xref: /linux-6.15/include/linux/kexec.h (revision 2bac648d)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef LINUX_KEXEC_H
3 #define LINUX_KEXEC_H
4 
5 #define IND_DESTINATION_BIT 0
6 #define IND_INDIRECTION_BIT 1
7 #define IND_DONE_BIT        2
8 #define IND_SOURCE_BIT      3
9 
10 #define IND_DESTINATION  (1 << IND_DESTINATION_BIT)
11 #define IND_INDIRECTION  (1 << IND_INDIRECTION_BIT)
12 #define IND_DONE         (1 << IND_DONE_BIT)
13 #define IND_SOURCE       (1 << IND_SOURCE_BIT)
14 #define IND_FLAGS (IND_DESTINATION | IND_INDIRECTION | IND_DONE | IND_SOURCE)
15 
16 #if !defined(__ASSEMBLY__)
17 
18 #include <linux/vmcore_info.h>
19 #include <linux/crash_reserve.h>
20 #include <asm/io.h>
21 #include <linux/range.h>
22 
23 #include <uapi/linux/kexec.h>
24 #include <linux/verification.h>
25 
26 extern note_buf_t __percpu *crash_notes;
27 
28 #ifdef CONFIG_KEXEC_CORE
29 #include <linux/list.h>
30 #include <linux/compat.h>
31 #include <linux/ioport.h>
32 #include <linux/module.h>
33 #include <linux/highmem.h>
34 #include <asm/kexec.h>
35 #include <linux/crash_core.h>
36 
37 /* Verify architecture specific macros are defined */
38 
39 #ifndef KEXEC_SOURCE_MEMORY_LIMIT
40 #error KEXEC_SOURCE_MEMORY_LIMIT not defined
41 #endif
42 
43 #ifndef KEXEC_DESTINATION_MEMORY_LIMIT
44 #error KEXEC_DESTINATION_MEMORY_LIMIT not defined
45 #endif
46 
47 #ifndef KEXEC_CONTROL_MEMORY_LIMIT
48 #error KEXEC_CONTROL_MEMORY_LIMIT not defined
49 #endif
50 
51 #ifndef KEXEC_CONTROL_MEMORY_GFP
52 #define KEXEC_CONTROL_MEMORY_GFP (GFP_KERNEL | __GFP_NORETRY)
53 #endif
54 
55 #ifndef KEXEC_CONTROL_PAGE_SIZE
56 #error KEXEC_CONTROL_PAGE_SIZE not defined
57 #endif
58 
59 #ifndef KEXEC_ARCH
60 #error KEXEC_ARCH not defined
61 #endif
62 
63 #ifndef KEXEC_CRASH_CONTROL_MEMORY_LIMIT
64 #define KEXEC_CRASH_CONTROL_MEMORY_LIMIT KEXEC_CONTROL_MEMORY_LIMIT
65 #endif
66 
67 #ifndef KEXEC_CRASH_MEM_ALIGN
68 #define KEXEC_CRASH_MEM_ALIGN PAGE_SIZE
69 #endif
70 
71 /*
72  * This structure is used to hold the arguments that are used when loading
73  * kernel binaries.
74  */
75 
76 typedef unsigned long kimage_entry_t;
77 
78 struct kexec_segment {
79 	/*
80 	 * This pointer can point to user memory if kexec_load() system
81 	 * call is used or will point to kernel memory if
82 	 * kexec_file_load() system call is used.
83 	 *
84 	 * Use ->buf when expecting to deal with user memory and use ->kbuf
85 	 * when expecting to deal with kernel memory.
86 	 */
87 	union {
88 		void __user *buf;
89 		void *kbuf;
90 	};
91 	size_t bufsz;
92 	unsigned long mem;
93 	size_t memsz;
94 };
95 
96 #ifdef CONFIG_COMPAT
97 struct compat_kexec_segment {
98 	compat_uptr_t buf;
99 	compat_size_t bufsz;
100 	compat_ulong_t mem;	/* User space sees this as a (void *) ... */
101 	compat_size_t memsz;
102 };
103 #endif
104 
105 #ifdef CONFIG_KEXEC_FILE
106 struct purgatory_info {
107 	/*
108 	 * Pointer to elf header at the beginning of kexec_purgatory.
109 	 * Note: kexec_purgatory is read only
110 	 */
111 	const Elf_Ehdr *ehdr;
112 	/*
113 	 * Temporary, modifiable buffer for sechdrs used for relocation.
114 	 * This memory can be freed post image load.
115 	 */
116 	Elf_Shdr *sechdrs;
117 	/*
118 	 * Temporary, modifiable buffer for stripped purgatory used for
119 	 * relocation. This memory can be freed post image load.
