[tip:perf/urgent] perf cs-etm: Fix potential NULL pointer dereference found by the smatch tool

[tip-bot for Leo Yan]

Commit-ID:  0702f23c983b8a921853c33a9f59b9cf0975d36e
Gitweb:     https://git.kernel.org/tip/0702f23c983b8a921853c33a9f59b9cf0975d36e
Author:     Leo Yan <leo.yan@xxxxxxxxxx>
AuthorDate: Mon, 8 Jul 2019 22:39:37 +0800
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Tue, 9 Jul 2019 10:13:27 -0300

perf cs-etm: Fix potential NULL pointer dereference found by the smatch tool

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@xxxxxxxxxx>
Reviewed-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Suzuki Poulouse <suzuki.poulose@xxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20190708143937.7722-5-leo.yan@xxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@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 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,