xref: /linux-6.15/include/linux/kexec.h (revision bbb03029)
1 #ifndef LINUX_KEXEC_H
2 #define LINUX_KEXEC_H
3 
4 #define IND_DESTINATION_BIT 0
5 #define IND_INDIRECTION_BIT 1
6 #define IND_DONE_BIT        2
7 #define IND_SOURCE_BIT      3
8 
9 #define IND_DESTINATION  (1 << IND_DESTINATION_BIT)
10 #define IND_INDIRECTION  (1 << IND_INDIRECTION_BIT)
11 #define IND_DONE         (1 << IND_DONE_BIT)
12 #define IND_SOURCE       (1 << IND_SOURCE_BIT)
13 #define IND_FLAGS (IND_DESTINATION | IND_INDIRECTION | IND_DONE | IND_SOURCE)
14 
15 #if !defined(__ASSEMBLY__)
16 
17 #include <linux/crash_core.h>
18 #include <asm/io.h>
19 
20 #include <uapi/linux/kexec.h>
21 
22 #ifdef CONFIG_KEXEC_CORE
23 #include <linux/list.h>
24 #include <linux/compat.h>
25 #include <linux/ioport.h>
26 #include <linux/module.h>
27 #include <asm/kexec.h>
28 
29 /* Verify architecture specific macros are defined */
30 
31 #ifndef KEXEC_SOURCE_MEMORY_LIMIT
32 #error KEXEC_SOURCE_MEMORY_LIMIT not defined
33 #endif
34 
35 #ifndef KEXEC_DESTINATION_MEMORY_LIMIT
36 #error KEXEC_DESTINATION_MEMORY_LIMIT not defined
37 #endif
38 
39 #ifndef KEXEC_CONTROL_MEMORY_LIMIT
40 #error KEXEC_CONTROL_MEMORY_LIMIT not defined
41 #endif
42 
43 #ifndef KEXEC_CONTROL_MEMORY_GFP
44 #define KEXEC_CONTROL_MEMORY_GFP (GFP_KERNEL | __GFP_NORETRY)
45 #endif
46 
47 #ifndef KEXEC_CONTROL_PAGE_SIZE
48 #error KEXEC_CONTROL_PAGE_SIZE not defined
49 #endif
50 
51 #ifndef KEXEC_ARCH
52 #error KEXEC_ARCH not defined
53 #endif
54 
55 #ifndef KEXEC_CRASH_CONTROL_MEMORY_LIMIT
56 #define KEXEC_CRASH_CONTROL_MEMORY_LIMIT KEXEC_CONTROL_MEMORY_LIMIT
57 #endif
58 
59 #ifndef KEXEC_CRASH_MEM_ALIGN
60 #define KEXEC_CRASH_MEM_ALIGN PAGE_SIZE
61 #endif
62 
63 #define KEXEC_CORE_NOTE_NAME	CRASH_CORE_NOTE_NAME
64 
65 /*
66  * This structure is used to hold the arguments that are used when loading
67  * kernel binaries.
68  */
69 
70 typedef unsigned long kimage_entry_t;
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 #ifdef CONFIG_KEXEC_FILE
100 struct purgatory_info {
101 	/* Pointer to elf header of read only purgatory */
102 	Elf_Ehdr *ehdr;
103 
104 	/* Pointer to purgatory sechdrs which are modifiable */
105 	Elf_Shdr *sechdrs;
106 	/*
107 	 * Temporary buffer location where purgatory is loaded and relocated
108 	 * This memory can be freed post image load
109 	 */
110 	void *purgatory_buf;
111 
112 	/* Address where purgatory is finally loaded and is executed from */
113 	unsigned long purgatory_load_addr;
114 };
115 
116 typedef int (kexec_probe_t)(const char *kernel_buf, unsigned long kernel_size);
117 typedef void *(kexec_load_t)(struct kimage *image, char *kernel_buf,
118 			     unsigned long kernel_len, char *initrd,
119 			     unsigned long initrd_len, char *cmdline,
120 			     unsigned long cmdline_len);
121 typedef int (kexec_cleanup_t)(void *loader_data);
122 
123 #ifdef CONFIG_KEXEC_VERIFY_SIG
124 typedef int (kexec_verify_sig_t)(const char *kernel_buf,
125 				 unsigned long kernel_len);
126 #endif
127 
128 struct kexec_file_ops {
129 	kexec_probe_t *probe;
130 	kexec_load_t *load;
131 	kexec_cleanup_t *cleanup;
132 #ifdef CONFIG_KEXEC_VERIFY_SIG
133 	kexec_verify_sig_t *verify_sig;
134 #endif
135 };
136 
137 /**
138  * struct kexec_buf - parameters for finding a place for a buffer in memory
139  * @image:	kexec image in which memory to search.
