Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932267Ab2BXRZk (ORCPT ); Fri, 24 Feb 2012 12:25:40 -0500 Received: from e9.ny.us.ibm.com ([32.97.182.139]:57672 "EHLO e9.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755964Ab2BXRZj (ORCPT ); Fri, 24 Feb 2012 12:25:39 -0500 Message-ID: <4F47C800.4090903@linux.vnet.ibm.com> Date: Fri, 24 Feb 2012 09:25:20 -0800 From: Dave Hansen User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.27) Gecko/20120216 Lightning/1.0b2 Thunderbird/3.1.19 MIME-Version: 1.0 To: Christoph Lameter CC: "Eric W. Biederman" , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC][PATCH] fix move/migrate_pages() race on task struct References: <20120223180740.C4EC4156@kernel> <4F468F09.5050200@linux.vnet.ibm.com> <4F469BC7.50705@linux.vnet.ibm.com> <4F47BF56.6010602@linux.vnet.ibm.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Content-Scanned: Fidelis XPS MAILER x-cbid: 12022417-7182-0000-0000-000000E21CCF Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 558 Lines: 15 On 02/24/2012 09:08 AM, Christoph Lameter wrote: > cpuset_mems_allowed takes a mutex. Hmmm... Under rcu? > > security_task_movememory does some kind of security hook. > > Is that all safe? If not then we need to take a refcount on the task > struct after all. Urg, no we can't sleep under an rcu_read_lock(). -- 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/