xref: /linux-6.15/include/linux/kexec.h (revision c819e2cf)
1 #ifndef LINUX_KEXEC_H
2 #define LINUX_KEXEC_H
3 
4 #include <uapi/linux/kexec.h>
5 
6 #ifdef CONFIG_KEXEC
7 #include <linux/list.h>
8 #include <linux/linkage.h>
9 #include <linux/compat.h>
10 #include <linux/ioport.h>
11 #include <linux/elfcore.h>
12 #include <linux/elf.h>
13 #include <linux/module.h>
14 #include <asm/kexec.h>
15 
16 /* Verify architecture specific macros are defined */
17 
18 #ifndef KEXEC_SOURCE_MEMORY_LIMIT
19 #error KEXEC_SOURCE_MEMORY_LIMIT not defined
20 #endif
21 
22 #ifndef KEXEC_DESTINATION_MEMORY_LIMIT
23 #error KEXEC_DESTINATION_MEMORY_LIMIT not defined
24 #endif
25 
26 #ifndef KEXEC_CONTROL_MEMORY_LIMIT
27 #error KEXEC_CONTROL_MEMORY_LIMIT not defined
28 #endif
29 
30 #ifndef KEXEC_CONTROL_PAGE_SIZE
31 #error KEXEC_CONTROL_PAGE_SIZE not defined
32 #endif
33 
34 #ifndef KEXEC_ARCH
35 #error KEXEC_ARCH not defined
36 #endif
37 
38 #ifndef KEXEC_CRASH_CONTROL_MEMORY_LIMIT
39 #define KEXEC_CRASH_CONTROL_MEMORY_LIMIT KEXEC_CONTROL_MEMORY_LIMIT
40 #endif
41 
42 #ifndef KEXEC_CRASH_MEM_ALIGN
43 #define KEXEC_CRASH_MEM_ALIGN PAGE_SIZE
44 #endif
45 
46 #define KEXEC_NOTE_HEAD_BYTES ALIGN(sizeof(struct elf_note), 4)
47 #define KEXEC_CORE_NOTE_NAME "CORE"
48 #define KEXEC_CORE_NOTE_NAME_BYTES ALIGN(sizeof(KEXEC_CORE_NOTE_NAME), 4)
49 #define KEXEC_CORE_NOTE_DESC_BYTES ALIGN(sizeof(struct elf_prstatus), 4)
50 /*
51  * The per-cpu notes area is a list of notes terminated by a "NULL"
52  * note header.  For kdump, the code in vmcore.c runs in the context
53  * of the second kernel to combine them into one note.
54  */
55 #ifndef KEXEC_NOTE_BYTES
56 #define KEXEC_NOTE_BYTES ( (KEXEC_NOTE_HEAD_BYTES * 2) +		\
57 			    KEXEC_CORE_NOTE_NAME_BYTES +		\
58 			    KEXEC_CORE_NOTE_DESC_BYTES )
59 #endif
60 
61 /*
62  * This structure is used to hold the arguments that are used when loading
63  * kernel binaries.
64  */
65 
66 typedef unsigned long kimage_entry_t;
67 #define IND_DESTINATION  0x1
68 #define IND_INDIRECTION  0x2
69 #define IND_DONE         0x4
70 #define IND_SOURCE       0x8
71 
72 struct kexec_segment {
73 	/*
74 	 * This pointer can point to user memory if kexec_load() system
75 	 * call is used or will point to kernel memory if
76 	 * kexec_file_load() system call is used.
77 	 *
78 	 * Use ->buf when expecting to deal with user memory and use ->kbuf
79 	 * when expecting to deal with kernel memory.
