kernel/crash_core.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * crash.c - kernel crash support code.
   4  * Copyright (C) 2002-2004 Eric Biederman  <ebiederm@xmission.com>
   5  */
   6
   7 #include <linux/crash_core.h>
   8 #include <linux/utsname.h>
   9 #include <linux/vmalloc.h>
  10
  11 #include <asm/page.h>
  12 #include <asm/sections.h>
  13
  14 #include <crypto/sha1.h>
  15
  16 /* vmcoreinfo stuff */
  17 unsigned char *vmcoreinfo_data;
  18 size_t vmcoreinfo_size;
  19 u32 *vmcoreinfo_note;
  20
  21 /* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */
  22 static unsigned char *vmcoreinfo_data_safecopy;
  23
  24 /*
  25  * parsing the "crashkernel" commandline
  26  *
  27  * this code is intended to be called from architecture specific code
  28  */
  29
  30
  31 /*
  32  * This function parses command lines in the format
  33  *
  34  *   crashkernel=ramsize-range:size[,...][@offset]
  35  *
  36  * The function returns 0 on success and -EINVAL on failure.
  37  */
  38 static int __init parse_crashkernel_mem(char *cmdline,
  39                                         unsigned long long system_ram,
  40                                         unsigned long long *crash_size,
  41                                         unsigned long long *crash_base)
  42 {
  43         char *cur = cmdline, *tmp;
  44
  45         /* for each entry of the comma-separated list */
  46         do {
  47                 unsigned long long start, end = ULLONG_MAX, size;
  48
  49                 /* get the start of the range */
  50                 start = memparse(cur, &tmp);
  51                 if (cur == tmp) {
  52                         pr_warn("crashkernel: Memory value expected\n");
  53                         return -EINVAL;
  54                 }
  55                 cur = tmp;
  56                 if (*cur != '-') {
  57                         pr_warn("crashkernel: '-' expected\n");
  58                         return -EINVAL;
  59                 }
  60                 cur++;
  61
  62                 /* if no ':' is here, than we read the end */
  63                 if (*cur != ':') {
  64                         end = memparse(cur, &tmp);
  65                         if (cur == tmp) {
  66                                 pr_warn("crashkernel: Memory value expected\n");
  67                                 return -EINVAL;
  68                         }
  69                         cur = tmp;
  70                         if (end <= start) {
  71                                 pr_warn("crashkernel: end <= start\n");
  72                                 return -EINVAL;
  73                         }
  74                 }
  75
  76                 if (*cur != ':') {
  77                         pr_warn("crashkernel: ':' expected\n");
  78                         return -EINVAL;
  79                 }
  80                 cur++;
  81
  82                 size = memparse(cur, &tmp);
  83                 if (cur == tmp) {
  84                         pr_warn("Memory value expected\n");
  85                         return -EINVAL;
  86                 }
  87                 cur = tmp;
  88                 if (size >= system_ram) {
  89                         pr_warn("crashkernel: invalid size\n");
  90                         return -EINVAL;
  91                 }
  92
  93                 /* match ? */
  94                 if (system_ram >= start && system_ram < end) {
  95                         *crash_size = size;
  96                         break;
  97                 }
  98         } while (*cur++ == ',');
  99
 100         if (*crash_size > 0) {
 101                 while (*cur && *cur != ' ' && *cur != '@')
 102                         cur++;
 103                 if (*cur == '@') {
 104                         cur++;
 105                         *crash_base = memparse(cur, &tmp);
 106                         if (cur == tmp) {
 107                                 pr_warn("Memory value expected after '@'\n");
 108                                 return -EINVAL;
 109                         }
 110                 }
 111         } else
 112                 pr_info("crashkernel size resulted in zero bytes\n");
 113
 114         return 0;
 115 }
 116
 117 /*
 118  * That function parses "simple" (old) crashkernel command lines like
 119  *
 120  *      crashkernel=size[@offset]
 121  *
 122  * It returns 0 on success and -EINVAL on failure.
