summaryrefslogtreecommitdiffstats
path: root/include/linux/kexec.h
blob: 1776eb2e43a444c3b83ffa08806b6361d4444f17 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef LINUX_KEXEC_H
#define LINUX_KEXEC_H

#define IND_DESTINATION_BIT 0
#define IND_INDIRECTION_BIT 1
#define IND_DONE_BIT        2
#define IND_SOURCE_BIT      3

#define IND_DESTINATION  (1 << IND_DESTINATION_BIT)
#define IND_INDIRECTION  (1 << IND_INDIRECTION_BIT)
#define IND_DONE         (1 << IND_DONE_BIT)
#define IND_SOURCE       (1 << IND_SOURCE_BIT)
#define IND_FLAGS (IND_DESTINATION | IND_INDIRECTION | IND_DONE | IND_SOURCE)

#if !defined(__ASSEMBLY__)

#include <linux/crash_core.h>
#include <asm/io.h>

#include <uapi/linux/kexec.h>

#ifdef CONFIG_KEXEC_CORE
#include <linux/list.h>
#include <linux/compat.h>
#include <linux/ioport.h>
#include <linux/module.h>
#include <asm/kexec.h>

/* Verify architecture specific macros are defined */

#ifndef KEXEC_SOURCE_MEMORY_LIMIT
#error KEXEC_SOURCE_MEMORY_LIMIT not defined
#endif

#ifndef KEXEC_DESTINATION_MEMORY_LIMIT
#error KEXEC_DESTINATION_MEMORY_LIMIT not defined
#endif

#ifndef KEXEC_CONTROL_MEMORY_LIMIT
#error KEXEC_CONTROL_MEMORY_LIMIT not defined
#endif

#ifndef KEXEC_CONTROL_MEMORY_GFP
#define KEXEC_CONTROL_MEMORY_GFP (GFP_KERNEL | __GFP_NORETRY)
#endif

#ifndef KEXEC_CONTROL_PAGE_SIZE
#error KEXEC_CONTROL_PAGE_SIZE not defined
#endif

#ifndef KEXEC_ARCH
#error KEXEC_ARCH not defined
#endif

#ifndef KEXEC_CRASH_CONTROL_MEMORY_LIMIT
#define KEXEC_CRASH_CONTROL_MEMORY_LIMIT KEXEC_CONTROL_MEMORY_LIMIT
#endif

#ifndef KEXEC_CRASH_MEM_ALIGN
#define KEXEC_CRASH_MEM_ALIGN PAGE_SIZE
#endif

#define KEXEC_CORE_NOTE_NAME	CRASH_CORE_NOTE_NAME

/*
 * This structure is used to hold the arguments that are used when loading
 * kernel binaries.
 */

typedef unsigned long kimage_entry_t;

struct kexec_segment {
	/*
	 * This pointer can point to user memory if kexec_load() system
	 * call is used or will point to kernel memory if
	 * kexec_file_load() system call is used.
	 *
	 * Use ->buf when expecting to deal with user memory and use ->kbuf
	 * when expecting to deal with kernel memory.
	 */
	union {
		void __user *buf;
		void *kbuf;
	};
	size_t bufsz;
	unsigned long mem;
	size_t memsz;
};

#ifdef CONFIG_COMPAT
struct compat_kexec_segment {
	compat_uptr_t buf;
	compat_size_t bufsz;
	compat_ulong_t mem;	/* User space sees this as a (void *) ... */
	compat_size_t memsz;
};
#endif

#ifdef CONFIG_KEXEC_FILE
struct purgatory_info {
	/*
	 * Pointer to elf header at the beginning of kexec_purgatory.
	 * Note: kexec_purgatory is read only
	 */
	const Elf_Ehdr *ehdr;
	/*
	 * Temporary, modifiable buffer for sechdrs used for relocation.
	 * This memory can be freed post image load.
	 */
	Elf_Shdr *sechdrs;
	/*
	 * Temporary, modifiable buffer for stripped purgatory used for
	 * relocation. This memory can be freed post image load.
	 */
	void *purgatory_buf;
};

struct kimage;

typedef int (kexec_probe_t)(const char *kernel_buf, unsigned long kernel_size);
typedef void *(kexec_load_t)(struct kimage *image, char *kernel_buf,
			     unsigned long kernel_len, char *initrd,
			     unsigned long initrd_len, char *cmdline,
			     unsigned long cmdline_len);
typedef int (kexec_cleanup_t)(void *loader_data);

