tracing/filters: Fix MATCH_END_ONLY filter matching

For '*foo' pattern, we should allow any string ending with
'foo', but event filtering incorrectly disallows strings
like bar_foo_foo:

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <4B4E8735.6070604@cn.fujitsu.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 11c3973e6552..49e44dd17851 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -275,9 +275,10 @@ static int regex_match_middle(char *str, struct regex *r, int len)
 
 static int regex_match_end(char *str, struct regex *r, int len)
 {
-        char *ptr = strstr(str, r->pattern);
+        int strlen = len - 1;
 
-        if (ptr && (ptr[r->len] == 0))
+        if (strlen >= r->len &&
+            memcmp(str + strlen - r->len, r->pattern, r->len) == 0)
                 return 1;
         return 0;
 }