xref: /linux/include/linux/kexec.h (revision f4af41bf)
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 #define KEXEC_CORE_NOTE_NAME	CRASH_CORE_NOTE_NAME
72 
73 /*
74  * This structure is used to hold the arguments that are used when loading
75  * kernel binaries.
76  */
77 
78 typedef unsigned long kimage_entry_t;
79 
80 struct kexec_segment {
81 	/*
82 	 * This pointer can point to user memory if kexec_load() system
83 	 * call is used or will point to kernel memory if
84 	 * kexec_file_load() system call is used.
85 	 *
86 	 * Use ->buf when expecting to deal with user memory and use ->kbuf
87 	 * when expecting to deal with kernel memory.
88 	 */
89 	union {
90 		void __user *buf;
91 		void *kbuf;
92 	};
93 	size_t bufsz;
94 	unsigned long mem;
95 	size_t memsz;
96 };
97 
98 #ifdef CONFIG_COMPAT
99 struct compat_kexec_segment {
100 	compat_uptr_t buf;
101 	compat_size_t bufsz;
102 	compat_ulong_t mem;	/* User space sees this as a (void *) ... */
103 	compat_size_t memsz;
104 };
105 #endif
106 
107 #ifdef CONFIG_KEXEC_FILE
108 struct purgatory_info {
109 	/*
110 	 * Pointer to elf header at the beginning of kexec_purgatory.
111 	 * Note: kexec_purgatory is read only
112 	 */
113 	const Elf_Ehdr *ehdr;
114 	/*
115 	 * Temporary, modifiable buffer for sechdrs used for relocation.
116 	 * This memory can be freed post image load.
117 	 */
118 	Elf_Shdr *sechdrs;
119 	/*
120 	 * Temporary, modifiable buffer for stripped purgatory used for
121 	 * relocation. This memory can be freed post image load.
122 	 */
123 	void *purgatory_buf;
124 };
125 
126 struct kimage;
127 
128 typedef int (kexec_probe_t)(const char *kernel_buf, unsigned long kernel_size);
129 typedef void *(kexec_load_t)(struct kimage *image, char *kernel_buf,
130 			     unsigned long kernel_len, char *initrd,
131 			     unsigned long initrd_len, char *cmdline,
132 			     unsigned long cmdline_len);
133 typedef int (kexec_cleanup_t)(void *loader_data);
134 
135 #ifdef CONFIG_KEXEC_SIG
136 typedef int (kexec_verify_sig_t)(const char *kernel_buf,
137 				 unsigned long kernel_len);
138 #endif
139 
140 struct kexec_file_ops {
141 	kexec_probe_t *probe;
142 	kexec_load_t *load;
143 	kexec_cleanup_t *cleanup;
144 #ifdef CONFIG_KEXEC_SIG
145 	kexec_verify_sig_t *verify_sig;
146 #endif
147 };
148 
149 extern const struct kexec_file_ops * const kexec_file_loaders[];
150 
151 int kexec_image_probe_default(struct kimage *image, void *buf,
152 			      unsigned long buf_len);
153 int kexec_image_post_load_cleanup_default(struct kimage *image);
154 
155 /*
156  * If kexec_buf.mem is set to this value, kexec_locate_mem_hole()
157  * will try to allocate free memory. Arch may overwrite it.
158  */
159 #ifndef KEXEC_BUF_MEM_UNKNOWN
160 #define KEXEC_BUF_MEM_UNKNOWN 0
161 #endif
162 
163 /**
164  * struct kexec_buf - parameters for finding a place for a buffer in memory
165  * @image:	kexec image in which memory to search.
166  * @buffer:	Contents which will be copied to the allocated memory.
167  * @bufsz:	Size of @buffer.
168  * @mem:	On return will have address of the buffer in memory.
169  * @memsz:	Size for the buffer in memory.
170  * @buf_align:	Minimum alignment needed.
171  * @buf_min:	The buffer can't be placed below this address.
172  * @buf_max:	The buffer can't be placed above this address.
173  * @top_down:	Allocate from top of memory.