#ifdef CONFIG_KEXEC_SIG
typedef int (kexec_verify_sig_t)(const char *kernel_buf,
				 unsigned long kernel_len);
#endif

struct kexec_file_ops {
	kexec_probe_t *probe;
	kexec_load_t *load;
	kexec_cleanup_t *cleanup;
#ifdef CONFIG_KEXEC_SIG
	kexec_verify_sig_t *verify_sig;
#endif
};

extern const struct kexec_file_ops * const kexec_file_loaders[];

int kexec_image_probe_default(struct kimage *image, void *buf,
			      unsigned long buf_len);
int kexec_image_post_load_cleanup_default(struct kimage *image);

/*
 * If kexec_buf.mem is set to this value, kexec_locate_mem_hole()
 * will try to allocate free memory. Arch may overwrite it.
 */
#ifndef KEXEC_BUF_MEM_UNKNOWN
#define KEXEC_BUF_MEM_UNKNOWN 0
#endif

/**
 * struct kexec_buf - parameters for finding a place for a buffer in memory
 * @image:	kexec image in which memory to search.
 * @buffer:	Contents which will be copied to the allocated memory.
 * @bufsz:	Size of @buffer.
 * @mem:	On return will have address of the buffer in memory.
 * @memsz:	Size for the buffer in memory.
 * @buf_align:	Minimum alignment needed.
 * @buf_min:	The buffer can't be placed below this address.
 * @buf_max:	The buffer can't be placed above this address.
 * @top_down:	Allocate from top of memory.
 */
struct kexec_buf {
	struct kimage *image;
	void *buffer;
	unsigned long bufsz;
	unsigned long mem;
	unsigned long memsz;
	unsigned long buf_align;
	unsigned long buf_min;
	unsigned long buf_max;
	bool top_down;
};

int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf);
int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
				   void *buf, unsigned int size,
				   bool get_value);
void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name);

int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
					 unsigned long buf_len);
void * __weak arch_kexec_kernel_image_load(struct kimage *image);
int __weak arch_kexec_apply_relocations_add(struct purgatory_info *pi,
					    Elf_Shdr *section,
					    const Elf_Shdr *relsec,
					    const Elf_Shdr *symtab);
int __weak arch_kexec_apply_relocations(struct purgatory_info *pi,
					Elf_Shdr *section,
					const Elf_Shdr *relsec,
					const Elf_Shdr *symtab);

extern int kexec_add_buffer(struct kexec_buf *kbuf);
int kexec_locate_mem_hole(struct kexec_buf *kbuf);

/* Alignment required for elf header segment */
#define ELF_CORE_HEADER_ALIGN   4096

struct crash_mem_range {
	u64 start, end;
};

struct crash_mem {
	unsigned int max_nr_ranges;
	unsigned int nr_ranges;
	struct crash_mem_range ranges[0];
};

extern int crash_exclude_mem_range(struct crash_mem *mem,
				   unsigned long long mstart,
				   unsigned long long mend);
extern int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map,
				       void **addr, unsigned long *sz);
#endif /* CONFIG_KEXEC_FILE */

#ifdef CONFIG_KEXEC_ELF
struct kexec_elf_info {
	/*
	 * Where the ELF binary contents are kept.
	 * Memory managed by the user of the struct.
	 */
	const char *buffer;

	const struct elfhdr *ehdr;
	const struct elf_phdr *proghdrs;
};

int kexec_build_elf_info(const char *buf, size_t len, struct elfhdr *ehdr,
			       struct kexec_elf_info *elf_info);

int kexec_elf_load(struct kimage *image, struct elfhdr *ehdr,
			 struct kexec_elf_info *elf_info,
			 struct kexec_buf *kbuf,
			 unsigned long *lowest_load_addr);

void kexec_free_elf_info(struct kexec_elf_info *elf_info);
int kexec_elf_probe(const char *buf, unsigned long len);
#endif
struct kimage {
	kimage_entry_t head;
	kimage_entry_t *entry;
	kimage_entry_t *last_entry;

	unsigned long start;
	struct page *control_code_page;
	struct page *swap_page;
	void *vmcoreinfo_data_copy; /* locates in the crash memory */

	unsigned long nr_segments;
	struct kexec_segment segment[KEXEC_SEGMENT_MAX];

	struct list_head control_pages;
	struct list_head dest_pages;
	struct list_head unusable_pages;

