From: John Garry <john.garry@xxxxxxxxxx> [ Upstream commit fe7a98b9d9b36e5c8a22d76b67d29721f153f66e ] The error code is not set at all in the sys event iter function. This may lead to an uninitialized value of "ret" in metricgroup__add_metric() when no CPU metric is added. Fix by properly setting the error code. It is not necessary to init "ret" to 0 in metricgroup__add_metric(), as if we have no CPU or sys event metric matching, then "has_match" should be 0 and "ret" is set to -EINVAL. However gcc cannot detect that it may not have been set after the map_for_each_metric() loop for CPU metrics, which is strange. Fixes: be335ec28efa8 ("perf metricgroup: Support adding metrics for system PMUs") Signed-off-by: John Garry <john.garry@xxxxxxxxxx> Acked-by: Ian Rogers <irogers@xxxxxxxxxx> Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Kajol Jain <kjain@xxxxxxxxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Link: http://lore.kernel.org/lkml/1623335580-187317-3-git-send-email-john.garry@xxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- tools/perf/util/metricgroup.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c index 1af71ac1cc68..939aed36e0c2 100644 --- a/tools/perf/util/metricgroup.c +++ b/tools/perf/util/metricgroup.c @@ -1072,16 +1072,18 @@ static int metricgroup__add_metric_sys_event_iter(struct pmu_event *pe, ret = add_metric(d->metric_list, pe, d->metric_no_group, &m, NULL, d->ids); if (ret) - return ret; + goto out; ret = resolve_metric(d->metric_no_group, d->metric_list, NULL, d->ids); if (ret) - return ret; + goto out; *(d->has_match) = true; - return *d->ret; +out: + *(d->ret) = ret; + return ret; } static int metricgroup__add_metric(const char *metric, bool metric_no_group, -- 2.30.2