LXR linux/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
  71typedef unsigned long kimage_entry_t;
  72
  73struct 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
  92struct 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
 101struct 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
 119struct kimage;
 120
 121typedef int (kexec_probe_t)(const char *kernel_buf, unsigned long kernel_size);
 122typedef 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);
 126typedef int (kexec_cleanup_t)(void *loader_data);
 127
 128#ifdef CONFIG_KEXEC_SIG
 129typedef int (kexec_verify_sig_t)(const char *kernel_buf,
 130                                 unsigned long kernel_len);
 131#endif
 132
 133struct kexec_file_ops {
 134        kexec_probe_t *probe;
 135        kexec_load_t *load;
 136        kexec_cleanup_t *cleanup;
 137#ifdef CONFIG_KEXEC_SIG
 138        kexec_verify_sig_t *verify_sig;
 139#endif
 140};
 141
 142extern const struct kexec_file_ops * const kexec_file_loaders[];
 143
 144int kexec_image_probe_default(struct kimage *image, void *buf,
 145                              unsigned long buf_len);
 146int kexec_image_post_load_cleanup_default(struct kimage *image);
 147
 148/*
 149 * If kexec_buf.mem is set to this value, kexec_locate_mem_hole()
 150 * will try to allocate free memory. Arch may overwrite it.
 151 */
 152#ifndef KEXEC_BUF_MEM_UNKNOWN
 153#define KEXEC_BUF_MEM_UNKNOWN 0
 154#endif
 155
 156/**
 157 * struct kexec_buf - parameters for finding a place for a buffer in memory
 158 * @image:      kexec image in which memory to search.
 159 * @buffer:     Contents which will be copied to the allocated memory.
 160 * @bufsz:      Size of @buffer.
 161 * @mem:        On return will have address of the buffer in memory.
 162 * @memsz:      Size for the buffer in memory.
 163 * @buf_align:  Minimum alignment needed.
 164 * @buf_min:    The buffer can't be placed below this address.
 165 * @buf_max:    The buffer can't be placed above this address.
 166 * @top_down:   Allocate from top of memory.
 167 */
 168struct kexec_buf {
 169        struct kimage *image;
 170        void *buffer;
 171        unsigned long bufsz;
 172        unsigned long mem;
 173        unsigned long memsz;
 174        unsigned long buf_align;
 175        unsigned long buf_min;
 176        unsigned long buf_max;
 177        bool top_down;
 178};
 179
 180int kexec_load_purgatory(struct kimage *image, struct kexec_buf *kbuf);
 181int kexec_purgatory_get_set_symbol(struct kimage *image, const char *name,
 182                                   void *buf, unsigned int size,
 183                                   bool get_value);
 184void *kexec_purgatory_get_symbol_addr(struct kimage *image, const char *name);
 185
 186/* Architectures may override the below functions */
 187int arch_kexec_kernel_image_probe(struct kimage *image, void *buf,
 188                                  unsigned long buf_len);
 189void *arch_kexec_kernel_image_load(struct kimage *image);
 190int arch_kexec_apply_relocations_add(struct purgatory_info *pi,
 191                                     Elf_Shdr *section,
 192                                     const Elf_Shdr *relsec,
 193                                     const Elf_Shdr *symtab);
 194int arch_kexec_apply_relocations(struct purgatory_info *pi,
 195                                 Elf_Shdr *section,
 196                                 const Elf_Shdr *relsec,
 197                                 const Elf_Shdr *symtab);
 198int arch_kimage_file_post_load_cleanup(struct kimage *image);
 199#ifdef CONFIG_KEXEC_SIG
 200int arch_kexec_kernel_verify_sig(struct kimage *image, void *buf,
 201                                 unsigned long buf_len);
 202#endif
 203int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf);
 204
 205extern int kexec_add_buffer(struct kexec_buf *kbuf);
 206int kexec_locate_mem_hole(struct kexec_buf *kbuf);
 207
 208/* Alignment required for elf header segment */
 209#define ELF_CORE_HEADER_ALIGN   4096
 210
 211struct crash_mem_range {
 212        u64 start, end;
 213};
 214
 215struct crash_mem {
 216        unsigned int max_nr_ranges;
 217        unsigned int nr_ranges;
 218        struct crash_mem_range ranges[];
 219};
 220
 221extern int crash_exclude_mem_range(struct crash_mem *mem,
 222                                   unsigned long long mstart,
 223                                   unsigned long long mend);
 224extern int crash_prepare_elf64_headers(struct crash_mem *mem, int kernel_map,
 225                                       void **addr, unsigned long *sz);
 226#endif /* CONFIG_KEXEC_FILE */
 227
 228#ifdef CONFIG_KEXEC_ELF
 229struct kexec_elf_info {
 230        /*
 231         * Where the ELF binary contents are kept.
