linux/kernel/crash_core.c
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   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 */
  18unsigned char *vmcoreinfo_data;
  19size_t vmcoreinfo_size;
  20u32 *vmcoreinfo_note;
  21
  22/* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */
  23static 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 */
  39static 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 */
 125static 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
 150static __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 */
 163static 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
 189static __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                }
 220next:
 221                p = strstr(p+1, name);
 222        }
 223
 224        if (!ck_cmdline)
 225                return NULL;
 226
 227        return ck_cmdline;
 228}
 229
 230static 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 */
 271int __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
 280int __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
 289int __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
 298Elf_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
 315void final_note(Elf_Word *buf)
 316{
 317        memset(buf, 0, sizeof(struct elf_note));
 318}
 319
 320static 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
 331void 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
 339void 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
 352void 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 */
 373void __weak arch_crash_save_vmcoreinfo(void)
 374{}
 375
 376phys_addr_t __weak paddr_vmcoreinfo_note(void)
 377{
 378        return __pa(vmcoreinfo_note);
 379}
 380EXPORT_SYMBOL(paddr_vmcoreinfo_note);
 381
 382static 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
 482subsys_initcall(crash_save_vmcoreinfo_init);
 483