Subject: Re: [PATCH] net: fix race in the receive/select

From: Jarek Poplawski <[email-masked]>
Date: Sun, 28 Jun 2009 23:48:46 +0200

On Sun, Jun 28, 2009 at 08:04:12PM +0200, Oleg Nesterov wrote:
> On 06/28, Jarek Poplawski wrote:
...
> > Hmm... of course:
> >
> > static inline void sock_poll_wait(struct file * filp, struct sock *sk, poll_table *p)
> > {
> >  	if (p && sk->sk_sleep) {
> >  		__poll_wait(filp, sk->sk_sleep, p);
> >  		/*
> >  		 * fat comment
> >  		 */
> >  		smp_mb(); // or smp_mb__after_unlock();
> >  	}
> > }
> 
> Perhaps it makes sense to check ->sk_sleep != NULL in sock_poll_wait(), but
> I don't think we need __poll_wait(). poll_wait() is inline, I think gcc
> will optimize out "if (p && wait_address)" check if poll_wait() is called
> from sock_poll_wait().

Sure, to me it looks a bit more readable, but let Jiri choose.;-)

Cheers,
Jarek P.