[PATCH 22/75] tools lib traceevent: Add sanity check to is_timestamp_in_us()

[Arnaldo Carvalho de Melo]

From: Tzvetomir Stoyanov <tstoyanov@xxxxxxxxxx>

This patch adds a sanity check to is_timestamp_in_us() input parameter
trace_clock. It avoids a potential segfault in this function for the
case trace_clock is NULL.

Reported-by: Slavomir Kaslev <kaslevs@xxxxxxxxxx>
Signed-off-by: Tzvetomir Stoyanov <tstoyanov@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/20181128145552.68c4f87b@xxxxxxxxxxxxxxxxxx
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/lib/traceevent/event-parse.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index fbd6d6813fab..2b5cb33046ce 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -5409,7 +5409,7 @@ void tep_event_info(struct trace_seq *s, struct tep_event_format *event,
 
 static bool is_timestamp_in_us(char *trace_clock, bool use_trace_clock)
 {
-	if (!use_trace_clock)
+	if (!trace_clock || !use_trace_clock)
 		return true;
 
 	if (!strcmp(trace_clock, "local") || !strcmp(trace_clock, "global")
-- 
2.19.2