[PATCH v1 2/2] perf metrics: Fix segv for metrics with no events

From: Ian Rogers
Date: Fri Feb 23 2024 - 20:15:09 EST


A metric may have no events, for example, the transaction metrics on
x86 are dependent on there being TSX events. Fix a segv where an evsel
of NULL is dereferenced for a metric leader value.

Fixes: a59fb796a36b ("perf metrics: Compute unmerged uncore metrics individually")
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
tools/perf/util/metricgroup.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index 2d6865c392ef..79ef6095ab28 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -44,7 +44,7 @@ struct metric_event *metricgroup__lookup(struct rblist *metric_events,
if (!metric_events)
return NULL;

- if (evsel->metric_leader)
+ if (evsel && evsel->metric_leader)
me.evsel = evsel->metric_leader;
nd = rblist__find(metric_events, &me);
if (nd)
--
2.44.0.rc0.258.g7320e95886-goog