[ 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@linaro.org Acked-by: Jiri Olsa jolsa@kernel.org Cc: Adrian Hunter adrian.hunter@intel.com Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Alexey Budankov alexey.budankov@linux.intel.com Cc: Alexios Zavras alexios.zavras@intel.com Cc: Andi Kleen ak@linux.intel.com Cc: Changbin Du changbin.du@intel.com Cc: David S. Miller davem@davemloft.net Cc: Davidlohr Bueso dave@stgolabs.net Cc: Eric Saint-Etienne eric.saint.etienne@oracle.com Cc: Jin Yao yao.jin@linux.intel.com Cc: Konstantin Khlebnikov khlebnikov@yandex-team.ru Cc: Mathieu Poirier mathieu.poirier@linaro.org Cc: Namhyung Kim namhyung@kernel.org Cc: Peter Zijlstra peterz@infradead.org Cc: Rasmus Villemoes linux@rasmusvillemoes.dk Cc: Song Liu songliubraving@fb.com Cc: Suzuki Poulouse suzuki.poulose@arm.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Thomas Richter tmricht@linux.ibm.com Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20190702103420.27540-9-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 da55081aefc6..c49e8ea1a42c 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -1145,6 +1145,9 @@ 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)