174  */
175 struct kexec_buf {
176 	struct kimage *image;
177 	void *buffer;
178 	unsigned long bufsz;
179 	unsigned long mem;
180 	unsigned long memsz;
181 	unsigned long buf_align;
182 	unsigned long buf_min;
183 	unsigned long buf_max;
184 	bool top_down;
185 };
186 
187 int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf);
188 int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
189 				   void *buf, unsigned int size,
190 				   bool get_value);
191 void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name);
192 
193 #ifndef arch_kexec_kernel_image_probe
194 static inline int
arch_kexec_kernel_image_probe(struct kimage * image,void * buf,unsigned long buf_len)195 arch_kexec_kernel_image_probe(struct kimage *image, void *buf, unsigned long buf_len)
196 {
197 	return kexec_image_probe_default(image, buf, buf_len);
198 }
199 #endif
200 
201 #ifndef arch_kimage_file_post_load_cleanup
arch_kimage_file_post_load_cleanup(struct kimage * image)202 static inline int arch_kimage_file_post_load_cleanup(struct kimage *image)
203 {
204 	return kexec_image_post_load_cleanup_default(image);
205 }
206 #endif
207 
208 #ifdef CONFIG_KEXEC_SIG
209 #ifdef CONFIG_SIGNED_PE_FILE_VERIFICATION
210 int kexec_kernel_verify_pe_sig(const char *kernel, unsigned long kernel_len);
211 #endif
212 #endif
213 
214 extern int kexec_add_buffer(struct kexec_buf *kbuf);
215 int kexec_locate_mem_hole(struct kexec_buf *kbuf);
216 
217 #ifndef arch_kexec_locate_mem_hole
218 /**
219  * arch_kexec_locate_mem_hole - Find free memory to place the segments.
220  * @kbuf:                       Parameters for the memory search.
221  *
222  * On success, kbuf->mem will have the start address of the memory region found.
223  *
224  * Return: 0 on success, negative errno on error.
225  */
arch_kexec_locate_mem_hole(struct kexec_buf * kbuf)226 static inline int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf)
227 {
228 	return kexec_locate_mem_hole(kbuf);
229 }
230 #endif
231 
232 #ifndef arch_kexec_apply_relocations_add
233 /*
234  * arch_kexec_apply_relocations_add - apply relocations of type RELA
235  * @pi:		Purgatory to be relocated.
236  * @section:	Section relocations applying to.
237  * @relsec:	Section containing RELAs.
238  * @symtab:	Corresponding symtab.
239  *
240  * Return: 0 on success, negative errno on error.
241  */
242 static inline int
arch_kexec_apply_relocations_add(struct purgatory_info * pi,Elf_Shdr * section,const Elf_Shdr * relsec,const Elf_Shdr * symtab)243 arch_kexec_apply_relocations_add(struct purgatory_info *pi, Elf_Shdr *section,
244 				 const Elf_Shdr *relsec, const Elf_Shdr *symtab)
245 {
246 	pr_err("RELA relocation unsupported.\n");
247 	return -ENOEXEC;
248 }
249 #endif
250 
251 #ifndef arch_kexec_apply_relocations
252 /*
253  * arch_kexec_apply_relocations - apply relocations of type REL
254  * @pi:		Purgatory to be relocated.
255  * @section:	Section relocations applying to.
256  * @relsec:	Section containing RELs.
257  * @symtab:	Corresponding symtab.
258  *
259  * Return: 0 on success, negative errno on error.
260  */
261 static inline int
arch_kexec_apply_relocations(struct purgatory_info * pi,Elf_Shdr * section,const Elf_Shdr * relsec,const Elf_Shdr * symtab)262 arch_kexec_apply_relocations(struct purgatory_info *pi, Elf_Shdr *section,
263 			     const Elf_Shdr *relsec, const Elf_Shdr *symtab)
264 {
265 	pr_err("REL relocation unsupported.\n");
266 	return -ENOEXEC;
267 }
268 #endif
269 #endif /* CONFIG_KEXEC_FILE */
270 
271 #ifdef CONFIG_KEXEC_ELF
272 struct kexec_elf_info {
273 	/*
274 	 * Where the ELF binary contents are kept.
275 	 * Memory managed by the user of the struct.
