LXR linux/kernel/crash

   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/crash_core.h>
   8#include <linux/utsname.h>
   9#include <linux/vmalloc.h>
  10
  11#include <asm/page.h>
  12#include <asm/sections.h>
  13
  14/* vmcoreinfo stuff */
  15unsigned char *vmcoreinfo_data;
  16size_t vmcoreinfo_size;
  17u32 *vmcoreinfo_note;
  18
  19/* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */
  20static unsigned char *vmcoreinfo_data_safecopy;
  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 */
  36static 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        } else
 110                pr_info("crashkernel size resulted in zero bytes\n");
 111
 112        return 0;
 113}
 114
 115/*
 116 * That function parses "simple" (old) crashkernel command lines like
 117 *
 118 *      crashkernel=size[@offset]
 119 *
 120 * It returns 0 on success and -EINVAL on failure.
 121 */
 122static int __init parse_crashkernel_simple(char *cmdline,
 123                                           unsigned long long *crash_size,
 124                                           unsigned long long *crash_base)
 125{
 126        char *cur = cmdline;
 127
 128        *crash_size = memparse(cmdline, &cur);
 129        if (cmdline == cur) {
 130                pr_warn("crashkernel: memory value expected\n");
 131                return -EINVAL;
 132        }
 133
 134        if (*cur == '@')
 135                *crash_base = memparse(cur+1, &cur);
 136        else if (*cur != ' ' && *cur != '\0') {
 137                pr_warn("crashkernel: unrecognized char: %c\n", *cur);
 138                return -EINVAL;
 139        }
 140
 141        return 0;
 142}
 143
 144#define SUFFIX_HIGH 0
 145#define SUFFIX_LOW  1
 146#define SUFFIX_NULL 2
 147static __initdata char *suffix_tbl[] = {
 148        [SUFFIX_HIGH] = ",high",
 149        [SUFFIX_LOW]  = ",low",
 150        [SUFFIX_NULL] = NULL,
 151};
 152
 153/*
 154 * That function parses "suffix"  crashkernel command lines like
 155 *
 156 *      crashkernel=size,[high|low]
 157 *
 158 * It returns 0 on success and -EINVAL on failure.
 159 */
 160static int __init parse_crashkernel_suffix(char *cmdline,
 161                                           unsigned long long   *crash_size,
 162                                           const char *suffix)
 163{
 164        char *cur = cmdline;
 165
 166        *crash_size = memparse(cmdline, &cur);
 167        if (cmdline == cur) {
 168                pr_warn("crashkernel: memory value expected\n");
 169                return -EINVAL;
 170        }
 171
 172        /* check with suffix */
 173        if (strncmp(cur, suffix, strlen(suffix))) {
 174                pr_warn("crashkernel: unrecognized char: %c\n", *cur);
 175                return -EINVAL;
 176        }
 177        cur += strlen(suffix);
 178        if (*cur != ' ' && *cur != '\0') {
 179                pr_warn("crashkernel: unrecognized char: %c\n", *cur);
 180                return -EINVAL;
 181        }
 182
 183        return 0;
 184}
 185
 186static __init char *get_last_crashkernel(char *cmdline,
 187                             const char *name,
 188                             const char *suffix)
 189{
 190        char *p = cmdline, *ck_cmdline = NULL;
 191
 192        /* find crashkernel and use the last one if there are more */
 193        p = strstr(p, name);
 194        while (p) {
 195                char *end_p = strchr(p, ' ');
 196                char *q;
 197
 198                if (!end_p)
 199                        end_p = p + strlen(p);
 200
 201                if (!suffix) {
 202                        int i;
 203
 204                        /* skip the one with any known suffix */
 205                        for (i = 0; suffix_tbl[i]; i++) {
 206                                q = end_p - strlen(suffix_tbl[i]);
 207                                if (!strncmp(q, suffix_tbl[i],
 208                                             strlen(suffix_tbl[i])))
 209                                        goto next;
 210                        }
 211                        ck_cmdline = p;
 212                } else {
 213                        q = end_p - strlen(suffix);
 214                        if (!strncmp(q, suffix, strlen(suffix)))
 215                                ck_cmdline = p;
 216                }
 217next:
 218                p = strstr(p+1, name);
 219        }
 220
 221        if (!ck_cmdline)
 222                return NULL;
 223
 224        return ck_cmdline;
 225}
 226
 227static int __init __parse_crashkernel(char *cmdline,
 228                             unsigned long long system_ram,
 229                             unsigned long long *crash_size,
 230                             unsigned long long *crash_base,
 231                             const char *name,
 232                             const char *suffix)
 233{
 234        char    *first_colon, *first_space;
 235        char    *ck_cmdline;
 236
 237        BUG_ON(!crash_size || !crash_base);
 238        *crash_size = 0;
 239        *crash_base = 0;
 240
 241        ck_cmdline = get_last_crashkernel(cmdline, name, suffix);
 242
 243        if (!ck_cmdline)
 244                return -EINVAL;
 245
 246        ck_cmdline += strlen(name);
 247
 248        if (suffix)
 249                return parse_crashkernel_suffix(ck_cmdline, crash_size,
 250                                suffix);
 251        /*
 252         * if the commandline contains a ':', then that's the extended
 253         * syntax -- if not, it must be the classic syntax
 254         */
 255        first_colon = strchr(ck_cmdline, ':');
 256        first_space = strchr(ck_cmdline, ' ');
 257        if (first_colon && (!first_space || first_colon < first_space))
 258                return parse_crashkernel_mem(ck_cmdline, system_ram,
 259                                crash_size, crash_base);
 260
 261        return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base);
 262}
 263
 264/*
 265 * That function is the entry point for command line parsing and should be
 266 * called from the arch-specific code.
