[PATCH net-next 2/5] libbpf: prefer global symbols as bpf program name source

From: Roman Gushchin
Date: Thu Nov 30 2017 - 08:44:06 EST


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 cglist /sys/fs/cgroup/system.slice/tmp.mount/
16 device LBB0_10

Fix this by preferring global symbols as program name.
For instance:

$ bpftool cglist /sys/fs/cgroup/system.slice/tmp.mount/
17 device bpf_prog1

Signed-off-by: Roman Gushchin <guro@xxxxxx>
Cc: Martin KaFai Lau <kafai@xxxxxx>
Cc: Alexei Starovoitov <ast@xxxxxxxxxx>
Cc: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Cc: Jakub Kicinski <jakub.kicinski@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 9f2410beaa18..5191afd46556 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