diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c index dc9a8967ab8c..a1ae2a3e9fef 100644 --- a/tools/bpf/bpftool/map.c +++ b/tools/bpf/bpftool/map.c @@ -215,70 +215,6 @@ err_end_obj: return ret; } -static int get_btf(struct bpf_map_info *map_info, struct btf **btf) -{ - struct bpf_btf_info btf_info = { 0 }; - __u32 len = sizeof(btf_info); - __u32 last_size; - int btf_fd; - void *ptr; - int err; - - err = 0; - *btf = NULL; - btf_fd = bpf_btf_get_fd_by_id(map_info->btf_id); - if (btf_fd < 0) - return 0; - - /* we won't know btf_size until we call bpf_obj_get_info_by_fd(). so - * let's start with a sane default - 4KiB here - and resize it only if - * bpf_obj_get_info_by_fd() needs a bigger buffer. - */ - btf_info.btf_size = 4096; - last_size = btf_info.btf_size; - ptr = malloc(last_size); - if (!ptr) { - err = -ENOMEM; - goto exit_free; - } - - bzero(ptr, last_size); - btf_info.btf = ptr_to_u64(ptr); - err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len); - - if (!err && btf_info.btf_size > last_size) { - void *temp_ptr; - - last_size = btf_info.btf_size; - temp_ptr = realloc(ptr, last_size); - if (!temp_ptr) { - err = -ENOMEM; - goto exit_free; - } - ptr = temp_ptr; - bzero(ptr, last_size); - btf_info.btf = ptr_to_u64(ptr); - err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len); - } - - if (err || btf_info.btf_size > last_size) { - err = errno; - goto exit_free; - } - - *btf = btf__new((__u8 *)btf_info.btf, btf_info.btf_size, NULL); - if (IS_ERR(*btf)) { - err = PTR_ERR(*btf); - *btf = NULL; - } - -exit_free: - close(btf_fd); - free(ptr); - - return err; -} - static json_writer_t *get_btf_writer(void) { json_writer_t *jw = jsonw_new(stdout); @@ -775,7 +711,7 @@ static int do_dump(int argc, char **argv) prev_key = NULL; - err = get_btf(&info, &btf); + err = btf_get_from_id(info.btf_id, &btf); if (err) { p_err("failed to get btf"); goto exit_free; @@ -919,7 +855,7 @@ static int do_lookup(int argc, char **argv) } /* here means bpf_map_lookup_elem() succeeded */ - err = get_btf(&info, &btf); + err = btf_get_from_id(info.btf_id, &btf); if (err) { p_err("failed to get btf"); goto exit_free; diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c index fe87cb48a6a9..13ddc4bd24ee 100644 --- a/tools/lib/bpf/btf.c +++ b/tools/lib/bpf/btf.c @@ -49,6 +49,11 @@ struct bpf_func_info_min { __u32 type_id; }; +static inline __u64 ptr_to_u64(const void *ptr) +{ + return (__u64) (unsigned long) ptr; +} + static int btf_add_type(struct btf *btf, struct btf_type *t) { if (btf->types_size - btf->nr_types < 2) { @@ -410,6 +415,70 @@ const char *btf__name_by_offset(const struct btf *btf, __u32 offset) return NULL; } +int btf_get_from_id(__u32 id, struct btf **btf) +{ + struct bpf_btf_info btf_info = { 0 }; + __u32 len = sizeof(btf_info); + __u32 last_size; + int btf_fd; + void *ptr; + int err; + + err = 0; + *btf = NULL; + btf_fd = bpf_btf_get_fd_by_id(id); + if (btf_fd < 0) + return 0; + + /* we won't know btf_size until we call bpf_obj_get_info_by_fd(). so + * let's start with a sane default - 4KiB here - and resize it only if + * bpf_obj_get_info_by_fd() needs a bigger buffer. + */ + btf_info.btf_size = 4096; + last_size = btf_info.btf_size; + ptr = malloc(last_size); + if (!ptr) { + err = -ENOMEM; + goto exit_free; + } + + bzero(ptr, last_size); + btf_info.btf = ptr_to_u64(ptr); + err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len); + + if (!err && btf_info.btf_size > last_size) { + void *temp_ptr; + + last_size = btf_info.btf_size; + temp_ptr = realloc(ptr, last_size); + if (!temp_ptr) { + err = -ENOMEM; + goto exit_free; + } + ptr = temp_ptr; + bzero(ptr, last_size); + btf_info.btf = ptr_to_u64(ptr); + err = bpf_obj_get_info_by_fd(btf_fd, &btf_info, &len); + } + + if (err || btf_info.btf_size > last_size) { + err = errno; + goto exit_free; + } + + *btf = btf__new((__u8 *)btf_info.btf, btf_info.btf_size, NULL); + if (IS_ERR(*btf)) { + err = PTR_ERR(*btf); + *btf = NULL; + } + +exit_free: + close(btf_fd); + free(ptr); + + return err; +} + static int btf_ext_validate_func_info(const void *finfo, __u32 size, btf_print_fn_t err_log) { diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h index 578171e8cb26..386b2ffc32a3 100644 --- a/tools/lib/bpf/btf.h +++ b/tools/lib/bpf/btf.h @@ -69,6 +69,7 @@ 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__fd(const struct btf *btf); LIBBPF_API const char *btf__name_by_offset(const struct btf *btf, __u32 offset); +LIBBPF_API int btf_get_from_id(__u32 id, struct btf **btf); struct btf_ext *btf_ext__new(__u8 *data, __u32 size, btf_print_fn_t err_log); void btf_ext__free(struct btf_ext *btf_ext);