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

[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
...@@ -741,10 +741,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted. ...@@ -741,10 +741,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
See Documentation/block/cfq-iosched.txt and See Documentation/block/cfq-iosched.txt and
Documentation/block/deadline-iosched.txt for details. 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 Specifies physical address of start of kernel core
image elf header. Generally kexec loader will image elf header and optionally the size. Generally
pass this option to capture kernel. kexec loader will pass this option to capture kernel.
See Documentation/kdump/kdump.txt for details. See Documentation/kdump/kdump.txt for details.
enable_mtrr_cleanup [X86] enable_mtrr_cleanup [X86]
......
...@@ -10,6 +10,7 @@ ...@@ -10,6 +10,7 @@
#define ELFCORE_ADDR_ERR (-2ULL) #define ELFCORE_ADDR_ERR (-2ULL)
extern unsigned long long elfcorehdr_addr; extern unsigned long long elfcorehdr_addr;
extern unsigned long long elfcorehdr_size;
extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
unsigned long, int); unsigned long, int);
......
...@@ -19,9 +19,16 @@ unsigned long saved_max_pfn; ...@@ -19,9 +19,16 @@ unsigned long saved_max_pfn;
*/ */
unsigned long long elfcorehdr_addr = ELFCORE_ADDR_MAX; 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 * 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. * 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) static int __init setup_elfcorehdr(char *arg)
{ {
...@@ -29,6 +36,10 @@ static int __init setup_elfcorehdr(char *arg) ...@@ -29,6 +36,10 @@ static int __init setup_elfcorehdr(char *arg)
if (!arg) if (!arg)
return -EINVAL; return -EINVAL;
elfcorehdr_addr = memparse(arg, &end); elfcorehdr_addr = memparse(arg, &end);
if (*end == '@') {
elfcorehdr_size = elfcorehdr_addr;
elfcorehdr_addr = memparse(end + 1, &end);
}
return end > arg ? 0 : -EINVAL; return end > arg ? 0 : -EINVAL;
} }
early_param("elfcorehdr", setup_elfcorehdr); early_param("elfcorehdr", setup_elfcorehdr);
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