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[VMCOREINFO_BYTES];
  18 u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
  19 size_t vmcoreinfo_size;
  20 size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data);
  21
  22 /*
  23  * parsing the "crashkernel" commandline
  24  *
  25  * this code is intended to be called from architecture specific code
  26  */
  27
  28
  29 /*
  30  * This function parses command lines in the format
  31  *
  32  *   crashkernel=ramsize-range:size[,...][@offset]
  33  *
  34  * The function returns 0 on success and -EINVAL on failure.
  35  */
  36 static int __init parse_crashkernel_mem(char *cmdline,
  37                                         unsigned long long system_ram,
  38                                         unsigned long long *crash_size,
  39                                         unsigned long long *crash_base)
  40 {
  41         char *cur = cmdline, *tmp;
  42
  43         /* for each entry of the comma-separated list */
  44         do {
  45                 unsigned long long start, end = ULLONG_MAX, size;
  46
  47                 /* get the start of the range */
  48                 start = memparse(cur, &tmp);
  49                 if (cur == tmp) {
  50                         pr_warn("crashkernel: Memory value expected\n");
  51                         return -EINVAL;
  52                 }
  53                 cur = tmp;
  54                 if (*cur != '-') {
  55                         pr_warn("crashkernel: '-' expected\n");
  56                         return -EINVAL;
  57                 }
  58                 cur++;
  59
  60                 /* if no ':' is here, than we read the end */
  61                 if (*cur != ':') {
  62                         end = memparse(cur, &tmp);
  63                         if (cur == tmp) {
  64                                 pr_warn("crashkernel: Memory value expected\n");
  65                                 return -EINVAL;
  66                         }
  67                         cur = tmp;
  68                         if (end <= start) {
  69                                 pr_warn("crashkernel: end <= start\n");
  70                                 return -EINVAL;
  71                         }
  72                 }
  73
  74                 if (*cur != ':') {
  75                         pr_warn("crashkernel: ':' expected\n");
  76                         return -EINVAL;
  77                 }
  78                 cur++;
  79
  80                 size = memparse(cur, &tmp);
  81                 if (cur == tmp) {
  82                         pr_warn("Memory value expected\n");
  83                         return -EINVAL;
  84                 }
  85                 cur = tmp;
  86                 if (size >= system_ram) {
  87                         pr_warn("crashkernel: invalid size\n");
  88                         return -EINVAL;
  89                 }
  90
  91                 /* match ? */
  92                 if (system_ram >= start && system_ram < end) {
  93                         *crash_size = size;
  94                         break;
  95                 }
  96         } while (*cur++ == ',');
  97
  98         if (*crash_size > 0) {
  99                 while (*cur && *cur != ' ' && *cur != '@')
 100                         cur++;
 101                 if (*cur == '@') {
 102                         cur++;
 103                         *crash_base = memparse(cur, &tmp);
 104                         if (cur == tmp) {
 105                                 pr_warn("Memory value expected after '@'\n");
 106                                 return -EINVAL;
 107                         }
 108                 }
 109         }
 110
 111         return 0;
 112 }
 113
 114 /*
 115  * That function parses "simple" (old) crashkernel command lines like
 116  *
 117  *      crashkernel=size[@offset]
 118  *
 119  * It returns 0 on success and -EINVAL on failure.
