Messages in this thread Patch in this message | | | From | Chunyu Hu <> | Subject | [PATCH] tracing: Don't display trigger file for events that don't have register func | Date | Mon, 2 May 2016 22:14:14 +0800 |
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Currently register function of the event 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 perf to read event format, and most of them don't have regisgter function except events/ftrace/function.) can't be enabled at all, and an oops will be hit when setting up trigger for those events, so just not showing them is an easy way to avoid the oops.
Signed-off-by: Chunyu Hu <chuhu@redhat.com> --- kernel/trace/trace_events.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index da1eeb6..9fb99fd 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2138,9 +2138,10 @@ event_create_dir(struct dentry *parent, struct trace_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); - + if (call->class->reg) { + trace_create_file("trigger", 0644, file->dir, file, + &event_trigger_fops); + } #ifdef CONFIG_HIST_TRIGGERS trace_create_file("hist", 0444, file->dir, file, &event_hist_fops); -- 1.8.3.1
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