[PATCH AUTOSEL 5.2 133/171] perf intel-bts: Fix potential NULL pointer dereference found by the smatch tool

[Sasha Levin]

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

[ Upstream commit 1d481458816d9424c8a05833ce0ebe72194a350e ]

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 <leo....@linaro.org>
Acked-by: Adrian Hunter <adrian.hun...@intel.com>
Cc: Alexander Shishkin <alexander.shish...@linux.intel.com>
Cc: Andi Kleen <a...@linux.intel.com>
Cc: Jiri Olsa <jo...@redhat.com>
Cc: Mathieu Poirier <mathieu.poir...@linaro.org>
Cc: Namhyung Kim <namhy...@kernel.org>
Cc: Suzuki Poulouse <suzuki.poul...@arm.com>
Cc: linux-arm-ker...@lists.infradead.org
Link: http://lkml.kernel.org/r/20190708143937.7722-3-leo....@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 tools/perf/util/intel-bts.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/intel-bts.c b/tools/perf/util/intel-bts.c
index e32dbffebb2f..625ad3639a7e 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;
        }
 
-- 
2.20.1