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/crash_core.h>
19#include <asm/io.h>
20#include <linux/range.h>
21
22#include <uapi/linux/kexec.h>
23#include <linux/verification.h>
24
25extern note_buf_t __percpu *crash_notes;
26
27#ifdef CONFIG_KEXEC_CORE
28#include <linux/list.h>
29#include <linux/compat.h>
30#include <linux/ioport.h>
31#include <linux/module.h>
32#include <linux/highmem.h>
33#include <asm/kexec.h>
34
35/* Verify architecture specific macros are defined */
36
37#ifndef KEXEC_SOURCE_MEMORY_LIMIT
38#error KEXEC_SOURCE_MEMORY_LIMIT not defined
39#endif
40
41#ifndef KEXEC_DESTINATION_MEMORY_LIMIT
42#error KEXEC_DESTINATION_MEMORY_LIMIT not defined
43#endif
44
45#ifndef KEXEC_CONTROL_MEMORY_LIMIT
46#error KEXEC_CONTROL_MEMORY_LIMIT not defined
47#endif
48
49#ifndef KEXEC_CONTROL_MEMORY_GFP
50#define KEXEC_CONTROL_MEMORY_GFP (GFP_KERNEL | __GFP_NORETRY)
51#endif
52
53#ifndef KEXEC_CONTROL_PAGE_SIZE
54#error KEXEC_CONTROL_PAGE_SIZE not defined
55#endif
56
57#ifndef KEXEC_ARCH
58#error KEXEC_ARCH not defined
59#endif
60
61#ifndef KEXEC_CRASH_CONTROL_MEMORY_LIMIT
62#define KEXEC_CRASH_CONTROL_MEMORY_LIMIT KEXEC_CONTROL_MEMORY_LIMIT
63#endif
64
65#ifndef KEXEC_CRASH_MEM_ALIGN
66#define KEXEC_CRASH_MEM_ALIGN PAGE_SIZE
67#endif
68
69#define KEXEC_CORE_NOTE_NAME CRASH_CORE_NOTE_NAME
70
71/*
72 * This structure is used to hold the arguments that are used when loading
73 * kernel binaries.
74 */
75
76typedef unsigned long kimage_entry_t;
77
78struct 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
97struct 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
106struct 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
124struct kimage;
125
126typedef int (kexec_probe_t)(const char *kernel_buf, unsigned long kernel_size);
127typedef 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);
131typedef int (kexec_cleanup_t)(void *loader_data);
132
133#ifdef CONFIG_KEXEC_SIG
134typedef int (kexec_verify_sig_t)(const char *kernel_buf,
135 unsigned long kernel_len);
136#endif
137
138struct 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
147extern const struct kexec_file_ops * const kexec_file_loaders[];
148
149int kexec_image_probe_default(struct kimage *image, void *buf,
150 unsigned long buf_len);
151int 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 */
173struct 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
185int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf);
186int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
187 void *buf, unsigned int size,
188 bool get_value);
189void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name);
190
191#ifndef arch_kexec_kernel_image_probe
192static inline int
193arch_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
200static 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
208int kexec_kernel_verify_pe_sig(const char *kernel, unsigned long kernel_len);
209#endif
210#endif
211
212extern int kexec_add_buffer(struct kexec_buf *kbuf);
213int 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 */
224static 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 */
240static inline int
241arch_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 */
259static inline int
260arch_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
270struct 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
281int kexec_build_elf_info(const char *buf, size_t len, struct elfhdr *ehdr,
282 struct kexec_elf_info *elf_info);
283
284int 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
289void kexec_free_elf_info(struct kexec_elf_info *elf_info);
290int kexec_elf_probe(const char *buf, unsigned long len);
291#endif
292struct 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, allow changes to elfcorehdr of kexec_load'd image */
321 unsigned int update_elfcorehdr:1;
322#endif
323
324#ifdef ARCH_HAS_KIMAGE_ARCH
325 struct kimage_arch arch;
326#endif
327
328#ifdef CONFIG_KEXEC_FILE
329 /* Additional fields for file based kexec syscall */
330 void *kernel_buf;
331 unsigned long kernel_buf_len;
332
333 void *initrd_buf;
334 unsigned long initrd_buf_len;
335
336 char *cmdline_buf;
337 unsigned long cmdline_buf_len;
338
339 /* File operations provided by image loader */
340 const struct kexec_file_ops *fops;
341
342 /* Image loader handling the kernel can store a pointer here */
343 void *image_loader_data;
344
345 /* Information for loading purgatory */
346 struct purgatory_info purgatory_info;
347#endif
348
349#ifdef CONFIG_CRASH_HOTPLUG
350 int hp_action;
351 int elfcorehdr_index;
352 bool elfcorehdr_updated;
353#endif
354
355#ifdef CONFIG_IMA_KEXEC
356 /* Virtual address of IMA measurement buffer for kexec syscall */
357 void *ima_buffer;
358
359 phys_addr_t ima_buffer_addr;
360 size_t ima_buffer_size;
361#endif
362
363 /* Core ELF header buffer */
364 void *elf_headers;
