From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754900Ab3KKRQM (ORCPT ); Mon, 11 Nov 2013 12:16:12 -0500 Received: from service87.mimecast.com ([91.220.42.44]:35118 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753173Ab3KKRQE convert rfc822-to-8bit (ORCPT ); Mon, 11 Nov 2013 12:16:04 -0500 Message-ID: <528110B1.4060402@arm.com> Date: Mon, 11 Nov 2013 17:15:29 +0000 From: Jonathan Austin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130804 Thunderbird/17.0.8 MIME-Version: 1.0 To: Ming Lei CC: Axel Lin , Michal Marek , Rusty Russell , Russell King , Linux Kernel Mailing List , linux-arm-kernel , =?UTF-8?B?VXdlIA==?= =?UTF-8?B?S2xlaW5lLUvDtm5pZw==?= Subject: Re: kernel BUG at kernel/kallsyms.c:222! References: <1383789208.5970.1.camel@phoenix> <87zjpf4w0j.fsf@rustcorp.com.au> <87y54vzszo.fsf@rustcorp.com.au> In-Reply-To: X-OriginalArrivalTime: 11 Nov 2013 17:16:02.0087 (UTC) FILETIME=[B25F3B70:01CEDF01] X-MC-Unique: 113111117160203901 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/11/13 10:41, Ming Lei wrote: > Hi, > > On Mon, Nov 11, 2013 at 5:57 PM, Ming Lei wrote: >> Hi, >> >> On Mon, Nov 11, 2013 at 4:37 PM, Axel Lin wrote: >>> 2013/11/11 Ming Lei : >>> >>> Hi Ming, >>> >>> commit f6537f2f "scripts/kallsyms: filter symbols not in kernel address space", >>> uses CONFIG_PAGE_OFFSET as kernel_start_addr. >>> However, for !CONFIG_MMU case we have : >>> PAGE_OFFSET != CONFIG_PAGE_OFFSET. >> >> Yes, it is the cause, and strictly speaking, commit f6537f2f is wrong, >> but triggered with bogus CONFIG_PAGE_OFFSET if !CONFIG_MMU. >> >> We can fix it either by Rusty's patch or removing the bogus >> CONFIG_PAGE_OFFSET for !CONFIG_MMU. > > Rusty, maybe we need revert commit f6537f2f "scripts/kallsyms: filter > symbols not in kernel address space", since CONFIG_PAGE_OFFSET > may be bogus on !MMU or not defined on ARCHs(most of 64bit arch, > no regression report because scripts/kallsyms may get zero > kernel_start_addr) > For me on Cortex-R7 (nommu) f6537f2f breaks boot (Oops very early on...) and reverting it fixes the problem... However, as you note, we have a 'bogus' CONFIG_PAGE_OFFSET (0xC0000000) for !MMU so another approach would be to fix that... I've tested the patch below and it solves the ARM side of things - so gives you an option other than a complete revert. Happy to put this in to RMK's patch system if you'd prefer not to have to revert and he's happy with the patch. Jonny -------->8----------- diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index d601be3..6756651 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1609,6 +1609,7 @@ endchoice config PAGE_OFFSET hex + default PHYS_OFFSET if !MMU default 0x40000000 if VMSPLIT_1G default 0x80000000 if VMSPLIT_2G default 0xC0000000