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