 123  */
 124 static int __init parse_crashkernel_simple(char *cmdline,
 125                                            unsigned long long *crash_size,
 126                                            unsigned long long *crash_base)
 127 {
 128         char *cur = cmdline;
 129
 130         *crash_size = memparse(cmdline, &cur);
 131         if (cmdline == cur) {
 132                 pr_warn("crashkernel: memory value expected\n");
 133                 return -EINVAL;
 134         }
 135
 136         if (*cur == '@')
 137                 *crash_base = memparse(cur+1, &cur);
 138         else if (*cur != ' ' && *cur != '\0') {
 139                 pr_warn("crashkernel: unrecognized char: %c\n", *cur);
 140                 return -EINVAL;
 141         }
 142
 143         return 0;
 144 }
 145
 146 #define SUFFIX_HIGH 0
 147 #define SUFFIX_LOW  1
 148 #define SUFFIX_NULL 2
 149 static __initdata char *suffix_tbl[] = {
 150         [SUFFIX_HIGH] = ",high",
 151         [SUFFIX_LOW]  = ",low",
 152         [SUFFIX_NULL] = NULL,
 153 };
 154
 155 /*
 156  * That function parses "suffix"  crashkernel command lines like
 157  *
 158  *      crashkernel=size,[high|low]
 159  *
 160  * It returns 0 on success and -EINVAL on failure.
 161  */
 162 static int __init parse_crashkernel_suffix(char *cmdline,
 163                                            unsigned long long   *crash_size,
 164                                            const char *suffix)
 165 {
 166         char *cur = cmdline;
 167
 168         *crash_size = memparse(cmdline, &cur);
 169         if (cmdline == cur) {
 170                 pr_warn("crashkernel: memory value expected\n");
 171                 return -EINVAL;
 172         }
 173
 174         /* check with suffix */
 175         if (strncmp(cur, suffix, strlen(suffix))) {
 176                 pr_warn("crashkernel: unrecognized char: %c\n", *cur);
 177                 return -EINVAL;
 178         }
 179         cur += strlen(suffix);
 180         if (*cur != ' ' && *cur != '\0') {
 181                 pr_warn("crashkernel: unrecognized char: %c\n", *cur);
 182                 return -EINVAL;
 183         }
 184
 185         return 0;
 186 }
 187
 188 static __init char *get_last_crashkernel(char *cmdline,
 189                              const char *name,
 190                              const char *suffix)
 191 {
 192         char *p = cmdline, *ck_cmdline = NULL;
 193
 194         /* find crashkernel and use the last one if there are more */
 195         p = strstr(p, name);
 196         while (p) {
 197                 char *end_p = strchr(p, ' ');
 198                 char *q;
 199
 200                 if (!end_p)
 201                         end_p = p + strlen(p);
 202
 203                 if (!suffix) {
 204                         int i;
 205
 206                         /* skip the one with any known suffix */
 207                         for (i = 0; suffix_tbl[i]; i++) {
 208                                 q = end_p - strlen(suffix_tbl[i]);
 209                                 if (!strncmp(q, suffix_tbl[i],
 210                                              strlen(suffix_tbl[i])))
 211                                         goto next;
 212                         }
 213                         ck_cmdline = p;
 214                 } else {
 215                         q = end_p - strlen(suffix);
 216                         if (!strncmp(q, suffix, strlen(suffix)))
 217                                 ck_cmdline = p;
 218                 }
 219 next:
 220                 p = strstr(p+1, name);
 221         }
 222
 223         if (!ck_cmdline)
 224                 return NULL;
 225
 226         return ck_cmdline;
 227 }
 228
 229 static int __init __parse_crashkernel(char *cmdline,
 230                              unsigned long long system_ram,
 231                              unsigned long long *crash_size,
 232                              unsigned long long *crash_base,
 233                              const char *name,
 234                              const char *suffix)
 235 {
 236         char    *first_colon, *first_space;
 237         char    *ck_cmdline;
 238
 239         BUG_ON(!crash_size || !crash_base);
 240         *crash_size = 0;
 241         *crash_base = 0;
 242
 243         ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
 244
 245         if (!ck_cmdline)
 246                 return -EINVAL;
 247
 248         ck_cmdline += strlen(name);
 249
 250         if (suffix)
 251                 return parse_crashkernel_suffix(ck_cmdline, crash_size,
 252                                 suffix);
 253         /*
 254          * if the commandline contains a ':', then that's the extended
 255          * syntax -- if not, it must be the classic syntax
 256          */
 257         first_colon = strchr(ck_cmdline, ':');
 258         first_space = strchr(ck_cmdline, ' ');
 259         if (first_colon && (!first_space || first_colon < first_space))
 260                 return parse_crashkernel_mem(ck_cmdline, system_ram,
 261                                 crash_size, crash_base);
 262
 263         return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base);
 264 }
 265
 266 /*
 267  * That function is the entry point for command line parsing and should be
 268  * called from the arch-specific code.
