Re: [PATCH] uprobes: Remove redundant spinlock in uprobe_deny_signal

[Google]

On Wed, 31 Jul 2024 16:12:32 +0200
Oleg Nesterov <oleg@xxxxxxxxxx> wrote:

> On 07/31, Liao Chang wrote:
> >
> > --- a/kernel/events/uprobes.c
> > +++ b/kernel/events/uprobes.c
> > @@ -1979,9 +1979,7 @@ bool uprobe_deny_signal(void)
> >  	WARN_ON_ONCE(utask->state != UTASK_SSTEP);
> >  
> >  	if (task_sigpending(t)) {
> > -		spin_lock_irq(&t->sighand->siglock);
> >  		clear_tsk_thread_flag(t, TIF_SIGPENDING);
> > -		spin_unlock_irq(&t->sighand->siglock);
> 
> Agreed, in this case ->siglock buys nothing, another signal can come
> right after spin_unlock().
> 
> Acked-by: Oleg Nesterov <oleg@xxxxxxxxxx>
> 
> 

Looks good to me.

Acked-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>

Peter, can you pick this?

Thanks,

-- 
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>