From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756212AbXISQPs (ORCPT ); Wed, 19 Sep 2007 12:15:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757195AbXISQPc (ORCPT ); Wed, 19 Sep 2007 12:15:32 -0400 Received: from public.id2-vpn.continvity.gns.novell.com ([195.33.99.129]:28686 "EHLO public.id2-vpn.continvity.gns.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757331AbXISQPb convert rfc822-to-8bit (ORCPT ); Wed, 19 Sep 2007 12:15:31 -0400 Message-Id: <46F16779.76E4.0078.0@novell.com> X-Mailer: Novell GroupWise Internet Agent 7.0.2 HP Date: Wed, 19 Sep 2007 17:16:25 +0100 From: "Jan Beulich" To: "Andi Kleen" Cc: Subject: Re: [PATCH] i386/PAE: avoid temporarily inconsistent pte-s References: <46F150CB.76E4.0078.0@novell.com> <200709191809.47351.ak@suse.de> In-Reply-To: <200709191809.47351.ak@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >>> Andi Kleen 19.09.07 18:09 >>> >On Wednesday 19 September 2007 16:39:39 Jan Beulich wrote: >> One more of these issues (which were considered fixed a few releases >> back): Other than on x86-64, i386 allows set_fixmap() to replace >> already present mappings. Consequently, on PAE, care must be taken to >> not update the high half of a pte while the low half is still holding >> the old value. > >Hmm perhaps it would be better to just forbid it on i386 too. >Do you know who uses it? PCI's mmconfig accessor. One could of course make it call clear_fixmap() prior to establishing a new mapping, but I thought that was not intended and is the reason for allowing this. Jan