Subject: Re: [PATCH V2] net: add accounting for socket backlog

From: Zhu Yi <[email-masked]>
Date: Tue, 02 Mar 2010 10:34:02 +0800

On Mon, 2010-03-01 at 19:43 +0800, Eric Dumazet wrote:
> Thinking again about this, doing this zero initialization at the very
> end of __release_sock() solves the problem of potential infinite loop
> in
> __release_sock(). Since producer will hit the backlog limit.
> 
> Thanks
> 
> diff --git a/net/core/sock.c b/net/core/sock.c
> index 305cba4..544cf4a 100644
> --- a/net/core/sock.c
> +++ b/net/core/sock.c
> @@ -1542,6 +1542,11 @@ static void __release_sock(struct sock *sk)
>  
>                 bh_lock_sock(sk);
>         } while ((skb = sk->sk_backlog.head) != NULL);
> +       /*
> +        * Doing this zeroing at the end of this function guarantee we
> can not
> +        * loop forever while a wild producer attempts to flood us
> +        */
> +       sk->sk_backlog.len = 0;
>  } 

Very good point. I'll add your sob in my next patch.

Thanks,
-yi