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