[PATCH 6.8 425/715] perf stat: Avoid metric-only segv

[Sasha Levin]

From: Ian Rogers <irogers@xxxxxxxxxx>

[ Upstream commit 2543947c77e0e224bda86b4e7220c2f6714da463 ]

Cycles is recognized as part of a hard coded metric in stat-shadow.c,
it may call print_metric_only with a NULL fmt string leading to a
segfault. Handle the NULL fmt explicitly.

Fixes: 088519f318be ("perf stat: Move the display functions to stat-display.c")
Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
Reviewed-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: K Prateek Nayak <kprateek.nayak@xxxxxxx>
Cc: James Clark <james.clark@xxxxxxx>
Cc: Kaige Ye <ye@xxxxxxxxx>
Cc: John Garry <john.g.garry@xxxxxxxxxx>
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240209204947.3873294-4-irogers@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 tools/perf/util/stat-display.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/stat-display.c b/tools/perf/util/stat-display.c
index 8c61f8627ebc9..b7d00a538d703 100644
--- a/tools/perf/util/stat-display.c
+++ b/tools/perf/util/stat-display.c
@@ -560,7 +560,7 @@ static void print_metric_only(struct perf_stat_config *config,
 	if (color)
 		mlen += strlen(color) + sizeof(PERF_COLOR_RESET) - 1;
 
-	color_snprintf(str, sizeof(str), color ?: "", fmt, val);
+	color_snprintf(str, sizeof(str), color ?: "", fmt ?: "", val);
 	fprintf(out, "%*s ", mlen, str);
 	os->first = false;
 }
-- 
2.43.0