 120  */
 121 static int __init parse_crashkernel_simple(char *cmdline,
 122                                            unsigned long long *crash_size,
 123                                            unsigned long long *crash_base)
 124 {
 125         char *cur = cmdline;
 126
 127         *crash_size = memparse(cmdline, &cur);
 128         if (cmdline == cur) {
 129                 pr_warn("crashkernel: memory value expected\n");
 130                 return -EINVAL;
 131         }
 132
 133         if (*cur == '@')
 134                 *crash_base = memparse(cur+1, &cur);
 135         else if (*cur != ' ' && *cur != '\0') {
 136                 pr_warn("crashkernel: unrecognized char: %c\n", *cur);
 137                 return -EINVAL;
 138         }
 139
 140         return 0;
 141 }
 142
 143 #define SUFFIX_HIGH 0
 144 #define SUFFIX_LOW  1
 145 #define SUFFIX_NULL 2
 146 static __initdata char *suffix_tbl[] = {
 147         [SUFFIX_HIGH] = ",high",
 148         [SUFFIX_LOW]  = ",low",
 149         [SUFFIX_NULL] = NULL,
 150 };
 151
 152 /*
 153  * That function parses "suffix"  crashkernel command lines like
 154  *
 155  *      crashkernel=size,[high|low]
 156  *
 157  * It returns 0 on success and -EINVAL on failure.
 158  */
 159 static int __init parse_crashkernel_suffix(char *cmdline,
 160                                            unsigned long long   *crash_size,
 161                                            const char *suffix)
 162 {
 163         char *cur = cmdline;
 164
 165         *crash_size = memparse(cmdline, &cur);
 166         if (cmdline == cur) {
 167                 pr_warn("crashkernel: memory value expected\n");
 168                 return -EINVAL;
 169         }
 170
 171         /* check with suffix */
 172         if (strncmp(cur, suffix, strlen(suffix))) {
 173                 pr_warn("crashkernel: unrecognized char: %c\n", *cur);
 174                 return -EINVAL;
 175         }
 176         cur += strlen(suffix);
 177         if (*cur != ' ' && *cur != '\0') {
 178                 pr_warn("crashkernel: unrecognized char: %c\n", *cur);
 179                 return -EINVAL;
 180         }
 181
 182         return 0;
 183 }
 184
 185 static __init char *get_last_crashkernel(char *cmdline,
 186                              const char *name,
 187                              const char *suffix)
 188 {
 189         char *p = cmdline, *ck_cmdline = NULL;
 190
 191         /* find crashkernel and use the last one if there are more */
 192         p = strstr(p, name);
 193         while (p) {
 194                 char *end_p = strchr(p, ' ');
 195                 char *q;
 196
 197                 if (!end_p)
 198                         end_p = p + strlen(p);
 199
 200                 if (!suffix) {
 201                         int i;
 202
 203                         /* skip the one with any known suffix */
 204                         for (i = 0; suffix_tbl[i]; i++) {
 205                                 q = end_p - strlen(suffix_tbl[i]);
 206                                 if (!strncmp(q, suffix_tbl[i],
 207                                              strlen(suffix_tbl[i])))
 208                                         goto next;
 209                         }
 210                         ck_cmdline = p;
 211                 } else {
 212                         q = end_p - strlen(suffix);
 213                         if (!strncmp(q, suffix, strlen(suffix)))
 214                                 ck_cmdline = p;
 215                 }
 216 next:
 217                 p = strstr(p+1, name);
 218         }
 219
 220         if (!ck_cmdline)
 221                 return NULL;
 222
 223         return ck_cmdline;
 224 }
 225
 226 static int __init __parse_crashkernel(char *cmdline,
 227                              unsigned long long system_ram,
 228                              unsigned long long *crash_size,
 229                              unsigned long long *crash_base,
 230                              const char *name,
 231                              const char *suffix)
 232 {
 233         char    *first_colon, *first_space;
 234         char    *ck_cmdline;
 235
 236         BUG_ON(!crash_size || !crash_base);
 237         *crash_size = 0;
 238         *crash_base = 0;
 239
 240         ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
 241
 242         if (!ck_cmdline)
 243                 return -EINVAL;
 244
 245         ck_cmdline += strlen(name);
 246
 247         if (suffix)
 248                 return parse_crashkernel_suffix(ck_cmdline, crash_size,
 249                                 suffix);
 250         /*
 251          * if the commandline contains a ':', then that's the extended
 252          * syntax -- if not, it must be the classic syntax
 253          */
 254         first_colon = strchr(ck_cmdline, ':');
 255         first_space = strchr(ck_cmdline, ' ');
 256         if (first_colon && (!first_space || first_colon < first_space))
 257                 return parse_crashkernel_mem(ck_cmdline, system_ram,
 258                                 crash_size, crash_base);
 259
 260         return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base);
 261 }
 262
 263 /*
 264  * That function is the entry point for command line parsing and should be
 265  * called from the arch-specific code.
