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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef LINUX_CRASH_DUMP_H
#define LINUX_CRASH_DUMP_H
#include <linux/kexec.h>
#include <linux/proc_fs.h>
#include <linux/elf.h>
#include <asm/pgtable.h> /* for pgprot_t */
#ifdef CONFIG_CRASH_DUMP
#define ELFCORE_ADDR_MAX (-1ULL)
#define ELFCORE_ADDR_ERR (-2ULL)
extern unsigned long long elfcorehdr_addr;
extern unsigned long long elfcorehdr_size;
extern int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size);
extern void elfcorehdr_free(unsigned long long addr);
extern ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos);
extern ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos);
extern int remap_oldmem_pfn_range(struct vm_area_struct *vma,
unsigned long from, unsigned long pfn,
unsigned long size, pgprot_t prot);
extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
unsigned long, int);
void vmcore_cleanup(void);
/* 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 32-bit ELF or 64-bit ELF vmcores. In case of 32-bit
* only architecture, vmcore_elf64_check_arch can be set to zero.
*/
#ifndef vmcore_elf32_check_arch
#define vmcore_elf32_check_arch(x) elf_check_arch(x)
#endif
#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 true if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic
* of previous kernel.
*/
static inline bool is_kdump_kernel(void)
{
return elfcorehdr_addr != ELFCORE_ADDR_MAX;
}
/* 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 bool is_kdump_kernel(void) { return 0; }
#endif /* CONFIG_CRASH_DUMP */
extern unsigned long saved_max_pfn;
#endif /* LINUX_CRASHDUMP_H */
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