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/init.h> 10 #include <linux/utsname.h> 11 #include <linux/vmalloc.h> 12 13 #include <asm/page.h> 14 #include <asm/sections.h> 15 16 #include <crypto/sha1.h> 17 18 /* vmcoreinfo stuff */ 19 unsigned char *vmcoreinfo_data; 20 size_t vmcoreinfo_size; 21 u32 *vmcoreinfo_note; 22 23 /* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */ 24 static unsigned char *vmcoreinfo_data_safecopy; 25 26 /* 27 * parsing the "crashkernel" commandline 28 * 29 * this code is intended to be called from architecture specific code 30 */ 31 32 33 /* 34 * This function parses command lines in the format 35 * 36 * crashkernel=ramsize-range:size[,...][@offset] 37 * 38 * The function returns 0 on success and -EINVAL on failure. 39 */ 40 static int __init parse_crashkernel_mem(char *cmdline, 41 unsigned long long system_ram, 42 unsigned long long *crash_size, 43 unsigned long long *crash_base) 44 { 45 char *cur = cmdline, *tmp; 46 47 /* for each entry of the comma-separated list */ 48 do { 49 unsigned long long start, end = ULLONG_MAX, size; 50 51 /* get the start of the range */ 52 start = memparse(cur, &tmp); 53 if (cur == tmp) { 54 pr_warn("crashkernel: Memory value expected\n"); 55 return -EINVAL; 56 } 57 cur = tmp; 58 if (*cur != '-') { 59 pr_warn("crashkernel: '-' expected\n"); 60 return -EINVAL; 61 } 62 cur++; 63 64 /* if no ':' is here, than we read the end */ 65 if (*cur != ':') { 66 end = memparse(cur, &tmp); 67 if (cur == tmp) { 68 pr_warn("crashkernel: Memory value expected\n"); 69 return -EINVAL; 70 } 71 cur = tmp; 72 if (end <= start) { 73 pr_warn("crashkernel: end <= start\n"); 74 return -EINVAL; 75 } 76 } 77 78 if (*cur != ':') { 79 pr_warn("crashkernel: ':' expected\n"); 80 return -EINVAL; 81 } 82 cur++; 83 84 size = memparse(cur, &tmp); 85 if (cur == tmp) { 86 pr_warn("Memory value expected\n"); 87 return -EINVAL; 88 } 89 cur = tmp; 90 if (size >= system_ram) { 91 pr_warn("crashkernel: invalid size\n"); 92 return -EINVAL; 93 } 94 95 /* match ? */ 96 if (system_ram >= start && system_ram < end) { 97 *crash_size = size; 98 break; 99 } 100 } while (*cur++ == ','); 101 102 if (*crash_size > 0) { 103 while (*cur && *cur != ' ' && *cur != '@') 104 cur++; 105 if (*cur == '@') { 106 cur++; 107 *crash_base = memparse(cur, &tmp); 108 if (cur == tmp) { 109 pr_warn("Memory value expected after '@'\n"); 110 return -EINVAL; 111 } 112 } 113 } else 114 pr_info("crashkernel size resulted in zero bytes\n"); 115 116 return 0; 117 } 118 119 /* 120 * That function parses "simple" (old) crashkernel command lines like 121 * 122 * crashkernel=size[@offset] 123 * 124 * It returns 0 on success and -EINVAL on failure. 125 */ 126 static int __init parse_crashkernel_simple(char *cmdline, 127 unsigned long long *crash_size, 128 unsigned long long *crash_base) 129 { 130 char *cur = cmdline; 131 132 *crash_size = memparse(cmdline, &cur); 133 if (cmdline == cur) { 134 pr_warn("crashkernel: memory value expected\n"); 135 return -EINVAL; 136 } 137 138 if (*cur == '@') 139 *crash_base = memparse(cur+1, &cur); 140 else if (*cur != ' ' && *cur != '\0') { 141 pr_warn("crashkernel: unrecognized char: %c\n", *cur); 142 return -EINVAL; 143 } 144 145 return 0; 146 } 147 148 #define SUFFIX_HIGH 0 149 #define SUFFIX_LOW 1 150 #define SUFFIX_NULL 2 151 static __initdata char *suffix_tbl[] = { 152 [SUFFIX_HIGH] = ",high", 153 [SUFFIX_LOW] = ",low", 154 [SUFFIX_NULL] = NULL, 155 }; 156 157 /* 158 * That function parses "suffix" crashkernel command lines like 159 * 160 * crashkernel=size,[high|low] 161 * 162 * It returns 0 on success and -EINVAL on failure. 