120 	 */
121 	void *purgatory_buf;
122 };
123 
124 struct kimage;
125 
126 typedef int (kexec_probe_t)(const char *kernel_buf, unsigned long kernel_size);
127 typedef void *(kexec_load_t)(struct kimage *image, char *kernel_buf,
128 			     unsigned long kernel_len, char *initrd,
129 			     unsigned long initrd_len, char *cmdline,
130 			     unsigned long cmdline_len);
131 typedef int (kexec_cleanup_t)(void *loader_data);
132 
133 #ifdef CONFIG_KEXEC_SIG
134 typedef int (kexec_verify_sig_t)(const char *kernel_buf,
135 				 unsigned long kernel_len);
136 #endif
137 
138 struct kexec_file_ops {
139 	kexec_probe_t *probe;
140 	kexec_load_t *load;
141 	kexec_cleanup_t *cleanup;
142 #ifdef CONFIG_KEXEC_SIG
143 	kexec_verify_sig_t *verify_sig;
144 #endif
145 };
146 
147 extern const struct kexec_file_ops * const kexec_file_loaders[];
148 
149 int kexec_image_probe_default(struct kimage *image, void *buf,
150 			      unsigned long buf_len);
151 int kexec_image_post_load_cleanup_default(struct kimage *image);
152 
153 /*
154  * If kexec_buf.mem is set to this value, kexec_locate_mem_hole()
155  * will try to allocate free memory. Arch may overwrite it.
156  */
157 #ifndef KEXEC_BUF_MEM_UNKNOWN
158 #define KEXEC_BUF_MEM_UNKNOWN 0
159 #endif
160 
161 /**
162  * struct kexec_buf - parameters for finding a place for a buffer in memory
163  * @image:	kexec image in which memory to search.
164  * @buffer:	Contents which will be copied to the allocated memory.
165  * @bufsz:	Size of @buffer.
166  * @mem:	On return will have address of the buffer in memory.
167  * @memsz:	Size for the buffer in memory.
168  * @buf_align:	Minimum alignment needed.
169  * @buf_min:	The buffer can't be placed below this address.
170  * @buf_max:	The buffer can't be placed above this address.
171  * @top_down:	Allocate from top of memory.
172  */
173 struct kexec_buf {
174 	struct kimage *image;
175 	void *buffer;
176 	unsigned long bufsz;
177 	unsigned long mem;
178 	unsigned long memsz;
179 	unsigned long buf_align;
180 	unsigned long buf_min;
181 	unsigned long buf_max;
182 	bool top_down;
183 };
184 
185 int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf);
186 int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
187 				   void *buf, unsigned int size,
188 				   bool get_value);
189 void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name);
190 
191 #ifndef arch_kexec_kernel_image_probe
192 static inline int
193 arch_kexec_kernel_image_probe(struct kimage *image, void *buf, unsigned long buf_len)
194 {
195 	return kexec_image_probe_default(image, buf, buf_len);
196 }
197 #endif
198 
199 #ifndef arch_kimage_file_post_load_cleanup
200 static inline int arch_kimage_file_post_load_cleanup(struct kimage *image)
201 {
202 	return kexec_image_post_load_cleanup_default(image);
203 }
204 #endif
205 
206 #ifdef CONFIG_KEXEC_SIG
207 #ifdef CONFIG_SIGNED_PE_FILE_VERIFICATION
208 int kexec_kernel_verify_pe_sig(const char *kernel, unsigned long kernel_len);
209 #endif
210 #endif
211 
212 extern int kexec_add_buffer(struct kexec_buf *kbuf);
213 int kexec_locate_mem_hole(struct kexec_buf *kbuf);
214 
215 #ifndef arch_kexec_locate_mem_hole
216 /**
217  * arch_kexec_locate_mem_hole - Find free memory to place the segments.
218  * @kbuf:                       Parameters for the memory search.
219  *
220  * On success, kbuf->mem will have the start address of the memory region found.
221  *
222  * Return: 0 on success, negative errno on error.
223  */
224 static inline int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf)
225 {
226 	return kexec_locate_mem_hole(kbuf);
227 }
228 #endif
229 
230 #ifndef arch_kexec_apply_relocations_add
231 /*
232  * arch_kexec_apply_relocations_add - apply relocations of type RELA
233  * @pi:		Purgatory to be relocated.
234  * @section:	Section relocations applying to.
235  * @relsec:	Section containing RELAs.
236  * @symtab:	Corresponding symtab.
237  *
238  * Return: 0 on success, negative errno on error.