 269  */
 270 int __init parse_crashkernel(char *cmdline,
 271                              unsigned long long system_ram,
 272                              unsigned long long *crash_size,
 273                              unsigned long long *crash_base)
 274 {
 275         return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
 276                                         "crashkernel=", NULL);
 277 }
 278
 279 int __init parse_crashkernel_high(char *cmdline,
 280                              unsigned long long system_ram,
 281                              unsigned long long *crash_size,
 282                              unsigned long long *crash_base)
 283 {
 284         return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
 285                                 "crashkernel=", suffix_tbl[SUFFIX_HIGH]);
 286 }
 287
 288 int __init parse_crashkernel_low(char *cmdline,
 289                              unsigned long long system_ram,
 290                              unsigned long long *crash_size,
 291                              unsigned long long *crash_base)
 292 {
 293         return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
 294                                 "crashkernel=", suffix_tbl[SUFFIX_LOW]);
 295 }
 296
 297 Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
 298                           void *data, size_t data_len)
 299 {
 300         struct elf_note *note = (struct elf_note *)buf;
 301
 302         note->n_namesz = strlen(name) + 1;
 303         note->n_descsz = data_len;
 304         note->n_type   = type;
 305         buf += DIV_ROUND_UP(sizeof(*note), sizeof(Elf_Word));
 306         memcpy(buf, name, note->n_namesz);
 307         buf += DIV_ROUND_UP(note->n_namesz, sizeof(Elf_Word));
 308         memcpy(buf, data, data_len);
 309         buf += DIV_ROUND_UP(data_len, sizeof(Elf_Word));
 310
 311         return buf;
 312 }
 313
 314 void final_note(Elf_Word *buf)
 315 {
 316         memset(buf, 0, sizeof(struct elf_note));
 317 }
 318
 319 static void update_vmcoreinfo_note(void)
 320 {
 321         u32 *buf = vmcoreinfo_note;
 322
 323         if (!vmcoreinfo_size)
 324                 return;
 325         buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
 326                               vmcoreinfo_size);
 327         final_note(buf);
 328 }
 329
 330 void crash_update_vmcoreinfo_safecopy(void *ptr)
 331 {
 332         if (ptr)
 333                 memcpy(ptr, vmcoreinfo_data, vmcoreinfo_size);
 334
 335         vmcoreinfo_data_safecopy = ptr;
 336 }
 337
 338 void crash_save_vmcoreinfo(void)
 339 {
 340         if (!vmcoreinfo_note)
 341                 return;
 342
 343         /* Use the safe copy to generate vmcoreinfo note if have */
 344         if (vmcoreinfo_data_safecopy)
 345                 vmcoreinfo_data = vmcoreinfo_data_safecopy;
 346
 347         vmcoreinfo_append_str("CRASHTIME=%lld\n", ktime_get_real_seconds());
 348         update_vmcoreinfo_note();
 349 }
 350
 351 void vmcoreinfo_append_str(const char *fmt, ...)
