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/crash_core.h>
  19 #include <asm/io.h>
  20
  21 #include <uapi/linux/kexec.h>
  22
  23 #ifdef CONFIG_KEXEC_CORE
  24 #include <linux/list.h>
  25 #include <linux/compat.h>
  26 #include <linux/ioport.h>
  27 #include <linux/module.h>
  28 #include <asm/kexec.h>
  29
  30 /* Verify architecture specific macros are defined */
  31
  32 #ifndef KEXEC_SOURCE_MEMORY_LIMIT
  33 #error KEXEC_SOURCE_MEMORY_LIMIT not defined
  34 #endif
  35
  36 #ifndef KEXEC_DESTINATION_MEMORY_LIMIT
  37 #error KEXEC_DESTINATION_MEMORY_LIMIT not defined
  38 #endif
  39
  40 #ifndef KEXEC_CONTROL_MEMORY_LIMIT
  41 #error KEXEC_CONTROL_MEMORY_LIMIT not defined
  42 #endif
  43
  44 #ifndef KEXEC_CONTROL_MEMORY_GFP
  45 #define KEXEC_CONTROL_MEMORY_GFP (GFP_KERNEL | __GFP_NORETRY)
  46 #endif
  47
  48 #ifndef KEXEC_CONTROL_PAGE_SIZE
  49 #error KEXEC_CONTROL_PAGE_SIZE not defined
  50 #endif
  51
  52 #ifndef KEXEC_ARCH
  53 #error KEXEC_ARCH not defined
  54 #endif
  55
  56 #ifndef KEXEC_CRASH_CONTROL_MEMORY_LIMIT
  57 #define KEXEC_CRASH_CONTROL_MEMORY_LIMIT KEXEC_CONTROL_MEMORY_LIMIT
  58 #endif
  59
  60 #ifndef KEXEC_CRASH_MEM_ALIGN
  61 #define KEXEC_CRASH_MEM_ALIGN PAGE_SIZE
  62 #endif
  63
  64 #define KEXEC_CORE_NOTE_NAME    CRASH_CORE_NOTE_NAME
  65
  66 /*
  67  * This structure is used to hold the arguments that are used when loading
  68  * kernel binaries.
  69  */
  70
  71 typedef unsigned long kimage_entry_t;
  72
  73 struct kexec_segment {
  74         /*
  75          * This pointer can point to user memory if kexec_load() system
  76          * call is used or will point to kernel memory if
  77          * kexec_file_load() system call is used.
  78          *
  79          * Use ->buf when expecting to deal with user memory and use ->kbuf
  80          * when expecting to deal with kernel memory.
  81          */
  82         union {
  83                 void __user *buf;
  84                 void *kbuf;
  85         };
  86         size_t bufsz;
  87         unsigned long mem;
  88         size_t memsz;
  89 };
  90
  91 #ifdef CONFIG_COMPAT
  92 struct compat_kexec_segment {
  93         compat_uptr_t buf;
  94         compat_size_t bufsz;
  95         compat_ulong_t mem;     /* User space sees this as a (void *) ... */
  96         compat_size_t memsz;
  97 };
  98 #endif
  99
 100 #ifdef CONFIG_KEXEC_FILE
 101 struct purgatory_info {
 102         /*
 103          * Pointer to elf header at the beginning of kexec_purgatory.
 104          * Note: kexec_purgatory is read only
 105          */
 106         const Elf_Ehdr *ehdr;
 107         /*
 108          * Temporary, modifiable buffer for sechdrs used for relocation.
 109          * This memory can be freed post image load.
 110          */
 111         Elf_Shdr *sechdrs;
 112         /*
 113          * Temporary, modifiable buffer for stripped purgatory used for
 114          * relocation. This memory can be freed post image load.
 115          */
 116         void *purgatory_buf;
 117 };
 118
 119 struct kimage;
 120
 121 typedef int (kexec_probe_t)(const char *kernel_buf, unsigned long kernel_size);
 122 typedef void *(kexec_load_t)(struct kimage *image, char *kernel_buf,
 123                              unsigned long kernel_len, char *initrd,
 124                              unsigned long initrd_len, char *cmdline,
 125                              unsigned long cmdline_len);
 126 typedef int (kexec_cleanup_t)(void *loader_data);
 127
 128 #ifdef CONFIG_KEXEC_VERIFY_SIG
 129 typedef int (kexec_verify_sig_t)(const char *kernel_buf,
 130                                  unsigned long kernel_len);
 131 #endif
 132
 133 struct kexec_file_ops {
 134         kexec_probe_t *probe;
 135         kexec_load_t *load;
 136         kexec_cleanup_t *cleanup;
 137 #ifdef CONFIG_KEXEC_VERIFY_SIG
 138         kexec_verify_sig_t *verify_sig;
 139 #endif
 140 };
 141
 142 extern const struct kexec_file_ops * const kexec_file_loaders[];
 143
 144 int kexec_image_probe_default(struct kimage *image, void *buf,
 145                               unsigned long buf_len);
 146
 147 /**
 148  * struct kexec_buf - parameters for finding a place for a buffer in memory
 149  * @image:      kexec image in which memory to search.
