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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
60e64d46 VG |
2 | #ifndef LINUX_CRASH_DUMP_H |
3 | #define LINUX_CRASH_DUMP_H | |
4 | ||
60e64d46 | 5 | #include <linux/kexec.h> |
60e64d46 | 6 | #include <linux/proc_fs.h> |
1f536b9e | 7 | #include <linux/elf.h> |
65fddcfc | 8 | #include <linux/pgtable.h> |
2724273e | 9 | #include <uapi/linux/vmcore.h> |
60e64d46 | 10 | |
33709413 | 11 | /* For IS_ENABLED(CONFIG_CRASH_DUMP) */ |
666bfddb | 12 | #define ELFCORE_ADDR_MAX (-1ULL) |
85a0ee34 | 13 | #define ELFCORE_ADDR_ERR (-2ULL) |
36ac2617 | 14 | |
2030eae5 | 15 | extern unsigned long long elfcorehdr_addr; |
d3bf3795 | 16 | extern unsigned long long elfcorehdr_size; |
36ac2617 | 17 | |
33709413 | 18 | #ifdef CONFIG_CRASH_DUMP |
5ab03ac5 BH |
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); | |
be8a8d06 | 26 | |
5d8de293 MWO |
27 | ssize_t copy_oldmem_page(struct iov_iter *i, unsigned long pfn, size_t csize, |
28 | unsigned long offset); | |
29 | ssize_t copy_oldmem_page_encrypted(struct iov_iter *iter, unsigned long pfn, | |
30 | size_t csize, unsigned long offset); | |
992b649a | 31 | |
82e0703b | 32 | void vmcore_cleanup(void); |
666bfddb | 33 | |
79e03011 IC |
34 | /* Architecture code defines this if there are other possible ELF |
35 | * machine types, e.g. on bi-arch capable hardware. */ | |
36 | #ifndef vmcore_elf_check_arch_cross | |
37 | #define vmcore_elf_check_arch_cross(x) 0 | |
38 | #endif | |
39 | ||
9833c394 MW |
40 | /* |
41 | * Architecture code can redefine this if there are any special checks | |
e55d5312 DW |
42 | * needed for 32-bit ELF or 64-bit ELF vmcores. In case of 32-bit |
43 | * only architecture, vmcore_elf64_check_arch can be set to zero. | |
9833c394 | 44 | */ |
e55d5312 DW |
45 | #ifndef vmcore_elf32_check_arch |
46 | #define vmcore_elf32_check_arch(x) elf_check_arch(x) | |
47 | #endif | |
48 | ||
9833c394 MW |
49 | #ifndef vmcore_elf64_check_arch |
50 | #define vmcore_elf64_check_arch(x) (elf_check_arch(x) || vmcore_elf_check_arch_cross(x)) | |
51 | #endif | |
79e03011 | 52 | |
57cac4d1 VG |
53 | /* |
54 | * is_kdump_kernel() checks whether this kernel is booting after a panic of | |
55 | * previous kernel or not. This is determined by checking if previous kernel | |
56 | * has passed the elf core header address on command line. | |
57 | * | |
58 | * This is not just a test if CONFIG_CRASH_DUMP is enabled or not. It will | |
2650cb0c YB |
59 | * return true if CONFIG_CRASH_DUMP=y and if kernel is booting after a panic |
60 | * of previous kernel. | |
57cac4d1 VG |
61 | */ |
62 | ||
2650cb0c | 63 | static inline bool is_kdump_kernel(void) |
95b68dec | 64 | { |
2650cb0c | 65 | return elfcorehdr_addr != ELFCORE_ADDR_MAX; |
95b68dec | 66 | } |
85a0ee34 SH |
67 | |
68 | /* is_vmcore_usable() checks if the kernel is booting after a panic and | |
69 | * the vmcore region is usable. | |
70 | * | |
71 | * This makes use of the fact that due to alignment -2ULL is not | |
72 | * a valid pointer, much in the vain of IS_ERR(), except | |
73 | * dealing directly with an unsigned long long rather than a pointer. | |
74 | */ | |
75 | ||
76 | static inline int is_vmcore_usable(void) | |
