Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752489Ab0BNRzA (ORCPT ); Sun, 14 Feb 2010 12:55:00 -0500 Received: from charlotte.tuxdriver.com ([70.61.120.58]:40828 "EHLO smtp.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751919Ab0BNRy7 (ORCPT ); Sun, 14 Feb 2010 12:54:59 -0500 Date: Sun, 14 Feb 2010 12:54:45 -0500 From: Neil Horman To: Jiri Slaby Cc: Andrew Morton , Andi Kleen , linux-kernel@vger.kernel.org, Greg KH , Kay Sievers Subject: Re: oops in uevent_helper [was: mmotm 2010-01-13-12-17 uploaded] Message-ID: <20100214175445.GA1984@localhost.localdomain> References: <4B50C2FA.4020100@gmail.com> <4B50FC78.9010107@gmail.com> <20100122155237.e93a1c55.akpm@linux-foundation.org> <4B730EE3.4080405@gmail.com> <20100211205745.GA18202@basil.fritz.box> <20100211142513.b1fd6e7a.akpm@linux-foundation.org> <20100212052126.GA21783@one.firstfloor.org> <20100211212708.aa5bec1f.akpm@linux-foundation.org> <20100212170624.GB27303@hmsreliant.think-freely.org> <4B7833A4.90905@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4B7833A4.90905@gmail.com> User-Agent: Mutt/1.5.20 (2009-08-17) X-Spam-Score: -4.1 (----) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1327 Lines: 33 On Sun, Feb 14, 2010 at 06:32:20PM +0100, Jiri Slaby wrote: > On 02/12/2010 06:06 PM, Neil Horman wrote: > > Fix up remaining references to uevent_helper to play nice with Andi's > > uevent_helper/rcu changes. > > > > Some changes were made recently which modified uevent_helper to be an rcu > > protected pointer, rather than a static char array. This has led to a few > > missed points in which the sysfs path still assumed that: > > 1) the uevent_helper symbol could still be accessed safely without > > rcu_dereference > > 2) that the sysfs path could copy data to that pointer safely. > > > > I've fixed this by chaging the sysfs path so that it duplicates the string on > > uevent_helper_store, and freeing it (only if it doesn't point to the > > CONFIG_DEFAULT_UEVENT_HELPER string), in a call_rcu post-quiescent point. I've > > also fixed up the remaining references to the uevent_helper pointers to use > > rcu_dereference. > > > > Signed-off-by: Neil Horman > > Tested-by: Jiri Slaby > Thanks Jiri! Neil > -- > js > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/