Re: [PATCH] perf/ftrace: Fix WARNING in __unregister_ftrace_function

[Steven Rostedt <rostedt@goodmis.org>]

On Wed, 13 May 2026 12:16:07 -0400
Rik van Riel <riel@surriel.com> wrote:

> diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
> index a6bb7577e8c5..b9e33ae24867 100644
> --- a/kernel/trace/trace_event_perf.c
> +++ b/kernel/trace/trace_event_perf.c
> @@ -497,7 +497,14 @@ static int perf_ftrace_function_register(struct perf_event *event)
>  static int perf_ftrace_function_unregister(struct perf_event *event)
>  {
>  	struct ftrace_ops *ops = &event->ftrace_ops;
> -	int ret = unregister_ftrace_function(ops);
> +	int ret;
> +
> +	if (!(ops->flags & FTRACE_OPS_FL_ENABLED)) {
> +		ftrace_free_filter(ops);
> +		return 0;
> +	}
> +
> +	ret = unregister_ftrace_function(ops);
>  	ftrace_free_filter(ops);
>  	return ret;
>  }
> -- 

Instead of duplicating code, what about doing:

static int perf_ftrace_function_unregister(struct perf_event *event)
{
	struct ftrace_ops *ops = &event->ftrace_ops;
	int ret = 0;

	if (ops->flags & FTRACE_OPS_FL_ENABLED)
		ret = unregister_ftrace_function(ops);

	ftrace_free_filter(ops);
	return ret;
}


?

-- Steve