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 #include <linux/sizes.h>
  13
  14 #include <asm/page.h>
  15 #include <asm/sections.h>
  16
  17 #include <crypto/sha1.h>
  18
  19 #include "kallsyms_internal.h"
  20
  21 /* vmcoreinfo stuff */
  22 unsigned char *vmcoreinfo_data;
  23 size_t vmcoreinfo_size;
  24 u32 *vmcoreinfo_note;
  25
  26 /* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */
  27 static unsigned char *vmcoreinfo_data_safecopy;
  28
  29 /*
  30  * parsing the "crashkernel" commandline
  31  *
  32  * this code is intended to be called from architecture specific code
  33  */
  34
  35
  36 /*
  37  * This function parses command lines in the format
  38  *
  39  *   crashkernel=ramsize-range:size[,...][@offset]
  40  *
  41  * The function returns 0 on success and -EINVAL on failure.
  42  */
  43 static int __init parse_crashkernel_mem(char *cmdline,
  44                                         unsigned long long system_ram,
  45                                         unsigned long long *crash_size,
  46                                         unsigned long long *crash_base)
  47 {
  48         char *cur = cmdline, *tmp;
  49         unsigned long long total_mem = system_ram;
  50
  51         /*
  52          * Firmware sometimes reserves some memory regions for its own use,
  53          * so the system memory size is less than the actual physical memory
  54          * size. Work around this by rounding up the total size to 128M,
  55          * which is enough for most test cases.
  56          */
  57         total_mem = roundup(total_mem, SZ_128M);
  58
  59         /* for each entry of the comma-separated list */
  60         do {
  61                 unsigned long long start, end = ULLONG_MAX, size;
  62
  63                 /* get the start of the range */
  64                 start = memparse(cur, &tmp);
  65                 if (cur == tmp) {
  66                         pr_warn("crashkernel: Memory value expected\n");
  67                         return -EINVAL;
  68                 }
  69                 cur = tmp;
  70                 if (*cur != '-') {
  71                         pr_warn("crashkernel: '-' expected\n");
  72                         return -EINVAL;
  73                 }
  74                 cur++;
  75
  76                 /* if no ':' is here, than we read the end */
  77                 if (*cur != ':') {
  78                         end = memparse(cur, &tmp);
  79                         if (cur == tmp) {
  80                                 pr_warn("crashkernel: Memory value expected\n");
  81                                 return -EINVAL;
  82                         }
  83                         cur = tmp;
  84                         if (end <= start) {
  85                                 pr_warn("crashkernel: end <= start\n");
  86                                 return -EINVAL;
  87                         }
  88                 }
  89
  90                 if (*cur != ':') {
  91                         pr_warn("crashkernel: ':' expected\n");
  92                         return -EINVAL;
  93                 }
  94                 cur++;
  95
  96                 size = memparse(cur, &tmp);
  97                 if (cur == tmp) {
  98                         pr_warn("Memory value expected\n");
  99                         return -EINVAL;
 100                 }
 101                 cur = tmp;
 102                 if (size >= total_mem) {
 103                         pr_warn("crashkernel: invalid size\n");
 104                         return -EINVAL;
 105                 }
 106
 107                 /* match ? */
 108                 if (total_mem >= start && total_mem < end) {
 109                         *crash_size = size;
 110                         break;
 111                 }
 112         } while (*cur++ == ',');
 113
 114         if (*crash_size > 0) {
 115                 while (*cur && *cur != ' ' && *cur != '@')
 116                         cur++;
 117                 if (*cur == '@') {
 118                         cur++;
 119                         *crash_base = memparse(cur, &tmp);
 120                         if (cur == tmp) {
 121                                 pr_warn("Memory value expected after '@'\n");
 122                                 return -EINVAL;
 123                         }
 124                 }
 125         } else
 126                 pr_info("crashkernel size resulted in zero bytes\n");
 127
 128         return 0;
 129 }
 130
 131 /*
 132  * That function parses "simple" (old) crashkernel command lines like
 133  *
 134  *      crashkernel=size[@offset]
 135  *
 136  * It returns 0 on success and -EINVAL on failure.