276 	 */
277 	const char *buffer;
278 
279 	const struct elfhdr *ehdr;
280 	const struct elf_phdr *proghdrs;
281 };
282 
283 int kexec_build_elf_info(const char *buf, size_t len, struct elfhdr *ehdr,
284 			       struct kexec_elf_info *elf_info);
285 
286 int kexec_elf_load(struct kimage *image, struct elfhdr *ehdr,
287 			 struct kexec_elf_info *elf_info,
288 			 struct kexec_buf *kbuf,
289 			 unsigned long *lowest_load_addr);
290 
291 void kexec_free_elf_info(struct kexec_elf_info *elf_info);
292 int kexec_elf_probe(const char *buf, unsigned long len);
293 #endif
294 struct kimage {
295 	kimage_entry_t head;
296 	kimage_entry_t *entry;
297 	kimage_entry_t *last_entry;
298 
299 	unsigned long start;
300 	struct page *control_code_page;
301 	struct page *swap_page;
302 	void *vmcoreinfo_data_copy; /* locates in the crash memory */
303 
304 	unsigned long nr_segments;
305 	struct kexec_segment segment[KEXEC_SEGMENT_MAX];
306 
307 	struct list_head control_pages;
308 	struct list_head dest_pages;
309 	struct list_head unusable_pages;
310 
311 	/* Address of next control page to allocate for crash kernels. */
312 	unsigned long control_page;
313 
314 	/* Flags to indicate special processing */
315 	unsigned int type : 1;
316 #define KEXEC_TYPE_DEFAULT 0
317 #define KEXEC_TYPE_CRASH   1
318 	unsigned int preserve_context : 1;
319 	/* If set, we are using file mode kexec syscall */
320 	unsigned int file_mode:1;
321 #ifdef CONFIG_CRASH_HOTPLUG
322 	/* If set, it is safe to update kexec segments that are
323 	 * excluded from SHA calculation.
324 	 */
325 	unsigned int hotplug_support:1;
326 #endif
327 
328 #ifdef ARCH_HAS_KIMAGE_ARCH
329 	struct kimage_arch arch;
330 #endif
331 
332 #ifdef CONFIG_KEXEC_FILE
333 	/* Additional fields for file based kexec syscall */
334 	void *kernel_buf;
335 	unsigned long kernel_buf_len;
336 
337 	void *initrd_buf;
338 	unsigned long initrd_buf_len;
339 
340 	char *cmdline_buf;
341 	unsigned long cmdline_buf_len;
342 
343 	/* File operations provided by image loader */
344 	const struct kexec_file_ops *fops;
345 
346 	/* Image loader handling the kernel can store a pointer here */
347 	void *image_loader_data;
348 
349 	/* Information for loading purgatory */
350 	struct purgatory_info purgatory_info;
351 #endif
352 
353 #ifdef CONFIG_CRASH_HOTPLUG
354 	int hp_action;
355 	int elfcorehdr_index;
356 	bool elfcorehdr_updated;
357 #endif
358 
359 #ifdef CONFIG_IMA_KEXEC
360 	/* Virtual address of IMA measurement buffer for kexec syscall */
361 	void *ima_buffer;
362 
363 	phys_addr_t ima_buffer_addr;
364 	size_t ima_buffer_size;
365 #endif
366 
367 	/* Core ELF header buffer */
368 	void *elf_headers;
369 	unsigned long elf_headers_sz;
370 	unsigned long elf_load_addr;
371 };
372 
373 /* kexec interface functions */
374 extern void machine_kexec(struct kimage *image);
375 extern int machine_kexec_prepare(struct kimage *image);
376 extern void machine_kexec_cleanup(struct kimage *image);
377 extern int kernel_kexec(void);
378 extern struct page *kimage_alloc_control_pages(struct kimage *image,
379 						unsigned int order);
380 
381 #ifndef machine_kexec_post_load
machine_kexec_post_load(struct kimage * image)382 static inline int machine_kexec_post_load(struct kimage *image) { return 0; }
383 #endif
384 
385 extern struct kimage *kexec_image;
386 extern struct kimage *kexec_crash_image;
387 
388 bool kexec_load_permitted(int kexec_image_type);
389 
390 #ifndef kexec_flush_icache_page
391 #define kexec_flush_icache_page(page)
