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