,7 @@ struct bpf_link *bpf_program__attach_ksyscall(const struct bpf_program *prog, } /* Adapted from perf/util/string.c */ -static bool glob_match(const char *str, const char *pat) +bool glob_match(const char *str, const char *pat) { while (*str && *pat && *pat != '*') { if (*pat == '?') { /* Matches any single character */ diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index 92851c5f912d..ead551318fec 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -578,6 +578,8 @@ static inline bool is_pow_of_2(size_t x) #define PROG_LOAD_ATTEMPTS 5 int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size, int attempts); +bool glob_match(const char *str, const char *pat); + long elf_find_func_offset(Elf *elf, const char *binary_path, const char *name); long elf_find_func_offset_from_file(const char *binary_path, const char *name); @@ -591,4 +593,7 @@ void elf_close(struct elf_fd *elf_fd); int elf_resolve_syms_offsets(const char *binary_path, int cnt, const char **syms, unsigned long **poffsets); +int elf_resolve_pattern_offsets(const char *binary_path, const char *pattern, + unsigned long **poffsets, size_t *pcnt); + #endif /* __LIBBPF_LIBBPF_INTERNAL_H */ |