96ab2084b73ba051bf93988e6146717c1d71973f
[openwrt/staging/wigyori.git] /
1 From 74d0dcf7608b1bab116e297468ac51b57eb97ce0 Mon Sep 17 00:00:00 2001
2 From: Tony Ambardar <Tony.Ambardar@gmail.com>
3 Date: Thu, 20 Aug 2020 10:06:24 -0700
4 Subject: [PATCH] libbpf: fix build failure from uninitialized variable warning
5
6 While compiling libbpf, some GCC versions (at least 8.4.0) have difficulty
7 determining control flow and a emit warning for potentially uninitialized
8 usage of 'map', which results in a build error if using "-Werror":
9
10 In file included from libbpf.c:56:
11 libbpf.c: In function '__bpf_object__open':
12 libbpf_internal.h:59:2: warning: 'map' may be used uninitialized in this function [-Wmaybe-uninitialized]
13 libbpf_print(level, "libbpf: " fmt, ##__VA_ARGS__); \
14 ^~~~~~~~~~~~
15 libbpf.c:5032:18: note: 'map' was declared here
16 struct bpf_map *map, *targ_map;
17 ^~~
18
19 The warning/error is false based on code inspection, so silence it with a
20 NULL initialization.
21
22 Fixes: 646f02ffdd49 ("libbpf: Add BTF-defined map-in-map support")
23 Ref: 063e68813391 ("libbpf: Fix false uninitialized variable warning")
24
25 Signed-off-by: Tony Ambardar <Tony.Ambardar@gmail.com>
26 ---
27 tools/lib/bpf/libbpf.c | 2 +-
28 1 file changed, 1 insertion(+), 1 deletion(-)
29
30 --- a/tools/lib/bpf/libbpf.c
31 +++ b/tools/lib/bpf/libbpf.c
32 @@ -5030,8 +5030,8 @@ static int bpf_object__collect_map_relos
33 int i, j, nrels, new_sz;
34 const struct btf_var_secinfo *vi = NULL;
35 const struct btf_type *sec, *var, *def;
36 + struct bpf_map *map = NULL, *targ_map;
37 const struct btf_member *member;
38 - struct bpf_map *map, *targ_map;
39 const char *name, *mname;
40 Elf_Data *symbols;
41 unsigned int moff;