 267 */
 268int __init parse_crashkernel(char *cmdline,
 269                             unsigned long long system_ram,
 270                             unsigned long long *crash_size,
 271                             unsigned long long *crash_base)
 272{
 273        return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
 274                                        "crashkernel=", NULL);
 275}
 276
 277int __init parse_crashkernel_high(char *cmdline,
 278                             unsigned long long system_ram,
 279                             unsigned long long *crash_size,
 280                             unsigned long long *crash_base)
 281{
 282        return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
 283                                "crashkernel=", suffix_tbl[SUFFIX_HIGH]);
 284}
 285
 286int __init parse_crashkernel_low(char *cmdline,
 287                             unsigned long long system_ram,
 288                             unsigned long long *crash_size,
 289                             unsigned long long *crash_base)
 290{
 291        return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
 292                                "crashkernel=", suffix_tbl[SUFFIX_LOW]);
 293}
 294
 295Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type,
 296                          void *data, size_t data_len)
 297{
 298        struct elf_note *note = (struct elf_note *)buf;
 299
 300        note->n_namesz = strlen(name) + 1;
 301        note->n_descsz = data_len;
 302        note->n_type   = type;
 303        buf += DIV_ROUND_UP(sizeof(*note), sizeof(Elf_Word));
 304        memcpy(buf, name, note->n_namesz);
 305        buf += DIV_ROUND_UP(note->n_namesz, sizeof(Elf_Word));
 306        memcpy(buf, data, data_len);
 307        buf += DIV_ROUND_UP(data_len, sizeof(Elf_Word));
 308
 309        return buf;
 310}
 311
 312void final_note(Elf_Word *buf)
 313{
 314        memset(buf, 0, sizeof(struct elf_note));
 315}
 316
 317static void update_vmcoreinfo_note(void)
 318{
 319        u32 *buf = vmcoreinfo_note;
 320
 321        if (!vmcoreinfo_size)
 322                return;
 323        buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data,
 324                              vmcoreinfo_size);
 325        final_note(buf);
 326}
 327
 328void crash_update_vmcoreinfo_safecopy(void *ptr)
 329{
 330        if (ptr)
 331                memcpy(ptr, vmcoreinfo_data, vmcoreinfo_size);
 332
 333        vmcoreinfo_data_safecopy = ptr;
 334}
 335
 336void crash_save_vmcoreinfo(void)
 337{
 338        if (!vmcoreinfo_note)
 339                return;
 340
 341        /* Use the safe copy to generate vmcoreinfo note if have */
 342        if (vmcoreinfo_data_safecopy)
 343                vmcoreinfo_data = vmcoreinfo_data_safecopy;
 344
 345        vmcoreinfo_append_str("CRASHTIME=%lld\n", ktime_get_real_seconds());
 346        update_vmcoreinfo_note();
 347}
 348
 349void vmcoreinfo_append_str(const char *fmt, ...)
 350{
 351        va_list args;
 352        char buf[0x50];
 353        size_t r;
 354
 355        va_start(args, fmt);
 356        r = vscnprintf(buf, sizeof(buf), fmt, args);
 357        va_end(args);
 358
 359        r = min(r, (size_t)VMCOREINFO_BYTES - vmcoreinfo_size);
 360
 361        memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r);
 362
 363        vmcoreinfo_size += r;
 364}
 365
 366/*
 367 * provide an empty default implementation here -- architecture
 368 * code may override this
 369 */
 370void __weak arch_crash_save_vmcoreinfo(void)
 371{}
 372
 373phys_addr_t __weak paddr_vmcoreinfo_note(void)
 374{
 375        return __pa(vmcoreinfo_note);
 376}
 377EXPORT_SYMBOL(paddr_vmcoreinfo_note);
 378
 379static 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_ARRAY(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_ARRAY(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_swapbacked);
 456        VMCOREINFO_NUMBER(PG_slab);
 457#ifdef CONFIG_MEMORY_FAILURE
 458        VMCOREINFO_NUMBER(PG_hwpoison);
 459#endif
 460        VMCOREINFO_NUMBER(PG_head_mask);
 461#define PAGE_BUDDY_MAPCOUNT_VALUE       (~PG_buddy)
 462        VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE);
 463#ifdef CONFIG_HUGETLB_PAGE
 464        VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR);
 465#define PAGE_OFFLINE_MAPCOUNT_VALUE     (~PG_offline)
 466        VMCOREINFO_NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE);
 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