[for-next][PATCH 3/8] tracing: Have trigger filter parsing errors show up in error_log

[Steven Rostedt]

From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>

It is annoying that the filter parsing of triggers do not show up in the
error_log. Trying to figure out what is incorrect in the input is
difficult when it fails for a typo.

Have the errors of filter parsing show up in error_log as well.

Link: https://lore.kernel.org/linux-trace-kernel/20221213095602.083fa9fd@xxxxxxxxxxxxxxxxxx

Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Tom Zanussi <zanussi@xxxxxxxxxx>
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
 kernel/trace/trace_events_trigger.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 918730d74932..19ce9d22bfd7 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -1067,7 +1067,14 @@ int set_trigger_filter(char *filter_str,
 
 	/* The filter is for the 'trigger' event, not the triggered event */
 	ret = create_event_filter(file->tr, file->event_call,
-				  filter_str, false, &filter);
+				  filter_str, true, &filter);
+
+	/* Only enabled set_str for error handling */
+	if (filter) {
+		kfree(filter->filter_string);
+		filter->filter_string = NULL;
+	}
+
 	/*
 	 * If create_event_filter() fails, filter still needs to be freed.
 	 * Which the calling code will do with data->filter.
-- 
2.35.1