https://github.com/torvalds/linux
Tip revision: ddffeb8c4d0331609ef2581d84de4d763607bd37 authored by Linus Torvalds on 14 October 2012, 21:41:04 UTC
Linux 3.7-rc1
Linux 3.7-rc1
Tip revision: ddffeb8
crash_dump.h
#ifndef LINUX_CRASH_DUMP_H
#define LINUX_CRASH_DUMP_H
#ifdef CONFIG_CRASH_DUMP
#include <linux/kexec.h>
#include <linux/proc_fs.h>
#include <linux/elf.h>
#define ELFCORE_ADDR_MAX (-1ULL)
#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);
/* 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
#define vmcore_elf_check_arch_cross(x) 0
#endif
/*
* Architecture code can redefine this if there are any special checks
* needed for 64-bit ELF vmcores. In case of 32-bit only architecture,
* this can be set to zero.
*/
#ifndef vmcore_elf64_check_arch
#define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
#endif
/*
* is_kdump_kernel() checks whether this kernel is booting after a panic of
* previous kernel or not. This is determined by checking if previous kernel
* has passed the elf core header address on command line.
*
* This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will
* return 1 if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic of
* previous kernel.
*/
static inline int is_kdump_kernel(void)
{
return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0;
}
/* is_vmcore_usable() checks if the kernel is booting after a panic and
* the vmcore region is usable.
*
* This makes use of the fact that due to alignment -2ULL is not
* a valid pointer, much in the vain of IS_ERR(), except
* dealing directly with an unsigned long long rather than a pointer.
*/
static inline int is_vmcore_usable(void)
{
return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0;
}
/* vmcore_unusable() marks the vmcore as unusable,
* without disturbing the logic of is_kdump_kernel()
*/
static inline void vmcore_unusable(void)
{
if (is_kdump_kernel())
elfcorehdr_addr = ELFCORE_ADDR_ERR;
}
#define HAVE_OLDMEM_PFN_IS_RAM 1
extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn));
extern void unregister_oldmem_pfn_is_ram(void);
#else /* !CONFIG_CRASH_DUMP */
static inline int is_kdump_kernel(void) { return 0; }
#endif /* CONFIG_CRASH_DUMP */
extern unsigned long saved_max_pfn;
#endif /* LINUX_CRASHDUMP_H */