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_CORE
  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_MEMORY_GFP
  44 #define KEXEC_CONTROL_MEMORY_GFP GFP_KERNEL
  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_NOTE_HEAD_BYTES ALIGN(sizeof(struct elf_note), 4)
  64 #define KEXEC_CORE_NOTE_NAME "CORE"
  65 #define KEXEC_CORE_NOTE_NAME_BYTES ALIGN(sizeof(KEXEC_CORE_NOTE_NAME), 4)
  66 #define KEXEC_CORE_NOTE_DESC_BYTES ALIGN(sizeof(struct elf_prstatus), 4)
  67 /*
  68  * The per-cpu notes area is a list of notes terminated by a "NULL"
  69  * note header.  For kdump, the code in vmcore.c runs in the context
  70  * of the second kernel to combine them into one note.
  71  */
  72 #ifndef KEXEC_NOTE_BYTES
  73 #define KEXEC_NOTE_BYTES ( (KEXEC_NOTE_HEAD_BYTES * 2) +                \
  74                             KEXEC_CORE_NOTE_NAME_BYTES +                \
  75                             KEXEC_CORE_NOTE_DESC_BYTES )
  76 #endif
  77
  78 /*
  79  * This structure is used to hold the arguments that are used when loading
  80  * kernel binaries.
  81  */
  82
  83 typedef unsigned long kimage_entry_t;
  84
  85 struct kexec_segment {
  86         /*
  87          * This pointer can point to user memory if kexec_load() system
  88          * call is used or will point to kernel memory if
  89          * kexec_file_load() system call is used.
  90          *
  91          * Use ->buf when expecting to deal with user memory and use ->kbuf
  92          * when expecting to deal with kernel memory.
  93          */
  94         union {
  95                 void __user *buf;
  96                 void *kbuf;
  97         };
  98         size_t bufsz;
  99         unsigned long mem;
 100         size_t memsz;
 101 };
 102
 103 #ifdef CONFIG_COMPAT
 104 struct compat_kexec_segment {
 105         compat_uptr_t buf;
 106         compat_size_t bufsz;
 107         compat_ulong_t mem;     /* User space sees this as a (void *) ... */
 108         compat_size_t memsz;
 109 };
 110 #endif
 111
 112 struct kexec_sha_region {
 113         unsigned long start;
 114         unsigned long len;
 115 };
 116
 117 struct purgatory_info {
 118         /* Pointer to elf header of read only purgatory */
 119         Elf_Ehdr *ehdr;
 120
 121         /* Pointer to purgatory sechdrs which are modifiable */
 122         Elf_Shdr *sechdrs;
 123         /*
 124          * Temporary buffer location where purgatory is loaded and relocated
 125          * This memory can be freed post image load
 126          */
 127         void *purgatory_buf;
 128
 129         /* Address where purgatory is finally loaded and is executed from */
 130         unsigned long purgatory_load_addr;
 131 };
 132
 133 struct kimage {
 134         kimage_entry_t head;
 135         kimage_entry_t *entry;
 136         kimage_entry_t *last_entry;
 137
 138         unsigned long start;
 139         struct page *control_code_page;
 140         struct page *swap_page;
 141
 142         unsigned long nr_segments;
 143         struct kexec_segment segment[KEXEC_SEGMENT_MAX];
 144
 145         struct list_head control_pages;
 146         struct list_head dest_pages;
 147         struct list_head unusable_pages;
 148
 149         /* Address of next control page to allocate for crash kernels. */
 150         unsigned long control_page;
 151
 152         /* Flags to indicate special processing */
 153         unsigned int type : 1;
 154 #define KEXEC_TYPE_DEFAULT 0
 155 #define KEXEC_TYPE_CRASH   1
 156         unsigned int preserve_context : 1;
 157         /* If set, we are using file mode kexec syscall */
 158         unsigned int file_mode:1;
 159
 160 #ifdef ARCH_HAS_KIMAGE_ARCH
 161         struct kimage_arch arch;
 162 #endif
 163
 164         /* Additional fields for file based kexec syscall */
 165         void *kernel_buf;
 166         unsigned long kernel_buf_len;
 167
 168         void *initrd_buf;
 169         unsigned long initrd_buf_len;
 170
 171         char *cmdline_buf;
 172         unsigned long cmdline_buf_len;
 173
 174         /* File operations provided by image loader */
 175         struct kexec_file_ops *fops;
 176
 177         /* Image loader handling the kernel can store a pointer here */
 178         void *image_loader_data;
 179
 180         /* Information for loading purgatory */
 181         struct purgatory_info purgatory_info;
 182 };
 183
 184 /*
 185  * Keeps track of buffer parameters as provided by caller for requesting
 186  * memory placement of buffer.
