From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-next-2.6] net: fix rcu use in ip_route_output_slow Date: Sun, 26 Sep 2010 19:05:31 -0700 (PDT) Message-ID: <20100926.190531.233710747.davem@davemloft.net> References: <1285196665.2380.54.camel@edumazet-laptop> <20100922231221.GS2435@linux.vnet.ibm.com> <1285314363.2503.12.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: paulmck@linux.vnet.ibm.com, akpm@linux-foundation.org, netdev@vger.kernel.org To: eric.dumazet@gmail.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:57238 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758701Ab0I0CFL (ORCPT ); Sun, 26 Sep 2010 22:05:11 -0400 In-Reply-To: <1285314363.2503.12.camel@edumazet-laptop> Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet Date: Fri, 24 Sep 2010 09:46:03 +0200 > [PATCH net-next-2.6] net: fix rcu use in ip_route_output_slow > > __in_dev_get_rtnl(dev_out) is called while RTNL is not held, thus > triggers a lockdep fault. > > At this point, we only perform a raw test of dev_out->ip_ptr being NULL, > we dont need to make sure ip_ptr cant changed right after. > > We can use rcu_dereference_raw() for this. > > Reported-by: Andrew Morton > Acked-by: Paul E. McKenney > Signed-off-by: Eric Dumazet Applied, thanks everyone!