xref: /linux-6.15/include/linux/kexec.h (revision 6faeeea4)
1 #ifndef LINUX_KEXEC_H
2 #define LINUX_KEXEC_H
3 
4 #define IND_DESTINATION_BIT 0
5 #define IND_INDIRECTION_BIT 1
6 #define IND_DONE_BIT        2
7 #define IND_SOURCE_BIT      3
8 
9 #define IND_DESTINATION  (1 << IND_DESTINATION_BIT)
10 #define IND_INDIRECTION  (1 << IND_INDIRECTION_BIT)
11 #define IND_DONE         (1 << IND_DONE_BIT)
12 #define IND_SOURCE       (1 << IND_SOURCE_BIT)
13 #define IND_FLAGS (IND_DESTINATION | IND_INDIRECTION | IND_DONE | IND_SOURCE)
14 
15 #if !defined(__ASSEMBLY__)
16 
17 #include <uapi/linux/kexec.h>
18 
19 #ifdef CONFIG_KEXEC
20 #include <linux/list.h>
21 #include <linux/linkage.h>
22 #include <linux/compat.h>
23 #include <linux/ioport.h>
24 #include <linux/elfcore.h>
25 #include <linux/elf.h>
26 #include <linux/module.h>
27 #include <asm/kexec.h>
28 
29 /* Verify architecture specific macros are defined */
30 
31 #ifndef KEXEC_SOURCE_MEMORY_LIMIT
32 #error KEXEC_SOURCE_MEMORY_LIMIT not defined
33 #endif
34 
35 #ifndef KEXEC_DESTINATION_MEMORY_LIMIT
36 #error KEXEC_DESTINATION_MEMORY_LIMIT not defined
37 #endif
38 
39 #ifndef KEXEC_CONTROL_MEMORY_LIMIT
40 #error KEXEC_CONTROL_MEMORY_LIMIT not defined
41 #endif
42 
43 #ifndef KEXEC_CONTROL_PAGE_SIZE
44 #error KEXEC_CONTROL_PAGE_SIZE not defined
45 #endif
46 
47 #ifndef KEXEC_ARCH
48 #error KEXEC_ARCH not defined
49 #endif
50 
51 #ifndef KEXEC_CRASH_CONTROL_MEMORY_LIMIT
52 #define KEXEC_CRASH_CONTROL_MEMORY_LIMIT KEXEC_CONTROL_MEMORY_LIMIT
53 #endif
54 
55 #ifndef KEXEC_CRASH_MEM_ALIGN
56 #define KEXEC_CRASH_MEM_ALIGN PAGE_SIZE
57 #endif
58 
59 #define KEXEC_NOTE_HEAD_BYTES ALIGN(sizeof(struct elf_note), 4)
60 #define KEXEC_CORE_NOTE_NAME "CORE"
61 #define KEXEC_CORE_NOTE_NAME_BYTES ALIGN(sizeof(KEXEC_CORE_NOTE_NAME), 4)
62 #define KEXEC_CORE_NOTE_DESC_BYTES ALIGN(sizeof(struct elf_prstatus), 4)
63 /*
64  * The per-cpu notes area is a list of notes terminated by a "NULL"
65  * note header.  For kdump, the code in vmcore.c runs in the context
66  * of the second kernel to combine them into one note.
67  */
68 #ifndef KEXEC_NOTE_BYTES
69 #define KEXEC_NOTE_BYTES ( (KEXEC_NOTE_HEAD_BYTES * 2) +		\
70 			    KEXEC_CORE_NOTE_NAME_BYTES +		\
71 			    KEXEC_CORE_NOTE_DESC_BYTES )
72 #endif
73 
74 /*
75  * This structure is used to hold the arguments that are used when loading
76  * kernel binaries.
77  */
78 
79 typedef unsigned long kimage_entry_t;
80 
81 struct kexec_segment {
82 	/*
83 	 * This pointer can point to user memory if kexec_load() system
84 	 * call is used or will point to kernel memory if
85 	 * kexec_file_load() system call is used.
86 	 *
87 	 * Use ->buf when expecting to deal with user memory and use ->kbuf
88 	 * when expecting to deal with kernel memory.
