From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755501Ab1HSOUI (ORCPT ); Fri, 19 Aug 2011 10:20:08 -0400 Received: from mtagate7.uk.ibm.com ([194.196.100.167]:40382 "EHLO mtagate7.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755162Ab1HSOT6 (ORCPT ); Fri, 19 Aug 2011 10:19:58 -0400 Message-Id: <20110819141940.335341157@linux.vnet.ibm.com> User-Agent: quilt/0.48-1 Date: Fri, 19 Aug 2011 16:18:59 +0200 From: Michael Holzheu To: akpm@linux-foundation.org Cc: vgoyal@redhat.com, ebiederm@xmission.com, mahesh@linux.vnet.ibm.com, hbabu@us.ibm.com, oomichi@mxs.nes.nec.co.jp, horms@verge.net.au, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Subject: [patch 2/2] kdump: Add size to elfcorehdr kernel parameter References: <20110819141857.052232873@linux.vnet.ibm.com> Content-Disposition: inline; filename=s390-kdump-common-elfcorehdr-parm.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Michael Holzheu Currently only the address of the pre-allocated ELF header is passed with the elfcorehdr= kernel parameter. In order to reserve memory for the header in the 2nd kernel also the size is required. Current kdump architecture backends use different methods to do that, e.g. x86 uses the memmap= kernel parameter. On s390 there is no easy way to transfer this information. Therefore the elfcorehdr kernel parameter is extended to also pass the size. This now can also be used as standard mechanism by all future kdump architecture backends. The syntax of the kernel parameter is extended as follows: elfcorehdr=[size[KMG]@]offset[KMG] This change is backward compatible because elfcorehdr=size is still allowed. Signed-off-by: Michael Holzheu --- Documentation/kernel-parameters.txt | 6 +++--- include/linux/crash_dump.h | 1 + kernel/crash_dump.c | 11 +++++++++++ 3 files changed, 15 insertions(+), 3 deletions(-) --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -727,10 +727,10 @@ bytes respectively. Such letter suffixes See Documentation/block/as-iosched.txt and Documentation/block/deadline-iosched.txt for details. - elfcorehdr= [IA-64,PPC,SH,X86] + elfcorehdr=[size[KMG]@]offset[KMG] [IA64,PPC,SH,X86,S390] Specifies physical address of start of kernel core - image elf header. Generally kexec loader will - pass this option to capture kernel. + image elf header and optionally the size. Generally + kexec loader will pass this option to capture kernel. See Documentation/kdump/kdump.txt for details. enable_mtrr_cleanup [X86] --- a/include/linux/crash_dump.h +++ b/include/linux/crash_dump.h @@ -10,6 +10,7 @@ #define ELFCORE_ADDR_ERR (-2ULL) extern unsigned long long elfcorehdr_addr; +extern unsigned long long elfcorehdr_size; extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, unsigned long, int); --- a/kernel/crash_dump.c +++ b/kernel/crash_dump.c @@ -20,8 +20,15 @@ unsigned long saved_max_pfn; unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX; /* + * stores the size of elf header of crash image + */ +unsigned long long elfcorehdr_size; + +/* * elfcorehdr= specifies the location of elf core header stored by the crashed * kernel. This option will be passed by kexec loader to the capture kernel. + * + * Syntax: elfcorehdr=[size[KMG]@]offset[KMG] */ static int __init setup_elfcorehdr(char *arg) { @@ -29,6 +36,10 @@ static int __init setup_elfcorehdr(char if (!arg) return -EINVAL; elfcorehdr_addr = memparse(arg, &end); + if (*end == '@') { + elfcorehdr_size = elfcorehdr_addr; + elfcorehdr_addr = memparse(end + 1, &end); + } return end > arg ? 0 : -EINVAL; } early_param("elfcorehdr", setup_elfcorehdr);