[PATCH AUTOSEL for 4.15 18/78] libbpf: prefer global symbols as bpf program name source

From: Sasha Levin
Date: Thu Mar 08 2018 - 02:09:14 EST


From: Roman Gushchin <guro@xxxxxx>

[ Upstream commit fe4d44b23f6b38194a92c6b8a50d921a071c4db4 ]

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>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
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 5aa45f89da93..cda652a12880 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,
--
2.14.1