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