 352 {
 353         va_list args;
 354         char buf[0x50];
 355         size_t r;
 356
 357         va_start(args, fmt);
 358         r = vscnprintf(buf, sizeof(buf), fmt, args);
 359         va_end(args);
 360
 361         r = min(r, (size_t)VMCOREINFO_BYTES - vmcoreinfo_size);
 362
 363         memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
 364
 365         vmcoreinfo_size += r;
 366 }
 367
 368 /*
 369  * provide an empty default implementation here -- architecture
 370  * code may override this
 371  */
 372 void __weak arch_crash_save_vmcoreinfo(void)
 373 {}
 374
 375 phys_addr_t __weak paddr_vmcoreinfo_note(void)
 376 {
 377         return __pa(vmcoreinfo_note);
 378 }
 379 EXPORT_SYMBOL(paddr_vmcoreinfo_note);
 380
 381 #define NOTES_SIZE (&__stop_notes - &__start_notes)
 382 #define BUILD_ID_MAX SHA1_DIGEST_SIZE
 383 #define NT_GNU_BUILD_ID 3
 384
 385 struct elf_note_section {
 386         struct elf_note n_hdr;
 387         u8 n_data[];
 388 };
 389
 390 /*
 391  * Add build ID from .notes section as generated by the GNU ld(1)
 392  * or LLVM lld(1) --build-id option.
 393  */
 394 static void add_build_id_vmcoreinfo(void)
 395 {
 396         char build_id[BUILD_ID_MAX * 2 + 1];
 397         int n_remain = NOTES_SIZE;
 398
 399         while (n_remain >= sizeof(struct elf_note)) {
 400                 const struct elf_note_section *note_sec =
 401                         &__start_notes + NOTES_SIZE - n_remain;
 402                 const u32 n_namesz = note_sec->n_hdr.n_namesz;
 403
 404                 if (note_sec->n_hdr.n_type == NT_GNU_BUILD_ID &&
 405                     n_namesz != 0 &&
 406                     !strcmp((char *)&note_sec->n_data[0], "GNU")) {
 407                         if (note_sec->n_hdr.n_descsz <= BUILD_ID_MAX) {
 408                                 const u32 n_descsz = note_sec->n_hdr.n_descsz;
 409                                 const u8 *s = &note_sec->n_data[n_namesz];
 410
 411                                 s = PTR_ALIGN(s, 4);
 412                                 bin2hex(build_id, s, n_descsz);
 413                                 build_id[2 * n_descsz] = '\0';
 414                                 VMCOREINFO_BUILD_ID(build_id);
 415                                 return;
 416                         }
 417                         pr_warn("Build ID is too large to include in vmcoreinfo: %u > %u\n",
 418                                 note_sec->n_hdr.n_descsz,
 419                                 BUILD_ID_MAX);
 420                         return;
 421                 }
 422                 n_remain -= sizeof(struct elf_note) +
 423                         ALIGN(note_sec->n_hdr.n_namesz, 4) +
 424                         ALIGN(note_sec->n_hdr.n_descsz, 4);
 425         }
 426 }
 427
 428 static int __init crash_save_vmcoreinfo_init(void)
 429 {
 430         vmcoreinfo_data = (unsigned char *)get_zeroed_page(GFP_KERNEL);
 431         if (!vmcoreinfo_data) {
 432                 pr_warn("Memory allocation for vmcoreinfo_data failed\n");
 433                 return -ENOMEM;
 434         }
 435
 436         vmcoreinfo_note = alloc_pages_exact(VMCOREINFO_NOTE_SIZE,
 437                                                 GFP_KERNEL | __GFP_ZERO);
 438         if (!vmcoreinfo_note) {
 439                 free_page((unsigned long)vmcoreinfo_data);
 440                 vmcoreinfo_data = NULL;
 441                 pr_warn("Memory allocation for vmcoreinfo_note failed\n");
 442                 return -ENOMEM;
 443         }
 444
 445         VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
