From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422831AbXCWMLd (ORCPT ); Fri, 23 Mar 2007 08:11:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422833AbXCWMLd (ORCPT ); Fri, 23 Mar 2007 08:11:33 -0400 Received: from nf-out-0910.google.com ([64.233.182.190]:54520 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1422831AbXCWMLc (ORCPT ); Fri, 23 Mar 2007 08:11:32 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:user-agent:mime-version:to:cc:subject:references:in-reply-to:x-enigmail-version:content-type:content-transfer-encoding:from; b=XKKNQCd0uBzGylwg0sjHRmQ4AtyoB9RCJvW4HMMLYcnzqF2Dmt/0/Cp50GnNMg37NIXYbfF+/tfG0qmLryTq3QKsDumi6ciOehScnEoT2FRHUSSraznxAsnjAnLF+Y4rYiCKJ37CrUYxZqJoD3Zba+SLdkV3UHWqKGqRpnN/xpY= Message-ID: <4603C3C8.6000808@googlemail.com> Date: Fri, 23 Mar 2007 13:10:48 +0100 User-Agent: Thunderbird 1.5.0.10 (X11/20070302) MIME-Version: 1.0 To: vgoyal@in.ibm.com CC: Michal Piotrowski , Ingo Molnar , Thomas Gleixner , LKML Subject: Re: 2.6.21-rc4-rt0-kdump References: <6bffcb0e0703211338i2aa6f933ube53c6604c78e285@mail.gmail.com> <20070322093119.GA19394@elte.hu> <6bffcb0e0703220557h7ff64282qf378623452c07d03@mail.gmail.com> <4602843D.9000306@googlemail.com> <20070323052501.GA1421@in.ibm.com> In-Reply-To: <20070323052501.GA1421@in.ibm.com> X-Enigmail-Version: 0.94.1.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Michal Piotrowski Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Vivek Goyal napisał(a): > On Thu, Mar 22, 2007 at 02:27:25PM +0100, Michal Piotrowski wrote: >> Michal Piotrowski napisał(a): >>> On 22/03/07, Ingo Molnar wrote: >>>> * Michal Piotrowski wrote: >>>> >>>>> Hi Ingo, >>>>> 2.6.21-rc4-rt0 >>>>> BUG: at kernel/fork.c:1033 copy_process() >>>> thanks Michal - this is a real bug that affects upstream too. Find the >>>> fix below - i've test-booted it and it fixes the warning. >>> Problem is fixed, thanks. >> BTW. It seems that nobody uses -rt as a crash dump kernel ;) >> >> BUG: unable to handle kernel paging request at virtual address f7ebf8c4 >> printing eip: >> c1610192 >> *pde = 00000000 >> stopped custom tracer. >> Oops: 0000 [#1] >> PREEMPT >> Modules linked in: >> CPU: 0 >> EIP: 0060:[] Not tainted VLI >> EFLAGS: 00010206 (2.6.21-rc4-rt0-kdump #3) >> EIP is at copy_oldmem_page+0x4a/0xd0 >> eax: 000008c4 ebx: f7ebf000 ecx: 00000100 edx: 00000246 >> esi: f7ebf8c4 edi: c4c520fc ebp: c4d54e30 esp: c4d54e18 >> ds: 007b es: 007b fs: 00d8 gs: 0000 ss: 0068 preempt:00000001 >> Process swapper (pid: 1, ti=c4d54000 task=c4d52c20 task.ti=c4d54000) >> Stack: c17ab7e0 c183f982 c1969658 00000400 00000400 00037ebf c4d54e5c c16af187 >> 00037ebf c4c520fc 00000400 000008c4 00000000 00000000 c4c696e0 00000400 >> c4c520fc c4d54f94 c19a9cfd c4c520fc 00000400 c4d54f78 00000000 c1840996 >> Call Trace: >> [] read_from_oldmem+0x73/0x98 >> [] vmcore_init+0x26c/0xab7 >> [] init+0xaa/0x287 >> [] kernel_thread_helper+0x7/0x10 >> ======================= >> >> l *copy_oldmem_page+0x4a/0xd0 >> 0xc1610148 is in copy_oldmem_page (arch/i386/kernel/crash_dump.c:35). >> 30 * copying the data to a pre-allocated kernel page and then copying to user >> 31 * space in non-atomic context. >> 32 */ >> 33 ssize_t copy_oldmem_page(unsigned long pfn, char *buf, >> 34 size_t csize, unsigned long offset, int userbuf) >> 35 { >> 36 void *vaddr; >> 37 >> 38 if (!csize) >> 39 return 0; >> > > Can you please paste the disassembly of copy_oldmem_page() on your system. > Not sure from where this faulting address 0xf7ebf8c4 is coming. We are still > in vmcore_init(), so we should be copying the data to kernel buffers only. > This looks like a valid kernel address. > > Can you also put some printk() here to find out from where 0xf7ebf8c4 has > come? It does not look like a fixed kernel virutual address returned by > kmap_atomic_pfn(). Then is it passed by kernel as a parameter to > copy_oldmem_page()? I added printk(KERN_WARNING "copy_oldmem_page() pfn=%lu , buf=%s , nr_bytes=%d , offset=%lu , userbuf=%d\n", pfn, buf, nr_bytes, offset, userbuf); before tmp = copy_oldmem_page(pfn, buf, nr_bytes, offset, userbuf); result is here http://www.stardust.webpages.pl/files/tbf/bitis-gabonica/2.6.21-rc4-rt0/kdump-console2.log 'buf' might be broken. > > Thanks > Vivek > Regards, Michal -- Michal K. K. Piotrowski LTG - Linux Testers Group (PL) (http://www.stardust.webpages.pl/ltg/) LTG - Linux Testers Group (EN) (http://www.stardust.webpages.pl/linux_testers_group_en/)