	/* Address of next control page to allocate for crash kernels. */
	unsigned long control_page;

	/* Flags to indicate special processing */
	unsigned int type : 1;
#define KEXEC_TYPE_DEFAULT 0
#define KEXEC_TYPE_CRASH   1
	unsigned int preserve_context : 1;
	/* If set, we are using file mode kexec syscall */
	unsigned int file_mode:1;

#ifdef ARCH_HAS_KIMAGE_ARCH
	struct kimage_arch arch;
#endif

#ifdef CONFIG_KEXEC_FILE
	/* Additional fields for file based kexec syscall */
	void *kernel_buf;
	unsigned long kernel_buf_len;

	void *initrd_buf;
	unsigned long initrd_buf_len;

	char *cmdline_buf;
	unsigned long cmdline_buf_len;

	/* File operations provided by image loader */
	const struct kexec_file_ops *fops;

	/* Image loader handling the kernel can store a pointer here */
	void *image_loader_data;

	/* Information for loading purgatory */
	struct purgatory_info purgatory_info;
#endif
};

/* kexec interface functions */
extern void machine_kexec(struct kimage *image);
extern int machine_kexec_prepare(struct kimage *image);
extern void machine_kexec_cleanup(struct kimage *image);
extern int kernel_kexec(void);
extern struct page *kimage_alloc_control_pages(struct kimage *image,
						unsigned int order);
extern void __crash_kexec(struct pt_regs *);
extern void crash_kexec(struct pt_regs *);
int kexec_should_crash(struct task_struct *);
int kexec_crash_loaded(void);
void crash_save_cpu(struct pt_regs *regs, int cpu);
extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);

extern struct kimage *kexec_image;
extern struct kimage *kexec_crash_image;
extern int kexec_load_disabled;

#ifndef kexec_flush_icache_page
#define kexec_flush_icache_page(page)
#endif

/* List of defined/legal kexec flags */
#ifndef CONFIG_KEXEC_JUMP
#define KEXEC_FLAGS    KEXEC_ON_CRASH
#else
#define KEXEC_FLAGS    (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT)
#endif

/* List of defined/legal kexec file flags */
#define KEXEC_FILE_FLAGS	(KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \
				 KEXEC_FILE_NO_INITRAMFS)

/* Location of a reserved region to hold the crash kernel.
 */
extern struct resource crashk_res;
extern struct resource crashk_low_res;
extern note_buf_t __percpu *crash_notes;

/* flag to track if kexec reboot is in progress */
extern bool kexec_in_progress;

int crash_shrink_memory(unsigned long new_size);
size_t crash_get_memory_size(void);
void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);

void arch_kexec_protect_crashkres(void);
void arch_kexec_unprotect_crashkres(void);

#ifndef page_to_boot_pfn
static inline unsigned long page_to_boot_pfn(struct page *page)
{
	return page_to_pfn(page);
}
#endif

#ifndef boot_pfn_to_page
static inline struct page *boot_pfn_to_page(unsigned long boot_pfn)
{
	return pfn_to_page(boot_pfn);
}
#endif

#ifndef phys_to_boot_phys
static inline unsigned long phys_to_boot_phys(phys_addr_t phys)
{
	return phys;
}
#endif

#ifndef boot_phys_to_phys
static inline phys_addr_t boot_phys_to_phys(unsigned long boot_phys)
{
	return boot_phys;
}
#endif

static inline unsigned long virt_to_boot_phys(void *addr)
{
	return phys_to_boot_phys(__pa((unsigned long)addr));
}

static inline void *boot_phys_to_virt(unsigned long entry)
{
	return phys_to_virt(boot_phys_to_phys(entry));
}

#ifndef arch_kexec_post_alloc_pages
static inline int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp) { return 0; }
#endif

#ifndef arch_kexec_pre_free_pages
static inline void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages) { }
#endif

#else /* !CONFIG_KEXEC_CORE */
struct pt_regs;
struct task_struct;
static inline void __crash_kexec(struct pt_regs *regs) { }
static inline void crash_kexec(struct pt_regs *regs) { }
static inline int kexec_should_crash(struct task_struct *p) { return 0; }
static inline int kexec_crash_loaded(void) { return 0; }
#define kexec_in_progress false
#endif /* CONFIG_KEXEC_CORE */

#endif /* !defined(__ASSEBMLY__) */

#endif /* LINUX_KEXEC_H */
OpenPOWER on IntegriCloud