From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752768AbcBBDtM (ORCPT ); Mon, 1 Feb 2016 22:49:12 -0500 Received: from bh-25.webhostbox.net ([208.91.199.152]:55988 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751705AbcBBDtG (ORCPT ); Mon, 1 Feb 2016 22:49:06 -0500 Subject: Re: [lkp] [kallsyms] bf2d2b07db: kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] general protection fault: 0000 [#1] PREEMPT PREEMPT KASANKASAN To: Andrew Morton , kernel test robot References: <87r3h21p8w.fsf@yhuang-dev.intel.com> <20160201162006.fe29443a638368b4eecc456a@linux-foundation.org> Cc: Ard Biesheuvel , lkp@01.org, LKML , Arnd Bergmann , Rusty Russell , Michal Marek , Benjamin Herrenschmidt , "H. Peter Anvin" , Ingo Molnar , Michael Ellerman , Heiko Carstens , Kees Cook , Andrey Ryabinin From: Guenter Roeck Message-ID: <56B0272B.9030704@roeck-us.net> Date: Mon, 1 Feb 2016 19:48:59 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <20160201162006.fe29443a638368b4eecc456a@linux-foundation.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated_sender: linux@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: authenticated_id: linux@roeck-us.net X-Authenticated-Sender: bh-25.webhostbox.net: linux@roeck-us.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/01/2016 04:20 PM, Andrew Morton wrote: > On Thu, 28 Jan 2016 09:12:15 +0800 kernel test robot wrote: > >> FYI, we noticed the below changes on >> >> https://git.linaro.org/people/ard.biesheuvel/linux-arm arm64-kaslr-v4a >> commit bf2d2b07db19001ae0bd55826025b0ba47fae0c2 ("kallsyms: add support for relative offsets in kallsyms address table") >> >> >> +-----------------------------------------------------------+------------+------------+ >> | | 2c4d21df0f | bf2d2b07db | >> +-----------------------------------------------------------+------------+------------+ >> | boot_successes | 10 | 0 | >> | boot_failures | 6 | 36 | >> | Kernel_panic-not_syncing:Attempted_to_kill_init!exitcode= | 2 | | >> | IP-Config:Auto-configuration_of_network_failed | 4 | | >> | general_protection_fault:#[##]PREEMPT_PREEMPT_KASANKASAN | 0 | 36 | >> | general_protection_fault:#[##] | 0 | 36 | >> | BUG:kernel_boot_hang | 0 | 36 | >> +-----------------------------------------------------------+------------+------------+ >> >> >> >> [ 0.281636] kasan: CONFIG_KASAN_INLINE enabled >> >> [ 0.282416] kasan: GPF could be caused by NULL-ptr deref or user memory access >> [ 0.282416] kasan: GPF could be caused by NULL-ptr deref or user memory accessgeneral protection fault: 0000 [#1] general protection fault: 0000 [#1] PREEMPT PREEMPT KASANKASAN >> >> [ 0.284561] Modules linked in: >> [ 0.284561] Modules linked in: >> >> [ 0.285136] CPU: 0 PID: 1 Comm: swapper Not tainted 4.5.0-rc1-00036-gbf2d2b0 #1 >> [ 0.285136] CPU: 0 PID: 1 Comm: swapper Not tainted 4.5.0-rc1-00036-gbf2d2b0 #1 >> [ 0.286438] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 >> [ 0.286438] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014 >> [ 0.288000] task: ffff88000fcb0000 ti: ffff88000fcb8000 task.ti: ffff88000fcb8000 >> [ 0.288000] task: ffff88000fcb0000 ti: ffff88000fcb8000 task.ti: ffff88000fcb8000 >> [ 0.289287] RIP: 0010:[] > > I'm not sufficiently familiar with KASAN to be able to interpret this. > Perhaps Andrey can shed some light? > > The lack of symbol decoding is a problem. > > CONFIG_KALLSYMS=y > CONFIG_KALLSYMS_ALL=y > CONFIG_KALLSYMS_BASE_RELATIVE=y > > It should be there. Perhaps it is not because this error is itself > (possibly) related to kallsyms changes? > Probably. I had seen something similar (crash and no symbols) with an earlier version of the patch, if the symbols were not created. There might be a message in the log, indicating that kallsyms failed to generate the symbols. Guenter