89 	 */
90 	union {
91 		void __user *buf;
92 		void *kbuf;
93 	};
94 	size_t bufsz;
95 	unsigned long mem;
96 	size_t memsz;
97 };
98 
99 #ifdef CONFIG_COMPAT
100 struct compat_kexec_segment {
101 	compat_uptr_t buf;
102 	compat_size_t bufsz;
103 	compat_ulong_t mem;	/* User space sees this as a (void *) ... */
104 	compat_size_t memsz;
105 };
106 #endif
107 
108 struct kexec_sha_region {
109 	unsigned long start;
110 	unsigned long len;
111 };
112 
113 struct purgatory_info {
114 	/* Pointer to elf header of read only purgatory */
115 	Elf_Ehdr *ehdr;
116 
117 	/* Pointer to purgatory sechdrs which are modifiable */
118 	Elf_Shdr *sechdrs;
119 	/*
120 	 * Temporary buffer location where purgatory is loaded and relocated
121 	 * This memory can be freed post image load
122 	 */
123 	void *purgatory_buf;
124 
125 	/* Address where purgatory is finally loaded and is executed from */
126 	unsigned long purgatory_load_addr;
127 };
128 
129 struct kimage {
130 	kimage_entry_t head;
131 	kimage_entry_t *entry;
132 	kimage_entry_t *last_entry;
133 
134 	unsigned long start;
135 	struct page *control_code_page;
136 	struct page *swap_page;
137 
138 	unsigned long nr_segments;
139 	struct kexec_segment segment[KEXEC_SEGMENT_MAX];
140 
141 	struct list_head control_pages;
142 	struct list_head dest_pages;
143 	struct list_head unusable_pages;
144 
145 	/* Address of next control page to allocate for crash kernels. */
146 	unsigned long control_page;
147 
148 	/* Flags to indicate special processing */
149 	unsigned int type : 1;
150 #define KEXEC_TYPE_DEFAULT 0
151 #define KEXEC_TYPE_CRASH   1
152 	unsigned int preserve_context : 1;
153 	/* If set, we are using file mode kexec syscall */
154 	unsigned int file_mode:1;
155 
156 #ifdef ARCH_HAS_KIMAGE_ARCH
157 	struct kimage_arch arch;
158 #endif
159 
160 	/* Additional fields for file based kexec syscall */
161 	void *kernel_buf;
162 	unsigned long kernel_buf_len;
163 
164 	void *initrd_buf;
165 	unsigned long initrd_buf_len;
166 
167 	char *cmdline_buf;
168 	unsigned long cmdline_buf_len;
169 
170 	/* File operations provided by image loader */
171 	struct kexec_file_ops *fops;
172 
173 	/* Image loader handling the kernel can store a pointer here */
174 	void *image_loader_data;
175 
176 	/* Information for loading purgatory */
177 	struct purgatory_info purgatory_info;
178 };
179 
180 /*
181  * Keeps track of buffer parameters as provided by caller for requesting
182  * memory placement of buffer.
183  */
184 struct kexec_buf {
185 	struct kimage *image;
186 	char *buffer;
187 	unsigned long bufsz;
188 	unsigned long mem;
189 	unsigned long memsz;
190 	unsigned long buf_align;
191 	unsigned long buf_min;
192 	unsigned long buf_max;
193 	bool top_down;		/* allocate from top of memory hole */
194 };
195 
196 typedef int (kexec_probe_t)(const char *kernel_buf, unsigned long kernel_size);
197 typedef void *(kexec_load_t)(struct kimage *image, char *kernel_buf,
198 			     unsigned long kernel_len, char *initrd,
199 			     unsigned long initrd_len, char *cmdline,
200 			     unsigned long cmdline_len);
201 typedef int (kexec_cleanup_t)(void *loader_data);
202 typedef int (kexec_verify_sig_t)(const char *kernel_buf,
203 				 unsigned long kernel_len);
204 
205 struct kexec_file_ops {
206 	kexec_probe_t *probe;
207 	kexec_load_t *load;
208 	kexec_cleanup_t *cleanup;
209 	kexec_verify_sig_t *verify_sig;
210 };
211 
212 /* kexec interface functions */
213 extern void machine_kexec(struct kimage *image);
214 extern int machine_kexec_prepare(struct kimage *image);
215 extern void machine_kexec_cleanup(struct kimage *image);
216 extern asmlinkage long sys_kexec_load(unsigned long entry,
217 					unsigned long nr_segments,
218 					struct kexec_segment __user *segments,
219 					unsigned long flags);
220 extern int kernel_kexec(void);
221 extern int kexec_add_buffer(struct kimage *image, char *buffer,
222 			    unsigned long bufsz, unsigned long memsz,
223 			    unsigned long buf_align, unsigned long buf_min,
224 			    unsigned long buf_max, bool top_down,
225 			    unsigned long *load_addr);
226 extern struct page *kimage_alloc_control_pages(struct kimage *image,
227 						unsigned int order);