392 #endif
393 
394 /* List of defined/legal kexec flags */
395 #ifndef CONFIG_KEXEC_JUMP
396 #define KEXEC_FLAGS    (KEXEC_ON_CRASH | KEXEC_UPDATE_ELFCOREHDR | KEXEC_CRASH_HOTPLUG_SUPPORT)
397 #else
398 #define KEXEC_FLAGS    (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT | KEXEC_UPDATE_ELFCOREHDR | \
399 			KEXEC_CRASH_HOTPLUG_SUPPORT)
400 #endif
401 
402 /* List of defined/legal kexec file flags */
403 #define KEXEC_FILE_FLAGS	(KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \
404 				 KEXEC_FILE_NO_INITRAMFS | KEXEC_FILE_DEBUG)
405 
406 /* flag to track if kexec reboot is in progress */
407 extern bool kexec_in_progress;
408 
409 #ifndef page_to_boot_pfn
page_to_boot_pfn(struct page * page)410 static inline unsigned long page_to_boot_pfn(struct page *page)
411 {
412 	return page_to_pfn(page);
413 }
414 #endif
415 
416 #ifndef boot_pfn_to_page
boot_pfn_to_page(unsigned long boot_pfn)417 static inline struct page *boot_pfn_to_page(unsigned long boot_pfn)
418 {
419 	return pfn_to_page(boot_pfn);
420 }
421 #endif
422 
423 #ifndef phys_to_boot_phys
phys_to_boot_phys(phys_addr_t phys)424 static inline unsigned long phys_to_boot_phys(phys_addr_t phys)
425 {
426 	return phys;
427 }
428 #endif
429 
430 #ifndef boot_phys_to_phys
boot_phys_to_phys(unsigned long boot_phys)431 static inline phys_addr_t boot_phys_to_phys(unsigned long boot_phys)
432 {
433 	return boot_phys;
434 }
435 #endif
436 
437 #ifndef crash_free_reserved_phys_range
crash_free_reserved_phys_range(unsigned long begin,unsigned long end)438 static inline void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
439 {
440 	unsigned long addr;
441 
442 	for (addr = begin; addr < end; addr += PAGE_SIZE)
443 		free_reserved_page(boot_pfn_to_page(addr >> PAGE_SHIFT));
444 }
445 #endif
446 
virt_to_boot_phys(void * addr)447 static inline unsigned long virt_to_boot_phys(void *addr)
448 {
449 	return phys_to_boot_phys(__pa((unsigned long)addr));
450 }
451 
boot_phys_to_virt(unsigned long entry)452 static inline void *boot_phys_to_virt(unsigned long entry)
453 {
454 	return phys_to_virt(boot_phys_to_phys(entry));
455 }
456 
457 #ifndef arch_kexec_post_alloc_pages
arch_kexec_post_alloc_pages(void * vaddr,unsigned int pages,gfp_t gfp)458 static inline int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp) { return 0; }
459 #endif
460 
461 #ifndef arch_kexec_pre_free_pages
arch_kexec_pre_free_pages(void * vaddr,unsigned int pages)462 static inline void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages) { }
463 #endif
464 
465 extern bool kexec_file_dbg_print;
466 
467 #define kexec_dprintk(fmt, arg...) \
468         do { if (kexec_file_dbg_print) pr_info(fmt, ##arg); } while (0)
469 
470 #else /* !CONFIG_KEXEC_CORE */
471 struct pt_regs;
472 struct task_struct;
__crash_kexec(struct pt_regs * regs)473 static inline void __crash_kexec(struct pt_regs *regs) { }
crash_kexec(struct pt_regs * regs)474 static inline void crash_kexec(struct pt_regs *regs) { }
kexec_should_crash(struct task_struct * p)475 static inline int kexec_should_crash(struct task_struct *p) { return 0; }
kexec_crash_loaded(void)476 static inline int kexec_crash_loaded(void) { return 0; }
477 #define kexec_in_progress false
478 #endif /* CONFIG_KEXEC_CORE */
479 
480 #ifdef CONFIG_KEXEC_SIG
481 void set_kexec_sig_enforced(void);
482 #else
set_kexec_sig_enforced(void)483 static inline void set_kexec_sig_enforced(void) {}
484 #endif
485 
486 #endif /* !defined(__ASSEBMLY__) */
487 
488 #endif /* LINUX_KEXEC_H */
489