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
21#include <uapi/linux/kexec.h>
22#include <linux/verification.h>
23
24/* Location of a reserved region to hold the crash kernel.
25 */
26extern struct resource crashk_res;
27extern struct resource crashk_low_res;
28extern note_buf_t __percpu *crash_notes;
29
30#ifdef CONFIG_KEXEC_CORE
31#include <linux/list.h>
32#include <linux/compat.h>
33#include <linux/ioport.h>
34#include <linux/module.h>
35#include <asm/kexec.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
78typedef unsigned long kimage_entry_t;
79
80struct 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
99struct 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
108struct 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
126struct kimage;
127
128typedef int (kexec_probe_t)(const char *kernel_buf, unsigned long kernel_size);
129typedef 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);
133typedef int (kexec_cleanup_t)(void *loader_data);
134
135#ifdef CONFIG_KEXEC_SIG
136typedef int (kexec_verify_sig_t)(const char *kernel_buf,
137 unsigned long kernel_len);
138#endif
139
140struct 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
149extern const struct kexec_file_ops * const kexec_file_loaders[];
150
151int kexec_image_probe_default(struct kimage *image, void *buf,
152 unsigned long buf_len);
153int 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 */
175struct 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
187int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf);
188int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
189 void *buf, unsigned int size,
190 bool get_value);
191void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name);
192void *kexec_image_load_default(struct kimage *image);
193
194#ifndef arch_kexec_kernel_image_probe
195static inline int
196arch_kexec_kernel_image_probe(struct kimage *image, void *buf, unsigned long buf_len)
197{
198 return kexec_image_probe_default(image, buf, buf_len);
199}
200#endif
201
202#ifndef arch_kimage_file_post_load_cleanup
203static inline int arch_kimage_file_post_load_cleanup(struct kimage *image)
204{
205 return kexec_image_post_load_cleanup_default(image);
206}
207#endif
208
209#ifndef arch_kexec_kernel_image_load
210static inline void *arch_kexec_kernel_image_load(struct kimage *image)
211{
212 return kexec_image_load_default(image);
213}
214#endif
215
216#ifdef CONFIG_KEXEC_SIG
217#ifdef CONFIG_SIGNED_PE_FILE_VERIFICATION
218int kexec_kernel_verify_pe_sig(const char *kernel, unsigned long kernel_len);
219#endif
220#endif
221
222extern int kexec_add_buffer(struct kexec_buf *kbuf);
223int kexec_locate_mem_hole(struct kexec_buf *kbuf);
224
225#ifndef arch_kexec_locate_mem_hole
226/**
227 * arch_kexec_locate_mem_hole - Find free memory to place the segments.
228 * @kbuf: Parameters for the memory search.
229 *
230 * On success, kbuf->mem will have the start address of the memory region found.
231 *
232 * Return: 0 on success, negative errno on error.
233 */
234static inline int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf)
235{
236 return kexec_locate_mem_hole(kbuf);
237}
238#endif
239
240/* Alignment required for elf header segment */
241#define ELF_CORE_HEADER_ALIGN 4096
242
243struct crash_mem_range {
244 u64 start, end;
245};
246
247struct crash_mem {
248 unsigned int max_nr_ranges;
249 unsigned int nr_ranges;
250 struct crash_mem_range ranges[];
251};
252
253extern int crash_exclude_mem_range(struct crash_mem *mem,
254 unsigned long long mstart,
255 unsigned long long mend);
256extern int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
257 void **addr, unsigned long *sz);
258
259#ifndef arch_kexec_apply_relocations_add
260/*
261 * arch_kexec_apply_relocations_add - apply relocations of type RELA
262 * @pi: Purgatory to be relocated.
263 * @section: Section relocations applying to.
264 * @relsec: Section containing RELAs.
265 * @symtab: Corresponding symtab.
266 *
267 * Return: 0 on success, negative errno on error.
268 */
269static inline int
270arch_kexec_apply_relocations_add(struct purgatory_info *pi, Elf_Shdr *section,
271 const Elf_Shdr *relsec, const Elf_Shdr *symtab)
272{
273 pr_err("RELA relocation unsupported.\n");
274 return -ENOEXEC;
275}
276#endif
277
278#ifndef arch_kexec_apply_relocations
279/*
280 * arch_kexec_apply_relocations - apply relocations of type REL
281 * @pi: Purgatory to be relocated.
282 * @section: Section relocations applying to.
283 * @relsec: Section containing RELs.
284 * @symtab: Corresponding symtab.
285 *
286 * Return: 0 on success, negative errno on error.
287 */
288static inline int
289arch_kexec_apply_relocations(struct purgatory_info *pi, Elf_Shdr *section,
290 const Elf_Shdr *relsec, const Elf_Shdr *symtab)
291{
292 pr_err("REL relocation unsupported.\n");
293 return -ENOEXEC;
294}
295#endif
296#endif /* CONFIG_KEXEC_FILE */
297
298#ifdef CONFIG_KEXEC_ELF
299struct kexec_elf_info {
300 /*
301 * Where the ELF binary contents are kept.
302 * Memory managed by the user of the struct.
