Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262060AbUK0GDB (ORCPT ); Sat, 27 Nov 2004 01:03:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262085AbUK0DtT (ORCPT ); Fri, 26 Nov 2004 22:49:19 -0500 Received: from zeus.kernel.org ([204.152.189.113]:5572 "EHLO zeus.kernel.org") by vger.kernel.org with ESMTP id S262543AbUKZTds (ORCPT ); Fri, 26 Nov 2004 14:33:48 -0500 Message-ID: <41A71A13.2010008@in.ibm.com> Date: Fri, 26 Nov 2004 17:27:07 +0530 From: Hariprasad Nellitheertha User-Agent: Mozilla Thunderbird 0.8 (X11/20040913) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Akinobu Mita CC: Badari Pulavarty , Andrew Morton , Linux Kernel Mailing List , varap@us.ibm.com Subject: Re: [PATCH] kdump: Fix for boot problems on SMP References: <419CACE2.7060408@in.ibm.com> <41A20DB5.2050302@in.ibm.com> <1101170617.4987.268.camel@dyn318077bld.beaverton.ibm.com> <200411260221.49888.amgta@yacht.ocn.ne.jp> In-Reply-To: <200411260221.49888.amgta@yacht.ocn.ne.jp> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1972 Lines: 60 Akinobu Mita wrote: > On Tuesday 23 November 2004 09:43, Badari Pulavarty wrote: > >>gdb is not showing the stack info properly, on my saved vmcore. >>I thought vmlinux is not matching the vmcore, so I verified that >>vmcore and vmlinux matchup. But still no luck... >> >># gdb ../linux-2.6.9/vmlinux vmcore.2 > > > [...] > > >>(gdb) bt >>#0 default_idle () at arch/i386/kernel/process.c:108 >>#1 0xc04cdff8 in init_thread_union () >>#2 0xc0101b86 in cpu_idle () at arch/i386/kernel/process.c:196 >>#3 0xc04cea20 in start_kernel () at init/main.c:523 >>#4 0xc0100211 in L6 () at /tmp/cch2z2jk.s:2054 >>Cannot access memory at address 0x550007 > > > > I think the panic was happened on the CPU except for CPU#0. > > Currently vmcore contains only CPU#0's register contents. > Therefore, GDB always shows backtrace of CPU#0. > > > fs/proc/vmcore.c: > > static void elf_vmcore_store_hdr(char *bufp, int nphdr, int dataoff) > { > ... > /* 1 - Get the registers from the reserved memory area */ > reg_ppos = BACKUP_END + CRASH_RELOCATE_SIZE; > read_from_oldmem(reg_buf, REG_SIZE, ®_ppos, 0); > elf_core_copy_regs(&prstatus.pr_reg, (struct pt_regs *)reg_buf); > buf = storenote(¬es[0], buf); > > > In this place, "reg_ppos" is the pointer to the copy of relocated > crash_smp_regs[0]. > kdump should save the "crash_smp_regs[**panic_cpu**]". > > Or, it is better to save all crash_smp_regs[NR_CPUS]. > In other words: I am actually working on patches to export the registers of all processors as elf notes sections. Similar to what multi-threaded core dump does. This will enable gdb to correctly analyze the stack trace on all processors. Thanks and Regards, Hari - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/