 137  */
 138 static int __init parse_crashkernel_simple(char *cmdline,
 139                                            unsigned long long *crash_size,
 140                                            unsigned long long *crash_base)
 141 {
 142         char *cur = cmdline;
 143
 144         *crash_size = memparse(cmdline, &cur);
 145         if (cmdline == cur) {
 146                 pr_warn("crashkernel: memory value expected\n");
 147                 return -EINVAL;
 148         }
 149
 150         if (*cur == '@')
 151                 *crash_base = memparse(cur+1, &cur);
 152         else if (*cur != ' ' && *cur != '\0') {
 153                 pr_warn("crashkernel: unrecognized char: %c\n", *cur);
 154                 return -EINVAL;
 155         }
 156
 157         return 0;
 158 }
 159
 160 #define SUFFIX_HIGH 0
 161 #define SUFFIX_LOW  1
 162 #define SUFFIX_NULL 2
 163 static __initdata char *suffix_tbl[] = {
 164         [SUFFIX_HIGH] = ",high",
 165         [SUFFIX_LOW]  = ",low",
 166         [SUFFIX_NULL] = NULL,
 167 };
 168
 169 /*
 170  * That function parses "suffix"  crashkernel command lines like
 171  *
 172  *      crashkernel=size,[high|low]
 173  *
 174  * It returns 0 on success and -EINVAL on failure.
 175  */
 176 static int __init parse_crashkernel_suffix(char *cmdline,
 177                                            unsigned long long   *crash_size,
 178                                            const char *suffix)
 179 {
 180         char *cur = cmdline;
 181
 182         *crash_size = memparse(cmdline, &cur);
 183         if (cmdline == cur) {
 184                 pr_warn("crashkernel: memory value expected\n");
 185                 return -EINVAL;
 186         }
 187
 188         /* check with suffix */
 189         if (strncmp(cur, suffix, strlen(suffix))) {
 190                 pr_warn("crashkernel: unrecognized char: %c\n", *cur);
 191                 return -EINVAL;
 192         }
 193         cur += strlen(suffix);
 194         if (*cur != ' ' && *cur != '\0') {
 195                 pr_warn("crashkernel: unrecognized char: %c\n", *cur);
 196                 return -EINVAL;
 197         }
 198
 199         return 0;
 200 }
 201
 202 static __init char *get_last_crashkernel(char *cmdline,
 203                              const char *name,
 204                              const char *suffix)
 205 {
 206         char *p = cmdline, *ck_cmdline = NULL;
 207
 208         /* find crashkernel and use the last one if there are more */
 209         p = strstr(p, name);
 210         while (p) {
 211                 char *end_p = strchr(p, ' ');
 212                 char *q;
 213
 214                 if (!end_p)
 215                         end_p = p + strlen(p);
 216
 217                 if (!suffix) {
 218                         int i;
 219
 220                         /* skip the one with any known suffix */
 221                         for (i = 0; suffix_tbl[i]; i++) {
 222                                 q = end_p - strlen(suffix_tbl[i]);
 223                                 if (!strncmp(q, suffix_tbl[i],
 224                                              strlen(suffix_tbl[i])))
 225                                         goto next;
 226                         }
 227                         ck_cmdline = p;
 228                 } else {
 229                         q = end_p - strlen(suffix);
 230                         if (!strncmp(q, suffix, strlen(suffix)))
 231                                 ck_cmdline = p;
 232                 }
 233 next:
 234                 p = strstr(p+1, name);
 235         }
 236
 237         return ck_cmdline;
 238 }
 239
 240 static int __init __parse_crashkernel(char *cmdline,
 241                              unsigned long long system_ram,
 242                              unsigned long long *crash_size,
 243                              unsigned long long *crash_base,
 244                              const char *name,
 245                              const char *suffix)
 246 {
 247         char    *first_colon, *first_space;
 248         char    *ck_cmdline;
 249
 250         BUG_ON(!crash_size || !crash_base);
 251         *crash_size = 0;
 252         *crash_base = 0;
 253
 254         ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
 255         if (!ck_cmdline)
 256                 return -ENOENT;
 257
 258         ck_cmdline += strlen(name);
 259
 260         if (suffix)
 261                 return parse_crashkernel_suffix(ck_cmdline, crash_size,
 262                                 suffix);
 263         /*
 264          * if the commandline contains a ':', then that's the extended
 265          * syntax -- if not, it must be the classic syntax
 266          */
 267         first_colon = strchr(ck_cmdline, ':');
 268         first_space = strchr(ck_cmdline, ' ');
 269         if (first_colon && (!first_space || first_colon < first_space))
 270                 return parse_crashkernel_mem(ck_cmdline, system_ram,
 271                                 crash_size, crash_base);
 272
 273         return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base);
 274 }
 275
 276 /*
 277  * That function is the entry point for command line parsing and should be
 278  * called from the arch-specific code.
 279  */
 280 int __init parse_crashkernel(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=", NULL);
 287 }
 288
 289 int __init parse_crashkernel_high(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_HIGH]);
 296 }
 297
 298 int __init parse_crashkernel_low(char *cmdline,
 299                              unsigned long long system_ram,
 300                              unsigned long long *crash_size,
 301                              unsigned long long *crash_base)
 302 {
 303         return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
 304                                 "crashkernel=", suffix_tbl[SUFFIX_LOW]);
 305 }
 306
 307 /*
 308  * Add a dummy early_param handler to mark crashkernel= as a known command line
 309  * parameter and suppress incorrect warnings in init/main.c.
