perf intel-bts: 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/intel-bts.c:898
  intel_bts_process_auxtrace_info() error: we previously assumed
  'session->itrace_synth_opts' could be null (see line 894)

  tools/perf/util/intel-bts.c:899
  intel_bts_process_auxtrace_info() warn: variable dereferenced before
  check 'session->itrace_synth_opts' (see line 898)

  tools/perf/util/intel-bts.c
  894         if (session->itrace_synth_opts && session->itrace_synth_opts->set) {
  895                 bts->synth_opts = *session->itrace_synth_opts;
  896         } else {
  897                 itrace_synth_opts__set_default(&bts->synth_opts,
  898                                 session->itrace_synth_opts->default_no_sample);
                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^
  899                 if (session->itrace_synth_opts)
                          ^^^^^^^^^^^^^^^^^^^^^^^^^^
  900                         bts->synth_opts.thread_stack =
  901                                 session->itrace_synth_opts->thread_stack;
  902         }

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

Signed-off-by: Leo Yan <[email protected]>
Acked-by: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mathieu Poirier <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Suzuki Poulouse <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

1 files changed, 2 insertions, 3 deletions

diff --git a/tools/perf/util/intel-bts.c b/tools/perf/util/intel-bts.c
index 5a21bcdb8ef7..5560e95afdda 100644
--- a/tools/perf/util/intel-bts.c
+++ b/tools/perf/util/intel-bts.c
@@ -891,13 +891,12 @@ int intel_bts_process_auxtrace_info(union perf_event *event,
 	if (dump_trace)
 		return 0;
 
-	if (session->itrace_synth_opts && session->itrace_synth_opts->set) {
+	if (session->itrace_synth_opts->set) {
 		bts->synth_opts = *session->itrace_synth_opts;
 	} else {
 		itrace_synth_opts__set_default(&bts->synth_opts,
 				session->itrace_synth_opts->default_no_sample);
-		if (session->itrace_synth_opts)
-			bts->synth_opts.thread_stack =
+		bts->synth_opts.thread_stack =
 				session->itrace_synth_opts->thread_stack;
 	}