perf pmu: Suppress potential format-truncation warning
authorBen Hutchings <ben@decadent.org.uk>
Sun, 11 Nov 2018 18:45:24 +0000 (18:45 +0000)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Thu, 22 Nov 2018 01:39:56 +0000 (22:39 -0300)
commit11a64a05dc649815670b1be9fe63d205cb076401
treeec1a0864e45db38f4e00bf818a84912c82ceb04e
parent4787eff3fa88f62fede6ed7afa06477ae6bf984d
perf pmu: Suppress potential format-truncation warning

Depending on which functions are inlined in util/pmu.c, the snprintf()
calls in perf_pmu__parse_{scale,unit,per_pkg,snapshot}() might trigger a
warning:

  util/pmu.c: In function 'pmu_aliases':
  util/pmu.c:178:31: error: '%s' directive output may be truncated writing up to 255 bytes into a region of size between 0 and 4095 [-Werror=format-truncation=]
    snprintf(path, PATH_MAX, "%s/%s.unit", dir, name);
                               ^~

I found this when trying to build perf from Linux 3.16 with gcc 8.
However I can reproduce the problem in mainline if I force
__perf_pmu__new_alias() to be inlined.

Suppress this by using scnprintf() as has been done elsewhere in perf.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20181111184524.fux4taownc6ndbx6@decadent.org.uk
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools/perf/util/pmu.c