 310  */
 311 static int __init parse_crashkernel_dummy(char *arg)
 312 {
 313         return 0;
 314 }
 315 early_param("crashkernel", parse_crashkernel_dummy);
 316
 317 Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
 318                           void *data, size_t data_len)
 319 {
 320         struct elf_note *note = (struct elf_note *)buf;
 321
 322         note->n_namesz = strlen(name) + 1;
 323         note->n_descsz = data_len;
 324         note->n_type   = type;
 325         buf += DIV_ROUND_UP(sizeof(*note), sizeof(Elf_Word));
 326         memcpy(buf, name, note->n_namesz);
 327         buf += DIV_ROUND_UP(note->n_namesz, sizeof(Elf_Word));
 328         memcpy(buf, data, data_len);
 329         buf += DIV_ROUND_UP(data_len, sizeof(Elf_Word));
 330
 331         return buf;
 332 }
 333
 334 void final_note(Elf_Word *buf)
 335 {
 336         memset(buf, 0, sizeof(struct elf_note));
 337 }
 338
 339 static void update_vmcoreinfo_note(void)
 340 {
 341         u32 *buf = vmcoreinfo_note;
 342
 343         if (!vmcoreinfo_size)
 344                 return;
 345         buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
 346                               vmcoreinfo_size);
 347         final_note(buf);
 348 }
 349
 350 void crash_update_vmcoreinfo_safecopy(void *ptr)
 351 {
 352         if (ptr)
 353                 memcpy(ptr, vmcoreinfo_data, vmcoreinfo_size);
 354
 355         vmcoreinfo_data_safecopy = ptr;
 356 }
 357
 358 void crash_save_vmcoreinfo(void)
 359 {
 360         if (!vmcoreinfo_note)
 361                 return;
 362
 363         /* Use the safe copy to generate vmcoreinfo note if have */
 364         if (vmcoreinfo_data_safecopy)
 365                 vmcoreinfo_data = vmcoreinfo_data_safecopy;
 366
 367         vmcoreinfo_append_str("CRASHTIME=%lld\n", ktime_get_real_seconds());
 368         update_vmcoreinfo_note();
 369 }
 370
 371 void vmcoreinfo_append_str(const char *fmt, ...)
 372 {
 373         va_list args;
 374         char buf[0x50];
 375         size_t r;
 376
 377         va_start(args, fmt);
 378         r = vscnprintf(buf, sizeof(buf), fmt, args);
 379         va_end(args);
 380
 381         r = min(r, (size_t)VMCOREINFO_BYTES - vmcoreinfo_size);
 382
 383         memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
 384
 385         vmcoreinfo_size += r;
 386 }
 387
 388 /*
 389  * provide an empty default implementation here -- architecture
 390  * code may override this
 391  */
 392 void __weak arch_crash_save_vmcoreinfo(void)
 393 {}
 394
 395 phys_addr_t __weak paddr_vmcoreinfo_note(void)
 396 {
 397         return __pa(vmcoreinfo_note);
 398 }
 399 EXPORT_SYMBOL(paddr_vmcoreinfo_note);
 400
 401 static int __init crash_save_vmcoreinfo_init(void)
 402 {
 403         vmcoreinfo_data = (unsigned char *)get_zeroed_page(GFP_KERNEL);
 404         if (!vmcoreinfo_data) {
 405                 pr_warn("Memory allocation for vmcoreinfo_data failed\n");
 406                 return -ENOMEM;
 407         }
 408
 409         vmcoreinfo_note = alloc_pages_exact(VMCOREINFO_NOTE_SIZE,
 410                                                 GFP_KERNEL | __GFP_ZERO);
 411         if (!vmcoreinfo_note) {
 412                 free_page((unsigned long)vmcoreinfo_data);
 413                 vmcoreinfo_data = NULL;
 414                 pr_warn("Memory allocation for vmcoreinfo_note failed\n");
 415                 return -ENOMEM;
 416         }
 417
 418         VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
 419         VMCOREINFO_BUILD_ID();
 420         VMCOREINFO_PAGESIZE(PAGE_SIZE);
 421
 422         VMCOREINFO_SYMBOL(init_uts_ns);
 423         VMCOREINFO_OFFSET(uts_namespace, name);
 424         VMCOREINFO_SYMBOL(node_online_map);
 425 #ifdef CONFIG_MMU
