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