include/linux/kexec.h

   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 <linux/crash_core.h>
  18 #include <asm/io.h>
  19
  20 #include <uapi/linux/kexec.h>
  21
  22 #ifdef CONFIG_KEXEC_CORE
  23 #include <linux/list.h>
  24 #include <linux/compat.h>
  25 #include <linux/ioport.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_MEMORY_GFP
  44 #define KEXEC_CONTROL_MEMORY_GFP (GFP_KERNEL | __GFP_NORETRY)
  45 #endif
  46
  47 #ifndef KEXEC_CONTROL_PAGE_SIZE
  48 #error KEXEC_CONTROL_PAGE_SIZE not defined
  49 #endif
  50
  51 #ifndef KEXEC_ARCH
  52 #error KEXEC_ARCH not defined
  53 #endif
  54
  55 #ifndef KEXEC_CRASH_CONTROL_MEMORY_LIMIT
  56 #define KEXEC_CRASH_CONTROL_MEMORY_LIMIT KEXEC_CONTROL_MEMORY_LIMIT
  57 #endif
  58
  59 #ifndef KEXEC_CRASH_MEM_ALIGN
  60 #define KEXEC_CRASH_MEM_ALIGN PAGE_SIZE
  61 #endif
  62
  63 #define KEXEC_CORE_NOTE_NAME    CRASH_CORE_NOTE_NAME
  64
  65 /*
  66  * The per-cpu notes area is a list of notes terminated by a "NULL"
  67  * note header.  For kdump, the code in vmcore.c runs in the context
  68  * of the second kernel to combine them into one note.
  69  */
  70 #ifndef KEXEC_NOTE_BYTES
  71 #define KEXEC_NOTE_BYTES        CRASH_CORE_NOTE_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 #ifdef CONFIG_KEXEC_FILE
 109 struct purgatory_info {
 110         /* Pointer to elf header of read only purgatory */
 111         Elf_Ehdr *ehdr;
 112
 113         /* Pointer to purgatory sechdrs which are modifiable */
 114         Elf_Shdr *sechdrs;
 115         /*
 116          * Temporary buffer location where purgatory is loaded and relocated
 117          * This memory can be freed post image load
 118          */
 119         void *purgatory_buf;
 120
 121         /* Address where purgatory is finally loaded and is executed from */
 122         unsigned long purgatory_load_addr;
 123 };
 124
 125 typedef int (kexec_probe_t)(const char *kernel_buf, unsigned long kernel_size);
 126 typedef void *(kexec_load_t)(struct kimage *image, char *kernel_buf,
 127                              unsigned long kernel_len, char *initrd,
 128                              unsigned long initrd_len, char *cmdline,
 129                              unsigned long cmdline_len);
 130 typedef int (kexec_cleanup_t)(void *loader_data);
 131
 132 #ifdef CONFIG_KEXEC_VERIFY_SIG
 133 typedef int (kexec_verify_sig_t)(const char *kernel_buf,
 134                                  unsigned long kernel_len);
 135 #endif
 136
 137 struct kexec_file_ops {
 138         kexec_probe_t *probe;
 139         kexec_load_t *load;
 140         kexec_cleanup_t *cleanup;
 141 #ifdef CONFIG_KEXEC_VERIFY_SIG
 142         kexec_verify_sig_t *verify_sig;
 143 #endif
 144 };
 145
 146 /**
 147  * struct kexec_buf - parameters for finding a place for a buffer in memory
 148  * @image:      kexec image in which memory to search.
 149  * @buffer:     Contents which will be copied to the allocated memory.
 150  * @bufsz:      Size of @buffer.
 151  * @mem:        On return will have address of the buffer in memory.
 152  * @memsz:      Size for the buffer in memory.
 153  * @buf_align:  Minimum alignment needed.
 154  * @buf_min:    The buffer can't be placed below this address.
 155  * @buf_max:    The buffer can't be placed above this address.
 156  * @top_down:   Allocate from top of memory.
 157  */
 158 struct kexec_buf {
 159         struct kimage *image;
 160         void *buffer;
 161         unsigned long bufsz;
 162         unsigned long mem;
 163         unsigned long memsz;
 164         unsigned long buf_align;
 165         unsigned long buf_min;
 166         unsigned long buf_max;
 167         bool top_down;
 168 };
 169
 170 int __weak arch_kexec_walk_mem(struct kexec_buf *kbuf,
 171                                int (*func)(u64, u64, void *));
 172 extern int kexec_add_buffer(struct kexec_buf *kbuf);
 173 int kexec_locate_mem_hole(struct kexec_buf *kbuf);
 174 #endif /* CONFIG_KEXEC_FILE */
 175
 176 struct kimage {
 177         kimage_entry_t head;
 178         kimage_entry_t *entry;
 179         kimage_entry_t *last_entry;
 180
 181         unsigned long start;
 182         struct page *control_code_page;
 183         struct page *swap_page;
 184
 185         unsigned long nr_segments;
 186         struct kexec_segment segment[KEXEC_SEGMENT_MAX];
 187
 188         struct list_head control_pages;
 189         struct list_head dest_pages;
 190         struct list_head unusable_pages;
 191
 192         /* Address of next control page to allocate for crash kernels. */
 193         unsigned long control_page;
 194
 195         /* Flags to indicate special processing */
 196         unsigned int type : 1;
 197 #define KEXEC_TYPE_DEFAULT 0
 198 #define KEXEC_TYPE_CRASH   1
 199         unsigned int preserve_context : 1;
 200         /* If set, we are using file mode kexec syscall */
 201         unsigned int file_mode:1;
 202
 203 #ifdef ARCH_HAS_KIMAGE_ARCH
 204         struct kimage_arch arch;
 205 #endif
 206
 207 #ifdef CONFIG_KEXEC_FILE
 208         /* Additional fields for file based kexec syscall */
 209         void *kernel_buf;
 210         unsigned long kernel_buf_len;
 211
 212         void *initrd_buf;
 213         unsigned long initrd_buf_len;
 214
 215         char *cmdline_buf;