365 unsigned long elf_headers_sz;
366 unsigned long elf_load_addr;
367};
368
369/* kexec interface functions */
370extern void machine_kexec(struct kimage *image);
371extern int machine_kexec_prepare(struct kimage *image);
372extern void machine_kexec_cleanup(struct kimage *image);
373extern int kernel_kexec(void);
374extern struct page *kimage_alloc_control_pages(struct kimage *image,
375 unsigned int order);
376
377#ifndef machine_kexec_post_load
378static inline int machine_kexec_post_load(struct kimage *image) { return 0; }
379#endif
380
381extern void __crash_kexec(struct pt_regs *);
382extern void crash_kexec(struct pt_regs *);
383int kexec_should_crash(struct task_struct *);
384int kexec_crash_loaded(void);
385void crash_save_cpu(struct pt_regs *regs, int cpu);
386extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);
387
388extern struct kimage *kexec_image;
389extern struct kimage *kexec_crash_image;
390
391bool kexec_load_permitted(int kexec_image_type);
392
393#ifndef kexec_flush_icache_page
394#define kexec_flush_icache_page(page)
395#endif
396
397/* List of defined/legal kexec flags */
398#ifndef CONFIG_KEXEC_JUMP
399#define KEXEC_FLAGS (KEXEC_ON_CRASH | KEXEC_UPDATE_ELFCOREHDR)
400#else
401#define KEXEC_FLAGS (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT | KEXEC_UPDATE_ELFCOREHDR)
402#endif
403
404/* List of defined/legal kexec file flags */
405#define KEXEC_FILE_FLAGS (KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \
406 KEXEC_FILE_NO_INITRAMFS)
407
408/* flag to track if kexec reboot is in progress */
409extern bool kexec_in_progress;
410
411int crash_shrink_memory(unsigned long new_size);
412ssize_t crash_get_memory_size(void);
413
414#ifndef arch_kexec_protect_crashkres
415/*
416 * Protection mechanism for crashkernel reserved memory after
417 * the kdump kernel is loaded.
418 *
419 * Provide an empty default implementation here -- architecture
420 * code may override this
421 */
422static inline void arch_kexec_protect_crashkres(void) { }
423#endif
424
425#ifndef arch_kexec_unprotect_crashkres
426static inline void arch_kexec_unprotect_crashkres(void) { }
427#endif
428
429#ifndef page_to_boot_pfn
430static inline unsigned long page_to_boot_pfn(struct page *page)
431{
432 return page_to_pfn(page);
433}
434#endif
435
436#ifndef boot_pfn_to_page
437static inline struct page *boot_pfn_to_page(unsigned long boot_pfn)
438{
439 return pfn_to_page(boot_pfn);
440}
441#endif
442
443#ifndef phys_to_boot_phys
444static inline unsigned long phys_to_boot_phys(phys_addr_t phys)
445{
446 return phys;
447}
448#endif
449
450#ifndef boot_phys_to_phys
451static inline phys_addr_t boot_phys_to_phys(unsigned long boot_phys)
452{
453 return boot_phys;
454}
455#endif
456
457#ifndef crash_free_reserved_phys_range
458static inline void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
459{
460 unsigned long addr;
461
462 for (addr = begin; addr < end; addr += PAGE_SIZE)
463 free_reserved_page(page: boot_pfn_to_page(boot_pfn: addr >> PAGE_SHIFT));
464}
465#endif
466
467static inline unsigned long virt_to_boot_phys(void *addr)
468{
469 return phys_to_boot_phys(__pa((unsigned long)addr));
470}
471
472static inline void *boot_phys_to_virt(unsigned long entry)
473{
474 return phys_to_virt(address: boot_phys_to_phys(boot_phys: entry));
475}
476
477#ifndef arch_kexec_post_alloc_pages
478static inline int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp) { return 0; }
479#endif
480
481#ifndef arch_kexec_pre_free_pages
482static inline void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages) { }
483#endif
484
485#ifndef arch_crash_handle_hotplug_event
486static inline void arch_crash_handle_hotplug_event(struct kimage *image) { }
487#endif
488
489int crash_check_update_elfcorehdr(void);
490
491#ifndef crash_hotplug_cpu_support
492static inline int crash_hotplug_cpu_support(void) { return 0; }
493#endif
494
495#ifndef crash_hotplug_memory_support
496static inline int crash_hotplug_memory_support(void) { return 0; }
497#endif
498
499#ifndef crash_get_elfcorehdr_size
500static inline unsigned int crash_get_elfcorehdr_size(void) { return 0; }
501#endif
502
503#else /* !CONFIG_KEXEC_CORE */
504struct pt_regs;
505struct task_struct;
506static inline void __crash_kexec(struct pt_regs *regs) { }
507static inline void crash_kexec(struct pt_regs *regs) { }
508static inline int kexec_should_crash(struct task_struct *p) { return 0; }
509static inline int kexec_crash_loaded(void) { return 0; }
510#define kexec_in_progress false
511#endif /* CONFIG_KEXEC_CORE */
512
513#ifdef CONFIG_KEXEC_SIG
514void set_kexec_sig_enforced(void);
515#else
516static inline void set_kexec_sig_enforced(void) {}
517#endif
518
519#endif /* !defined(__ASSEBMLY__) */
520
521#endif /* LINUX_KEXEC_H */
522

source code of linux/include/linux/kexec.h