163 */ 164 static int __init parse_crashkernel_suffix(char *cmdline, 165 unsigned long long *crash_size, 166 const char *suffix) 167 { 168 char *cur = cmdline; 169 170 *crash_size = memparse(cmdline, &cur); 171 if (cmdline == cur) { 172 pr_warn("crashkernel: memory value expected\n"); 173 return -EINVAL; 174 } 175 176 /* check with suffix */ 177 if (strncmp(cur, suffix, strlen(suffix))) { 178 pr_warn("crashkernel: unrecognized char: %c\n", *cur); 179 return -EINVAL; 180 } 181 cur += strlen(suffix); 182 if (*cur != ' ' && *cur != '\0') { 183 pr_warn("crashkernel: unrecognized char: %c\n", *cur); 184 return -EINVAL; 185 } 186 187 return 0; 188 } 189 190 static __init char *get_last_crashkernel(char *cmdline, 191 const char *name, 192 const char *suffix) 193 { 194 char *p = cmdline, *ck_cmdline = NULL; 195 196 /* find crashkernel and use the last one if there are more */ 197 p = strstr(p, name); 198 while (p) { 199 char *end_p = strchr(p, ' '); 200 char *q; 201 202 if (!end_p) 203 end_p = p + strlen(p); 204 205 if (!suffix) { 206 int i; 207 208 /* skip the one with any known suffix */ 209 for (i = 0; suffix_tbl[i]; i++) { 210 q = end_p - strlen(suffix_tbl[i]); 211 if (!strncmp(q, suffix_tbl[i], 212 strlen(suffix_tbl[i]))) 213 goto next; 214 } 215 ck_cmdline = p; 216 } else { 217 q = end_p - strlen(suffix); 218 if (!strncmp(q, suffix, strlen(suffix))) 219 ck_cmdline = p; 220 } 221 next: 222 p = strstr(p+1, name); 223 } 224 225 if (!ck_cmdline) 226 return NULL; 227 228 return ck_cmdline; 229 } 230 231 static int __init __parse_crashkernel(char *cmdline, 232 unsigned long long system_ram, 233 unsigned long long *crash_size, 234 unsigned long long *crash_base, 235 const char *name, 236 const char *suffix) 237 { 238 char *first_colon, *first_space; 239 char *ck_cmdline; 240 241 BUG_ON(!crash_size || !crash_base); 242 *crash_size = 0; 243 *crash_base = 0; 244 245 ck_cmdline = get_last_crashkernel(cmdline, name, suffix); 246 247 if (!ck_cmdline) 248 return -EINVAL; 249 250 ck_cmdline += strlen(name); 251 252 if (suffix) 253 return parse_crashkernel_suffix(ck_cmdline, crash_size, 254 suffix); 255 /* 256 * if the commandline contains a ':', then that's the extended 257 * syntax -- if not, it must be the classic syntax 258 */ 259 first_colon = strchr(ck_cmdline, ':'); 260 first_space = strchr(ck_cmdline, ' '); 261 if (first_colon && (!first_space || first_colon < first_space)) 262 return parse_crashkernel_mem(ck_cmdline, system_ram, 263 crash_size, crash_base); 264 265 return parse_crashkernel_simple(ck_cmdline, crash_size, crash_base); 266 } 267 268 /* 269 * That function is the entry point for command line parsing and should be 270 * called from the arch-specific code. 271 */ 272 int __init parse_crashkernel(char *cmdline, 273 unsigned long long system_ram, 274 unsigned long long *crash_size, 275 unsigned long long *crash_base) 276 { 277 return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base, 278 "crashkernel=", NULL); 