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 #include <crypto/sha.h> 15 16 /* vmcoreinfo stuff */ 17 unsigned char *vmcoreinfo_data; 18 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 } 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 */ 124 static 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 2 149 static __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 */ 162 static 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 } 187 188 static __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 } 219 next: 220 p = strstr(p+1, name); 221 } 222 223 if (!ck_cmdline) 224 return NULL; 225 226 return ck_cmdline; 227 } 228 229 static 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 */ 270 int __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 } 278 279 int __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 } 287 288 int __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 } 296 297 Elf_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 } 313 314 void final_note(Elf_Word *buf) 315 { 316 memset(buf, 0, sizeof(struct elf_note)); 317 } 318 319 static 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 } 329 330 void crash_update_vmcoreinfo_safecopy(void *ptr) 331 { 332 if (ptr) 333 memcpy(ptr, vmcoreinfo_data, vmcoreinfo_size); 334 335 vmcoreinfo_data_safecopy = ptr; 336 } 337 338 void 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 } 350 351 void 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 */ 372 void __weak arch_crash_save_vmcoreinfo(void) 373 {} 374 375 phys_addr_t __weak paddr_vmcoreinfo_note(void) 376 { 377 return __pa(vmcoreinfo_note); 378 } 379 EXPORT_SYMBOL(paddr_vmcoreinfo_note); 380 381 #define NOTES_SIZE (&__stop_notes - &__start_notes) 382 #define BUILD_ID_MAX SHA1_DIGEST_SIZE 383 #define NT_GNU_BUILD_ID 3 384 385 struct elf_note_section { 386 struct elf_note n_hdr; 387 u8 n_data[]; 388 }; 389 390 /* 391 * Add build ID from .notes section as generated by the GNU ld(1) 392 * or LLVM lld(1) --build-id option. 393 */ 394 static void add_build_id_vmcoreinfo(void) 395 { 396 char build_id[BUILD_ID_MAX * 2 + 1]; 397 int n_remain = NOTES_SIZE; 398 399 while (n_remain >= sizeof(struct elf_note)) { 400 const struct elf_note_section *note_sec = 401 &__start_notes + NOTES_SIZE - n_remain; 402 const u32 n_namesz = note_sec->n_hdr.n_namesz; 403 404 if (note_sec->n_hdr.n_type == NT_GNU_BUILD_ID && 405 n_namesz != 0 && 406 !strcmp((char *)¬e_sec->n_data[0], "GNU")) { 407 if (note_sec->n_hdr.n_descsz <= BUILD_ID_MAX) { 408 const u32 n_descsz = note_sec->n_hdr.n_descsz; 409 const u8 *s = ¬e_sec->n_data[n_namesz]; 410 411 s = PTR_ALIGN(s, 4); 412 bin2hex(build_id, s, n_descsz); 413 build_id[2 * n_descsz] = '\0'; 414 VMCOREINFO_BUILD_ID(build_id); 415 return; 416 } 417 pr_warn("Build ID is too large to include in vmcoreinfo: %u > %u\n", 418 note_sec->n_hdr.n_descsz, 419 BUILD_ID_MAX); 420 return; 421 } 422 n_remain -= sizeof(struct elf_note) + 423 ALIGN(note_sec->n_hdr.n_namesz, 4) + 424 ALIGN(note_sec->n_hdr.n_descsz, 4); 425 } 426 } 427 428 static int __init crash_save_vmcoreinfo_init(void) 429 { 430 vmcoreinfo_data = (unsigned char *)get_zeroed_page(GFP_KERNEL); 431 if (!vmcoreinfo_data) { 432 pr_warn("Memory allocation for vmcoreinfo_data failed\n"); 433 return -ENOMEM; 434 } 