303 */
304 const char *buffer;
305
306 const struct elfhdr *ehdr;
307 const struct elf_phdr *proghdrs;
308};
309
310int kexec_build_elf_info(const char *buf, size_t len, struct elfhdr *ehdr,
311 struct kexec_elf_info *elf_info);
312
313int kexec_elf_load(struct kimage *image, struct elfhdr *ehdr,
314 struct kexec_elf_info *elf_info,
315 struct kexec_buf *kbuf,
316 unsigned long *lowest_load_addr);
317
318void kexec_free_elf_info(struct kexec_elf_info *elf_info);
319int kexec_elf_probe(const char *buf, unsigned long len);
320#endif
321struct kimage {
322 kimage_entry_t head;
323 kimage_entry_t *entry;
324 kimage_entry_t *last_entry;
325
326 unsigned long start;
327 struct page *control_code_page;
328 struct page *swap_page;
329 void *vmcoreinfo_data_copy; /* locates in the crash memory */
330
331 unsigned long nr_segments;
332 struct kexec_segment segment[KEXEC_SEGMENT_MAX];
333
334 struct list_head control_pages;
335 struct list_head dest_pages;
336 struct list_head unusable_pages;
337
338 /* Address of next control page to allocate for crash kernels. */
339 unsigned long control_page;
340
341 /* Flags to indicate special processing */
342 unsigned int type : 1;
343#define KEXEC_TYPE_DEFAULT 0
344#define KEXEC_TYPE_CRASH 1
345 unsigned int preserve_context : 1;
346 /* If set, we are using file mode kexec syscall */
347 unsigned int file_mode:1;
348
349#ifdef ARCH_HAS_KIMAGE_ARCH
350 struct kimage_arch arch;
351#endif
352
353#ifdef CONFIG_KEXEC_FILE
354 /* Additional fields for file based kexec syscall */
355 void *kernel_buf;
356 unsigned long kernel_buf_len;
357
358 void *initrd_buf;
359 unsigned long initrd_buf_len;
360
361 char *cmdline_buf;
362 unsigned long cmdline_buf_len;
363
364 /* File operations provided by image loader */
365 const struct kexec_file_ops *fops;
366
367 /* Image loader handling the kernel can store a pointer here */
368 void *image_loader_data;
369
370 /* Information for loading purgatory */
371 struct purgatory_info purgatory_info;
372#endif
373
374#ifdef CONFIG_IMA_KEXEC
375 /* Virtual address of IMA measurement buffer for kexec syscall */
376 void *ima_buffer;
377
378 phys_addr_t ima_buffer_addr;
379 size_t ima_buffer_size;
380#endif
381
382 /* Core ELF header buffer */
383 void *elf_headers;
384 unsigned long elf_headers_sz;
385 unsigned long elf_load_addr;
386};
387
388/* kexec interface functions */
389extern void machine_kexec(struct kimage *image);
390extern int machine_kexec_prepare(struct kimage *image);
391extern void machine_kexec_cleanup(struct kimage *image);
392extern int kernel_kexec(void);
393extern struct page *kimage_alloc_control_pages(struct kimage *image,
394 unsigned int order);
395
396#ifndef machine_kexec_post_load
397static inline int machine_kexec_post_load(struct kimage *image) { return 0; }
398#endif
399
400extern void __crash_kexec(struct pt_regs *);
401extern void crash_kexec(struct pt_regs *);
402int kexec_should_crash(struct task_struct *);
403int kexec_crash_loaded(void);
404void crash_save_cpu(struct pt_regs *regs, int cpu);
405extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);
406
407extern struct kimage *kexec_image;
408extern struct kimage *kexec_crash_image;
409extern int kexec_load_disabled;
410
411#ifndef kexec_flush_icache_page
412#define kexec_flush_icache_page(page)
413#endif
414
415/* List of defined/legal kexec flags */
416#ifndef CONFIG_KEXEC_JUMP
417#define KEXEC_FLAGS KEXEC_ON_CRASH
418#else
419#define KEXEC_FLAGS (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT)
420#endif
421
422/* List of defined/legal kexec file flags */
423#define KEXEC_FILE_FLAGS (KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \
424 KEXEC_FILE_NO_INITRAMFS)
425
426/* flag to track if kexec reboot is in progress */
427extern bool kexec_in_progress;
428
429int crash_shrink_memory(unsigned long new_size);
430size_t crash_get_memory_size(void);
431
432#ifndef arch_kexec_protect_crashkres
433/*
434 * Protection mechanism for crashkernel reserved memory after
435 * the kdump kernel is loaded.
436 *
437 * Provide an empty default implementation here -- architecture
438 * code may override this
439 */
440static inline void arch_kexec_protect_crashkres(void) { }
441#endif
442
443#ifndef arch_kexec_unprotect_crashkres
444static inline void arch_kexec_unprotect_crashkres(void) { }
445#endif
446
447#ifndef page_to_boot_pfn
448static inline unsigned long page_to_boot_pfn(struct page *page)
449{
450 return page_to_pfn(page);
451}
452#endif
453
454#ifndef boot_pfn_to_page
455static inline struct page *boot_pfn_to_page(unsigned long boot_pfn)
456{
457 return pfn_to_page(boot_pfn);
458}
459#endif
460
461#ifndef phys_to_boot_phys
462static inline unsigned long phys_to_boot_phys(phys_addr_t phys)
463{
464 return phys;
465}
466#endif
467
468#ifndef boot_phys_to_phys
469static inline phys_addr_t boot_phys_to_phys(unsigned long boot_phys)
470{
471 return boot_phys;
472}
473#endif
474
475#ifndef crash_free_reserved_phys_range
476static inline void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
477{
478 unsigned long addr;
479
480 for (addr = begin; addr < end; addr += PAGE_SIZE)
481 free_reserved_page(boot_pfn_to_page(addr >> PAGE_SHIFT));
482}
483#endif
484
485static inline unsigned long virt_to_boot_phys(void *addr)
486{
487 return phys_to_boot_phys(__pa((unsigned long)addr));
488}
489
490static inline void *boot_phys_to_virt(unsigned long entry)
491{
492 return phys_to_virt(boot_phys_to_phys(entry));
493}
494
495#ifndef arch_kexec_post_alloc_pages
496static inline int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp) { return 0; }
497#endif
498
499#ifndef arch_kexec_pre_free_pages
500static inline void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages) { }
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