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 <uapi/linux/vmcore.h>
9
10 #include <asm/pgtable.h> /* for pgprot_t */
11
12 #ifdef CONFIG_CRASH_DUMP
13 #define ELFCORE_ADDR_MAX (-1ULL)
14 #define ELFCORE_ADDR_ERR (-2ULL)
15
16 extern unsigned long long elfcorehdr_addr;
17 extern unsigned long long elfcorehdr_size;
18
19 extern int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size);
20 extern void elfcorehdr_free(unsigned long long addr);
21 extern ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos);
22 extern ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos);
23 extern int remap_oldmem_pfn_range(struct vm_area_struct *vma,
24 unsigned long from, unsigned long pfn,
25 unsigned long size, pgprot_t prot);
26
27 extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
28 unsigned long, int);
29 extern ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf,
30 size_t csize, unsigned long offset,
31 int userbuf);
32
33 void vmcore_cleanup(void);
34
35 /* Architecture code defines this if there are other possible ELF
36 * machine types, e.g. on bi-arch capable hardware. */
37 #ifndef vmcore_elf_check_arch_cross
38 #define vmcore_elf_check_arch_cross(x) 0
39 #endif
40
41 /*
42 * Architecture code can redefine this if there are any special checks
43 * needed for 32-bit ELF or 64-bit ELF vmcores. In case of 32-bit
44 * only architecture, vmcore_elf64_check_arch can be set to zero.
45 */
46 #ifndef vmcore_elf32_check_arch
47 #define vmcore_elf32_check_arch(x) elf_check_arch(x)
48 #endif
49
50 #ifndef vmcore_elf64_check_arch
51 #define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x))
52 #endif
53
54 /*
55 * is_kdump_kernel() checks whether this kernel is booting after a panic of
56 * previous kernel or not. This is determined by checking if previous kernel
57 * has passed the elf core header address on command line.
58 *
59 * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will
60 * return true if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic
61 * of previous kernel.
62 */
63
is_kdump_kernel(void)64 static inline bool is_kdump_kernel(void)
65 {
66 return elfcorehdr_addr != ELFCORE_ADDR_MAX;
67 }
68
69 /* is_vmcore_usable() checks if the kernel is booting after a panic and
70 * the vmcore region is usable.
71 *
72 * This makes use of the fact that due to alignment -2ULL is not
73 * a valid pointer, much in the vain of IS_ERR(), except
74 * dealing directly with an unsigned long long rather than a pointer.
75 */
76
is_vmcore_usable(void)77 static inline int is_vmcore_usable(void)
78 {
79 return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0;
80 }
81
82 /* vmcore_unusable() marks the vmcore as unusable,
83 * without disturbing the logic of is_kdump_kernel()
84 */
85
vmcore_unusable(void)86 static inline void vmcore_unusable(void)
87 {
88 if (is_kdump_kernel())
89 elfcorehdr_addr = ELFCORE_ADDR_ERR;
90 }
91
92 #define HAVE_OLDMEM_PFN_IS_RAM 1
93 extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn));
94 extern void unregister_oldmem_pfn_is_ram(void);
95
96 #else /* !CONFIG_CRASH_DUMP */
is_kdump_kernel(void)97 static inline bool is_kdump_kernel(void) { return 0; }
98 #endif /* CONFIG_CRASH_DUMP */
99
100 extern unsigned long saved_max_pfn;
101
102 /* Device Dump information to be filled by drivers */
103 struct 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
111 int vmcore_add_device_dump(struct vmcoredd_data *data);
112 #else
vmcore_add_device_dump(struct vmcoredd_data * data)113 static 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
120 ssize_t read_from_oldmem(char *buf, size_t count,
121 u64 *ppos, int userbuf,
122 bool encrypted);
123 #else
read_from_oldmem(char * buf,size_t count,u64 * ppos,int userbuf,bool encrypted)124 static 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 */
133