 150  * @buffer:     Contents which will be copied to the allocated memory.
 151  * @bufsz:      Size of @buffer.
 152  * @mem:        On return will have address of the buffer in memory.
 153  * @memsz:      Size for the buffer in memory.
 154  * @buf_align:  Minimum alignment needed.
 155  * @buf_min:    The buffer can't be placed below this address.
 156  * @buf_max:    The buffer can't be placed above this address.
 157  * @top_down:   Allocate from top of memory.
 158  */
 159 struct kexec_buf {
 160         struct kimage *image;
 161         void *buffer;
 162         unsigned long bufsz;
 163         unsigned long mem;
 164         unsigned long memsz;
 165         unsigned long buf_align;
 166         unsigned long buf_min;
 167         unsigned long buf_max;
 168         bool top_down;
 169 };
 170
 171 int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf);
 172 int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
 173                                    void *buf, unsigned int size,
 174                                    bool get_value);
 175 void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name);
 176
 177 int __weak arch_kexec_apply_relocations_add(struct purgatory_info *pi,
 178                                             Elf_Shdr *section,
 179                                             const Elf_Shdr *relsec,
 180                                             const Elf_Shdr *symtab);
 181 int __weak arch_kexec_apply_relocations(struct purgatory_info *pi,
 182                                         Elf_Shdr *section,
 183                                         const Elf_Shdr *relsec,
 184                                         const Elf_Shdr *symtab);
 185
 186 int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
 187                                int (*func)(struct resource *, void *));
 188 extern int kexec_add_buffer(struct kexec_buf *kbuf);
 189 int kexec_locate_mem_hole(struct kexec_buf *kbuf);
 190
 191 /* Alignment required for elf header segment */
 192 #define ELF_CORE_HEADER_ALIGN   4096
 193
 194 struct crash_mem_range {
 195         u64 start, end;
 196 };
 197
 198 struct crash_mem {
 199         unsigned int max_nr_ranges;
 200         unsigned int nr_ranges;
 201         struct crash_mem_range ranges[0];
 202 };
 203
 204 extern int crash_exclude_mem_range(struct crash_mem *mem,
 205                                    unsigned long long mstart,
 206                                    unsigned long long mend);
 207 extern int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map,
 208                                        void **addr, unsigned long *sz);
 209 #endif /* CONFIG_KEXEC_FILE */
 210
 211 struct kimage {
 212         kimage_entry_t head;
 213         kimage_entry_t *entry;
 214         kimage_entry_t *last_entry;
 215
 216         unsigned long start;
 217         struct page *control_code_page;
 218         struct page *swap_page;
 219         void *vmcoreinfo_data_copy; /* locates in the crash memory */
 220
 221         unsigned long nr_segments;
 222         struct kexec_segment segment[KEXEC_SEGMENT_MAX];
 223
 224         struct list_head control_pages;
 225         struct list_head dest_pages;
 226         struct list_head unusable_pages;
 227
 228         /* Address of next control page to allocate for crash kernels. */
 229         unsigned long control_page;
 230
 231         /* Flags to indicate special processing */
 232         unsigned int type : 1;
 233 #define KEXEC_TYPE_DEFAULT 0
 234 #define KEXEC_TYPE_CRASH   1
 235         unsigned int preserve_context : 1;
 236         /* If set, we are using file mode kexec syscall */
 237         unsigned int file_mode:1;
 238
 239 #ifdef ARCH_HAS_KIMAGE_ARCH
 240         struct kimage_arch arch;
 241 #endif
 242
 243 #ifdef CONFIG_KEXEC_FILE
 244         /* Additional fields for file based kexec syscall */
 245         void *kernel_buf;
 246         unsigned long kernel_buf_len;
 247
 248         void *initrd_buf;
 249         unsigned long initrd_buf_len;
 250
 251         char *cmdline_buf;
