[v3,bpf-next,2/3] libbpf: add btf__str_by_offset() as a more generic variant of name_by_offset

Commit Message

Andrii Nakryiko Sept. 29, 2020, 2:05 a.m. UTC

BTF strings are used not just for names, they can be arbitrary strings used
for CO-RE relocations, line/func infos, etc. Thus "name_by_offset" terminology
is too specific and might be misleading. Instead, introduce
btf__str_by_offset() API which uses generic string terminology.

Acked-by: John Fastabend <[e-mail]>
Signed-off-by: Andrii Nakryiko <[e-mail]>
---
 tools/lib/bpf/btf.c      | 7 ++++++-
 tools/lib/bpf/btf.h      | 1 +
 tools/lib/bpf/libbpf.map | 1 +
 3 files changed, 8 insertions(+), 1 deletion(-)

Patch

diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
index 7533088b2524..2d0b1e12f50e 100644
--- a/tools/lib/bpf/btf.c
+++ b/tools/lib/bpf/btf.c
@@ -1025,7 +1025,7 @@  const void *btf__get_raw_data(const struct btf *btf_ro, __u32 *size)
 	return btf->raw_data;
 }
 
-const char *btf__name_by_offset(const struct btf *btf, __u32 offset)
+const char *btf__str_by_offset(const struct btf *btf, __u32 offset)
 {
 	if (offset < btf->hdr->str_len)
 		return btf->strs_data + offset;
@@ -1033,6 +1033,11 @@  const char *btf__name_by_offset(const struct btf *btf, __u32 offset)
 		return NULL;
 }
 
+const char *btf__name_by_offset(const struct btf *btf, __u32 offset)
+{
+	return btf__str_by_offset(btf, offset);
+}
+
 int btf__get_from_id(__u32 id, struct btf **btf)
 {
 	struct bpf_btf_info btf_info = { 0 };
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index d6629a2e8ebf..f7dec0144c3c 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -49,6 +49,7 @@  LIBBPF_API int btf__fd(const struct btf *btf);
 LIBBPF_API void btf__set_fd(struct btf *btf, int fd);
 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);
+LIBBPF_API const char *btf__str_by_offset(const struct btf *btf, __u32 offset);
 LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
 LIBBPF_API int btf__get_map_kv_tids(const struct btf *btf, const char *map_name,
 				    __u32 expected_key_size,
diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map
index 0216ee6fdc2b..6b10ebad69c6 100644
--- a/tools/lib/bpf/libbpf.map
+++ b/tools/lib/bpf/libbpf.map
@@ -327,6 +327,7 @@  LIBBPF_0.2.0 {
 		btf__add_volatile;
 		btf__find_str;
 		btf__new_empty;
+		btf__str_by_offset;
 		perf_buffer__buffer_cnt;
 		perf_buffer__buffer_fd;
 		perf_buffer__epoll_fd;