diff mbox series

[48/54] tracing: Uninitialized variable in create_tracing_map_fields()

Message ID TY1PR01MB1692B229650ACD3489DDD59796090@TY1PR01MB1692.jpnprd01.prod.outlook.com (mailing list archive)
State New, archived
Headers show
Series [01/54] tracing: Remove redundant unread variable ret | expand

Commit Message

Motai.Hirotaka@aj.MitsubishiElectric.co.jp Aug. 29, 2018, 12:17 p.m. UTC 
Smatch complains that idx can be used uninitialized when we check if
(idx < 0).  It has to be the first iteration through the loop and the
HIST_FIELD_FL_STACKTRACE bit has to be clear and the HIST_FIELD_FL_VAR
bit has to be set to reach the bug.

Link: http://lkml.kernel.org/r/20180328114815.GC29050@mwanda

Fixes: 30350d65ac56 ("tracing: Add variable support to hist triggers")
Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
(cherry picked from commit b28d7b2dc27f0eef1ae608b49d6860f2463910f1)
Signed-off-by: Hirotaka MOTAI <Motai.Hirotaka@aj.MitsubishiElectric.co.jp>
---
 kernel/trace/trace_events_hist.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 15ea11c2..0d7b3ffb 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -4453,17 +4453,17 @@  static void destroy_hist_data(struct hist_trigger_data *hist_data)
 	kfree(hist_data);
 }
 
 static int create_tracing_map_fields(struct hist_trigger_data *hist_data)
 {
 	struct tracing_map *map = hist_data->map;
 	struct ftrace_event_field *field;
 	struct hist_field *hist_field;
-	int i, idx;
+	int i, idx = 0;
 
 	for_each_hist_field(i, hist_data) {
 		hist_field = hist_data->fields[i];
 		if (hist_field->flags & HIST_FIELD_FL_KEY) {
 			tracing_map_cmp_fn_t cmp_fn;
 
 			field = hist_field->field;