 216         unsigned long cmdline_buf_len;
 217
 218         /* File operations provided by image loader */
 219         struct kexec_file_ops *fops;
 220
 221         /* Image loader handling the kernel can store a pointer here */
 222         void *image_loader_data;
 223
 224         /* Information for loading purgatory */
 225         struct purgatory_info purgatory_info;
 226 #endif
 227 };
 228
 229 /* kexec interface functions */
 230 extern void machine_kexec(struct kimage *image);
 231 extern int machine_kexec_prepare(struct kimage *image);
 232 extern void machine_kexec_cleanup(struct kimage *image);
 233 extern asmlinkage long sys_kexec_load(unsigned long entry,
 234                                         unsigned long nr_segments,
 235                                         struct kexec_segment __user *segments,
 236                                         unsigned long flags);
 237 extern int kernel_kexec(void);
 238 extern struct page *kimage_alloc_control_pages(struct kimage *image,
 239                                                 unsigned int order);
 240 extern int kexec_load_purgatory(struct kimage *image, unsigned long min,
 241                                 unsigned long max, int top_down,
 242                                 unsigned long *load_addr);
 243 extern int kexec_purgatory_get_set_symbol(struct kimage *image,
 244                                           const char *name, void *buf,
 245                                           unsigned int size, bool get_value);
 246 extern void *kexec_purgatory_get_symbol_addr(struct kimage *image,
 247                                              const char *name);
 248 extern void __crash_kexec(struct pt_regs *);
 249 extern void crash_kexec(struct pt_regs *);
 250 int kexec_should_crash(struct task_struct *);
 251 int kexec_crash_loaded(void);
 252 void crash_save_cpu(struct pt_regs *regs, int cpu);
 253
 254 extern struct kimage *kexec_image;
 255 extern struct kimage *kexec_crash_image;
 256 extern int kexec_load_disabled;
 257
 258 #ifndef kexec_flush_icache_page
 259 #define kexec_flush_icache_page(page)
 260 #endif
 261
 262 /* List of defined/legal kexec flags */
 263 #ifndef CONFIG_KEXEC_JUMP
 264 #define KEXEC_FLAGS    KEXEC_ON_CRASH
 265 #else
 266 #define KEXEC_FLAGS    (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT)
 267 #endif
 268
 269 /* List of defined/legal kexec file flags */
 270 #define KEXEC_FILE_FLAGS        (KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \
 271                                  KEXEC_FILE_NO_INITRAMFS)
 272
 273 /* Location of a reserved region to hold the crash kernel.
 274  */
 275 extern struct resource crashk_res;
 276 extern struct resource crashk_low_res;
 277 extern note_buf_t __percpu *crash_notes;
 278
 279 /* flag to track if kexec reboot is in progress */
 280 extern bool kexec_in_progress;
 281
 282 int crash_shrink_memory(unsigned long new_size);
 283 size_t crash_get_memory_size(void);
 284 void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);
 285
 286 int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
 287                                          unsigned long buf_len);
 288 void * __weak arch_kexec_kernel_image_load(struct kimage *image);
 289 int __weak arch_kimage_file_post_load_cleanup(struct kimage *image);
 290 int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
 291                                         unsigned long buf_len);
 292 int __weak arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr,
 293                                         Elf_Shdr *sechdrs, unsigned int relsec);
 294 int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
 295                                         unsigned int relsec);
 296 void arch_kexec_protect_crashkres(void);
 297 void arch_kexec_unprotect_crashkres(void);
 298
 299 #ifndef page_to_boot_pfn
 300 static inline unsigned long page_to_boot_pfn(struct page *page)
 301 {
 302         return page_to_pfn(page);
 303 }
 304 #endif
 305
 306 #ifndef boot_pfn_to_page
 307 static inline struct page *boot_pfn_to_page(unsigned long boot_pfn)
 308 {
 309         return pfn_to_page(boot_pfn);
 310 }
 311 #endif
 312
 313 #ifndef phys_to_boot_phys
 314 static inline unsigned long phys_to_boot_phys(phys_addr_t phys)
 315 {
 316         return phys;
 317 }
 318 #endif
 319
 320 #ifndef boot_phys_to_phys
 321 static inline phys_addr_t boot_phys_to_phys(unsigned long boot_phys)
 322 {
 323         return boot_phys;
 324 }
 325 #endif
 326
 327 static inline unsigned long virt_to_boot_phys(void *addr)
 328 {
 329         return phys_to_boot_phys(__pa((unsigned long)addr));
 330 }
 331
 332 static inline void *boot_phys_to_virt(unsigned long entry)
 333 {
 334         return phys_to_virt(boot_phys_to_phys(entry));
 335 }
 336
 337 #else /* !CONFIG_KEXEC_CORE */
 338 struct pt_regs;
 339 struct task_struct;
 340 static inline void __crash_kexec(struct pt_regs *regs) { }
 341 static inline void crash_kexec(struct pt_regs *regs) { }
 342 static inline int kexec_should_crash(struct task_struct *p) { return 0; }
 343 static inline int kexec_crash_loaded(void) { return 0; }
 344 #define kexec_in_progress false
 345 #endif /* CONFIG_KEXEC_CORE */
 346
 347 #endif /* !defined(__ASSEBMLY__) */
 348
 349 #endif /* LINUX_KEXEC_H */