77 | { | |
78 | return is_kdump_kernel() && elfcorehdr_addr != ELFCORE_ADDR_ERR ? 1 : 0; | |
79 | } | |
80 | ||
81 | /* vmcore_unusable() marks the vmcore as unusable, | |
82 | * without disturbing the logic of is_kdump_kernel() | |
83 | */ | |
84 | ||
85 | static inline void vmcore_unusable(void) | |
86 | { | |
87 | if (is_kdump_kernel()) | |
88 | elfcorehdr_addr = ELFCORE_ADDR_ERR; | |
89 | } | |
997c136f | 90 | |
cc5f2704 DH |
91 | /** |
92 | * struct vmcore_cb - driver callbacks for /proc/vmcore handling | |
93 | * @pfn_is_ram: check whether a PFN really is RAM and should be accessed when | |
94 | * reading the vmcore. Will return "true" if it is RAM or if the | |
95 | * callback cannot tell. If any callback returns "false", it's not | |
96 | * RAM and the page must not be accessed; zeroes should be | |
97 | * indicated in the vmcore instead. For example, a ballooned page | |
98 | * contains no data and reading from such a page will cause high | |
99 | * load in the hypervisor. | |
100 | * @next: List head to manage registered callbacks internally; initialized by | |
101 | * register_vmcore_cb(). | |
102 | * | |
103 | * vmcore callbacks allow drivers managing physical memory ranges to | |
104 | * coordinate with vmcore handling code, for example, to prevent accessing | |
105 | * physical memory ranges that should not be accessed when reading the vmcore, | |
106 | * although included in the vmcore header as memory ranges to dump. | |
107 | */ | |
108 | struct vmcore_cb { | |
109 | bool (*pfn_is_ram)(struct vmcore_cb *cb, unsigned long pfn); | |
110 | struct list_head next; | |
111 | }; | |
112 | extern void register_vmcore_cb(struct vmcore_cb *cb); | |
113 | extern void unregister_vmcore_cb(struct vmcore_cb *cb); | |
997c136f | 114 | |
95b68dec | 115 | #else /* !CONFIG_CRASH_DUMP */ |
5605f419 | 116 | static inline bool is_kdump_kernel(void) { return false; } |
60e64d46 | 117 | #endif /* CONFIG_CRASH_DUMP */ |
95b68dec | 118 | |
2724273e RL |
119 | /* Device Dump information to be filled by drivers */ |
120 | struct vmcoredd_data { | |
121 | char dump_name[VMCOREDD_MAX_NAME_BYTES]; /* Unique name of the dump */ | |
122 | unsigned int size; /* Size of the dump */ | |
123 | /* Driver's registered callback to be invoked to collect dump */ | |
124 | int (*vmcoredd_callback)(struct vmcoredd_data *data, void *buf); | |
125 | }; | |
126 | ||
127 | #ifdef CONFIG_PROC_VMCORE_DEVICE_DUMP | |
128 | int vmcore_add_device_dump(struct vmcoredd_data *data); | |
129 | #else | |
130 | static inline int vmcore_add_device_dump(struct vmcoredd_data *data) | |
131 | { | |
132 | return -EOPNOTSUPP; | |
133 | } | |
134 | #endif /* CONFIG_PROC_VMCORE_DEVICE_DUMP */ | |
ae7eb82a TJB |
135 | |
136 | #ifdef CONFIG_PROC_VMCORE | |
e0690479 MWO |
137 | ssize_t read_from_oldmem(struct iov_iter *iter, size_t count, |
138 | u64 *ppos, bool encrypted); | |
ae7eb82a | 139 | #else |
e0690479 MWO |
140 | static inline ssize_t read_from_oldmem(struct iov_iter *iter, size_t count, |
141 | u64 *ppos, bool encrypted) | |
ae7eb82a TJB |
142 | { |
143 | return -EOPNOTSUPP; | |
144 | } | |
145 | #endif /* CONFIG_PROC_VMCORE */ | |
146 | ||
60e64d46 | 147 | #endif /* LINUX_CRASHDUMP_H */ |