diff options
authorSteven Rostedt (Red Hat) <rostedt@goodmis.org>2016-02-24 09:04:24 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-03-03 15:06:24 -0800
commiteb63a905ff5f0d258693fd9991a94bc49188dcc3 (patch)
parentbd54a801362f13ac756b4de4bb65d1a48c7d5fad (diff)
tracing: Fix showing function event in available_events
commit d045437a169f899dfb0f6f7ede24cc042543ced9 upstream. The ftrace:function event is only displayed for parsing the function tracer data. It is not used to enable function tracing, and does not include an "enable" file in its event directory. Originally, this event was kept separate from other events because it did not have a ->reg parameter. But perf added a "reg" parameter for its use which caused issues, because it made the event available to functions where it was not compatible for. Commit 9b63776fa3ca9 "tracing: Do not enable function event with enable" added a TRACE_EVENT_FL_IGNORE_ENABLE flag that prevented the function event from being enabled by normal trace events. But this commit missed keeping the function event from being displayed by the "available_events" directory, which is used to show what events can be enabled by set_event. One documented way to enable all events is to: cat available_events > set_event But because the function event is displayed in the available_events, this now causes an INVALID error: cat: write error: Invalid argument Reported-by: Chunyu Hu <chuhu@redhat.com> Fixes: 9b63776fa3ca9 "tracing: Do not enable function event with enable" Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 5a898f15bfc6..7d054b7671ec 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -602,7 +602,8 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
* The ftrace subsystem is for showing formats only.
* They can not be enabled or disabled via the event files.
- if (call->class && call->class->reg)
+ if (call->class && call->class->reg &&
+ !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
return file;