Re: [RFC PATCH] tracing: fix return value in __ftrace_event_enable_disable for TRACE_REG_UNREGISTER

[Steven Rostedt]

On Tue, 18 Mar 2025 11:07:00 +0900
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> wrote:

> > --- a/kernel/trace/trace_events.c
> > +++ b/kernel/trace/trace_events.c
> > @@ -790,7 +790,7 @@ static int __ftrace_event_enable_disable(struct trace_event_file *file,
> >  				clear_bit(EVENT_FILE_FL_RECORDED_TGID_BIT, &file->flags);
> >  			}
> >  
> > -			call->class->reg(call, TRACE_REG_UNREGISTER, file);
> > +			ret = call->class->reg(call, TRACE_REG_UNREGISTER, file);  
> 
> This is not enough. As same as enable failure, this function needs to handle
> this error to report it and break.

Perhaps all we should do here is:

			WARN_ON_ONCE(ret);

-- Steve