 187  */
 188 struct kexec_buf {
 189         struct kimage *image;
 190         char *buffer;
 191         unsigned long bufsz;
 192         unsigned long mem;
 193         unsigned long memsz;
 194         unsigned long buf_align;
 195         unsigned long buf_min;
 196         unsigned long buf_max;
 197         bool top_down;          /* allocate from top of memory hole */
 198 };
 199
 200 typedef int (kexec_probe_t)(const char *kernel_buf, unsigned long kernel_size);
 201 typedef void *(kexec_load_t)(struct kimage *image, char *kernel_buf,
 202                              unsigned long kernel_len, char *initrd,
 203                              unsigned long initrd_len, char *cmdline,
 204                              unsigned long cmdline_len);
 205 typedef int (kexec_cleanup_t)(void *loader_data);
 206 typedef int (kexec_verify_sig_t)(const char *kernel_buf,
 207                                  unsigned long kernel_len);
 208
 209 struct kexec_file_ops {
 210         kexec_probe_t *probe;
 211         kexec_load_t *load;
 212         kexec_cleanup_t *cleanup;
 213         kexec_verify_sig_t *verify_sig;
 214 };
 215
 216 /* kexec interface functions */
 217 extern void machine_kexec(struct kimage *image);
 218 extern int machine_kexec_prepare(struct kimage *image);
 219 extern void machine_kexec_cleanup(struct kimage *image);
 220 extern asmlinkage long sys_kexec_load(unsigned long entry,
 221                                         unsigned long nr_segments,
 222                                         struct kexec_segment __user *segments,
 223                                         unsigned long flags);
 224 extern int kernel_kexec(void);
 225 extern int kexec_add_buffer(struct kimage *image, char *buffer,
 226                             unsigned long bufsz, unsigned long memsz,
 227                             unsigned long buf_align, unsigned long buf_min,
 228                             unsigned long buf_max, bool top_down,
 229                             unsigned long *load_addr);
 230 extern struct page *kimage_alloc_control_pages(struct kimage *image,
 231                                                 unsigned int order);
 232 extern int kexec_load_purgatory(struct kimage *image, unsigned long min,
 233                                 unsigned long max, int top_down,
 234                                 unsigned long *load_addr);
 235 extern int kexec_purgatory_get_set_symbol(struct kimage *image,
 236                                           const char *name, void *buf,
 237                                           unsigned int size, bool get_value);
 238 extern void *kexec_purgatory_get_symbol_addr(struct kimage *image,
 239                                              const char *name);
 240 extern void __crash_kexec(struct pt_regs *);
 241 extern void crash_kexec(struct pt_regs *);
 242 int kexec_should_crash(struct task_struct *);
 243 void crash_save_cpu(struct pt_regs *regs, int cpu);
 244 void crash_save_vmcoreinfo(void);
 245 void crash_map_reserved_pages(void);
 246 void crash_unmap_reserved_pages(void);
 247 void arch_crash_save_vmcoreinfo(void);
 248 __printf(1, 2)
 249 void vmcoreinfo_append_str(const char *fmt, ...);
 250 unsigned long paddr_vmcoreinfo_note(void);
 251
 252 #define VMCOREINFO_OSRELEASE(value) \
 253         vmcoreinfo_append_str("OSRELEASE=%s\n", value)
 254 #define VMCOREINFO_PAGESIZE(value) \
 255         vmcoreinfo_append_str("PAGESIZE=%ld\n", value)
 256 #define VMCOREINFO_SYMBOL(name) \
 257         vmcoreinfo_append_str("SYMBOL(%s)=%lx\n", #name, (unsigned long)&name)
 258 #define VMCOREINFO_SIZE(name) \
 259         vmcoreinfo_append_str("SIZE(%s)=%lu\n", #name, \
 260                               (unsigned long)sizeof(name))
 261 #define VMCOREINFO_STRUCT_SIZE(name) \
 262         vmcoreinfo_append_str("SIZE(%s)=%lu\n", #name, \
 263                               (unsigned long)sizeof(struct name))
