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 if (!ck_cmdline) 247 return -ENOENT; 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 */ 271 int __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 } 279 280 int __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 } 288 289 int __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 } 297 298 /* 299 * Add a dummy early_param handler to mark crashkernel= as a known command line 300 * parameter and suppress incorrect warnings in init/main.c. 301 */ 302 static int __init parse_crashkernel_dummy(char *arg) 303 { 304 return 0; 305 } 306 early_param("crashkernel", parse_crashkernel_dummy); 307 308 Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type, 309 void *data, size_t data_len) 310 { 311 struct elf_note *note = (struct elf_note *)buf; 312 313 note->n_namesz = strlen(name) + 1; 314 note->n_descsz = data_len; 315 note->n_type = type; 316 buf += DIV_ROUND_UP(sizeof(*note), sizeof(Elf_Word)); 317 memcpy(buf, name, note->n_namesz); 318 buf += DIV_ROUND_UP(note->n_namesz, sizeof(Elf_Word)); 319 memcpy(buf, data, data_len); 320 buf += DIV_ROUND_UP(data_len, sizeof(Elf_Word)); 321 322 return buf; 323 } 324 325 void final_note(Elf_Word *buf) 326 { 327 memset(buf, 0, sizeof(struct elf_note)); 328 } 329 330 static void update_vmcoreinfo_note(void) 331 { 332 u32 *buf = vmcoreinfo_note; 333 334 if (!vmcoreinfo_size) 335 return; 336 buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data, 337 vmcoreinfo_size); 338 final_note(buf); 339 } 340 341 void crash_update_vmcoreinfo_safecopy(void *ptr) 342 { 343 if (ptr) 344 memcpy(ptr, vmcoreinfo_data, vmcoreinfo_size); 345 346 vmcoreinfo_data_safecopy = ptr; 347 } 348 349 void crash_save_vmcoreinfo(void) 350 { 351 if (!vmcoreinfo_note) 352 return; 353 354 /* Use the safe copy to generate vmcoreinfo note if have */ 355 if (vmcoreinfo_data_safecopy) 356 vmcoreinfo_data = vmcoreinfo_data_safecopy; 357 358 vmcoreinfo_append_str("CRASHTIME=%lld\n", ktime_get_real_seconds()); 359 update_vmcoreinfo_note(); 360 } 361 362 void vmcoreinfo_append_str(const char *fmt, ...) 363 { 364 va_list args; 365 char buf[0x50]; 366 size_t r; 367 368 va_start(args, fmt); 369 r = vscnprintf(buf, sizeof(buf), fmt, args); 370 va_end(args); 371 372 r = min(r, (size_t)VMCOREINFO_BYTES - vmcoreinfo_size); 373 374 memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r); 375 376 vmcoreinfo_size += r; 377 } 378 379 /* 380 * provide an empty default implementation here -- architecture 381 * code may override this 382 */ 383 void __weak arch_crash_save_vmcoreinfo(void) 384 {} 385 386 phys_addr_t __weak paddr_vmcoreinfo_note(void) 387 { 388 return __pa(vmcoreinfo_note); 389 } 390 EXPORT_SYMBOL(paddr_vmcoreinfo_note); 391 392 static int __init crash_save_vmcoreinfo_init(void) 393 { 394 vmcoreinfo_data = (unsigned char *)get_zeroed_page(GFP_KERNEL); 395 if (!vmcoreinfo_data) { 396 pr_warn("Memory allocation for vmcoreinfo_data failed\n"); 397 return -ENOMEM; 398 } 399 400 vmcoreinfo_note = alloc_pages_exact(VMCOREINFO_NOTE_SIZE, 401 GFP_KERNEL | __GFP_ZERO); 402 if (!vmcoreinfo_note) { 403 free_page((unsigned long)vmcoreinfo_data); 404 vmcoreinfo_data = NULL; 405 pr_warn("Memory allocation for vmcoreinfo_note failed\n"); 406 return -ENOMEM; 407 } 408 409 VMCOREINFO_OSRELEASE(init_uts_ns.name.release); 410 VMCOREINFO_BUILD_ID(); 411 VMCOREINFO_PAGESIZE(PAGE_SIZE); 412 413 VMCOREINFO_SYMBOL(init_uts_ns); 414 VMCOREINFO_OFFSET(uts_namespace, name); 415 VMCOREINFO_SYMBOL(node_online_map); 416 #ifdef CONFIG_MMU 417 VMCOREINFO_SYMBOL_ARRAY(swapper_pg_dir); 418 #endif 419 VMCOREINFO_SYMBOL(_stext); 420 VMCOREINFO_SYMBOL(vmap_area_list); 421 422 #ifndef CONFIG_NUMA 423 VMCOREINFO_SYMBOL(mem_map); 424 VMCOREINFO_SYMBOL(contig_page_data); 425 #endif 426 #ifdef CONFIG_SPARSEMEM 427 VMCOREINFO_SYMBOL_ARRAY(mem_section); 428 VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS); 429 VMCOREINFO_STRUCT_SIZE(mem_section); 430 VMCOREINFO_OFFSET(mem_section, section_mem_map); 431 VMCOREINFO_NUMBER(SECTION_SIZE_BITS); 432 VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS); 433 #endif 434 VMCOREINFO_STRUCT_SIZE(page); 435 VMCOREINFO_STRUCT_SIZE(pglist_data); 436 VMCOREINFO_STRUCT_SIZE(zone); 437 VMCOREINFO_STRUCT_SIZE(free_area); 438 VMCOREINFO_STRUCT_SIZE(list_head); 439 VMCOREINFO_SIZE(nodemask_t); 440 VMCOREINFO_OFFSET(page, flags); 441 VMCOREINFO_OFFSET(page, _refcount); 442 VMCOREINFO_OFFSET(page, mapping); 443 VMCOREINFO_OFFSET(page, lru); 444 VMCOREINFO_OFFSET(page, _mapcount); 445 VMCOREINFO_OFFSET(page, private); 446 VMCOREINFO_OFFSET(page, compound_dtor); 447 VMCOREINFO_OFFSET(page, compound_order); 448 VMCOREINFO_OFFSET(page, compound_head); 449 VMCOREINFO_OFFSET(pglist_data, node_zones); 450 VMCOREINFO_OFFSET(pglist_data, nr_zones); 451 #ifdef CONFIG_FLATMEM 452 VMCOREINFO_OFFSET(pglist_data, node_mem_map); 453 #endif 454 VMCOREINFO_OFFSET(pglist_data, node_start_pfn); 455 VMCOREINFO_OFFSET(pglist_data, node_spanned_pages); 456 VMCOREINFO_OFFSET(pglist_data, node_id); 457 VMCOREINFO_OFFSET(zone, free_area); 458 VMCOREINFO_OFFSET(zone, vm_stat); 459 VMCOREINFO_OFFSET(zone, spanned_pages); 460 VMCOREINFO_OFFSET(free_area, free_list); 461 VMCOREINFO_OFFSET(list_head, next); 462 VMCOREINFO_OFFSET(list_head, prev); 463 VMCOREINFO_OFFSET(vmap_area, va_start); 464 VMCOREINFO_OFFSET(vmap_area, list); 465 VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER); 466 log_buf_vmcoreinfo_setup(); 467 VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES); 468 VMCOREINFO_NUMBER(NR_FREE_PAGES); 469 VMCOREINFO_NUMBER(PG_lru); 470 VMCOREINFO_NUMBER(PG_private); 471 VMCOREINFO_NUMBER(PG_swapcache); 472 VMCOREINFO_NUMBER(PG_swapbacked); 473 VMCOREINFO_NUMBER(PG_slab); 474 #ifdef CONFIG_MEMORY_FAILURE 475 VMCOREINFO_NUMBER(PG_hwpoison); 476 #endif 477 VMCOREINFO_NUMBER(PG_head_mask); 478 #define PAGE_BUDDY_MAPCOUNT_VALUE (~PG_buddy) 479 VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE); 480 #ifdef CONFIG_HUGETLB_PAGE 481 VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR); 482 #define PAGE_OFFLINE_MAPCOUNT_VALUE (~PG_offline) 483 VMCOREINFO_NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE); 484 #endif 485 486 arch_crash_save_vmcoreinfo(); 487 update_vmcoreinfo_note(); 488 489 return 0; 490 } 491 492 subsys_initcall(crash_save_vmcoreinfo_init); 493