435 436 vmcoreinfo_note = alloc_pages_exact(VMCOREINFO_NOTE_SIZE, 437 GFP_KERNEL | __GFP_ZERO); 438 if (!vmcoreinfo_note) { 439 free_page((unsigned long)vmcoreinfo_data); 440 vmcoreinfo_data = NULL; 441 pr_warn("Memory allocation for vmcoreinfo_note failed\n"); 442 return -ENOMEM; 443 } 444 445 VMCOREINFO_OSRELEASE(init_uts_ns.name.release); 446 add_build_id_vmcoreinfo(); 447 VMCOREINFO_PAGESIZE(PAGE_SIZE); 448 449 VMCOREINFO_SYMBOL(init_uts_ns); 450 VMCOREINFO_SYMBOL(node_online_map); 451 #ifdef CONFIG_MMU 452 VMCOREINFO_SYMBOL_ARRAY(swapper_pg_dir); 453 #endif 454 VMCOREINFO_SYMBOL(_stext); 455 VMCOREINFO_SYMBOL(vmap_area_list); 456 457 #ifndef CONFIG_NEED_MULTIPLE_NODES 458 VMCOREINFO_SYMBOL(mem_map); 459 VMCOREINFO_SYMBOL(contig_page_data); 460 #endif 461 #ifdef CONFIG_SPARSEMEM 462 VMCOREINFO_SYMBOL_ARRAY(mem_section); 463 VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS); 464 VMCOREINFO_STRUCT_SIZE(mem_section); 465 VMCOREINFO_OFFSET(mem_section, section_mem_map); 466 VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS); 467 #endif 468 VMCOREINFO_STRUCT_SIZE(page); 469 VMCOREINFO_STRUCT_SIZE(pglist_data); 470 VMCOREINFO_STRUCT_SIZE(zone); 471 VMCOREINFO_STRUCT_SIZE(free_area); 472 VMCOREINFO_STRUCT_SIZE(list_head); 473 VMCOREINFO_SIZE(nodemask_t); 474 VMCOREINFO_OFFSET(page, flags); 475 VMCOREINFO_OFFSET(page, _refcount); 476 VMCOREINFO_OFFSET(page, mapping); 477 VMCOREINFO_OFFSET(page, lru); 478 VMCOREINFO_OFFSET(page, _mapcount); 479 VMCOREINFO_OFFSET(page, private); 480 VMCOREINFO_OFFSET(page, compound_dtor); 481 VMCOREINFO_OFFSET(page, compound_order); 482 VMCOREINFO_OFFSET(page, compound_head); 483 VMCOREINFO_OFFSET(pglist_data, node_zones); 484 VMCOREINFO_OFFSET(pglist_data, nr_zones); 485 #ifdef CONFIG_FLAT_NODE_MEM_MAP 486 VMCOREINFO_OFFSET(pglist_data, node_mem_map); 487 #endif 488 VMCOREINFO_OFFSET(pglist_data, node_start_pfn); 489 VMCOREINFO_OFFSET(pglist_data, node_spanned_pages); 490 VMCOREINFO_OFFSET(pglist_data, node_id); 491 VMCOREINFO_OFFSET(zone, free_area); 492 VMCOREINFO_OFFSET(zone, vm_stat); 493 VMCOREINFO_OFFSET(zone, spanned_pages); 494 VMCOREINFO_OFFSET(free_area, free_list); 495 VMCOREINFO_OFFSET(list_head, next); 496 VMCOREINFO_OFFSET(list_head, prev); 497 VMCOREINFO_OFFSET(vmap_area, va_start); 498 VMCOREINFO_OFFSET(vmap_area, list); 499 VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER); 500 log_buf_vmcoreinfo_setup(); 501 VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES); 502 VMCOREINFO_NUMBER(NR_FREE_PAGES); 503 VMCOREINFO_NUMBER(PG_lru); 504 VMCOREINFO_NUMBER(PG_private); 505 VMCOREINFO_NUMBER(PG_swapcache); 506 VMCOREINFO_NUMBER(PG_swapbacked); 507 VMCOREINFO_NUMBER(PG_slab); 508 #ifdef CONFIG_MEMORY_FAILURE 509 VMCOREINFO_NUMBER(PG_hwpoison); 510 #endif 511 VMCOREINFO_NUMBER(PG_head_mask); 512 #define PAGE_BUDDY_MAPCOUNT_VALUE (~PG_buddy) 513 VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE); 514 #ifdef CONFIG_HUGETLB_PAGE 515 VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR); 516 #define PAGE_OFFLINE_MAPCOUNT_VALUE (~PG_offline) 517 VMCOREINFO_NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE); 518 #endif 519 520 arch_crash_save_vmcoreinfo(); 521 update_vmcoreinfo_note(); 522 523 return 0; 524 } 525 526 subsys_initcall(crash_save_vmcoreinfo_init); 527