| From | Ben Hutchings <> | Date | Tue, 02 Apr 2019 14:38:27 +0100 | Subject | [PATCH 3.16 13/99] perf pmu: Suppress potential format-truncation warning |
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3.16.65-rc1 review patch. If anyone has any objections, please let me know.
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From: Ben Hutchings <ben@decadent.org.uk>
commit 11a64a05dc649815670b1be9fe63d205cb076401 upstream.
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> Link: http://lkml.kernel.org/r/20181111184524.fux4taownc6ndbx6@decadent.org.uk Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> [bwh: Dropped the parts that don't apply to 3.16] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- tools/perf/util/pmu.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -107,7 +107,7 @@ static int perf_pmu__parse_scale(struct char path[PATH_MAX]; const char *lc; - 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) @@ -150,7 +150,7 @@ static int perf_pmu__parse_unit(struct p 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)
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