tools lib traceevent: Check return value of realloc()

If realloc() fails, it'll leak the buffer.  Also increate buffer size
only if the allocation succeeded.

Signed-off-by: Namhyung Kim <[email protected]>
Reviewed-by: Jiri Olsa <[email protected]>
Acked-by: Steven Rostedt <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Steven Rostedt <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

1 files changed, 9 insertions, 4 deletions

diff --git a/tools/lib/traceevent/trace-seq.c b/tools/lib/traceevent/trace-seq.c
index f7112138e6af..e454a2c66cac 100644
--- a/tools/lib/traceevent/trace-seq.c
+++ b/tools/lib/traceevent/trace-seq.c
@@ -91,11 +91,16 @@ void trace_seq_destroy(struct trace_seq *s)
 
 static void expand_buffer(struct trace_seq *s)
 {
-	s->buffer_size += TRACE_SEQ_BUF_SIZE;
-	s->buffer = realloc(s->buffer, s->buffer_size);
-	if (WARN_ONCE(!s->buffer,
-		      "Can't allocate trace_seq buffer memory"))
+	char *buf;
+
+	buf = realloc(s->buffer, s->buffer_size + TRACE_SEQ_BUF_SIZE);
+	if (WARN_ONCE(!buf, "Can't allocate trace_seq buffer memory")) {
 		s->state = TRACE_SEQ__MEM_ALLOC_FAILED;
+		return;
+	}
+
+	s->buffer = buf;
+	s->buffer_size += TRACE_SEQ_BUF_SIZE;
 }
 
 /**