 266  */
 267 int __init parse_crashkernel(char *cmdline,
 268                              unsigned long long system_ram,
 269                              unsigned long long *crash_size,
 270                              unsigned long long *crash_base)
 271 {
 272         return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
 273                                         "crashkernel=", NULL);
 274 }
 275
 276 int __init parse_crashkernel_high(char *cmdline,
 277                              unsigned long long system_ram,
 278                              unsigned long long *crash_size,
 279                              unsigned long long *crash_base)
 280 {
 281         return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
 282                                 "crashkernel=", suffix_tbl[SUFFIX_HIGH]);
 283 }
 284
 285 int __init parse_crashkernel_low(char *cmdline,
 286                              unsigned long long system_ram,
 287                              unsigned long long *crash_size,
 288                              unsigned long long *crash_base)
 289 {
 290         return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
 291                                 "crashkernel=", suffix_tbl[SUFFIX_LOW]);
 292 }
 293
 294 Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
 295                           void *data, size_t data_len)
 296 {
 297         struct elf_note *note = (struct elf_note *)buf;
 298
 299         note->n_namesz = strlen(name) + 1;
 300         note->n_descsz = data_len;
 301         note->n_type   = type;
 302         buf += DIV_ROUND_UP(sizeof(*note), sizeof(Elf_Word));
 303         memcpy(buf, name, note->n_namesz);
 304         buf += DIV_ROUND_UP(note->n_namesz, sizeof(Elf_Word));
 305         memcpy(buf, data, data_len);
 306         buf += DIV_ROUND_UP(data_len, sizeof(Elf_Word));
 307
 308         return buf;
 309 }
 310
 311 void final_note(Elf_Word *buf)
 312 {
 313         memset(buf, 0, sizeof(struct elf_note));
 314 }
 315
 316 static void update_vmcoreinfo_note(void)
 317 {
 318         u32 *buf = vmcoreinfo_note;
 319
 320         if (!vmcoreinfo_size)
 321                 return;
 322         buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
 323                               vmcoreinfo_size);
 324         final_note(buf);
 325 }
 326
 327 void crash_save_vmcoreinfo(void)
 328 {
 329         vmcoreinfo_append_str("CRASHTIME=%ld\n", get_seconds());
 330         update_vmcoreinfo_note();
 331 }
 332
 333 void vmcoreinfo_append_str(const char *fmt, ...)
