Commit d3bf3795 authored by Michael Holzheu's avatar Michael Holzheu Committed by Martin Schwidefsky
Browse files

[S390] kdump: Add size to elfcorehdr kernel parameter 



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.

Acked-by: default avatarVivek Goyal <vgoyal@redhat.com>
Acked-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarMichael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 3d214fae

Documentation/kernel-parameters.txt

+3 −3
Original line number Diff line number Diff line
@@ -741,10 +741,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. 
			See Documentation/block/cfq-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]

include/linux/crash_dump.h

+1 −0
Original line number Diff line number Diff line
@@ -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);

kernel/crash_dump.c

+11 −0
Original line number Diff line number Diff line
@@ -19,9 +19,16 @@ 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 *arg) 
	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);

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