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) <mhira...@kernel.org> 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