Commit 11a64a05 authored Nov 11, 2018 by Ben Hutchings Committed by Arnaldo Carvalho de Melo Nov 21, 2018

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>

parent 4787eff3

tools/perf/util/pmu.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -145,7 +145,7 @@ static int perf_pmu__parse_scale(struct perf_pmu_alias alias, char dir, char *
		int fd, ret = -1;
		char path[PATH_MAX];

		snprintf(path, PATH_MAX, "%s/%s.scale", dir, name);
		scnprintf(path, PATH_MAX, "%s/%s.scale", dir, name);

		fd = open(path, O_RDONLY);
		if (fd == -1)
		@@ -175,7 +175,7 @@ static int perf_pmu__parse_unit(struct perf_pmu_alias alias, char dir, char *n
		ssize_t sret;
		int fd;

		snprintf(path, PATH_MAX, "%s/%s.unit", dir, name);
		scnprintf(path, PATH_MAX, "%s/%s.unit", dir, name);

		fd = open(path, O_RDONLY);
		if (fd == -1)
		@@ -205,7 +205,7 @@ perf_pmu__parse_per_pkg(struct perf_pmu_alias alias, char dir, char *name)
		char path[PATH_MAX];
		int fd;

		snprintf(path, PATH_MAX, "%s/%s.per-pkg", dir, name);
		scnprintf(path, PATH_MAX, "%s/%s.per-pkg", dir, name);

		fd = open(path, O_RDONLY);
		if (fd == -1)
		@@ -223,7 +223,7 @@ static int perf_pmu__parse_snapshot(struct perf_pmu_alias *alias,
		char path[PATH_MAX];
		int fd;

		snprintf(path, PATH_MAX, "%s/%s.snapshot", dir, name);
		scnprintf(path, PATH_MAX, "%s/%s.snapshot", dir, name);

		fd = open(path, O_RDONLY);
		if (fd == -1)

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