 252         unsigned long cmdline_buf_len;
 253
 254         /* File operations provided by image loader */
 255         const struct kexec_file_ops *fops;
 256
 257         /* Image loader handling the kernel can store a pointer here */
 258         void *image_loader_data;
 259
 260         /* Information for loading purgatory */
 261         struct purgatory_info purgatory_info;
 262 #endif
 263 };
 264
 265 /* kexec interface functions */
 266 extern void machine_kexec(struct kimage *image);
 267 extern int machine_kexec_prepare(struct kimage *image);
 268 extern void machine_kexec_cleanup(struct kimage *image);
 269 extern int kernel_kexec(void);
 270 extern struct page *kimage_alloc_control_pages(struct kimage *image,
 271                                                 unsigned int order);
 272 extern void __crash_kexec(struct pt_regs *);
 273 extern void crash_kexec(struct pt_regs *);
 274 int kexec_should_crash(struct task_struct *);
 275 int kexec_crash_loaded(void);
 276 void crash_save_cpu(struct pt_regs *regs, int cpu);
 277 extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);
 278
 279 extern struct kimage *kexec_image;
 280 extern struct kimage *kexec_crash_image;
 281 extern int kexec_load_disabled;
 282
 283 #ifndef kexec_flush_icache_page
 284 #define kexec_flush_icache_page(page)
 285 #endif
 286
 287 /* List of defined/legal kexec flags */
 288 #ifndef CONFIG_KEXEC_JUMP
 289 #define KEXEC_FLAGS    KEXEC_ON_CRASH
 290 #else
 291 #define KEXEC_FLAGS    (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT)
 292 #endif
 293
 294 /* List of defined/legal kexec file flags */
 295 #define KEXEC_FILE_FLAGS        (KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \
 296                                  KEXEC_FILE_NO_INITRAMFS)
 297
 298 /* Location of a reserved region to hold the crash kernel.
 299  */
 300 extern struct resource crashk_res;
 301 extern struct resource crashk_low_res;
 302 extern note_buf_t __percpu *crash_notes;
 303
 304 /* flag to track if kexec reboot is in progress */
 305 extern bool kexec_in_progress;
 306
 307 int crash_shrink_memory(unsigned long new_size);
 308 size_t crash_get_memory_size(void);
 309 void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);
 310
 311 void arch_kexec_protect_crashkres(void);
 312 void arch_kexec_unprotect_crashkres(void);
 313
 314 #ifndef page_to_boot_pfn
 315 static inline unsigned long page_to_boot_pfn(struct page *page)
 316 {
 317         return page_to_pfn(page);
 318 }
 319 #endif
 320
 321 #ifndef boot_pfn_to_page
 322 static inline struct page *boot_pfn_to_page(unsigned long boot_pfn)
 323 {
 324         return pfn_to_page(boot_pfn);
 325 }
 326 #endif
 327
 328 #ifndef phys_to_boot_phys
 329 static inline unsigned long phys_to_boot_phys(phys_addr_t phys)
 330 {
 331         return phys;
 332 }
 333 #endif
 334
 335 #ifndef boot_phys_to_phys
 336 static inline phys_addr_t boot_phys_to_phys(unsigned long boot_phys)
 337 {
 338         return boot_phys;
 339 }
 340 #endif
 341
 342 static inline unsigned long virt_to_boot_phys(void *addr)
 343 {
 344         return phys_to_boot_phys(__pa((unsigned long)addr));
 345 }
 346
 347 static inline void *boot_phys_to_virt(unsigned long entry)
 348 {
 349         return phys_to_virt(boot_phys_to_phys(entry));
 350 }
 351
 352 #ifndef arch_kexec_post_alloc_pages
 353 static inline int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp) { return 0; }
 354 #endif
 355
 356 #ifndef arch_kexec_pre_free_pages
 357 static inline void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages) { }
 358 #endif
 359
 360 #else /* !CONFIG_KEXEC_CORE */
 361 struct pt_regs;
 362 struct task_struct;
 363 static inline void __crash_kexec(struct pt_regs *regs) { }
 364 static inline void crash_kexec(struct pt_regs *regs) { }
 365 static inline int kexec_should_crash(struct task_struct *p) { return 0; }
 366 static inline int kexec_crash_loaded(void) { return 0; }
 367 #define kexec_in_progress false
 368 #endif /* CONFIG_KEXEC_CORE */
 369
 370 #endif /* !defined(__ASSEBMLY__) */
 371
 372 #endif /* LINUX_KEXEC_H */