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