80 	 */
81 	union {
82 		void __user *buf;
83 		void *kbuf;
84 	};
85 	size_t bufsz;
86 	unsigned long mem;
87 	size_t memsz;
88 };
89 
90 #ifdef CONFIG_COMPAT
91 struct compat_kexec_segment {
92 	compat_uptr_t buf;
93 	compat_size_t bufsz;
94 	compat_ulong_t mem;	/* User space sees this as a (void *) ... */
95 	compat_size_t memsz;
96 };
97 #endif
98 
99 struct kexec_sha_region {
100 	unsigned long start;
101 	unsigned long len;
102 };
103 
104 struct purgatory_info {
105 	/* Pointer to elf header of read only purgatory */
106 	Elf_Ehdr *ehdr;
107 
108 	/* Pointer to purgatory sechdrs which are modifiable */
109 	Elf_Shdr *sechdrs;
110 	/*
111 	 * Temporary buffer location where purgatory is loaded and relocated
112 	 * This memory can be freed post image load
113 	 */
114 	void *purgatory_buf;
115 
116 	/* Address where purgatory is finally loaded and is executed from */
117 	unsigned long purgatory_load_addr;
118 };
119 
120 struct kimage {
121 	kimage_entry_t head;
122 	kimage_entry_t *entry;
123 	kimage_entry_t *last_entry;
124 
125 	unsigned long destination;
126 
127 	unsigned long start;
128 	struct page *control_code_page;
129 	struct page *swap_page;
130 
131 	unsigned long nr_segments;
132 	struct kexec_segment segment[KEXEC_SEGMENT_MAX];
133 
134 	struct list_head control_pages;
135 	struct list_head dest_pages;
136 	struct list_head unusable_pages;
137 
138 	/* Address of next control page to allocate for crash kernels. */
139 	unsigned long control_page;
140 
141 	/* Flags to indicate special processing */
142 	unsigned int type : 1;
143 #define KEXEC_TYPE_DEFAULT 0
144 #define KEXEC_TYPE_CRASH   1
145 	unsigned int preserve_context : 1;
146 	/* If set, we are using file mode kexec syscall */
147 	unsigned int file_mode:1;
148 
149 #ifdef ARCH_HAS_KIMAGE_ARCH
150 	struct kimage_arch arch;
151 #endif
152 
153 	/* Additional fields for file based kexec syscall */
154 	void *kernel_buf;
155 	unsigned long kernel_buf_len;
156 
157 	void *initrd_buf;
158 	unsigned long initrd_buf_len;
159 
160 	char *cmdline_buf;
161 	unsigned long cmdline_buf_len;
162 
163 	/* File operations provided by image loader */
164 	struct kexec_file_ops *fops;
165 
166 	/* Image loader handling the kernel can store a pointer here */
167 	void *image_loader_data;
168 
169 	/* Information for loading purgatory */
170 	struct purgatory_info purgatory_info;
171 };
172 
173 /*
174  * Keeps track of buffer parameters as provided by caller for requesting
175  * memory placement of buffer.
176  */
177 struct kexec_buf {
178 	struct kimage *image;
179 	char *buffer;
180 	unsigned long bufsz;
181 	unsigned long mem;
182 	unsigned long memsz;
183 	unsigned long buf_align;
184 	unsigned long buf_min;
185 	unsigned long buf_max;
186 	bool top_down;		/* allocate from top of memory hole */
187 };
188 
189 typedef int (kexec_probe_t)(const char *kernel_buf, unsigned long kernel_size);
190 typedef void *(kexec_load_t)(struct kimage *image, char *kernel_buf,
191 			     unsigned long kernel_len, char *initrd,
192 			     unsigned long initrd_len, char *cmdline,
193 			     unsigned long cmdline_len);
194 typedef int (kexec_cleanup_t)(void *loader_data);
195 typedef int (kexec_verify_sig_t)(const char *kernel_buf,
196 				 unsigned long kernel_len);
197 
198 struct kexec_file_ops {
199 	kexec_probe_t *probe;
200 	kexec_load_t *load;
201 	kexec_cleanup_t *cleanup;
202 	kexec_verify_sig_t *verify_sig;
203 };
204 
205 /* kexec interface functions */
206 extern void machine_kexec(struct kimage *image);
207 extern int machine_kexec_prepare(struct kimage *image);
208 extern void machine_kexec_cleanup(struct kimage *image);
209 extern asmlinkage long sys_kexec_load(unsigned long entry,
210 					unsigned long nr_segments,
211 					struct kexec_segment __user *segments,
212 					unsigned long flags);
213 extern int kernel_kexec(void);
214 extern int kexec_add_buffer(struct kimage *image, char *buffer,
215 			    unsigned long bufsz, unsigned long memsz,
216 			    unsigned long buf_align, unsigned long buf_min,
217 			    unsigned long buf_max, bool top_down,
218 			    unsigned long *load_addr);
219 extern struct page *kimage_alloc_control_pages(struct kimage *image,
220 						unsigned int order);
