Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
1#ifndef LINUX_CRASH_DUMP_H
2#define LINUX_CRASH_DUMP_H
3
4#ifdef CONFIG_CRASH_DUMP
5#include <linux/kexec.h>
6#include <linux/proc_fs.h>
7#include <linux/elf.h>
8
9#include <asm/pgtable.h> /* for pgprot_t */
10
11#define ELFCORE_ADDR_MAX (-1ULL)
12#define ELFCORE_ADDR_ERR (-2ULL)
13
14extern unsigned long long elfcorehdr_addr;
15extern unsigned long long elfcorehdr_size;
16
17extern int __weak elfcorehdr_alloc(unsigned long long *addr,
18 unsigned long long *size);
19extern void __weak elfcorehdr_free(unsigned long long addr);
20extern ssize_t __weak elfcorehdr_read(char *buf, size_t count, u64 *ppos);
21extern ssize_t __weak elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos);
22extern int __weak remap_oldmem_pfn_range(struct vm_area_struct *vma,
23 unsigned long from, unsigned long pfn,
24 unsigned long size, pgprot_t prot);
25
26extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
27 unsigned long, int);
28void vmcore_cleanup(void);
29
30/* Architecture code defines this if there are other possible ELF
31 * machine types, e.g. on bi-arch capable hardware. */
32#ifndef vmcore_elf_check_arch_cross
33#define vmcore_elf_check_arch_cross(x) 0
34#endif
35
36/*
37 * Architecture code can redefine this if there are any special checks
38 * needed for 64-bit ELF vmcores. In case of 32-bit only architecture,
39 * this can be set to zero.
40 */
41#ifndef vmcore_elf64_check_arch
42#define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
43#endif
44
45/*
46 * is_kdump_kernel() checks whether this kernel is booting after a panic of
47 * previous kernel or not. This is determined by checking if previous kernel
48 * has passed the elf core header address on command line.
49 *
50 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will
51 * return 1 if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic of
52 * previous kernel.
53 */
54
55static inline int is_kdump_kernel(void)
56{
57 return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0;
58}
59
60/* is_vmcore_usable() checks if the kernel is booting after a panic and
61 * the vmcore region is usable.
62 *
63 * This makes use of the fact that due to alignment -2ULL is not
64 * a valid pointer, much in the vain of IS_ERR(), except
65 * dealing directly with an unsigned long long rather than a pointer.
66 */
67
68static inline int is_vmcore_usable(void)
69{
70 return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0;
71}
72
73/* vmcore_unusable() marks the vmcore as unusable,
74 * without disturbing the logic of is_kdump_kernel()
75 */
76
77static inline void vmcore_unusable(void)
78{
79 if (is_kdump_kernel())
80 elfcorehdr_addr = ELFCORE_ADDR_ERR;
81}
82
83#define HAVE_OLDMEM_PFN_IS_RAM 1
84extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn));
85extern void unregister_oldmem_pfn_is_ram(void);
86
87#else /* !CONFIG_CRASH_DUMP */
88static inline int is_kdump_kernel(void) { return 0; }
89#endif /* CONFIG_CRASH_DUMP */
90
91extern unsigned long saved_max_pfn;
92#endif /* LINUX_CRASHDUMP_H */