Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964834AbVKQTlV (ORCPT ); Thu, 17 Nov 2005 14:41:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964832AbVKQTlV (ORCPT ); Thu, 17 Nov 2005 14:41:21 -0500 Received: from mx1.redhat.com ([66.187.233.31]:1518 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S964829AbVKQTlU (ORCPT ); Thu, 17 Nov 2005 14:41:20 -0500 Date: Thu, 17 Nov 2005 14:41:02 -0500 From: Dave Jones To: Hugh Dickins Cc: Andrew Morton , Nick Piggin , linux-kernel@vger.kernel.org Subject: Re: [PATCH 02/11] unpaged: private write VM_RESERVED Message-ID: <20051117194102.GE5772@redhat.com> Mail-Followup-To: Dave Jones , Hugh Dickins , Andrew Morton , Nick Piggin , linux-kernel@vger.kernel.org References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1329 Lines: 26 On Thu, Nov 17, 2005 at 07:30:04PM +0000, Hugh Dickins wrote: > The PageReserved removal in 2.6.15-rc1 issued a "deprecated" message > when you tried to mmap or mprotect MAP_PRIVATE PROT_WRITE a VM_RESERVED, > and failed with -EACCES: because do_wp_page lacks the refinement to COW > pages in those areas, nor do we expect to find anonymous pages in them; > and it seemed just bloat to add code for handling such a peculiar case. > But immediately it caused vbetool and ddcprobe (using lrmi) to fail. > > So revert the "deprecated" messages, letting mmap and mprotect succeed. > But leave do_wp_page's BUG_ON(vma->vm_flags & VM_RESERVED) in place > until we've added the code to do it right: so this particular patch is > only good if the app doesn't really need to write to that private area. > > Dave Jones has changed vbetool & ddcprobe to use MAP_SHARED or PROT_READ > just as well, but we don't want to force people to update their tools. Actually Dave Miller did the detective work on that one, I just rebuilt some packages, and spread the good word :) Dave - 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/