279 } 280 281 int __init parse_crashkernel_high(char *cmdline, 282 unsigned long long system_ram, 283 unsigned long long *crash_size, 284 unsigned long long *crash_base) 285 { 286 return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base, 287 "crashkernel=", suffix_tbl[SUFFIX_HIGH]); 288 } 289 290 int __init parse_crashkernel_low(char *cmdline, 291 unsigned long long system_ram, 292 unsigned long long *crash_size, 293 unsigned long long *crash_base) 294 { 295 return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base, 296 "crashkernel=", suffix_tbl[SUFFIX_LOW]); 297 } 298 299 /* 300 * Add a dummy early_param handler to mark crashkernel= as a known command line 301 * parameter and suppress incorrect warnings in init/main.c. 302 */ 303 static int __init parse_crashkernel_dummy(char *arg) 304 { 305 return 0; 306 } 307 early_param("crashkernel", parse_crashkernel_dummy); 308 309 Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type, 310 void *data, size_t data_len) 311 { 312 struct elf_note *note = (struct elf_note *)buf; 313 314 note->n_namesz = strlen(name) + 1; 315 note->n_descsz = data_len; 316 note->n_type = type; 317 buf += DIV_ROUND_UP(sizeof(*note), sizeof(Elf_Word)); 318 memcpy(buf, name, note->n_namesz); 319 buf += DIV_ROUND_UP(note->n_namesz, sizeof(Elf_Word)); 320 memcpy(buf, data, data_len); 321 buf += DIV_ROUND_UP(data_len, sizeof(Elf_Word)); 322 323 return buf; 324 } 325 326 void final_note(Elf_Word *buf) 327 { 328 memset(buf, 0, sizeof(struct elf_note)); 329 } 330 331 static void update_vmcoreinfo_note(void) 332 { 333 u32 *buf = vmcoreinfo_note; 334 335 if (!vmcoreinfo_size) 336 return; 337 buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data, 338 vmcoreinfo_size); 339 final_note(buf); 340 } 341 342 void crash_update_vmcoreinfo_safecopy(void *ptr) 343 { 344 if (ptr) 345 memcpy(ptr, vmcoreinfo_data, vmcoreinfo_size); 346 347 vmcoreinfo_data_safecopy = ptr; 348 } 349 350 void crash_save_vmcoreinfo(void) 351 { 352 if (!vmcoreinfo_note) 353 return; 354 355 /* Use the safe copy to generate vmcoreinfo note if have */ 356 if (vmcoreinfo_data_safecopy) 357 vmcoreinfo_data = vmcoreinfo_data_safecopy; 358 359 vmcoreinfo_append_str("CRASHTIME=%lld\n", ktime_get_real_seconds()); 360 update_vmcoreinfo_note(); 361 } 362 363 void vmcoreinfo_append_str(const char *fmt, ...) 364 { 365 va_list args; 366 char buf[0x50]; 367 size_t r; 368 369 va_start(args, fmt); 370 r = vscnprintf(buf, sizeof(buf), fmt, args); 371 va_end(args); 372 373 r = min(r, (size_t)VMCOREINFO_BYTES - vmcoreinfo_size); 374 375 memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r); 376 377 vmcoreinfo_size += r; 378 } 379 380 /* 381 * provide an empty default implementation here -- architecture 382 * code may override this 383 */ 384 void __weak arch_crash_save_vmcoreinfo(void) 385 {} 386 387 phys_addr_t __weak paddr_vmcoreinfo_note(void) 388 { 389 return __pa(vmcoreinfo_note); 390 } 391 EXPORT_SYMBOL(paddr_vmcoreinfo_note); 392 393 static int __init crash_save_vmcoreinfo_init(void) 394 { 395 vmcoreinfo_data = (unsigned char *)get_zeroed_page(GFP_KERNEL); 396 if (!vmcoreinfo_data) { 397 pr_warn("Memory allocation for vmcoreinfo_data failed\n"); 398 return -ENOMEM; 399 } 400 401 vmcoreinfo_note = alloc_pages_exact(VMCOREINFO_NOTE_SIZE, 