140  * @buffer:	Contents which will be copied to the allocated memory.
141  * @bufsz:	Size of @buffer.
142  * @mem:	On return will have address of the buffer in memory.
143  * @memsz:	Size for the buffer in memory.
144  * @buf_align:	Minimum alignment needed.
145  * @buf_min:	The buffer can't be placed below this address.
146  * @buf_max:	The buffer can't be placed above this address.
147  * @top_down:	Allocate from top of memory.
148  */
149 struct kexec_buf {
150 	struct kimage *image;
151 	void *buffer;
152 	unsigned long bufsz;
153 	unsigned long mem;
154 	unsigned long memsz;
155 	unsigned long buf_align;
156 	unsigned long buf_min;
157 	unsigned long buf_max;
158 	bool top_down;
159 };
160 
161 int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
162 			       int (*func)(u64, u64, void *));
163 extern int kexec_add_buffer(struct kexec_buf *kbuf);
164 int kexec_locate_mem_hole(struct kexec_buf *kbuf);
165 #endif /* CONFIG_KEXEC_FILE */
166 
167 struct kimage {
168 	kimage_entry_t head;
169 	kimage_entry_t *entry;
170 	kimage_entry_t *last_entry;
171 
172 	unsigned long start;
173 	struct page *control_code_page;
174 	struct page *swap_page;
175 	void *vmcoreinfo_data_copy; /* locates in the crash memory */
176 
177 	unsigned long nr_segments;
178 	struct kexec_segment segment[KEXEC_SEGMENT_MAX];
179 
180 	struct list_head control_pages;
181 	struct list_head dest_pages;
182 	struct list_head unusable_pages;
183 
184 	/* Address of next control page to allocate for crash kernels. */
185 	unsigned long control_page;
186 
187 	/* Flags to indicate special processing */
188 	unsigned int type : 1;
189 #define KEXEC_TYPE_DEFAULT 0
190 #define KEXEC_TYPE_CRASH   1
191 	unsigned int preserve_context : 1;
192 	/* If set, we are using file mode kexec syscall */
193 	unsigned int file_mode:1;
194 
195 #ifdef ARCH_HAS_KIMAGE_ARCH
196 	struct kimage_arch arch;
197 #endif
198 
199 #ifdef CONFIG_KEXEC_FILE
200 	/* Additional fields for file based kexec syscall */
201 	void *kernel_buf;
202 	unsigned long kernel_buf_len;
203 
204 	void *initrd_buf;
205 	unsigned long initrd_buf_len;
206 
207 	char *cmdline_buf;
208 	unsigned long cmdline_buf_len;
209 
210 	/* File operations provided by image loader */
211 	struct kexec_file_ops *fops;
212 
213 	/* Image loader handling the kernel can store a pointer here */
214 	void *image_loader_data;
215 
216 	/* Information for loading purgatory */
217 	struct purgatory_info purgatory_info;
218 #endif
219 };
220 
221 /* kexec interface functions */
222 extern void machine_kexec(struct kimage *image);
223 extern int machine_kexec_prepare(struct kimage *image);
224 extern void machine_kexec_cleanup(struct kimage *image);
225 extern asmlinkage long sys_kexec_load(unsigned long entry,
226 					unsigned long nr_segments,
227 					struct kexec_segment __user *segments,
228 					unsigned long flags);
229 extern int kernel_kexec(void);
230 extern struct page *kimage_alloc_control_pages(struct kimage *image,
231 						unsigned int order);
232 extern int kexec_load_purgatory(struct kimage *image, unsigned long min,
233 				unsigned long max, int top_down,
234 				unsigned long *load_addr);
235 extern int kexec_purgatory_get_set_symbol(struct kimage *image,
236 					  const char *name, void *buf,
237 					  unsigned int size, bool get_value);
238 extern void *kexec_purgatory_get_symbol_addr(struct kimage *image,
239 					     const char *name);
