diff options
Diffstat (limited to 'kernel/trace/trace_events_filter.c')
| -rw-r--r-- | kernel/trace/trace_events_filter.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 0dceb77d1d42..893a206bcba4 100644 --- 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; |