402 GFP_KERNEL | __GFP_ZERO); 403 if (!vmcoreinfo_note) { 404 free_page((unsigned long)vmcoreinfo_data); 405 vmcoreinfo_data = NULL; 406 pr_warn("Memory allocation for vmcoreinfo_note failed\n"); 407 return -ENOMEM; 408 } 409 410 VMCOREINFO_OSRELEASE(init_uts_ns.name.release); 411 VMCOREINFO_BUILD_ID(); 412 VMCOREINFO_PAGESIZE(PAGE_SIZE); 413 414 VMCOREINFO_SYMBOL(init_uts_ns); 415 VMCOREINFO_OFFSET(uts_namespace, name); 416 VMCOREINFO_SYMBOL(node_online_map); 417 #ifdef CONFIG_MMU 418 VMCOREINFO_SYMBOL_ARRAY(swapper_pg_dir); 419 #endif 420 VMCOREINFO_SYMBOL(_stext); 421 VMCOREINFO_SYMBOL(vmap_area_list); 422 423 #ifndef CONFIG_NUMA 424 VMCOREINFO_SYMBOL(mem_map); 425 VMCOREINFO_SYMBOL(contig_page_data); 426 #endif 427 #ifdef CONFIG_SPARSEMEM 428 VMCOREINFO_SYMBOL_ARRAY(mem_section); 429 VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS); 430 VMCOREINFO_STRUCT_SIZE(mem_section); 431 VMCOREINFO_OFFSET(mem_section, section_mem_map); 432 VMCOREINFO_NUMBER(SECTION_SIZE_BITS); 433 VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS); 434 #endif 435 VMCOREINFO_STRUCT_SIZE(page); 436 VMCOREINFO_STRUCT_SIZE(pglist_data); 437 VMCOREINFO_STRUCT_SIZE(zone); 438 VMCOREINFO_STRUCT_SIZE(free_area); 439 VMCOREINFO_STRUCT_SIZE(list_head); 440 VMCOREINFO_SIZE(nodemask_t); 441 VMCOREINFO_OFFSET(page, flags); 442 VMCOREINFO_OFFSET(page, _refcount); 443 VMCOREINFO_OFFSET(page, mapping); 444 VMCOREINFO_OFFSET(page, lru); 445 VMCOREINFO_OFFSET(page, _mapcount); 446 VMCOREINFO_OFFSET(page, private); 447 VMCOREINFO_OFFSET(page, compound_dtor); 448 VMCOREINFO_OFFSET(page, compound_order); 449 VMCOREINFO_OFFSET(page, compound_head); 450 VMCOREINFO_OFFSET(pglist_data, node_zones); 451 VMCOREINFO_OFFSET(pglist_data, nr_zones); 452 #ifdef CONFIG_FLATMEM 453 VMCOREINFO_OFFSET(pglist_data, node_mem_map); 454 #endif 455 VMCOREINFO_OFFSET(pglist_data, node_start_pfn); 456 VMCOREINFO_OFFSET(pglist_data, node_spanned_pages); 457 VMCOREINFO_OFFSET(pglist_data, node_id); 458 VMCOREINFO_OFFSET(zone, free_area); 459 VMCOREINFO_OFFSET(zone, vm_stat); 460 VMCOREINFO_OFFSET(zone, spanned_pages); 461 VMCOREINFO_OFFSET(free_area, free_list); 462 VMCOREINFO_OFFSET(list_head, next); 463 VMCOREINFO_OFFSET(list_head, prev); 464 VMCOREINFO_OFFSET(vmap_area, va_start); 465 VMCOREINFO_OFFSET(vmap_area, list); 466 VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER); 467 log_buf_vmcoreinfo_setup(); 468 VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES); 469 VMCOREINFO_NUMBER(NR_FREE_PAGES); 470 VMCOREINFO_NUMBER(PG_lru); 471 VMCOREINFO_NUMBER(PG_private); 472 VMCOREINFO_NUMBER(PG_swapcache); 473 VMCOREINFO_NUMBER(PG_swapbacked); 474 VMCOREINFO_NUMBER(PG_slab); 475 #ifdef CONFIG_MEMORY_FAILURE 476 VMCOREINFO_NUMBER(PG_hwpoison); 477 #endif 478 VMCOREINFO_NUMBER(PG_head_mask); 479 #define PAGE_BUDDY_MAPCOUNT_VALUE (~PG_buddy) 480 VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE); 481 #ifdef CONFIG_HUGETLB_PAGE 482 VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR); 483 #define PAGE_OFFLINE_MAPCOUNT_VALUE (~PG_offline) 484 VMCOREINFO_NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE); 485 #endif 486 487 arch_crash_save_vmcoreinfo(); 488 update_vmcoreinfo_note(); 489 490 return 0; 491 } 492 493 subsys_initcall(crash_save_vmcoreinfo_init); 494