 264 #define VMCOREINFO_OFFSET(name, field) \
 265         vmcoreinfo_append_str("OFFSET(%s.%s)=%lu\n", #name, #field, \
 266                               (unsigned long)offsetof(struct name, field))
 267 #define VMCOREINFO_LENGTH(name, value) \
 268         vmcoreinfo_append_str("LENGTH(%s)=%lu\n", #name, (unsigned long)value)
 269 #define VMCOREINFO_NUMBER(name) \
 270         vmcoreinfo_append_str("NUMBER(%s)=%ld\n", #name, (long)name)
 271 #define VMCOREINFO_CONFIG(name) \
 272         vmcoreinfo_append_str("CONFIG_%s=y\n", #name)
 273
 274 extern struct kimage *kexec_image;
 275 extern struct kimage *kexec_crash_image;
 276 extern int kexec_load_disabled;
 277
 278 #ifndef kexec_flush_icache_page
 279 #define kexec_flush_icache_page(page)
 280 #endif
 281
 282 /* List of defined/legal kexec flags */
 283 #ifndef CONFIG_KEXEC_JUMP
 284 #define KEXEC_FLAGS    KEXEC_ON_CRASH
 285 #else
 286 #define KEXEC_FLAGS    (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT)
 287 #endif
 288
 289 /* List of defined/legal kexec file flags */
 290 #define KEXEC_FILE_FLAGS        (KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \
 291                                  KEXEC_FILE_NO_INITRAMFS)
 292
 293 #define VMCOREINFO_BYTES           (4096)
 294 #define VMCOREINFO_NOTE_NAME       "VMCOREINFO"
 295 #define VMCOREINFO_NOTE_NAME_BYTES ALIGN(sizeof(VMCOREINFO_NOTE_NAME), 4)
 296 #define VMCOREINFO_NOTE_SIZE       (KEXEC_NOTE_HEAD_BYTES*2 + VMCOREINFO_BYTES \
 297                                     + VMCOREINFO_NOTE_NAME_BYTES)
 298
 299 /* Location of a reserved region to hold the crash kernel.
 300  */
 301 extern struct resource crashk_res;
 302 extern struct resource crashk_low_res;
 303 typedef u32 note_buf_t[KEXEC_NOTE_BYTES/4];
 304 extern note_buf_t __percpu *crash_notes;
 305 extern u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
 306 extern size_t vmcoreinfo_size;
 307 extern size_t vmcoreinfo_max_size;
 308
 309 /* flag to track if kexec reboot is in progress */
 310 extern bool kexec_in_progress;
 311
 312 int __init parse_crashkernel(char *cmdline, unsigned long long system_ram,
 313                 unsigned long long *crash_size, unsigned long long *crash_base);
 314 int parse_crashkernel_high(char *cmdline, unsigned long long system_ram,
 315                 unsigned long long *crash_size, unsigned long long *crash_base);
 316 int parse_crashkernel_low(char *cmdline, unsigned long long system_ram,
 317                 unsigned long long *crash_size, unsigned long long *crash_base);
 318 int crash_shrink_memory(unsigned long new_size);
 319 size_t crash_get_memory_size(void);
 320 void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);
 321
 322 int __weak arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
 323                                          unsigned long buf_len);
 324 void * __weak arch_kexec_kernel_image_load(struct kimage *image);
 325 int __weak arch_kimage_file_post_load_cleanup(struct kimage *image);
 326 int __weak arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
 327                                         unsigned long buf_len);
 328 int __weak arch_kexec_apply_relocations_add(const Elf_Ehdr *ehdr,
 329                                         Elf_Shdr *sechdrs, unsigned int relsec);
 330 int __weak arch_kexec_apply_relocations(const Elf_Ehdr *ehdr, Elf_Shdr *sechdrs,
 331                                         unsigned int relsec);
 332
 333 #else /* !CONFIG_KEXEC_CORE */
 334 struct pt_regs;
 335 struct task_struct;
 336 static inline void __crash_kexec(struct pt_regs *regs) { }
 337 static inline void crash_kexec(struct pt_regs *regs) { }
 338 static inline int kexec_should_crash(struct task_struct *p) { return 0; }
 339 #define kexec_in_progress false
 340 #endif /* CONFIG_KEXEC_CORE */
 341
 342 #endif /* !defined(__ASSEBMLY__) */
 343
 344 #endif /* LINUX_KEXEC_H */