 426         VMCOREINFO_SYMBOL_ARRAY(swapper_pg_dir);
 427 #endif
 428         VMCOREINFO_SYMBOL(_stext);
 429         VMCOREINFO_SYMBOL(vmap_area_list);
 430
 431 #ifndef CONFIG_NUMA
 432         VMCOREINFO_SYMBOL(mem_map);
 433         VMCOREINFO_SYMBOL(contig_page_data);
 434 #endif
 435 #ifdef CONFIG_SPARSEMEM
 436         VMCOREINFO_SYMBOL_ARRAY(mem_section);
 437         VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
 438         VMCOREINFO_STRUCT_SIZE(mem_section);
 439         VMCOREINFO_OFFSET(mem_section, section_mem_map);
 440         VMCOREINFO_NUMBER(SECTION_SIZE_BITS);
 441         VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS);
 442 #endif
 443         VMCOREINFO_STRUCT_SIZE(page);
 444         VMCOREINFO_STRUCT_SIZE(pglist_data);
 445         VMCOREINFO_STRUCT_SIZE(zone);
 446         VMCOREINFO_STRUCT_SIZE(free_area);
 447         VMCOREINFO_STRUCT_SIZE(list_head);
 448         VMCOREINFO_SIZE(nodemask_t);
 449         VMCOREINFO_OFFSET(page, flags);
 450         VMCOREINFO_OFFSET(page, _refcount);
 451         VMCOREINFO_OFFSET(page, mapping);
 452         VMCOREINFO_OFFSET(page, lru);
 453         VMCOREINFO_OFFSET(page, _mapcount);
 454         VMCOREINFO_OFFSET(page, private);
 455         VMCOREINFO_OFFSET(page, compound_dtor);
 456         VMCOREINFO_OFFSET(page, compound_order);
 457         VMCOREINFO_OFFSET(page, compound_head);
 458         VMCOREINFO_OFFSET(pglist_data, node_zones);
 459         VMCOREINFO_OFFSET(pglist_data, nr_zones);
 460 #ifdef CONFIG_FLATMEM
 461         VMCOREINFO_OFFSET(pglist_data, node_mem_map);
 462 #endif
 463         VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
 464         VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
 465         VMCOREINFO_OFFSET(pglist_data, node_id);
 466         VMCOREINFO_OFFSET(zone, free_area);
 467         VMCOREINFO_OFFSET(zone, vm_stat);
 468         VMCOREINFO_OFFSET(zone, spanned_pages);
 469         VMCOREINFO_OFFSET(free_area, free_list);
 470         VMCOREINFO_OFFSET(list_head, next);
 471         VMCOREINFO_OFFSET(list_head, prev);
 472         VMCOREINFO_OFFSET(vmap_area, va_start);
 473         VMCOREINFO_OFFSET(vmap_area, list);
 474         VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
 475         log_buf_vmcoreinfo_setup();
 476         VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
 477         VMCOREINFO_NUMBER(NR_FREE_PAGES);
 478         VMCOREINFO_NUMBER(PG_lru);
 479         VMCOREINFO_NUMBER(PG_private);
 480         VMCOREINFO_NUMBER(PG_swapcache);
 481         VMCOREINFO_NUMBER(PG_swapbacked);
 482         VMCOREINFO_NUMBER(PG_slab);
 483 #ifdef CONFIG_MEMORY_FAILURE
 484         VMCOREINFO_NUMBER(PG_hwpoison);
 485 #endif
 486         VMCOREINFO_NUMBER(PG_head_mask);
 487 #define PAGE_BUDDY_MAPCOUNT_VALUE       (~PG_buddy)
 488         VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
 489 #ifdef CONFIG_HUGETLB_PAGE
 490         VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR);
 491 #define PAGE_OFFLINE_MAPCOUNT_VALUE     (~PG_offline)
 492         VMCOREINFO_NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE);
 493 #endif
 494
 495 #ifdef CONFIG_KALLSYMS
 496         VMCOREINFO_SYMBOL(kallsyms_names);
 497         VMCOREINFO_SYMBOL(kallsyms_token_table);
 498         VMCOREINFO_SYMBOL(kallsyms_token_index);
 499 #ifdef CONFIG_KALLSYMS_BASE_RELATIVE
 500         VMCOREINFO_SYMBOL(kallsyms_offsets);
 501         VMCOREINFO_SYMBOL(kallsyms_relative_base);
 502 #else
 503         VMCOREINFO_SYMBOL(kallsyms_addresses);
 504 #endif /* CONFIG_KALLSYMS_BASE_RELATIVE */
 505 #endif /* CONFIG_KALLSYMS */
 506
 507         arch_crash_save_vmcoreinfo();
 508         update_vmcoreinfo_note();
 509
 510         return 0;
 511 }
 512
 513 subsys_initcall(crash_save_vmcoreinfo_init);