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