From: Leo Yan <leo.yan@xxxxxxxxxx>
[ Upstream commit f3c8d90757724982e5f07cd77d315eb64ca145ac ]
Based on the following report from Smatch, fix the potential
NULL pointer dereference check.
tools/perf/util/session.c:1252
dump_read() error: we previously assumed 'evsel' could be null
(see line 1249)
tools/perf/util/session.c
1240 static void dump_read(struct perf_evsel *evsel, union perf_event *event)
1241 {
1242 struct read_event *read_event = &event->read;
1243 u64 read_format;
1244
1245 if (!dump_trace)
1246 return;
1247
1248 printf(": %d %d %s %" PRIu64 "\n", event->read.pid, event->read.tid,
1249 evsel ? perf_evsel__name(evsel) : "FAIL",
1250 event->read.value);
1251
1252 read_format = evsel->attr.read_format;
^^^^^^^
'evsel' could be NULL pointer, for this case this patch directly bails
out without dumping read_event.
Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Alexey Budankov <alexey.budankov@xxxxxxxxxxxxxxx>
Cc: Alexios Zavras <alexios.zavras@xxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Changbin Du <changbin.du@xxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Cc: Eric Saint-Etienne <eric.saint.etienne@xxxxxxxxxx>
Cc: Jin Yao <yao.jin@xxxxxxxxxxxxxxx>
Cc: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Cc: Song Liu <songliubraving@xxxxxx>
Cc: Suzuki Poulouse <suzuki.poulose@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Thomas Richter <tmricht@xxxxxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20190702103420.27540-9-leo.yan@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
tools/perf/util/session.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index bad5f87ae001..656ef536b3ab 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1147,6 +1147,9 @@ static void dump_read(struct perf_evsel *evsel, union perf_event *event)
evsel ? perf_evsel__name(evsel) : "FAIL",
event->read.value);
+ if (!evsel)
+ return;
+
read_format = evsel->attr.read_format;
if (read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
--
2.20.1
