Messages in this thread Patch in this message | | | From | Kamal Mostafa <> | Subject | [PATCH 3.19.y-ckt 38/54] tracing: Don't display trigger file for events that can't be enabled | Date | Mon, 9 May 2016 17:04:57 -0700 |
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3.19.8-ckt21 -stable review patch. If anyone has any objections, please let me know.
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From: Chunyu Hu <chuhu@redhat.com>
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.
Link: http://lkml.kernel.org/r/1462275274-3911-1-git-send-email-chuhu@redhat.com
Fixes: 85f2b08268c01 ("tracing: Add basic event trigger framework") Signed-off-by: Chunyu Hu <chuhu@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- 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 5377441..2723b0a 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -1626,8 +1626,13 @@ 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); -- 2.7.4
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