240 extern void __crash_kexec(struct pt_regs *);
241 extern void crash_kexec(struct pt_regs *);
242 int kexec_should_crash(struct task_struct *);
243 int kexec_crash_loaded(void);
244 void crash_save_cpu(struct pt_regs *regs, int cpu);
245 extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);
246 
247 extern struct kimage *kexec_image;
248 extern struct kimage *kexec_crash_image;
249 extern int kexec_load_disabled;
250 
251 #ifndef kexec_flush_icache_page
252 #define kexec_flush_icache_page(page)
253 #endif
254 
255 /* List of defined/legal kexec flags */
256 #ifndef CONFIG_KEXEC_JUMP
257 #define KEXEC_FLAGS    KEXEC_ON_CRASH
258 #else
259 #define KEXEC_FLAGS    (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT)
260 #endif
261 
262 /* List of defined/legal kexec file flags */
263 #define KEXEC_FILE_FLAGS	(KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \
264 				 KEXEC_FILE_NO_INITRAMFS)
265 
266 /* Location of a reserved region to hold the crash kernel.
267  */
268 extern struct resource crashk_res;
269 extern struct resource crashk_low_res;
270 extern note_buf_t __percpu *crash_notes;
271 
272 /* flag to track if kexec reboot is in progress */
273 extern bool kexec_in_progress;
274 
275 int crash_shrink_memory(unsigned long new_size);
276 size_t crash_get_memory_size(void);
277 void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);
278 
279 int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
280 					 unsigned long buf_len);
281 void * __weak arch_kexec_kernel_image_load(struct kimage *image);
282 int __weak arch_kimage_file_post_load_cleanup(struct kimage *image);
283 int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
284 					unsigned long buf_len);
285 int __weak arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr,
286 					Elf_Shdr *sechdrs, unsigned int relsec);
287 int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
288 					unsigned int relsec);
289 void arch_kexec_protect_crashkres(void);
290 void arch_kexec_unprotect_crashkres(void);
291 
292 #ifndef page_to_boot_pfn
293 static inline unsigned long page_to_boot_pfn(struct page *page)
294 {
295 	return page_to_pfn(page);
296 }
297 #endif
298 
299 #ifndef boot_pfn_to_page
300 static inline struct page *boot_pfn_to_page(unsigned long boot_pfn)
301 {
302 	return pfn_to_page(boot_pfn);
303 }
304 #endif
305 
306 #ifndef phys_to_boot_phys
307 static inline unsigned long phys_to_boot_phys(phys_addr_t phys)
308 {
309 	return phys;
310 }
311 #endif
312 
313 #ifndef boot_phys_to_phys
314 static inline phys_addr_t boot_phys_to_phys(unsigned long boot_phys)
315 {
316 	return boot_phys;
317 }
318 #endif
319 
320 static inline unsigned long virt_to_boot_phys(void *addr)
321 {
322 	return phys_to_boot_phys(__pa((unsigned long)addr));
323 }
324 
325 static inline void *boot_phys_to_virt(unsigned long entry)
326 {
327 	return phys_to_virt(boot_phys_to_phys(entry));
328 }
329 
330 #else /* !CONFIG_KEXEC_CORE */
331 struct pt_regs;
332 struct task_struct;
333 static inline void __crash_kexec(struct pt_regs *regs) { }
334 static inline void crash_kexec(struct pt_regs *regs) { }
335 static inline int kexec_should_crash(struct task_struct *p) { return 0; }
336 static inline int kexec_crash_loaded(void) { return 0; }
337 #define kexec_in_progress false
338 #endif /* CONFIG_KEXEC_CORE */
339 
340 #endif /* !defined(__ASSEBMLY__) */
341 
342 #endif /* LINUX_KEXEC_H */
343