239  */
240 static inline int
241 arch_kexec_apply_relocations_add(struct purgatory_info *pi, Elf_Shdr *section,
242 				 const Elf_Shdr *relsec, const Elf_Shdr *symtab)
243 {
244 	pr_err("RELA relocation unsupported.\n");
245 	return -ENOEXEC;
246 }
247 #endif
248 
249 #ifndef arch_kexec_apply_relocations
250 /*
251  * arch_kexec_apply_relocations - apply relocations of type REL
252  * @pi:		Purgatory to be relocated.
253  * @section:	Section relocations applying to.
254  * @relsec:	Section containing RELs.
255  * @symtab:	Corresponding symtab.
256  *
257  * Return: 0 on success, negative errno on error.
258  */
259 static inline int
260 arch_kexec_apply_relocations(struct purgatory_info *pi, Elf_Shdr *section,
261 			     const Elf_Shdr *relsec, const Elf_Shdr *symtab)
262 {
263 	pr_err("REL relocation unsupported.\n");
264 	return -ENOEXEC;
265 }
266 #endif
267 #endif /* CONFIG_KEXEC_FILE */
268 
269 #ifdef CONFIG_KEXEC_ELF
270 struct kexec_elf_info {
271 	/*
272 	 * Where the ELF binary contents are kept.
273 	 * Memory managed by the user of the struct.
274 	 */
275 	const char *buffer;
276 
277 	const struct elfhdr *ehdr;
278 	const struct elf_phdr *proghdrs;
279 };
280 
281 int kexec_build_elf_info(const char *buf, size_t len, struct elfhdr *ehdr,
282 			       struct kexec_elf_info *elf_info);
283 
284 int kexec_elf_load(struct kimage *image, struct elfhdr *ehdr,
285 			 struct kexec_elf_info *elf_info,
286 			 struct kexec_buf *kbuf,
287 			 unsigned long *lowest_load_addr);
288 
289 void kexec_free_elf_info(struct kexec_elf_info *elf_info);
290 int kexec_elf_probe(const char *buf, unsigned long len);
291 #endif
292 struct kimage {
293 	kimage_entry_t head;
294 	kimage_entry_t *entry;
295 	kimage_entry_t *last_entry;
296 
297 	unsigned long start;
298 	struct page *control_code_page;
299 	struct page *swap_page;
300 	void *vmcoreinfo_data_copy; /* locates in the crash memory */
301 
302 	unsigned long nr_segments;
303 	struct kexec_segment segment[KEXEC_SEGMENT_MAX];
304 
305 	struct list_head control_pages;
306 	struct list_head dest_pages;
307 	struct list_head unusable_pages;
308 
309 	/* Address of next control page to allocate for crash kernels. */
310 	unsigned long control_page;
311 
312 	/* Flags to indicate special processing */
313 	unsigned int type : 1;
314 #define KEXEC_TYPE_DEFAULT 0
315 #define KEXEC_TYPE_CRASH   1
316 	unsigned int preserve_context : 1;
317 	/* If set, we are using file mode kexec syscall */
318 	unsigned int file_mode:1;
319 #ifdef CONFIG_CRASH_HOTPLUG
320 	/* If set, it is safe to update kexec segments that are
321 	 * excluded from SHA calculation.
