From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754643AbaIVPqW (ORCPT ); Mon, 22 Sep 2014 11:46:22 -0400 Received: from mail-pa0-f48.google.com ([209.85.220.48]:33212 "EHLO mail-pa0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754490AbaIVPqU (ORCPT ); Mon, 22 Sep 2014 11:46:20 -0400 Date: Mon, 22 Sep 2014 08:46:15 -0700 From: Guenter Roeck To: Vivek Goyal Cc: Andrew Morton , Mikael Starvik , Jesper Nilsson , linux-kernel@vger.kernel.org Subject: Re: [PATCH] resource: Add NULL check in next_resource Message-ID: <20140922154615.GB5054@roeck-us.net> References: <1411314704-27072-1-git-send-email-linux@roeck-us.net> <20140922145812.GD4250@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140922145812.GD4250@redhat.com> 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 Mon, Sep 22, 2014 at 10:58:12AM -0400, Vivek Goyal wrote: > On Sun, Sep 21, 2014 at 08:51:44AM -0700, Guenter Roeck wrote: > > Commit 8c86e70acead ("resource: provide new functions to walk through > > resources") adds a suble new requirement that iomem_resource.child must > > not be NULL when walk_system_ram_range is called. This can cause a crash > > if it turns out that there are no children. The crash ('Unable to handle > > kernel NULL pointer dereference') is seen when trying to test a crisv32 > > image on kernels with this commit applied. > > > > Fix by adding a NULL check into next_resource(). > > > > Fixes: 8c86e70acead ("resource: provide new functions to walk through resources") > > One such problem was solved with following commit. > > commit 800df627e2eabaf4a921d342a1d5162c843b7fc2 > Author: Vivek Goyal > Date: Fri Aug 29 15:18:29 2014 -0700 > > resource: fix the case of null pointer access > > Do you have this patch applied in your tree? > Bisect suggests that I did. I know what happened: There was another problem that affected crisv32 in v3.17-rc5, which I tried to bisect. Bisect result pointed to your commit, but it wasn't the cause of the other problem. As a result, bisect did not catch the real problem but the NULL pointer problem instead. Please ignore my patch; I confirmed that commit 800df627e2ea already fixes the problem I tried to fix. Thanks, Guenter