 334 {
 335         va_list args;
 336         char buf[0x50];
 337         size_t r;
 338
 339         va_start(args, fmt);
 340         r = vscnprintf(buf, sizeof(buf), fmt, args);
 341         va_end(args);
 342
 343         r = min(r, vmcoreinfo_max_size - vmcoreinfo_size);
 344
 345         memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
 346
 347         vmcoreinfo_size += r;
 348 }
 349
 350 /*
 351  * provide an empty default implementation here -- architecture
 352  * code may override this
 353  */
 354 void __weak arch_crash_save_vmcoreinfo(void)
 355 {}
 356
 357 phys_addr_t __weak paddr_vmcoreinfo_note(void)
 358 {
 359         return __pa_symbol((unsigned long)(char *)&vmcoreinfo_note);
 360 }
 361
 362 static int __init crash_save_vmcoreinfo_init(void)
 363 {
 364         VMCOREINFO_OSRELEASE(init_uts_ns.name.release);
 365         VMCOREINFO_PAGESIZE(PAGE_SIZE);
 366
 367         VMCOREINFO_SYMBOL(init_uts_ns);
 368         VMCOREINFO_SYMBOL(node_online_map);
 369 #ifdef CONFIG_MMU
 370         VMCOREINFO_SYMBOL(swapper_pg_dir);
 371 #endif
 372         VMCOREINFO_SYMBOL(_stext);
 373         VMCOREINFO_SYMBOL(vmap_area_list);
 374
 375 #ifndef CONFIG_NEED_MULTIPLE_NODES
 376         VMCOREINFO_SYMBOL(mem_map);
 377         VMCOREINFO_SYMBOL(contig_page_data);
 378 #endif
 379 #ifdef CONFIG_SPARSEMEM
 380         VMCOREINFO_SYMBOL(mem_section);
 381         VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS);
 382         VMCOREINFO_STRUCT_SIZE(mem_section);
 383         VMCOREINFO_OFFSET(mem_section, section_mem_map);
 384 #endif
 385         VMCOREINFO_STRUCT_SIZE(page);
 386         VMCOREINFO_STRUCT_SIZE(pglist_data);
 387         VMCOREINFO_STRUCT_SIZE(zone);
 388         VMCOREINFO_STRUCT_SIZE(free_area);
 389         VMCOREINFO_STRUCT_SIZE(list_head);
 390         VMCOREINFO_SIZE(nodemask_t);
 391         VMCOREINFO_OFFSET(page, flags);
 392         VMCOREINFO_OFFSET(page, _refcount);
 393         VMCOREINFO_OFFSET(page, mapping);
 394         VMCOREINFO_OFFSET(page, lru);
 395         VMCOREINFO_OFFSET(page, _mapcount);
 396         VMCOREINFO_OFFSET(page, private);
 397         VMCOREINFO_OFFSET(page, compound_dtor);
 398         VMCOREINFO_OFFSET(page, compound_order);
 399         VMCOREINFO_OFFSET(page, compound_head);
 400         VMCOREINFO_OFFSET(pglist_data, node_zones);
 401         VMCOREINFO_OFFSET(pglist_data, nr_zones);
 402 #ifdef CONFIG_FLAT_NODE_MEM_MAP
 403         VMCOREINFO_OFFSET(pglist_data, node_mem_map);
 404 #endif
 405         VMCOREINFO_OFFSET(pglist_data, node_start_pfn);
 406         VMCOREINFO_OFFSET(pglist_data, node_spanned_pages);
 407         VMCOREINFO_OFFSET(pglist_data, node_id);
 408         VMCOREINFO_OFFSET(zone, free_area);
 409         VMCOREINFO_OFFSET(zone, vm_stat);
 410         VMCOREINFO_OFFSET(zone, spanned_pages);
 411         VMCOREINFO_OFFSET(free_area, free_list);
 412         VMCOREINFO_OFFSET(list_head, next);
 413         VMCOREINFO_OFFSET(list_head, prev);
 414         VMCOREINFO_OFFSET(vmap_area, va_start);
 415         VMCOREINFO_OFFSET(vmap_area, list);
 416         VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER);
 417         log_buf_vmcoreinfo_setup();
 418         VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES);
 419         VMCOREINFO_NUMBER(NR_FREE_PAGES);
 420         VMCOREINFO_NUMBER(PG_lru);
 421         VMCOREINFO_NUMBER(PG_private);
 422         VMCOREINFO_NUMBER(PG_swapcache);
 423         VMCOREINFO_NUMBER(PG_slab);
 424 #ifdef CONFIG_MEMORY_FAILURE
 425         VMCOREINFO_NUMBER(PG_hwpoison);
 426 #endif
 427         VMCOREINFO_NUMBER(PG_head_mask);
 428         VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
 429 #ifdef CONFIG_HUGETLB_PAGE
 430         VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR);
 431 #endif
 432
 433         arch_crash_save_vmcoreinfo();
 434         update_vmcoreinfo_note();
 435
 436         return 0;
 437 }
 438
 439 subsys_initcall(crash_save_vmcoreinfo_init);