[PATCH v4 net-next 2/4] libbpf: prefer global symbols as bpf program name source

[Roman Gushchin]

Libbpf picks the name of the first symbol in the corresponding
elf section to use as a program name. But without taking symbol's
scope into account it may end's up with some local label
as a program name. E.g.:

$ bpftool prog
1: type 15  name LBB0_10    tag 0390a5136ba23f5c
	loaded_at Dec 07/17:22  uid 0
	xlated 456B  not jited  memlock 4096B

Fix this by preferring global symbols as program name.

For instance:
$ bpftool prog
1: type 15  name bpf_prog1  tag 0390a5136ba23f5c
	loaded_at Dec 07/17:26  uid 0
	xlated 456B  not jited  memlock 4096B

Signed-off-by: Roman Gushchin <guro@xxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: Jakub Kicinski <jakub.kicinski@xxxxxxxxxxxxx>
Cc: Martin KaFai Lau <kafai@xxxxxx>
Cc: Quentin Monnet <quentin.monnet@xxxxxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
---
 tools/lib/bpf/libbpf.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 205b7822fa0a..65d0d0aff4fa 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -387,6 +387,8 @@ bpf_object__init_prog_names(struct bpf_object *obj)
 				continue;
 			if (sym.st_shndx != prog->idx)
 				continue;
+			if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL)
+				continue;
 
 			name = elf_strptr(obj->efile.elf,
 					  obj->efile.strtabidx,
-- 
2.14.3