Re: [PATCH] ftrace: fix perf-tracepoint OOPS

[Steven Rostedt]

On Wed, 5 Aug 2009, Peter Zijlstra wrote:

> Not all tracepoints are created equal, in specific the ftrace
> tracepoints are created with TRACE_EVENT_FORMAT() which does not
> generate the needed bits to tie them into perf counters.
> 
> For those events, don't create the 'id' file and fail ->profile_enable
> when their ID is specified through other means.
> 
> Reported-by: Chris Mason <chris.mason@xxxxxxxxxx>
> Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>

Acked-by: Steven Rostedt <rostedt@xxxxxxxxxxx>

-- Steve

> ---
>  kernel/trace/trace_event_profile.c |    2 +-
>  kernel/trace/trace_events.c        |    2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/trace/trace_event_profile.c b/kernel/trace/trace_event_profile.c
> index 5b5895a..11ba5bb 100644
> --- a/kernel/trace/trace_event_profile.c
> +++ b/kernel/trace/trace_event_profile.c
> @@ -14,7 +14,7 @@ int ftrace_profile_enable(int event_id)
>  
>  	mutex_lock(&event_mutex);
>  	list_for_each_entry(event, &ftrace_events, list) {
> -		if (event->id == event_id) {
> +		if (event->id == event_id && event->profile_enable) {
>  			ret = event->profile_enable(event);
>  			break;
>  		}
> diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
> index 90cdec5..e2b301d 100644
> --- a/kernel/trace/trace_events.c
> +++ b/kernel/trace/trace_events.c
> @@ -971,7 +971,7 @@ event_create_dir(struct ftrace_event_call *call, struct dentry *d_events,
>  		entry = trace_create_file("enable", 0644, call->dir, call,
>  					  enable);
>  
> -	if (call->id)
> +	if (call->id && call->profile_enable)
>  		entry = trace_create_file("id", 0444, call->dir, call,
>  					  id);
>  
> 
> 
> 
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