tracing/filters: strloc should be unsigned short

I forgot to update filter code accordingly in
"tracing/events: change the type of __str_loc_item to unsigned short"
(commt b0aae68cc5508f3c2fbf728988c954db4c8b8a53)

It can cause system crash:

 # echo 1 > tracing/events/irq/irq_handler_entry/enable
 # echo 'name == eth0' > tracing/events/irq/irq_handler_entry/filter

[ Impact: fix crash while filtering on __string() field ]

Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4A35B905.3090500@cn.fujitsu.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 1d81923..b24ab0e 100644 (file)
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -178,7 +178,7 @@ static int filter_pred_string(struct filter_pred *pred, void *event,
 static int filter_pred_strloc(struct filter_pred *pred, void *event,
                              int val1, int val2)
 {
-       int str_loc = *(int *)(event + pred->offset);
+       unsigned short str_loc = *(unsigned short *)(event + pred->offset);
        char *addr = (char *)(event + str_loc);
        int cmp, match;