[PATCH v1 11/11] perf cs-etm: Smatch: Fix potential NULL pointer dereference

[Leo Yan]

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         }

To dismiss the potential NULL pointer dereference, this patch validates
the pointer 'session->itrace_synth_opts' before access its elements.

Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
---
 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 0c7776b51045..b79df56eb9df 100644
--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -2540,7 +2540,7 @@ int cs_etm__process_auxtrace_info(union perf_event *event,
 
 	if (session->itrace_synth_opts && session->itrace_synth_opts->set) {
 		etm->synth_opts = *session->itrace_synth_opts;
-	} else {
+	} else if (session->itrace_synth_opts) {
 		itrace_synth_opts__set_default(&etm->synth_opts,
 				session->itrace_synth_opts->default_no_sample);
 		etm->synth_opts.callchain = false;
-- 
2.17.1