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         /* Pointer to elf header of read only purgatory */
 103         Elf_Ehdr *ehdr;
 104
 105         /* Pointer to purgatory sechdrs which are modifiable */
 106         Elf_Shdr *sechdrs;
 107         /*
 108          * Temporary buffer location where purgatory is loaded and relocated
 109          * This memory can be freed post image load
 110          */
 111         void *purgatory_buf;
 112
 113         /* Address where purgatory is finally loaded and is executed from */
 114         unsigned long purgatory_load_addr;
 115 };
 116
 117 typedef int (kexec_probe_t)(const char *kernel_buf, unsigned long kernel_size);
 118 typedef void *(kexec_load_t)(struct kimage *image, char *kernel_buf,
 119                              unsigned long kernel_len, char *initrd,
 120                              unsigned long initrd_len, char *cmdline,
 121                              unsigned long cmdline_len);
 122 typedef int (kexec_cleanup_t)(void *loader_data);
 123
 124 #ifdef CONFIG_KEXEC_VERIFY_SIG
 125 typedef int (kexec_verify_sig_t)(const char *kernel_buf,
 126                                  unsigned long kernel_len);
 127 #endif
 128
 129 struct kexec_file_ops {
 130         kexec_probe_t *probe;
 131         kexec_load_t *load;
 132         kexec_cleanup_t *cleanup;
 133 #ifdef CONFIG_KEXEC_VERIFY_SIG
 134         kexec_verify_sig_t *verify_sig;
 135 #endif
 136 };
 137
 138 /**
 139  * struct kexec_buf - parameters for finding a place for a buffer in memory
 140  * @image:      kexec image in which memory to search.
 141  * @buffer:     Contents which will be copied to the allocated memory.
 142  * @bufsz:      Size of @buffer.
 143  * @mem:        On return will have address of the buffer in memory.
 144  * @memsz:      Size for the buffer in memory.
 145  * @buf_align:  Minimum alignment needed.
 146  * @buf_min:    The buffer can't be placed below this address.
 147  * @buf_max:    The buffer can't be placed above this address.
 148  * @top_down:   Allocate from top of memory.
 149  */
 150 struct kexec_buf {
 151         struct kimage *image;
 152         void *buffer;
 153         unsigned long bufsz;
 154         unsigned long mem;
 155         unsigned long memsz;
 156         unsigned long buf_align;
 157         unsigned long buf_min;
 158         unsigned long buf_max;
 159         bool top_down;
 160 };
 161
 162 int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
 163                                int (*func)(struct resource *, void *));
 164 extern int kexec_add_buffer(struct kexec_buf *kbuf);
 165 int kexec_locate_mem_hole(struct kexec_buf *kbuf);
 166 #endif /* CONFIG_KEXEC_FILE */
 167
 168 struct kimage {
 169         kimage_entry_t head;
 170         kimage_entry_t *entry;
 171         kimage_entry_t *last_entry;
 172
 173         unsigned long start;
 174         struct page *control_code_page;
 175         struct page *swap_page;
 176         void *vmcoreinfo_data_copy; /* locates in the crash memory */
 177
 178         unsigned long nr_segments;
 179         struct kexec_segment segment[KEXEC_SEGMENT_MAX];
 180
 181         struct list_head control_pages;
 182         struct list_head dest_pages;
 183         struct list_head unusable_pages;
 184
 185         /* Address of next control page to allocate for crash kernels. */
 186         unsigned long control_page;
 187
 188         /* Flags to indicate special processing */
 189         unsigned int type : 1;
 190 #define KEXEC_TYPE_DEFAULT 0
 191 #define KEXEC_TYPE_CRASH   1
 192         unsigned int preserve_context : 1;
 193         /* If set, we are using file mode kexec syscall */
 194         unsigned int file_mode:1;
 195
 196 #ifdef ARCH_HAS_KIMAGE_ARCH
 197         struct kimage_arch arch;
 198 #endif
 199
 200 #ifdef CONFIG_KEXEC_FILE
 201         /* Additional fields for file based kexec syscall */
 202         void *kernel_buf;
 203         unsigned long kernel_buf_len;
 204
 205         void *initrd_buf;
 206         unsigned long initrd_buf_len;
 207
 208         char *cmdline_buf;
 209         unsigned long cmdline_buf_len;
 210
 211         /* File operations provided by image loader */
 212         struct kexec_file_ops *fops;
 213
 214         /* Image loader handling the kernel can store a pointer here */
 215         void *image_loader_data;
 216
 217         /* Information for loading purgatory */
 218         struct purgatory_info purgatory_info;
 219 #endif
 220 };
 221
 222 /* kexec interface functions */
 223 extern void machine_kexec(struct kimage *image);
 224 extern int machine_kexec_prepare(struct kimage *image);
 225 extern void machine_kexec_cleanup(struct kimage *image);
 226 extern asmlinkage long sys_kexec_load(unsigned long entry,
 227                                         unsigned long nr_segments,
