[PATCH 19/25] perf cs-etm: Fix potential NULL pointer dereference found by the smatch tool

Arnaldo Carvalho de Melo
2019-07-09T18:33:10Z

From: Leo Yan <leo.yan@linaro.org>

Based on the following report from Smatch, fix the potential NULL
pointer dereference check.

tools/perf/util/cs-etm.c:2545
cs_etm__process_auxtrace_info() error: we previously assumed
'session->itrace_synth_opts' could be null (see line 2541)

tools/perf/util/cs-etm.c
2541 if (session->itrace_synth_opts && session->itrace_synth_opts->set) {
2542 etm->synth_opts = *session->itrace_synth_opts;
2543 } else {
2544 itrace_synth_opts__set_default(&etm->synth_opts,
2545 session->itrace_synth_opts->default_no_sample);
^^^^^^^^^^^^^^^^^^^^^^^^^^
2546 etm->synth_opts.callchain = false;
2547 }

'session->itrace_synth_opts' is impossible to be a NULL pointer in
cs_etm__process_auxtrace_info(), thus this patch removes the NULL
test for 'session->itrace_synth_opts'.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/20190708143937.7722-5-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/cs-etm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
index 508e4a3ddc8c..67b88b599a53 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -2538,7 +2538,7 @@ int cs_etm__process_auxtrace_info(union perf_event *event,
return 0;
}

- if (session->itrace_synth_opts && session->itrace_synth_opts->set) {
+ if (session->itrace_synth_opts->set) {
etm->synth_opts = *session->itrace_synth_opts;
} else {
itrace_synth_opts__set_default(&etm->synth_opts,
--
2.21.0