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
17 extern unsigned long long elfcorehdr_addr;
18 extern unsigned long long elfcorehdr_size;
19
20 extern int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size);
21 extern void elfcorehdr_free(unsigned long long addr);
22 extern ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos);
23 extern ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos);
24 extern 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
28 extern ssize_t copy_oldmem_page(unsigned long, char *, size_t,
29 unsigned long, int);
30 extern ssize_t copy_oldmem_page_encrypted(unsigned long pfn, char *buf,
31 size_t csize, unsigned long offset,
32 int userbuf);
33
34 void 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
is_kdump_kernel(void)65 static 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
is_vmcore_usable(void)78 static 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
vmcore_unusable(void)87 static 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
94 extern int register_oldmem_pfn_is_ram(int (*fn)(unsigned long pfn));
95 extern void unregister_oldmem_pfn_is_ram(void);
96
97 #else /* !CONFIG_CRASH_DUMP */
is_kdump_kernel(void)98 static inline bool is_kdump_kernel(void) { return 0; }
99 #endif /* CONFIG_CRASH_DUMP */
100
101 /* Device Dump information to be filled by drivers */
102 struct 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
110 int vmcore_add_device_dump(struct vmcoredd_data *data);
111 #else
vmcore_add_device_dump(struct vmcoredd_data * data)112 static 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
119 ssize_t read_from_oldmem(char *buf, size_t count,
120 u64 *ppos, int userbuf,
121 bool encrypted);
122 #else
read_from_oldmem(char * buf,size_t count,u64 * ppos,int userbuf,bool encrypted)123 static 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 */
132
