From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756113AbZBVPSh (ORCPT ); Sun, 22 Feb 2009 10:18:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752793AbZBVPS1 (ORCPT ); Sun, 22 Feb 2009 10:18:27 -0500 Received: from smtp3.tech.numericable.fr ([82.216.111.39]:53141 "EHLO smtp3.tech.numericable.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753116AbZBVPS1 (ORCPT ); Sun, 22 Feb 2009 10:18:27 -0500 Message-ID: <49A16CBB.5060600@numericable.fr> Date: Sun, 22 Feb 2009 16:18:19 +0100 From: etienne User-Agent: Thunderbird 2.0.0.19 (X11/20090105) MIME-Version: 1.0 To: Tetsuo Handa CC: casey@schaufler-ca.com, paul.moore@hp.com, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH][SMACK] convert smack rule list to linux list References: <49A13E15.6020509@numericable.fr> <200902222040.CAB86425.VMOQHFFFtOSLOJ@I-love.SAKURA.ne.jp> <49A14FBE.7020206@numericable.fr> <200902222231.BDI18760.JFFLOQHMFOOSVt@I-love.SAKURA.ne.jp> In-Reply-To: <200902222231.BDI18760.JFFLOQHMFOOSVt@I-love.SAKURA.ne.jp> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Tetsuo Handa wrote: > etienne wrote: >> what's the best way, using a rcu variant for "list_for_each, container_of ...etc" ? >> (concurrent list insertion are already protected with a mutex, so rcu must the good idea for the read side) > Read side will need a read lock. > I think you need to change from "mutex" to "rw_semaphore" (on the assumption > that SMACK is safe against read locks that may sleep. If not, change from > "mutex" to "rw_spinlock"). > > Regards. > or a rcu_read_lock? since it disables preemption it means no user process will be able to change the list while it's read? regards, Etienne