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 <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 */