From a5b9065658287edc0d165d3754360d2e41c69a97 Mon Sep 17 00:00:00 2001 From: Chunyu Hu Date: Tue, 3 May 2016 19:34:34 +0800 Subject: [PATCH] tracing: Don't display trigger file for events that can't be enabled Orabug: 25227147 [ Upstream commit 854145e0a8e9a05f7366d240e2f99d9c1ca6d6dd ] 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. Link: http://lkml.kernel.org/r/1462275274-3911-1-git-send-email-chuhu@redhat.com Cc: stable@vger.kernel.org # 3.14+ Fixes: 85f2b08268c01 ("tracing: Add basic event trigger framework") Signed-off-by: Chunyu Hu Signed-off-by: Steven Rostedt Signed-off-by: Sasha Levin (cherry picked from commit 3216eb22857e515aa89f594f84c0ef2a36a59b08) Signed-off-by: Dhaval Giani --- kernel/trace/trace_events.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index c4de47fc5cca..860c11039154 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1625,8 +1625,13 @@ event_create_dir(struct dentry *parent, struct ftrace_event_file *file) 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); -- 2.50.1