kernel/crash_core.c

   1 /*
   2  * crash.c - kernel crash support code.
   3  * Copyright (C) 2002-2004 Eric Biederman  <ebiederm@xmission.com>
   4  *
   5  * This source code is licensed under the GNU General Public License,
   6  * Version 2.  See the file COPYING for more details.
   7  */
   8
   9 #include <linux/crash_core.h>
  10 #include <linux/utsname.h>
  11 #include <linux/vmalloc.h>
  12
  13 #include <asm/page.h>
  14 #include <asm/sections.h>
  15
  16 /* vmcoreinfo stuff */
  17 static unsigned char *vmcoreinfo_data;
  18 static 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         }
 112
 113         return 0;
 114 }
 115
 116 /*
 117  * That function parses "simple" (old) crashkernel command lines like
 118  *
 119  *      crashkernel=size[@offset]
 120  *
 121  * It returns 0 on success and -EINVAL on failure.
 122  */
 123 static int __init parse_crashkernel_simple(char *cmdline,
 124                                            unsigned long long *crash_size,
 125                                            unsigned long long *crash_base)
 126 {
 127         char *cur = cmdline;
 128
 129         *crash_size = memparse(cmdline, &cur);
 130         if (cmdline == cur) {
 131                 pr_warn("crashkernel: memory value expected\n");
 132                 return -EINVAL;
 133         }
 134
 135         if (*cur == '@')
 136                 *crash_base = memparse(cur+1, &cur);
 137         else if (*cur != ' ' && *cur != '\0') {
 138                 pr_warn("crashkernel: unrecognized char: %c\n", *cur);
 139                 return -EINVAL;
 140         }
 141
 142         return 0;
 143 }
 144
 145 #define SUFFIX_HIGH 0
 146 #define SUFFIX_LOW  1
 147 #define SUFFIX_NULL 2
 148 static __initdata char *suffix_tbl[] = {
 149         [SUFFIX_HIGH] = ",high",
 150         [SUFFIX_LOW]  = ",low",
 151         [SUFFIX_NULL] = NULL,
 152 };
 153
 154 /*
 155  * That function parses "suffix"  crashkernel command lines like
 156  *
 157  *      crashkernel=size,[high|low]
 158  *
 159  * It returns 0 on success and -EINVAL on failure.
 160  */
 161 static int __init parse_crashkernel_suffix(char *cmdline,
 162                                            unsigned long long   *crash_size,
 163                                            const char *suffix)
 164 {
 165         char *cur = cmdline;
 166
 167         *crash_size = memparse(cmdline, &cur);
 168         if (cmdline == cur) {
 169                 pr_warn("crashkernel: memory value expected\n");
 170                 return -EINVAL;
 171         }
 172
 173         /* check with suffix */
 174         if (strncmp(cur, suffix, strlen(suffix))) {
 175                 pr_warn("crashkernel: unrecognized char: %c\n", *cur);
 176                 return -EINVAL;
 177         }
 178         cur += strlen(suffix);
 179         if (*cur != ' ' && *cur != '\0') {
 180                 pr_warn("crashkernel: unrecognized char: %c\n", *cur);
 181                 return -EINVAL;
 182         }
 183
 184         return 0;
 185 }
 186
 187 static __init char *get_last_crashkernel(char *cmdline,
 188                              const char *name,
 189                              const char *suffix)
 190 {
 191         char *p = cmdline, *ck_cmdline = NULL;
 192
 193         /* find crashkernel and use the last one if there are more */
 194         p = strstr(p, name);
 195         while (p) {
 196                 char *end_p = strchr(p, ' ');
 197                 char *q;
 198
 199                 if (!end_p)
 200                         end_p = p + strlen(p);
 201
 202                 if (!suffix) {
 203                         int i;
 204
 205                         /* skip the one with any known suffix */
 206                         for (i = 0; suffix_tbl[i]; i++) {
 207                                 q = end_p - strlen(suffix_tbl[i]);
 208                                 if (!strncmp(q, suffix_tbl[i],
 209                                              strlen(suffix_tbl[i])))
 210                                         goto next;
 211                         }
 212                         ck_cmdline = p;
 213                 } else {
 214                         q = end_p - strlen(suffix);
 215                         if (!strncmp(q, suffix, strlen(suffix)))
 216                                 ck_cmdline = p;
 217                 }
 218 next:
 219                 p = strstr(p+1, name);
 220         }
 221
 222         if (!ck_cmdline)
 223                 return NULL;
 224
 225         return ck_cmdline;
 226 }
 227
 228 static int __init __parse_crashkernel(char *cmdline,
 229                              unsigned long long system_ram,
 230                              unsigned long long *crash_size,
 231                              unsigned long long *crash_base,
 232                              const char *name,
 233                              const char *suffix)
 234 {
 235         char    *first_colon, *first_space;
 236         char    *ck_cmdline;
 237
 238         BUG_ON(!crash_size || !crash_base);
 239         *crash_size = 0;
 240         *crash_base = 0;
 241
 242         ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
 243
 244         if (!ck_cmdline)
 245                 return -EINVAL;
 246
 247         ck_cmdline += strlen(name);
 248
 249         if (suffix)
 250                 return parse_crashkernel_suffix(ck_cmdline, crash_size,
 251                                 suffix);
 252         /*
 253          * if the commandline contains a ':', then that's the extended
 254          * syntax -- if not, it must be the classic syntax
 255          */
 256         first_colon = strchr(ck_cmdline, ':');
 257         first_space = strchr(ck_cmdline, ' ');
 258         if (first_colon && (!first_space || first_colon < first_space))
 259                 return parse_crashkernel_mem(ck_cmdline, system_ram,
 260                                 crash_size, crash_base);
 261
 262         return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base);
 263 }
 264
 265 /*
 266  * That function is the entry point for command line parsing and should be
 267  * called from the arch-specific code.