221 extern int kexec_load_purgatory(struct kimage *image, unsigned long min,
222 				unsigned long max, int top_down,
223 				unsigned long *load_addr);
224 extern int kexec_purgatory_get_set_symbol(struct kimage *image,
225 					  const char *name, void *buf,
226 					  unsigned int size, bool get_value);
227 extern void *kexec_purgatory_get_symbol_addr(struct kimage *image,
228 					     const char *name);
229 extern void crash_kexec(struct pt_regs *);
230 int kexec_should_crash(struct task_struct *);
231 void crash_save_cpu(struct pt_regs *regs, int cpu);
232 void crash_save_vmcoreinfo(void);
233 void crash_map_reserved_pages(void);
234 void crash_unmap_reserved_pages(void);
235 void arch_crash_save_vmcoreinfo(void);
236 __printf(1, 2)
237 void vmcoreinfo_append_str(const char *fmt, ...);
238 unsigned long paddr_vmcoreinfo_note(void);
239 
240 #define VMCOREINFO_OSRELEASE(value) \
241 	vmcoreinfo_append_str("OSRELEASE=%s\n", value)
242 #define VMCOREINFO_PAGESIZE(value) \
243 	vmcoreinfo_append_str("PAGESIZE=%ld\n", value)
244 #define VMCOREINFO_SYMBOL(name) \
245 	vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)&name)
246 #define VMCOREINFO_SIZE(name) \
247 	vmcoreinfo_append_str("SIZE(%s)=%lu\n", #name, \
248 			      (unsigned long)sizeof(name))
249 #define VMCOREINFO_STRUCT_SIZE(name) \
250 	vmcoreinfo_append_str("SIZE(%s)=%lu\n", #name, \
251 			      (unsigned long)sizeof(struct name))
252 #define VMCOREINFO_OFFSET(name, field) \
253 	vmcoreinfo_append_str("OFFSET(%s.%s)=%lu\n", #name, #field, \
254 			      (unsigned long)offsetof(struct name, field))
255 #define VMCOREINFO_LENGTH(name, value) \
256 	vmcoreinfo_append_str("LENGTH(%s)=%lu\n", #name, (unsigned long)value)
257 #define VMCOREINFO_NUMBER(name) \
258 	vmcoreinfo_append_str("NUMBER(%s)=%ld\n", #name, (long)name)
259 #define VMCOREINFO_CONFIG(name) \
260 	vmcoreinfo_append_str("CONFIG_%s=y\n", #name)
261 
262 extern struct kimage *kexec_image;
263 extern struct kimage *kexec_crash_image;
264 extern int kexec_load_disabled;
265 
266 #ifndef kexec_flush_icache_page
267 #define kexec_flush_icache_page(page)
268 #endif
269 
270 /* List of defined/legal kexec flags */
271 #ifndef CONFIG_KEXEC_JUMP
272 #define KEXEC_FLAGS    KEXEC_ON_CRASH
273 #else
274 #define KEXEC_FLAGS    (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT)
275 #endif
276 
277 /* List of defined/legal kexec file flags */
278 #define KEXEC_FILE_FLAGS	(KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \
279 				 KEXEC_FILE_NO_INITRAMFS)
280 
281 #define VMCOREINFO_BYTES           (4096)
282 #define VMCOREINFO_NOTE_NAME       "VMCOREINFO"
283 #define VMCOREINFO_NOTE_NAME_BYTES ALIGN(sizeof(VMCOREINFO_NOTE_NAME), 4)
284 #define VMCOREINFO_NOTE_SIZE       (KEXEC_NOTE_HEAD_BYTES*2 + VMCOREINFO_BYTES \
285 				    + VMCOREINFO_NOTE_NAME_BYTES)
286 
287 /* Location of a reserved region to hold the crash kernel.
288  */
289 extern struct resource crashk_res;
290 extern struct resource crashk_low_res;
291 typedef u32 note_buf_t[KEXEC_NOTE_BYTES/4];
292 extern note_buf_t __percpu *crash_notes;
293 extern u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
294 extern size_t vmcoreinfo_size;
295 extern size_t vmcoreinfo_max_size;
296 
297 /* flag to track if kexec reboot is in progress */
298 extern bool kexec_in_progress;
299 
300 int __init parse_crashkernel(char *cmdline, unsigned long long system_ram,
301 		unsigned long long *crash_size, unsigned long long *crash_base);
302 int parse_crashkernel_high(char *cmdline, unsigned long long system_ram,
303 		unsigned long long *crash_size, unsigned long long *crash_base);
304 int parse_crashkernel_low(char *cmdline, unsigned long long system_ram,
305 		unsigned long long *crash_size, unsigned long long *crash_base);
306 int crash_shrink_memory(unsigned long new_size);
307 size_t crash_get_memory_size(void);
308 void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);
309 
310 #else /* !CONFIG_KEXEC */
311 struct pt_regs;
312 struct task_struct;
313 static inline void crash_kexec(struct pt_regs *regs) { }
314 static inline int kexec_should_crash(struct task_struct *p) { return 0; }
315 #endif /* CONFIG_KEXEC */
316 #endif /* LINUX_KEXEC_H */
317