From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752987Ab3ABQaz (ORCPT ); Wed, 2 Jan 2013 11:30:55 -0500 Received: from mx1.redhat.com ([209.132.183.28]:30859 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752736Ab3ABQay (ORCPT ); Wed, 2 Jan 2013 11:30:54 -0500 Date: Wed, 2 Jan 2013 11:30:10 -0500 From: Dave Jones To: Chris Mason , Linux Kernel , Daniel Vetter , Chris Mason Subject: Re: memory corruption, possibly caused by i915 Message-ID: <20130102163010.GB14219@redhat.com> Mail-Followup-To: Dave Jones , Chris Mason , Linux Kernel , Daniel Vetter , Chris Mason References: <20130102155233.GA12479@redhat.com> <20130102160115.GB12838@shiny> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130102160115.GB12838@shiny> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 02, 2013 at 11:01:15AM -0500, Chris Mason wrote: > > [52460.280346] BUG: Bad page map in process panel-6-systray pte:ffff8800b665a0e8 pmd:b6659067 > > [52460.280848] addr:00000038bf3fd000 vm_flags:00000070 anon_vma: (null) mapping:ffff88011052fd98 index:1fd > > [52460.281547] vma->vm_ops->fault: filemap_fault+0x0/0x470 > > [52460.281878] vma->vm_file->f_op->mmap: btrfs_file_mmap+0x0/0x60 [btrfs] > > > > It's falling over in btrfs's mmap op, but I think it's just the victim here, > > of something else corrupting what had been mmaped in the panel process. > > It's a btrfs file, but this isn't in our mmap op. The traces are > finding bad pages at unmap time. Sorry, bad wording on my part. > > Daniel, can you think of additional sanity checks that could be added to > > the i915 driver ? (Even if at the expense of speed: a CONFIG_DEBUG option > > to prove correctness would be very worthwhile imo) > > If the bad pages are getting all the way to btrfs, > CONFIG_DEBUG_PAGE_ALOC may help? You've got lockdep on so maybe you > already enabled it. Yeah, already enabled. Thanks. Dave.