 268  */
 269 int __init parse_crashkernel(char *cmdline,
 270                              unsigned long long system_ram,
 271                              unsigned long long *crash_size,
 272                              unsigned long long *crash_base)
 273 {
 274         return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
 275                                         "crashkernel=", NULL);
 276 }
 277
 278 int __init parse_crashkernel_high(char *cmdline,
 279                              unsigned long long system_ram,
 280                              unsigned long long *crash_size,
 281                              unsigned long long *crash_base)
 282 {
 283         return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
 284                                 "crashkernel=", suffix_tbl[SUFFIX_HIGH]);
 285 }
 286
 287 int __init parse_crashkernel_low(char *cmdline,
 288                              unsigned long long system_ram,
 289                              unsigned long long *crash_size,
 290                              unsigned long long *crash_base)
 291 {
 292         return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
 293                                 "crashkernel=", suffix_tbl[SUFFIX_LOW]);
 294 }
 295
 296 Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
 297                           void *data, size_t data_len)
 298 {
 299         struct elf_note *note = (struct elf_note *)buf;
 300
 301         note->n_namesz = strlen(name) + 1;
 302         note->n_descsz = data_len;
 303         note->n_type   = type;
 304         buf += DIV_ROUND_UP(sizeof(*note), sizeof(Elf_Word));
 305         memcpy(buf, name, note->n_namesz);
 306         buf += DIV_ROUND_UP(note->n_namesz, sizeof(Elf_Word));
 307         memcpy(buf, data, data_len);
 308         buf += DIV_ROUND_UP(data_len, sizeof(Elf_Word));
 309
 310         return buf;
 311 }
 312
 313 void final_note(Elf_Word *buf)
 314 {
 315         memset(buf, 0, sizeof(struct elf_note));
 316 }
 317
 318 static void update_vmcoreinfo_note(void)
 319 {
 320         u32 *buf = vmcoreinfo_note;
 321
 322         if (!vmcoreinfo_size)
 323                 return;
 324         buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
 325                               vmcoreinfo_size);
 326         final_note(buf);
 327 }
 328
 329 void crash_update_vmcoreinfo_safecopy(void *ptr)
 330 {
 331         if (ptr)
 332                 memcpy(ptr, vmcoreinfo_data, vmcoreinfo_size);
 333
 334         vmcoreinfo_data_safecopy = ptr;
 335 }
 336
 337 void crash_save_vmcoreinfo(void)
 338 {
 339         if (!vmcoreinfo_note)
 340                 return;
 341
 342         /* Use the safe copy to generate vmcoreinfo note if have */
 343         if (vmcoreinfo_data_safecopy)
 344                 vmcoreinfo_data = vmcoreinfo_data_safecopy;
 345
 346         vmcoreinfo_append_str("CRASHTIME=%ld\n", get_seconds());
 347         update_vmcoreinfo_note();
 348 }
 349
 350 void vmcoreinfo_append_str(const char *fmt, ...)
