kernel/linux.git/samples/bpf/task_fd_query_user.c, branch v4.19.67Linux kernel stable tree (mirror)https://git.radix-linux.su/kernel/linux.git/atom?h=v4.19.672019-07-14T06:11:04+00:00samples, bpf: suppress compiler warning2019-07-14T06:11:04+00:00Matteo Crocemcroce@redhat.com2019-05-20T21:49:38+00:00urn:sha1:3c24a931e9720679a1ee23be51d2ca298baba785
[ Upstream commit a195cefff49f60054998333e81ee95170ce8bf92 ]
GCC 9 fails to calculate the size of local constant strings and produces a
false positive:
samples/bpf/task_fd_query_user.c: In function ‘test_debug_fs_uprobe’:
samples/bpf/task_fd_query_user.c:242:67: warning: ‘%s’ directive output may be truncated writing up to 255 bytes into a region of size 215 [-Wformat-truncation=]
242 | snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/events/%ss/%s/id",
| ^~
243 | event_type, event_alias);
| ~~~~~~~~~~~
samples/bpf/task_fd_query_user.c:242:2: note: ‘snprintf’ output between 45 and 300 bytes into a destination of size 256
242 | snprintf(buf, sizeof(buf), "/sys/kernel/debug/tracing/events/%ss/%s/id",
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
243 | event_type, event_alias);
| ~~~~~~~~~~~~~~~~~~~~~~~~
Workaround this by lowering the buffer size to a reasonable value.
Related GCC Bugzilla: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83431
Signed-off-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
samples/bpf: add a samples/bpf test for BPF_TASK_FD_QUERY2018-05-25T01:18:20+00:00Yonghong Songyhs@fb.com2018-05-24T18:21:56+00:00urn:sha1:ecb96f7fe153c7ff2fd31db64c52a53b7e6401ab
This is mostly to test kprobe/uprobe which needs kernel headers.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>