[05/25] perf trace: Fix potential NULL pointer dereference found by the smatch tool

Commit Message

Arnaldo Carvalho de Melo July 9, 2019, 6:31 p.m. UTC

From: Leo Yan <[e-mail]>

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

  tools/perf/builtin-trace.c:1044
  thread_trace__new() error: we previously assumed 'ttrace' could be
  null (see line 1041).

  tools/perf/builtin-trace.c
  1037 static struct thread_trace *thread_trace__new(void)
  1038 {
  1039         struct thread_trace *ttrace =  zalloc(sizeof(struct thread_trace));
  1040
  1041         if (ttrace)
  1042                 ttrace->files.max = -1;
  1043
  1044         ttrace->syscall_stats = intlist__new(NULL);
               ^^^^^^^^
  1045
  1046         return ttrace;
  1047 }

Signed-off-by: Leo Yan <[e-mail]>
Acked-by: Jiri Olsa <[e-mail]>
Cc: Adrian Hunter <[e-mail]>
Cc: Alexander Shishkin <[e-mail]>
Cc: Alexey Budankov <[e-mail]>
Cc: Alexios Zavras <[e-mail]>
Cc: Andi Kleen <[e-mail]>
Cc: Changbin Du <[e-mail]>
Cc: David S. Miller <[e-mail]>
Cc: Davidlohr Bueso <[e-mail]>
Cc: Eric Saint-Etienne <[e-mail]>
Cc: Jin Yao <[e-mail]>
Cc: Konstantin Khlebnikov <[e-mail]>
Cc: Mathieu Poirier <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Rasmus Villemoes <[e-mail]>
Cc: Song Liu <[e-mail]>
Cc: Suzuki Poulouse <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: Thomas Richter <[e-mail]>
Cc: [e-mail]
Link: http://lkml.kernel.org/r/[e-mail]
[ Just made it look like other tools/perf constructors, same end result ]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>
---
 tools/perf/builtin-trace.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Patch

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index d0eb7224dd36..e3fc9062f136 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -1038,10 +1038,10 @@  static struct thread_trace *thread_trace__new(void)
 {
 	struct thread_trace *ttrace =  zalloc(sizeof(struct thread_trace));
 
-	if (ttrace)
+	if (ttrace) {
 		ttrace->files.max = -1;
-
-	ttrace->syscall_stats = intlist__new(NULL);
+		ttrace->syscall_stats = intlist__new(NULL);
+	}
 
 	return ttrace;
 }