 351 {
 352         va_list args;
 353         char buf[0x50];
 354         size_t r;
 355
 356         va_start(args, fmt);
 357         r = vscnprintf(buf, sizeof(buf), fmt, args);
 358         va_end(args);
 359
 360         r = min(r, (size_t)VMCOREINFO_BYTES - vmcoreinfo_size);
 361
 362         memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
 363
 364         vmcoreinfo_size += r;
 365 }
 366
 367 /*
 368  * provide an empty default implementation here -- architecture
 369  * code may override this
 370  */
 371 void __weak arch_crash_save_vmcoreinfo(void)
 372 {}
 373
 374 phys_addr_t __weak paddr_vmcoreinfo_note(void)
 375 {
 376         return __pa(vmcoreinfo_note);
 377 }
 378
 379 static int __init crash_save_vmcoreinfo_init(void)
 380 {
 381         vmcoreinfo_data = (unsigned char *)get_zeroed_page(GFP_KERNEL);
 382         if (!vmcoreinfo_data) {
 383                 pr_warn("Memory allocation for vmcoreinfo_data failed\n");
 384                 return -ENOMEM;
 385         }
 386
 387         vmcoreinfo_note = alloc_pages_exact(VMCOREINFO_NOTE_SIZE,
 388                                                 GFP_KERNEL | __GFP_ZERO);
 389         if (!vmcoreinfo_note) {
 390                 free_page((unsigned long)vmcoreinfo_data);
 391                 vmcoreinfo_data = NULL;
 392                 pr_warn("Memory allocation for vmcoreinfo_note failed\n");
 393                 return -ENOMEM;
 394         }
 395
 396         VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
 397         VMCOREINFO_PAGESIZE(PAGE_SIZE);
 398
 399         VMCOREINFO_SYMBOL(init_uts_ns);
 400         VMCOREINFO_SYMBOL(node_online_map);
 401 #ifdef CONFIG_MMU
 402         VMCOREINFO_SYMBOL(swapper_pg_dir);
 403 #endif
 404         VMCOREINFO_SYMBOL(_stext);
 405         VMCOREINFO_SYMBOL(vmap_area_list);
 406
 407 #ifndef CONFIG_NEED_MULTIPLE_NODES
 408         VMCOREINFO_SYMBOL(mem_map);
 409         VMCOREINFO_SYMBOL(contig_page_data);
 410 #endif
 411 #ifdef CONFIG_SPARSEMEM
 412         VMCOREINFO_SYMBOL(mem_section);
 413         VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
 414         VMCOREINFO_STRUCT_SIZE(mem_section);
 415         VMCOREINFO_OFFSET(mem_section, section_mem_map);
 416 #endif
 417         VMCOREINFO_STRUCT_SIZE(page);
 418         VMCOREINFO_STRUCT_SIZE(pglist_data);
 419         VMCOREINFO_STRUCT_SIZE(zone);
 420         VMCOREINFO_STRUCT_SIZE(free_area);
 421         VMCOREINFO_STRUCT_SIZE(list_head);
 422         VMCOREINFO_SIZE(nodemask_t);
 423         VMCOREINFO_OFFSET(page, flags);
 424         VMCOREINFO_OFFSET(page, _refcount);
 425         VMCOREINFO_OFFSET(page, mapping);
 426         VMCOREINFO_OFFSET(page, lru);
 427         VMCOREINFO_OFFSET(page, _mapcount);
 428         VMCOREINFO_OFFSET(page, private);
 429         VMCOREINFO_OFFSET(page, compound_dtor);
 430         VMCOREINFO_OFFSET(page, compound_order);
 431         VMCOREINFO_OFFSET(page, compound_head);
 432         VMCOREINFO_OFFSET(pglist_data, node_zones);
 433         VMCOREINFO_OFFSET(pglist_data, nr_zones);
 434 #ifdef CONFIG_FLAT_NODE_MEM_MAP
 435         VMCOREINFO_OFFSET(pglist_data, node_mem_map);
 436 #endif
 437         VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
 438         VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
 439         VMCOREINFO_OFFSET(pglist_data, node_id);
 440         VMCOREINFO_OFFSET(zone, free_area);
 441         VMCOREINFO_OFFSET(zone, vm_stat);
 442         VMCOREINFO_OFFSET(zone, spanned_pages);
 443         VMCOREINFO_OFFSET(free_area, free_list);
 444         VMCOREINFO_OFFSET(list_head, next);
 445         VMCOREINFO_OFFSET(list_head, prev);
 446         VMCOREINFO_OFFSET(vmap_area, va_start);
 447         VMCOREINFO_OFFSET(vmap_area, list);
 448         VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
 449         log_buf_vmcoreinfo_setup();
 450         VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
 451         VMCOREINFO_NUMBER(NR_FREE_PAGES);
 452         VMCOREINFO_NUMBER(PG_lru);
 453         VMCOREINFO_NUMBER(PG_private);
 454         VMCOREINFO_NUMBER(PG_swapcache);
 455         VMCOREINFO_NUMBER(PG_slab);
 456 #ifdef CONFIG_MEMORY_FAILURE
 457         VMCOREINFO_NUMBER(PG_hwpoison);
 458 #endif
 459         VMCOREINFO_NUMBER(PG_head_mask);
 460         VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
 461 #ifdef CONFIG_HUGETLB_PAGE
 462         VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR);
 463 #endif
 464
 465         arch_crash_save_vmcoreinfo();
 466         update_vmcoreinfo_note();
 467
 468         return 0;
 469 }
 470
 471 subsys_initcall(crash_save_vmcoreinfo_init);