322 	 */
323 	unsigned int hotplug_support:1;
324 #endif
325 
326 #ifdef ARCH_HAS_KIMAGE_ARCH
327 	struct kimage_arch arch;
328 #endif
329 
330 #ifdef CONFIG_KEXEC_FILE
331 	/* Additional fields for file based kexec syscall */
332 	void *kernel_buf;
333 	unsigned long kernel_buf_len;
334 
335 	void *initrd_buf;
336 	unsigned long initrd_buf_len;
337 
338 	char *cmdline_buf;
339 	unsigned long cmdline_buf_len;
340 
341 	/* File operations provided by image loader */
342 	const struct kexec_file_ops *fops;
343 
344 	/* Image loader handling the kernel can store a pointer here */
345 	void *image_loader_data;
346 
347 	/* Information for loading purgatory */
348 	struct purgatory_info purgatory_info;
349 #endif
350 
351 #ifdef CONFIG_CRASH_HOTPLUG
352 	int hp_action;
353 	int elfcorehdr_index;
354 	bool elfcorehdr_updated;
355 #endif
356 
357 #ifdef CONFIG_IMA_KEXEC
358 	/* Virtual address of IMA measurement buffer for kexec syscall */
359 	void *ima_buffer;
360 
361 	phys_addr_t ima_buffer_addr;
362 	size_t ima_buffer_size;
363 #endif
364 
365 	/* Core ELF header buffer */
366 	void *elf_headers;
367 	unsigned long elf_headers_sz;
368 	unsigned long elf_load_addr;
369 };
370 
371 /* kexec interface functions */
372 extern void machine_kexec(struct kimage *image);
373 extern int machine_kexec_prepare(struct kimage *image);
374 extern void machine_kexec_cleanup(struct kimage *image);
375 extern int kernel_kexec(void);
376 extern struct page *kimage_alloc_control_pages(struct kimage *image,
377 						unsigned int order);
378 
379 #ifndef machine_kexec_post_load
380 static inline int machine_kexec_post_load(struct kimage *image) { return 0; }
381 #endif
382 
383 extern struct kimage *kexec_image;
384 extern struct kimage *kexec_crash_image;
385 
386 bool kexec_load_permitted(int kexec_image_type);
387 
388 #ifndef kexec_flush_icache_page
389 #define kexec_flush_icache_page(page)
390 #endif
391 
392 /* List of defined/legal kexec flags */
393 #ifndef CONFIG_KEXEC_JUMP
394 #define KEXEC_FLAGS    (KEXEC_ON_CRASH | KEXEC_UPDATE_ELFCOREHDR | KEXEC_CRASH_HOTPLUG_SUPPORT)
395 #else
396 #define KEXEC_FLAGS    (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT | KEXEC_UPDATE_ELFCOREHDR | \
397 			KEXEC_CRASH_HOTPLUG_SUPPORT)
398 #endif
399 
400 /* List of defined/legal kexec file flags */
401 #define KEXEC_FILE_FLAGS	(KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \
402 				 KEXEC_FILE_NO_INITRAMFS | KEXEC_FILE_DEBUG)
403 
404 /* flag to track if kexec reboot is in progress */
405 extern bool kexec_in_progress;
406 
407 #ifndef page_to_boot_pfn
408 static inline unsigned long page_to_boot_pfn(struct page *page)
409 {
410 	return page_to_pfn(page);
411 }
412 #endif
413 
414 #ifndef boot_pfn_to_page
415 static inline struct page *boot_pfn_to_page(unsigned long boot_pfn)
416 {
417 	return pfn_to_page(boot_pfn);
418 }
419 #endif
420 
421 #ifndef phys_to_boot_phys
422 static inline unsigned long phys_to_boot_phys(phys_addr_t phys)
423 {
424 	return phys;
425 }
426 #endif
427 
428 #ifndef boot_phys_to_phys
429 static inline phys_addr_t boot_phys_to_phys(unsigned long boot_phys)
430 {
431 	return boot_phys;
432 }
433 #endif
434 
435 #ifndef crash_free_reserved_phys_range
436 static inline void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
437 {
438 	unsigned long addr;
439 
440 	for (addr = begin; addr < end; addr += PAGE_SIZE)
441 		free_reserved_page(boot_pfn_to_page(addr >> PAGE_SHIFT));
442 }
443 #endif
444 
445 static inline unsigned long virt_to_boot_phys(void *addr)
446 {
447 	return phys_to_boot_phys(__pa((unsigned long)addr));
448 }
449 
450 static inline void *boot_phys_to_virt(unsigned long entry)
451 {
452 	return phys_to_virt(boot_phys_to_phys(entry));
453 }
454 
455 #ifndef arch_kexec_post_alloc_pages
456 static inline int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp) { return 0; }
457 #endif
458 
459 #ifndef arch_kexec_pre_free_pages
460 static inline void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages) { }
461 #endif
462 
463 extern bool kexec_file_dbg_print;
464 
465 #define kexec_dprintk(fmt, arg...) \
466         do { if (kexec_file_dbg_print) pr_info(fmt, ##arg); } while (0)
467 
468 #else /* !CONFIG_KEXEC_CORE */
469 struct pt_regs;
470 struct task_struct;
471 static inline void __crash_kexec(struct pt_regs *regs) { }
472 static inline void crash_kexec(struct pt_regs *regs) { }
473 static inline int kexec_should_crash(struct task_struct *p) { return 0; }
474 static inline int kexec_crash_loaded(void) { return 0; }
475 #define kexec_in_progress false
476 #endif /* CONFIG_KEXEC_CORE */
477 
478 #ifdef CONFIG_KEXEC_SIG
479 void set_kexec_sig_enforced(void);
480 #else
481 static inline void set_kexec_sig_enforced(void) {}
482 #endif
483 
484 #endif /* !defined(__ASSEBMLY__) */
485 
486 #endif /* LINUX_KEXEC_H */
487