include/linux/kexec.h

   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
 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
 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  */
 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
 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
 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
 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
 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
 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
 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
 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
 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
 447 static inline unsigned long virt_to_boot_phys(void *addr)
 448 {
 449         return phys_to_boot_phys(__pa((unsigned long)addr));
 450 }
 451
 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
 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
 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;
 473 static inline void __crash_kexec(struct pt_regs *regs) { }
 474 static inline void crash_kexec(struct pt_regs *regs) { }
 475 static inline int kexec_should_crash(struct task_struct *p) { return 0; }
 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
 483 static inline void set_kexec_sig_enforced(void) {}
 484 #endif
 485
 486 #endif /* !defined(__ASSEBMLY__) */
 487
 488 #endif /* LINUX_KEXEC_H */