Linux kernel mirror (for testing)
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linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef LINUX_CRASH_DUMP_H
3#define LINUX_CRASH_DUMP_H
4
5#include <linux/kexec.h>
6#include <linux/proc_fs.h>
7#include <linux/elf.h>
8#include <linux/pgtable.h>
9#include <uapi/linux/vmcore.h>
10
11#include <linux/pgtable.h> /* for pgprot_t */
12
13#ifdef CONFIG_CRASH_DUMP
14#define ELFCORE_ADDR_MAX (-1ULL)
15#define ELFCORE_ADDR_ERR (-2ULL)
16
17extern unsigned long long elfcorehdr_addr;
18extern unsigned long long elfcorehdr_size;
19
20extern int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size);
21extern void elfcorehdr_free(unsigned long long addr);
22extern ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos);
23extern ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos);
24extern int remap_oldmem_pfn_range(struct vm_area_struct *vma,
25 unsigned long from, unsigned long pfn,
26 unsigned long size, pgprot_t prot);
27
28extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
29 unsigned long, int);
30extern ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf,
31 size_t csize, unsigned long offset,
32 int userbuf);
33
34void vmcore_cleanup(void);
35
36/* Architecture code defines this if there are other possible ELF
37 * machine types, e.g. on bi-arch capable hardware. */
38#ifndef vmcore_elf_check_arch_cross
39#define vmcore_elf_check_arch_cross(x) 0
40#endif
41
42/*
43 * Architecture code can redefine this if there are any special checks
44 * needed for 32-bit ELF or 64-bit ELF vmcores. In case of 32-bit
45 * only architecture, vmcore_elf64_check_arch can be set to zero.
46 */
47#ifndef vmcore_elf32_check_arch
48#define vmcore_elf32_check_arch(x) elf_check_arch(x)
49#endif
50
51#ifndef vmcore_elf64_check_arch
52#define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
53#endif
54
55/*
56 * is_kdump_kernel() checks whether this kernel is booting after a panic of
57 * previous kernel or not. This is determined by checking if previous kernel
58 * has passed the elf core header address on command line.
59 *
60 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will
61 * return true if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic
62 * of previous kernel.
63 */
64
65static inline bool is_kdump_kernel(void)
66{
67 return elfcorehdr_addr != ELFCORE_ADDR_MAX;
68}
69
70/* is_vmcore_usable() checks if the kernel is booting after a panic and
71 * the vmcore region is usable.
72 *
73 * This makes use of the fact that due to alignment -2ULL is not
74 * a valid pointer, much in the vain of IS_ERR(), except
75 * dealing directly with an unsigned long long rather than a pointer.
76 */
77
78static inline int is_vmcore_usable(void)
79{
80 return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0;
81}
82
83/* vmcore_unusable() marks the vmcore as unusable,
84 * without disturbing the logic of is_kdump_kernel()
85 */
86
87static inline void vmcore_unusable(void)
88{
89 if (is_kdump_kernel())
90 elfcorehdr_addr = ELFCORE_ADDR_ERR;
91}
92
93#define HAVE_OLDMEM_PFN_IS_RAM 1
94extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn));
95extern void unregister_oldmem_pfn_is_ram(void);
96
97#else /* !CONFIG_CRASH_DUMP */
98static inline bool is_kdump_kernel(void) { return 0; }
99#endif /* CONFIG_CRASH_DUMP */
100
101/* Device Dump information to be filled by drivers */
102struct vmcoredd_data {
103 char dump_name[VMCOREDD_MAX_NAME_BYTES]; /* Unique name of the dump */
104 unsigned int size; /* Size of the dump */
105 /* Driver's registered callback to be invoked to collect dump */
106 int (*vmcoredd_callback)(struct vmcoredd_data *data, void *buf);
107};
108
109#ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP
110int vmcore_add_device_dump(struct vmcoredd_data *data);
111#else
112static inline int vmcore_add_device_dump(struct vmcoredd_data *data)
113{
114 return -EOPNOTSUPP;
115}
116#endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */
117
118#ifdef CONFIG_PROC_VMCORE
119ssize_t read_from_oldmem(char *buf, size_t count,
120 u64 *ppos, int userbuf,
121 bool encrypted);
122#else
123static inline ssize_t read_from_oldmem(char *buf, size_t count,
124 u64 *ppos, int userbuf,
125 bool encrypted)
126{
127 return -EOPNOTSUPP;
128}
129#endif /* CONFIG_PROC_VMCORE */
130
131#endif /* LINUX_CRASHDUMP_H */