Merge branches 'work.misc' and 'work.dcache' of git://git.kernel.org/pub/scm/linux...

[sfrench/cifs-2.6.git] / kernel / trace / trace_events_filter.c

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 0dceb77d1d42b3afa6c38dc7dce22ad163a48ad3..893a206bcba4f76dd504e246d9667475fd7ed456 100644 (file)
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1701,6 +1701,7 @@ static void create_filter_finish(struct filter_parse_error *pe)
  * @filter_str: filter string
  * @set_str: remember @filter_str and enable detailed error in filter
  * @filterp: out param for created filter (always updated on return)
+ *           Must be a pointer that references a NULL pointer.
  *
  * Creates a filter for @call with @filter_str.  If @set_str is %true,
  * @filter_str is copied and recorded in the new filter.
@@ -1718,6 +1719,10 @@ static int create_filter(struct trace_event_call *call,
        struct filter_parse_error *pe = NULL;
        int err;
 
+       /* filterp must point to NULL */
+       if (WARN_ON(*filterp))
+               *filterp = NULL;
+
        err = create_filter_start(filter_string, set_str, &pe, filterp);
        if (err)
                return err;