228 extern int kexec_load_purgatory(struct kimage *image, unsigned long min,
229 				unsigned long max, int top_down,
230 				unsigned long *load_addr);
231 extern int kexec_purgatory_get_set_symbol(struct kimage *image,
232 					  const char *name, void *buf,
233 					  unsigned int size, bool get_value);
234 extern void *kexec_purgatory_get_symbol_addr(struct kimage *image,
235 					     const char *name);
236 extern void crash_kexec(struct pt_regs *);
237 int kexec_should_crash(struct task_struct *);
238 void crash_save_cpu(struct pt_regs *regs, int cpu);
239 void crash_save_vmcoreinfo(void);
240 void crash_map_reserved_pages(void);
241 void crash_unmap_reserved_pages(void);
242 void arch_crash_save_vmcoreinfo(void);
243 __printf(1, 2)
244 void vmcoreinfo_append_str(const char *fmt, ...);
245 unsigned long paddr_vmcoreinfo_note(void);
246 
247 #define VMCOREINFO_OSRELEASE(value) \
248 	vmcoreinfo_append_str("OSRELEASE=%s\n", value)
249 #define VMCOREINFO_PAGESIZE(value) \
250 	vmcoreinfo_append_str("PAGESIZE=%ld\n", value)
251 #define VMCOREINFO_SYMBOL(name) \
252 	vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)&name)
253 #define VMCOREINFO_SIZE(name) \
254 	vmcoreinfo_append_str("SIZE(%s)=%lu\n", #name, \
255 			      (unsigned long)sizeof(name))
256 #define VMCOREINFO_STRUCT_SIZE(name) \
257 	vmcoreinfo_append_str("SIZE(%s)=%lu\n", #name, \
258 			      (unsigned long)sizeof(struct name))
259 #define VMCOREINFO_OFFSET(name, field) \
260 	vmcoreinfo_append_str("OFFSET(%s.%s)=%lu\n", #name, #field, \
261 			      (unsigned long)offsetof(struct name, field))
262 #define VMCOREINFO_LENGTH(name, value) \
263 	vmcoreinfo_append_str("LENGTH(%s)=%lu\n", #name, (unsigned long)value)
264 #define VMCOREINFO_NUMBER(name) \
265 	vmcoreinfo_append_str("NUMBER(%s)=%ld\n", #name, (long)name)
266 #define VMCOREINFO_CONFIG(name) \
267 	vmcoreinfo_append_str("CONFIG_%s=y\n", #name)
268 
269 extern struct kimage *kexec_image;
270 extern struct kimage *kexec_crash_image;
271 extern int kexec_load_disabled;
272 
273 #ifndef kexec_flush_icache_page
274 #define kexec_flush_icache_page(page)
275 #endif
276 
277 /* List of defined/legal kexec flags */
278 #ifndef CONFIG_KEXEC_JUMP
279 #define KEXEC_FLAGS    KEXEC_ON_CRASH
280 #else
281 #define KEXEC_FLAGS    (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT)
282 #endif
283 
284 /* List of defined/legal kexec file flags */
285 #define KEXEC_FILE_FLAGS	(KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \
286 				 KEXEC_FILE_NO_INITRAMFS)
287 
288 #define VMCOREINFO_BYTES           (4096)
289 #define VMCOREINFO_NOTE_NAME       "VMCOREINFO"
290 #define VMCOREINFO_NOTE_NAME_BYTES ALIGN(sizeof(VMCOREINFO_NOTE_NAME), 4)
291 #define VMCOREINFO_NOTE_SIZE       (KEXEC_NOTE_HEAD_BYTES*2 + VMCOREINFO_BYTES \
292 				    + VMCOREINFO_NOTE_NAME_BYTES)
293 
294 /* Location of a reserved region to hold the crash kernel.
295  */
296 extern struct resource crashk_res;
297 extern struct resource crashk_low_res;
298 typedef u32 note_buf_t[KEXEC_NOTE_BYTES/4];
299 extern note_buf_t __percpu *crash_notes;
300 extern u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
301 extern size_t vmcoreinfo_size;
302 extern size_t vmcoreinfo_max_size;
303 
304 /* flag to track if kexec reboot is in progress */
305 extern bool kexec_in_progress;
306 
307 int __init parse_crashkernel(char *cmdline, unsigned long long system_ram,
308 		unsigned long long *crash_size, unsigned long long *crash_base);
309 int parse_crashkernel_high(char *cmdline, unsigned long long system_ram,
310 		unsigned long long *crash_size, unsigned long long *crash_base);
311 int parse_crashkernel_low(char *cmdline, unsigned long long system_ram,
312 		unsigned long long *crash_size, unsigned long long *crash_base);
313 int crash_shrink_memory(unsigned long new_size);
314 size_t crash_get_memory_size(void);
315 void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);
316 
317 #else /* !CONFIG_KEXEC */
318 struct pt_regs;
319 struct task_struct;
320 static inline void crash_kexec(struct pt_regs *regs) { }
321 static inline int kexec_should_crash(struct task_struct *p) { return 0; }
322 #endif /* CONFIG_KEXEC */
323 
324 #endif /* !defined(__ASSEBMLY__) */
325 
326 #endif /* LINUX_KEXEC_H */
327