Patch "tracing: Don't display trigger file for events that can't be enabled" has been added to the 3.14-stable tree

This is a note to let you know that I've just added the patch titled

tracing: Don't display trigger file for events that can't be enabled

to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
tracing-don-t-display-trigger-file-for-events-that-can-t-be-enabled.patch
and it can be found in the queue-3.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Chunyu Hu <[email protected]>
Date: Tue, 3 May 2016 19:34:34 +0800
Subject: tracing: Don't display trigger file for events that can't be enabled

From: Chunyu Hu <[email protected]>

commit 854145e0a8e9a05f7366d240e2f99d9c1ca6d6dd upstream.

Currently register functions for events will be called through the 'reg' field of event class directly without any check when seting up triggers.

Triggers for events that don't support register through debug fs (events under events/ftrace are for trace-cmd to read event format, and most of them don't have a register function except events/ftrace/functionx) can't be enabled at all, and an oops will be hit when setting up trigger for those events, so just not creating them is an easy way to avoid the oops.

---
 kernel/trace/trace_events.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

@@ -1546,8 +1546,13 @@ event_create_dir(struct dentry *parent,
 	trace_create_file("filter", 0644, file->dir, file,
 			  &ftrace_event_filter_fops);
 
-	trace_create_file("trigger", 0644, file->dir, file,
-			  &event_trigger_fops);
+	/*
+	 * Only event directories that can be enabled should have
+	 * triggers.
+	 */
+	if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
+		trace_create_file("trigger", 0644, file->dir, file,
+				  &event_trigger_fops);
 
 	trace_create_file("format", 0444, file->dir, call,
 			  &ftrace_event_format_fops);

Patches currently in stable-queue which might be from [email protected] are

queue-3.14/tracing-don-t-display-trigger-file-for-events-that-can-t-be-enabled.patch