From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753038Ab1HHRFh (ORCPT ); Mon, 8 Aug 2011 13:05:37 -0400 Received: from cantor2.suse.de ([195.135.220.15]:59940 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751799Ab1HHRFf (ORCPT ); Mon, 8 Aug 2011 13:05:35 -0400 Date: Mon, 8 Aug 2011 10:03:00 -0700 From: Greg KH To: Ben Hutchings Cc: linux-kernel@vger.kernel.org, stable@kernel.org, Trond Myklebust , akpm@linux-foundation.org, torvalds@linux-foundation.org, stable-review@kernel.org, alan@lxorguk.ukuu.org.uk Subject: Re: [Stable-review] [07/55] SUNRPC: Fix a race between work-queue and rpc_killall_tasks Message-ID: <20110808170300.GA27419@suse.de> References: <20110806000249.573906795@clark.kroah.org> <1312738681.2591.1024.camel@deadeye> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1312738681.2591.1024.camel@deadeye> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Aug 07, 2011 at 06:38:01PM +0100, Ben Hutchings wrote: > On Fri, 2011-08-05 at 17:01 -0700, Greg KH wrote: > > 2.6.32-longterm review patch. If anyone has any objections, please let us know. > > > > ------------------ > > > > From: Trond Myklebust > > > > commit b55c59892e1f3b6c7d4b9ccffb4263e1486fb990 upstream. > > > > Since rpc_killall_tasks may modify the rpc_task's tk_action field > > without any locking, we need to be careful when dereferencing it. > [...] > > This isn't nearly careful enough to avoid races. You must at least use > the ACCESS_ONCE macro, otherwise the compiler can just optimise away the > local variable this introduces. Well, that's an upstream issue as well, right? Not much I can do here in the stable updates :) greg k-h