From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752631Ab1JHLOg (ORCPT ); Sat, 8 Oct 2011 07:14:36 -0400 Received: from moutng.kundenserver.de ([212.227.17.8]:64311 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751266Ab1JHLOe (ORCPT ); Sat, 8 Oct 2011 07:14:34 -0400 From: Arnd Bergmann To: linux-arm-kernel@lists.infradead.org Cc: Eric Miao , Paulo Marques , Kukjin Kim , Russell King - ARM Linux , Tomasz Figa , linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org, Ben Dooks Subject: Re: Question about "Inconsistent kallsyms data" Date: Sat, 08 Oct 2011 13:14:06 +0200 Message-ID: <8197014.WsynFjtK5s@wuerfel> User-Agent: KMail/4.7.1 (Linux/3.1.0-rc8nosema+; KDE/4.7.1; x86_64; ; ) In-Reply-To: References: <02ae01cc4d91$aed71670$0c854350$%kim@samsung.com> <4E382602.6050308@grupopie.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V02:K0:XCT9Yr6Ls9K6voE5pbY/fGIQ8fg4bXtyZG8Gz+rHy7A 7e5iZjABSIfo7yMbVgO58024DVTgKMDVroJ4p1ZmEGf4krfdEt QAoYlH9TpbUlddmVz6McrMd4lGTXmYn7X8wagWQz7bRXCKwKh5 k0HwJgtKUtwua6gOHzqBomN/yee+rTf1EBVTlWatF3/FtvoARh f+cHnDkrWDfk3RnqMo5pAuL/bIC5BxweFNZlqzINEWl/tpm45k f7uHocLJo4AlhoYLa5d9qNbth/soSL1rCnjuNZro3Xvr9+XO4C 2kN6iGlGjqQeNQaIrGLl0F/zlILB8JhnedWF9vUIa9jjwJQ5kD Um3RLSUcshiyduhdFU94= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Saturday 08 October 2011 18:17:49 Eric Miao wrote: > > > > To check inconsistencies, the Makefile compares ".tmp_System.map" and > > "System.map" for differences. > > > > On a normal build they should be identical, but if this fails with > > "Inconsistent kallsyms data" you could try comparing the two files to > > check which symbols are causing trouble. > > I met this issue today as well. Didn't have a chance to compare the > files, as I did a 'rm -fr ../build' and reconfigured/re-built everything, > and 'make O=../build clean' didn't work for me. I can easily reproduce it here, but it's extremely hard to nail down what is actually going on. For all I know, this depends on the specific configuration, source version and gcc version. If you change any of these in any meaningful way, the problem can go away or reappear. In one case, I've been able to get to the point where inserting a single 'nop' instruction in one (any) source file triggered the problem. This happens to be the point when one of the linker sections grows beyond some power-of-two boundary. If anyone wants to reproduce it, I can recommend taking a fast machine and the for-next+randconfig branch of git://git.linaro.org/people/arnd/arm-soc.git There is a script called randconfig.sh in it. Remove the KALLSYMS_EXTRA_PASS=1 line from it and run it for some time. After a few hours you will get multiple configurations for your compiler that show the problem. I've had one case where even with KALLSYMS_EXTRA_PASS=1 I was still getting inconsistent kallsyms data. Manually changing the Makefile to do a fourth run fixed it. Arnd