From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932881AbXCPJ2Q (ORCPT ); Fri, 16 Mar 2007 05:28:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932840AbXCPJ2Q (ORCPT ); Fri, 16 Mar 2007 05:28:16 -0400 Received: from 207.47.60.147.static.nextweb.net ([207.47.60.147]:36344 "EHLO rpc.xensource.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932881AbXCPJ2P (ORCPT ); Fri, 16 Mar 2007 05:28:15 -0400 From: Ian Campbell Subject: [PATCH] Allow i386 crash kernels to handle x86_64 dumps. Date: Fri, 16 Mar 2007 09:28:10 +0000 To: Andrew Morton Cc: Vivek Goyal , Horms , Magnus Damm , fastboot@lists.osdl.org, linux-kernel@vger.kernel.org Message-Id: <20070316092810.9044.68034.stgit@localhost.localdomain> Content-Type: text/plain; charset=utf-8; format=fixed Content-Transfer-Encoding: 8bit User-Agent: StGIT/0.11 X-OriginalArrivalTime: 16 Mar 2007 09:28:14.0159 (UTC) FILETIME=[6BF54DF0:01C767AD] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: Ian Campbell The specific case I am encountering is kdump under Xen with a 64 bit hypervisor and 32 bit kernel/userspace. The dump created is 64 bit due to the hypervisor but the dump kernel is 32 bit for maximum compatibility. It's possibly less likely to be useful in a purely native scenario but I see no reason to disallow it. Signed-off-by: Ian Campbell Acked-by: Vivek Goyal --- fs/proc/vmcore.c | 2 +- include/asm-i386/kexec.h | 3 +++ include/linux/crash_dump.h | 8 ++++++++ 3 files changed, 12 insertions(+), 1 deletions(-) diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index d960507..523e109 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -514,7 +514,7 @@ static int __init parse_crash_elf64_headers(void) /* Do some basic Verification. */ if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 || (ehdr.e_type != ET_CORE) || - !elf_check_arch(&ehdr) || + !vmcore_elf_check_arch(&ehdr) || ehdr.e_ident[EI_CLASS] != ELFCLASS64 || ehdr.e_ident[EI_VERSION] != EV_CURRENT || ehdr.e_version != EV_CURRENT || diff --git a/include/asm-i386/kexec.h b/include/asm-i386/kexec.h index 4dfc9f5..c76737e 100644 --- a/include/asm-i386/kexec.h +++ b/include/asm-i386/kexec.h @@ -47,6 +47,9 @@ /* The native architecture */ #define KEXEC_ARCH KEXEC_ARCH_386 +/* We can also handle crash dumps from 64 bit kernel. */ +#define vmcore_elf_check_arch_cross(x) ((x)->e_machine == EM_X86_64) + #define MAX_NOTE_BYTES 1024 /* CPU does not save ss and esp on stack if execution is already diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h index 3250365..db60dac 100644 --- a/include/linux/crash_dump.h +++ b/include/linux/crash_dump.h @@ -14,5 +14,13 @@ extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, extern const struct file_operations proc_vmcore_operations; extern struct proc_dir_entry *proc_vmcore; +/* Architecture code defines this if there are other possible ELF + * machine types, e.g. on bi-arch capable hardware. */ +#ifndef vmcore_elf_check_arch_cross(x) +#define vmcore_elf_check_arch_cross(x) 0 +#endif + +#define vmcore_elf_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x)) + #endif /* CONFIG_CRASH_DUMP */ #endif /* LINUX_CRASHDUMP_H */