Re: [PATCH bpf v1] libbpf: fix build failure from uninitialized variable warning

[Daniel Borkmann]

On 8/31/20 2:03 AM, Tony Ambardar wrote:

While compiling libbpf, some GCC versions (at least 8.4.0) have difficulty
determining control flow and a emit warning for potentially uninitialized
usage of 'map', which results in a build error if using "-Werror":

In file included from libbpf.c:56:
libbpf.c: In function '__bpf_object__open':
libbpf_internal.h:59:2: warning: 'map' may be used uninitialized in this 
function [-Wmaybe-uninitialized]
   libbpf_print(level, "libbpf: " fmt, ##__VA_ARGS__); \
   ^~~~~~~~~~~~
libbpf.c:5032:18: note: 'map' was declared here
   struct bpf_map *map, *targ_map;
                   ^~~

The warning/error is false based on code inspection, so silence it with a
NULL initialization.

Fixes: 646f02ffdd49 ("libbpf: Add BTF-defined map-in-map support")
Ref: 063e68813391 ("libbpf: Fix false uninitialized variable warning")

Signed-off-by: Tony Ambardar <tony.ambar...@gmail.com>

Applied, thanks!