tracing: Have trigger filter parsing errors show up in error_log

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@gandalf.local.home
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index 918730d..19ce9d2 100644 (file)
--- 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.