From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755419AbZBDCZg (ORCPT ); Tue, 3 Feb 2009 21:25:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752485AbZBDCZ1 (ORCPT ); Tue, 3 Feb 2009 21:25:27 -0500 Received: from terminus.zytor.com ([198.137.202.10]:50324 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752325AbZBDCZ0 (ORCPT ); Tue, 3 Feb 2009 21:25:26 -0500 Message-ID: <4988FBBD.9020608@kernel.org> Date: Tue, 03 Feb 2009 18:21:49 -0800 From: "H. Peter Anvin" Organization: Linux Kernel Organization, Inc. User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Jeremy Fitzhardinge CC: Ingo Molnar , the arch/x86 maintainers , Linux Kernel Mailing List , Xen-devel , Stable Kernel Subject: Re: [PATCH] xen: disable interrupts before saving in percpu References: <4988DAEA.6040608@goop.org> <4988EE04.7090006@kernel.org> <4988FA4A.6080002@goop.org> In-Reply-To: <4988FA4A.6080002@goop.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jeremy Fitzhardinge wrote: > H. Peter Anvin wrote: >> Jeremy Fitzhardinge wrote: >> >>> xen_mc_batch has a small preempt race where it takes the address of a >>> percpu variable immediately before disabling interrupts, thereby >>> leaving a small window in which we may migrate to another cpu and save >>> the flags in the wrong percpu variable. Disable interrupts before >>> saving the old flags in a percpu. >>> >> >> Applied to tip:core/xen, thanks! > > Can you push this Linusward too? > Just merged into tip:core/urgent, so it should end up in the next set of pull requests. -hpa