tree d2d64339ee4cec662fb39e76660f244661b12109
parent f7c2d64bac1be2ff32f8e4f500c6e5429c1003e0
author Matteo Croce <mcroce@redhat.com> 1558388978 +0200
committer Daniel Borkmann <daniel@iogearbox.net> 1558450520 +0200

samples, bpf: suppress compiler warning

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>