 446         add_build_id_vmcoreinfo();
 447         VMCOREINFO_PAGESIZE(PAGE_SIZE);
 448
 449         VMCOREINFO_SYMBOL(init_uts_ns);
 450         VMCOREINFO_OFFSET(uts_namespace, name);
 451         VMCOREINFO_SYMBOL(node_online_map);
 452 #ifdef CONFIG_MMU
 453         VMCOREINFO_SYMBOL_ARRAY(swapper_pg_dir);
 454 #endif
 455         VMCOREINFO_SYMBOL(_stext);
 456         VMCOREINFO_SYMBOL(vmap_area_list);
 457
 458 #ifndef CONFIG_NEED_MULTIPLE_NODES
 459         VMCOREINFO_SYMBOL(mem_map);
 460         VMCOREINFO_SYMBOL(contig_page_data);
 461 #endif
 462 #ifdef CONFIG_SPARSEMEM
 463         VMCOREINFO_SYMBOL_ARRAY(mem_section);
 464         VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
 465         VMCOREINFO_STRUCT_SIZE(mem_section);
 466         VMCOREINFO_OFFSET(mem_section, section_mem_map);
 467         VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS);
 468 #endif
 469         VMCOREINFO_STRUCT_SIZE(page);
 470         VMCOREINFO_STRUCT_SIZE(pglist_data);
 471         VMCOREINFO_STRUCT_SIZE(zone);
 472         VMCOREINFO_STRUCT_SIZE(free_area);
 473         VMCOREINFO_STRUCT_SIZE(list_head);
 474         VMCOREINFO_SIZE(nodemask_t);
 475         VMCOREINFO_OFFSET(page, flags);
 476         VMCOREINFO_OFFSET(page, _refcount);
 477         VMCOREINFO_OFFSET(page, mapping);
 478         VMCOREINFO_OFFSET(page, lru);
 479         VMCOREINFO_OFFSET(page, _mapcount);
 480         VMCOREINFO_OFFSET(page, private);
 481         VMCOREINFO_OFFSET(page, compound_dtor);
 482         VMCOREINFO_OFFSET(page, compound_order);
 483         VMCOREINFO_OFFSET(page, compound_head);
 484         VMCOREINFO_OFFSET(pglist_data, node_zones);
 485         VMCOREINFO_OFFSET(pglist_data, nr_zones);
 486 #ifdef CONFIG_FLAT_NODE_MEM_MAP
 487         VMCOREINFO_OFFSET(pglist_data, node_mem_map);
 488 #endif
 489         VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
 490         VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
 491         VMCOREINFO_OFFSET(pglist_data, node_id);
 492         VMCOREINFO_OFFSET(zone, free_area);
 493         VMCOREINFO_OFFSET(zone, vm_stat);
 494         VMCOREINFO_OFFSET(zone, spanned_pages);
 495         VMCOREINFO_OFFSET(free_area, free_list);
 496         VMCOREINFO_OFFSET(list_head, next);
 497         VMCOREINFO_OFFSET(list_head, prev);
 498         VMCOREINFO_OFFSET(vmap_area, va_start);
 499         VMCOREINFO_OFFSET(vmap_area, list);
 500         VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
 501         log_buf_vmcoreinfo_setup();
 502         VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
 503         VMCOREINFO_NUMBER(NR_FREE_PAGES);
 504         VMCOREINFO_NUMBER(PG_lru);
 505         VMCOREINFO_NUMBER(PG_private);
 506         VMCOREINFO_NUMBER(PG_swapcache);
 507         VMCOREINFO_NUMBER(PG_swapbacked);
 508         VMCOREINFO_NUMBER(PG_slab);
 509 #ifdef CONFIG_MEMORY_FAILURE
 510         VMCOREINFO_NUMBER(PG_hwpoison);
 511 #endif
 512         VMCOREINFO_NUMBER(PG_head_mask);
 513 #define PAGE_BUDDY_MAPCOUNT_VALUE       (~PG_buddy)
 514         VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
 515 #ifdef CONFIG_HUGETLB_PAGE
 516         VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR);
 517 #define PAGE_OFFLINE_MAPCOUNT_VALUE     (~PG_offline)
 518         VMCOREINFO_NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE);
 519 #endif
 520
 521         arch_crash_save_vmcoreinfo();
 522         update_vmcoreinfo_note();
 523
 524         return 0;
 525 }
 526
 527 subsys_initcall(crash_save_vmcoreinfo_init);