Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef LINUX_CRASH_DUMP_H
3#define LINUX_CRASH_DUMP_H
4
5#ifdef CONFIG_CRASH_DUMP
6#include <linux/kexec.h>
7#include <linux/proc_fs.h>
8#include <linux/elf.h>
9
10#include <asm/pgtable.h> /* for pgprot_t */
11
12#define ELFCORE_ADDR_MAX (-1ULL)
13#define ELFCORE_ADDR_ERR (-2ULL)
14
15extern unsigned long long elfcorehdr_addr;
16extern unsigned long long elfcorehdr_size;
17
18extern int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size);
19extern void elfcorehdr_free(unsigned long long addr);
20extern ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos);
21extern ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos);
22extern int 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 32-bit ELF or 64-bit ELF vmcores. In case of 32-bit
39 * only architecture, vmcore_elf64_check_arch can be set to zero.
40 */
41#ifndef vmcore_elf32_check_arch
42#define vmcore_elf32_check_arch(x) elf_check_arch(x)
43#endif
44
45#ifndef vmcore_elf64_check_arch
46#define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
47#endif
48
49/*
50 * is_kdump_kernel() checks whether this kernel is booting after a panic of
51 * previous kernel or not. This is determined by checking if previous kernel
52 * has passed the elf core header address on command line.
53 *
54 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will
55 * return 1 if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic of
56 * previous kernel.
57 */
58
59static inline int is_kdump_kernel(void)
60{
61 return (elfcorehdr_addr != ELFCORE_ADDR_MAX) ? 1 : 0;
62}
63
64/* is_vmcore_usable() checks if the kernel is booting after a panic and
65 * the vmcore region is usable.
66 *
67 * This makes use of the fact that due to alignment -2ULL is not
68 * a valid pointer, much in the vain of IS_ERR(), except
69 * dealing directly with an unsigned long long rather than a pointer.
70 */
71
72static inline int is_vmcore_usable(void)
73{
74 return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0;
75}
76
77/* vmcore_unusable() marks the vmcore as unusable,
78 * without disturbing the logic of is_kdump_kernel()
79 */
80
81static inline void vmcore_unusable(void)
82{
83 if (is_kdump_kernel())
84 elfcorehdr_addr = ELFCORE_ADDR_ERR;
85}
86
87#define HAVE_OLDMEM_PFN_IS_RAM 1
88extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn));
89extern void unregister_oldmem_pfn_is_ram(void);
90
91#else /* !CONFIG_CRASH_DUMP */
92static inline int is_kdump_kernel(void) { return 0; }
93#endif /* CONFIG_CRASH_DUMP */
94
95extern unsigned long saved_max_pfn;
96#endif /* LINUX_CRASHDUMP_H */