 232         * Memory managed by the user of the struct.
 233         */
 234        const char *buffer;
 235
 236        const struct elfhdr *ehdr;
 237        const struct elf_phdr *proghdrs;
 238};
 239
 240int kexec_build_elf_info(const char *buf, size_t len, struct elfhdr *ehdr,
 241                               struct kexec_elf_info *elf_info);
 242
 243int kexec_elf_load(struct kimage *image, struct elfhdr *ehdr,
 244                         struct kexec_elf_info *elf_info,
 245                         struct kexec_buf *kbuf,
 246                         unsigned long *lowest_load_addr);
 247
 248void kexec_free_elf_info(struct kexec_elf_info *elf_info);
 249int kexec_elf_probe(const char *buf, unsigned long len);
 250#endif
 251struct kimage {
 252        kimage_entry_t head;
 253        kimage_entry_t *entry;
 254        kimage_entry_t *last_entry;
 255
 256        unsigned long start;
 257        struct page *control_code_page;
 258        struct page *swap_page;
 259        void *vmcoreinfo_data_copy; /* locates in the crash memory */
 260
 261        unsigned long nr_segments;
 262        struct kexec_segment segment[KEXEC_SEGMENT_MAX];
 263
 264        struct list_head control_pages;
 265        struct list_head dest_pages;
 266        struct list_head unusable_pages;
 267
 268        /* Address of next control page to allocate for crash kernels. */
 269        unsigned long control_page;
 270
 271        /* Flags to indicate special processing */
 272        unsigned int type : 1;
 273#define KEXEC_TYPE_DEFAULT 0
 274#define KEXEC_TYPE_CRASH   1
 275        unsigned int preserve_context : 1;
 276        /* If set, we are using file mode kexec syscall */
 277        unsigned int file_mode:1;
 278
 279#ifdef ARCH_HAS_KIMAGE_ARCH
 280        struct kimage_arch arch;
 281#endif
 282
 283#ifdef CONFIG_KEXEC_FILE
 284        /* Additional fields for file based kexec syscall */
 285        void *kernel_buf;
 286        unsigned long kernel_buf_len;
 287
 288        void *initrd_buf;
 289        unsigned long initrd_buf_len;
 290
 291        char *cmdline_buf;
 292        unsigned long cmdline_buf_len;
 293
 294        /* File operations provided by image loader */
 295        const struct kexec_file_ops *fops;
 296
 297        /* Image loader handling the kernel can store a pointer here */
 298        void *image_loader_data;
 299
 300        /* Information for loading purgatory */
 301        struct purgatory_info purgatory_info;
 302#endif
 303
 304#ifdef CONFIG_IMA_KEXEC
 305        /* Virtual address of IMA measurement buffer for kexec syscall */
 306        void *ima_buffer;
 307
 308        phys_addr_t ima_buffer_addr;
 309        size_t ima_buffer_size;
 310#endif
 311
 312        /* Core ELF header buffer */
 313        void *elf_headers;
 314        unsigned long elf_headers_sz;
 315        unsigned long elf_load_addr;
 316};
 317
 318/* kexec interface functions */
 319extern void machine_kexec(struct kimage *image);
 320extern int machine_kexec_prepare(struct kimage *image);
 321extern void machine_kexec_cleanup(struct kimage *image);
 322extern int kernel_kexec(void);
 323extern struct page *kimage_alloc_control_pages(struct kimage *image,
 324                                                unsigned int order);
