Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755143Ab3GATdp (ORCPT ); Mon, 1 Jul 2013 15:33:45 -0400 Received: from e06smtp10.uk.ibm.com ([195.75.94.106]:60831 "EHLO e06smtp10.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754199Ab3GATcq (ORCPT ); Mon, 1 Jul 2013 15:32:46 -0400 From: Michael Holzheu To: Vivek Goyal , HATAYAMA Daisuke Cc: Jan Willeke , Martin Schwidefsky , Heiko Carstens , linux-kernel@vger.kernel.org, kexec@lists.infradead.org Subject: [PATCH v6 0/5] kdump: Allow ELF header creation in new kernel Date: Mon, 1 Jul 2013 21:32:34 +0200 Message-Id: <1372707159-10425-1-git-send-email-holzheu@linux.vnet.ibm.com> X-Mailer: git-send-email 1.8.2.2 X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13070119-4966-0000-0000-0000062B7BBD Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3831 Lines: 105 Hello Vivek and Hatayama, As discussed here the 6th version of the patch set. ChangeLog ========= v5 => v6) - Set elfcorehdr_addr to ELFCORE_ADDR_ERR after elfcorehdr_free() - Fix OLDMEM_SIZE/ZFCPDUMP_HSA_SIZE confusion - Remove return VM_FAULT_MAJOR/MINOR - Use find_or_create_page() in mmap_vmcore_fault() - Use kfree instead of vfree in elfcorehdr_free() v4 => v5) - Add weak function elfcorehdr_read_notes() to read ELF notes - Rename weak functions for ELF header access and use "vmcorehdr_" prefix - Generic vmcore code calls elfcorehdr_alloc() if elfcorehdr= is not specified - Add vmcore fault handler for mmap of non-resident memory regions - Add weak function remap_oldmem_pfn_range() to be used by zfcpdump for mmap v3 => v4) - Rebase to 3.10-rc2 + vmcore mmap patches v8 v2 => v3) - Get rid of ELFCORE_ADDR_NEWMEM - Make read_from_crash_header() only read from kernel - Move read_from_crash_header() to weak function arch_read_from_crash_header() - Implement read_from_crash_header() strong function for s390 - Set elfcorehdr_addr to address of new ELF header v1 => v2) - Rebase 3.10-rc2 + vmcore mmap patches - Introduced arch_get/free_crash_header() and ELFCORE_ADDR_NEWMEM Feature Description =================== For s390 we want to use /proc/vmcore for our SCSI stand-alone dump (zfcpdump). We have support where the first HSA_SIZE bytes are saved into a hypervisor owned memory area (HSA) before the kdump kernel is booted. When the kdump kernel starts, it is restricted to use only HSA_SIZE bytes. The advantages of this mechanism are: * No crashkernel memory has to be defined in the old kernel. * Early boot problems (before kexec_load has been done) can be dumped * Non-Linux systems can be dumped. We modify the s390 copy_oldmem_page() function to read from the HSA memory if memory below HSA_SIZE bytes is requested. Since we cannot use the kexec tool to load the kernel in this scenario, we have to build the ELF header in the 2nd (kdump/new) kernel. So with the following patch set we would like to introduce the new function that the ELF header for /proc/vmcore can be created in the 2nd kernel memory. The following steps are done during zfcpdump execution: 1. Production system crashes 2. User boots a SCSI disk that has been prepared with the zfcpdump tool 3. Hypervisor saves CPU state of boot CPU and HSA_SIZE bytes of memory into HSA 4. Boot loader loads kernel into low memory area 5. Kernel boots and uses only HSA_SIZE bytes of memory 6. Kernel saves registers of non-boot CPUs 7. Kernel does memory detection for dump memory map 8. Kernel creates ELF header for /proc/vmcore 9. /proc/vmcore uses this header for initialization 10. The zfcpdump user space reads /proc/vmcore to write dump to SCSI disk - copy_oldmem_page() copies from HSA for memory below HSA_SIZE - copy_oldmem_page() copies from real memory for memory above HSA_SIZE *** BLURB HERE *** Jan Willeke (1): s390/vmcore: Implement remap_oldmem_pfn_range for s390 Michael Holzheu (4): vmcore: Introduce ELF header in new memory feature s390/vmcore: Use ELF header in new memory feature vmcore: Introduce remap_oldmem_pfn_range() s390/vmcore: Use vmcore for zfcpdump arch/s390/Kconfig | 3 +- arch/s390/include/asm/sclp.h | 1 + arch/s390/kernel/crash_dump.c | 228 ++++++++++++++++++++++++++++++++++-------- drivers/s390/char/zcore.c | 6 +- fs/proc/vmcore.c | 145 +++++++++++++++++++++++---- include/linux/crash_dump.h | 9 ++ 6 files changed, 326 insertions(+), 66 deletions(-) -- 1.8.2.2 -- 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/