 228                                         struct kexec_segment __user *segments,
 229                                         unsigned long flags);
 230 extern int kernel_kexec(void);
 231 extern struct page *kimage_alloc_control_pages(struct kimage *image,
 232                                                 unsigned int order);
 233 extern int kexec_load_purgatory(struct kimage *image, unsigned long min,
 234                                 unsigned long max, int top_down,
 235                                 unsigned long *load_addr);
 236 extern int kexec_purgatory_get_set_symbol(struct kimage *image,
 237                                           const char *name, void *buf,
 238                                           unsigned int size, bool get_value);
 239 extern void *kexec_purgatory_get_symbol_addr(struct kimage *image,
 240                                              const char *name);
 241 extern void __crash_kexec(struct pt_regs *);
 242 extern void crash_kexec(struct pt_regs *);
 243 int kexec_should_crash(struct task_struct *);
 244 int kexec_crash_loaded(void);
 245 void crash_save_cpu(struct pt_regs *regs, int cpu);
 246 extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);
 247
 248 extern struct kimage *kexec_image;
 249 extern struct kimage *kexec_crash_image;
 250 extern int kexec_load_disabled;
 251
 252 #ifndef kexec_flush_icache_page
 253 #define kexec_flush_icache_page(page)
 254 #endif
 255
 256 /* List of defined/legal kexec flags */
 257 #ifndef CONFIG_KEXEC_JUMP
 258 #define KEXEC_FLAGS    KEXEC_ON_CRASH
 259 #else
 260 #define KEXEC_FLAGS    (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT)
 261 #endif
 262
 263 /* List of defined/legal kexec file flags */
 264 #define KEXEC_FILE_FLAGS        (KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \
 265                                  KEXEC_FILE_NO_INITRAMFS)
 266
 267 /* Location of a reserved region to hold the crash kernel.
 268  */
 269 extern struct resource crashk_res;
 270 extern struct resource crashk_low_res;
 271 extern note_buf_t __percpu *crash_notes;
 272
 273 /* flag to track if kexec reboot is in progress */
 274 extern bool kexec_in_progress;
 275
 276 int crash_shrink_memory(unsigned long new_size);
 277 size_t crash_get_memory_size(void);
 278 void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);
 279
 280 int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
 281                                          unsigned long buf_len);
 282 void * __weak arch_kexec_kernel_image_load(struct kimage *image);
 283 int __weak arch_kimage_file_post_load_cleanup(struct kimage *image);
 284 int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
 285                                         unsigned long buf_len);
 286 int __weak arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr,
 287                                         Elf_Shdr *sechdrs, unsigned int relsec);
 288 int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
 289                                         unsigned int relsec);
 290 void arch_kexec_protect_crashkres(void);
 291 void arch_kexec_unprotect_crashkres(void);
 292
 293 #ifndef page_to_boot_pfn
 294 static inline unsigned long page_to_boot_pfn(struct page *page)
 295 {
 296         return page_to_pfn(page);
 297 }
 298 #endif
 299
 300 #ifndef boot_pfn_to_page
 301 static inline struct page *boot_pfn_to_page(unsigned long boot_pfn)
 302 {
 303         return pfn_to_page(boot_pfn);
 304 }
 305 #endif
 306
 307 #ifndef phys_to_boot_phys
 308 static inline unsigned long phys_to_boot_phys(phys_addr_t phys)
 309 {
 310         return phys;
 311 }
 312 #endif
 313
 314 #ifndef boot_phys_to_phys
 315 static inline phys_addr_t boot_phys_to_phys(unsigned long boot_phys)
 316 {
 317         return boot_phys;
 318 }
 319 #endif
 320
 321 static inline unsigned long virt_to_boot_phys(void *addr)
 322 {
 323         return phys_to_boot_phys(__pa((unsigned long)addr));
 324 }
 325
 326 static inline void *boot_phys_to_virt(unsigned long entry)
 327 {
 328         return phys_to_virt(boot_phys_to_phys(entry));
 329 }
 330
 331 #ifndef arch_kexec_post_alloc_pages
 332 static inline int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp) { return 0; }
 333 #endif
 334
 335 #ifndef arch_kexec_pre_free_pages
 336 static inline void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages) { }
 337 #endif
 338
 339 #else /* !CONFIG_KEXEC_CORE */
 340 struct pt_regs;
 341 struct task_struct;
 342 static inline void __crash_kexec(struct pt_regs *regs) { }
 343 static inline void crash_kexec(struct pt_regs *regs) { }
 344 static inline int kexec_should_crash(struct task_struct *p) { return 0; }
 345 static inline int kexec_crash_loaded(void) { return 0; }
 346 #define kexec_in_progress false
 347 #endif /* CONFIG_KEXEC_CORE */
 348
 349 #endif /* !defined(__ASSEBMLY__) */
 350
 351 #endif /* LINUX_KEXEC_H */