 325int machine_kexec_post_load(struct kimage *image);
 326
 327extern void __crash_kexec(struct pt_regs *);
 328extern void crash_kexec(struct pt_regs *);
 329int kexec_should_crash(struct task_struct *);
 330int kexec_crash_loaded(void);
 331void crash_save_cpu(struct pt_regs *regs, int cpu);
 332extern int kimage_crash_copy_vmcoreinfo(struct kimage *image);
 333
 334extern struct kimage *kexec_image;
 335extern struct kimage *kexec_crash_image;
 336extern int kexec_load_disabled;
 337
 338#ifndef kexec_flush_icache_page
 339#define kexec_flush_icache_page(page)
 340#endif
 341
 342/* List of defined/legal kexec flags */
 343#ifndef CONFIG_KEXEC_JUMP
 344#define KEXEC_FLAGS    KEXEC_ON_CRASH
 345#else
 346#define KEXEC_FLAGS    (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT)
 347#endif
 348
 349/* List of defined/legal kexec file flags */
 350#define KEXEC_FILE_FLAGS        (KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \
 351                                 KEXEC_FILE_NO_INITRAMFS)
 352
 353/* Location of a reserved region to hold the crash kernel.
 354 */
 355extern struct resource crashk_res;
 356extern struct resource crashk_low_res;
 357extern note_buf_t __percpu *crash_notes;
 358
 359/* flag to track if kexec reboot is in progress */
 360extern bool kexec_in_progress;
 361
 362int crash_shrink_memory(unsigned long new_size);
 363size_t crash_get_memory_size(void);
 364void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);
 365
 366void arch_kexec_protect_crashkres(void);
 367void arch_kexec_unprotect_crashkres(void);
 368
 369#ifndef page_to_boot_pfn
 370static inline unsigned long page_to_boot_pfn(struct page *page)
 371{
 372        return page_to_pfn(page);
 373}
 374#endif
 375
 376#ifndef boot_pfn_to_page
 377static inline struct page *boot_pfn_to_page(unsigned long boot_pfn)
 378{
 379        return pfn_to_page(boot_pfn);
 380}
 381#endif
 382
 383#ifndef phys_to_boot_phys
 384static inline unsigned long phys_to_boot_phys(phys_addr_t phys)
 385{
 386        return phys;
 387}
 388#endif
 389
 390#ifndef boot_phys_to_phys
 391static inline phys_addr_t boot_phys_to_phys(unsigned long boot_phys)
 392{
 393        return boot_phys;
 394}
 395#endif
 396
 397static inline unsigned long virt_to_boot_phys(void *addr)
 398{
 399        return phys_to_boot_phys(__pa((unsigned long)addr));
 400}
 401
 402static inline void *boot_phys_to_virt(unsigned long entry)
 403{
 404        return phys_to_virt(boot_phys_to_phys(entry));
 405}
 406
 407#ifndef arch_kexec_post_alloc_pages
 408static inline int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, gfp_t gfp) { return 0; }
 409#endif
 410
 411#ifndef arch_kexec_pre_free_pages
 412static inline void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages) { }
 413#endif
 414
 415#else /* !CONFIG_KEXEC_CORE */
 416struct pt_regs;
 417struct task_struct;
 418static inline void __crash_kexec(struct pt_regs *regs) { }
 419static inline void crash_kexec(struct pt_regs *regs) { }
 420static inline int kexec_should_crash(struct task_struct *p) { return 0; }
 421static inline int kexec_crash_loaded(void) { return 0; }
 422#define kexec_in_progress false
 423#endif /* CONFIG_KEXEC_CORE */
 424
 425#endif /* !defined(__ASSEBMLY__) */
 426
 427#endif /* LINUX_KEXEC_H */
 428