When compiling selftests/bpf in optimized mode (-O2), GCC erroneously
complains about uninitialized token variable:
In file included from network_helpers.c:22:
network_helpers.c: In function ‘open_netns’:
test_progs.h:355:22: error: ‘token’ may be used uninitialized [-Werror=maybe-uninitialized]
355 | int ___err = libbpf_get_error(___res); \
| ^~~~~~~~~~~~~~~~~~~~~~~~
network_helpers.c:440:14: note: in expansion of macro ‘ASSERT_OK_PTR’
440 | if (!ASSERT_OK_PTR(token, "malloc token"))
| ^~~~~~~~~~~~~
In file included from /data/users/andriin/linux/tools/testing/selftests/bpf/tools/include/bpf/libbpf.h:21,
from bpf_util.h:9,
from network_helpers.c:20:
/data/users/andriin/linux/tools/testing/selftests/bpf/tools/include/bpf/libbpf_legacy.h:113:17: note: by argument 1 of type ‘const void *’ to ‘libbpf_get_error’ declared here
113 | LIBBPF_API long libbpf_get_error(const void *ptr);
| ^~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
make: *** [Makefile:522: /data/users/andriin/linux/tools/testing/selftests/bpf/network_helpers.o] Error 1
This is completely bogus becuase libbpf_get_error() doesn't dereference
pointer, but the only easy way to silence this is to allocate initialized
memory with calloc().
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20220705224818.4026623-2-andrii@kernel.org
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