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 return ck_cmdline; 226 } 227 228 static int __init __parse_crashkernel(char *cmdline, 229 unsigned long long system_ram, 230 unsigned long long *crash_size, 231 unsigned long long *crash_base, 232 const char *name, 233 const char *suffix) 234 { 235 char *first_colon, *first_space; 236 char *ck_cmdline; 237 238 BUG_ON(!crash_size || !crash_base); 239 *crash_size = 0; 240 *crash_base = 0; 241 242 ck_cmdline = get_last_crashkernel(cmdline, name, suffix); 243 if (!ck_cmdline) 244 return -ENOENT; 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 */ 268 int __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 } 276 277 int __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 } 285 286 int __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 } 294 295 /* 296 * Add a dummy early_param handler to mark crashkernel= as a known command line 297 * parameter and suppress incorrect warnings in init/main.c. 298 */ 299 static int __init parse_crashkernel_dummy(char *arg) 300 { 301 return 0; 302 } 303 early_param("crashkernel", parse_crashkernel_dummy); 304 305 Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type, 306 void *data, size_t data_len) 307 { 308 struct elf_note *note = (struct elf_note *)buf; 309 310 note->n_namesz = strlen(name) + 1; 311 note->n_descsz = data_len; 312 note->n_type = type; 313 buf += DIV_ROUND_UP(sizeof(*note), sizeof(Elf_Word)); 314 memcpy(buf, name, note->n_namesz); 315 buf += DIV_ROUND_UP(note->n_namesz, sizeof(Elf_Word)); 316 memcpy(buf, data, data_len); 317 buf += DIV_ROUND_UP(data_len, sizeof(Elf_Word)); 318 319 return buf; 320 } 321 322 void final_note(Elf_Word *buf) 323 { 324 memset(buf, 0, sizeof(struct elf_note)); 325 } 326 327 static void update_vmcoreinfo_note(void) 328 { 329 u32 *buf = vmcoreinfo_note; 330 331 if (!vmcoreinfo_size) 332 return; 333 buf = append_elf_note(buf, VMCOREINFO_NOTE_NAME, 0, vmcoreinfo_data, 334 vmcoreinfo_size); 335 final_note(buf); 336 } 337 338 void crash_update_vmcoreinfo_safecopy(void *ptr) 339 { 340 if (ptr) 341 memcpy(ptr, vmcoreinfo_data, vmcoreinfo_size); 342 343 vmcoreinfo_data_safecopy = ptr; 344 } 345 346 void crash_save_vmcoreinfo(void) 347 { 348 if (!vmcoreinfo_note) 349 return; 350 351 /* Use the safe copy to generate vmcoreinfo note if have */ 352 if (vmcoreinfo_data_safecopy) 353 vmcoreinfo_data = vmcoreinfo_data_safecopy; 354 355 vmcoreinfo_append_str("CRASHTIME=%lld\n", ktime_get_real_seconds()); 356 update_vmcoreinfo_note(); 357 } 358 359 void vmcoreinfo_append_str(const char *fmt, ...) 360 { 361 va_list args; 362 char buf[0x50]; 363 size_t r; 364 365 va_start(args, fmt); 366 r = vscnprintf(buf, sizeof(buf), fmt, args); 367 va_end(args); 368 369 r = min(r, (size_t)VMCOREINFO_BYTES - vmcoreinfo_size); 370 371 memcpy(&vmcoreinfo_data[vmcoreinfo_size], buf, r); 372 373 vmcoreinfo_size += r; 374 } 375 376 /* 377 * provide an empty default implementation here -- architecture 378 * code may override this 379 */ 380 void __weak arch_crash_save_vmcoreinfo(void) 381 {} 382 383 phys_addr_t __weak paddr_vmcoreinfo_note(void) 384 { 385 return __pa(vmcoreinfo_note); 386 } 387 EXPORT_SYMBOL(paddr_vmcoreinfo_note); 388 389 static int __init crash_save_vmcoreinfo_init(void) 390 { 391 vmcoreinfo_data = (unsigned char *)get_zeroed_page(GFP_KERNEL); 392 if (!vmcoreinfo_data) { 393 pr_warn("Memory allocation for vmcoreinfo_data failed\n"); 394 return -ENOMEM; 395 } 396 397 vmcoreinfo_note = alloc_pages_exact(VMCOREINFO_NOTE_SIZE, 398 GFP_KERNEL | __GFP_ZERO); 399 if (!vmcoreinfo_note) { 400 free_page((unsigned long)vmcoreinfo_data); 401 vmcoreinfo_data = NULL; 402 pr_warn("Memory allocation for vmcoreinfo_note failed\n"); 403 return -ENOMEM; 404 } 405 406 VMCOREINFO_OSRELEASE(init_uts_ns.name.release); 407 VMCOREINFO_BUILD_ID(); 408 VMCOREINFO_PAGESIZE(PAGE_SIZE); 409 410 VMCOREINFO_SYMBOL(init_uts_ns); 411 VMCOREINFO_OFFSET(uts_namespace, name); 412 VMCOREINFO_SYMBOL(node_online_map); 413 #ifdef CONFIG_MMU 414 VMCOREINFO_SYMBOL_ARRAY(swapper_pg_dir); 415 #endif 416 VMCOREINFO_SYMBOL(_stext); 417 VMCOREINFO_SYMBOL(vmap_area_list); 418 419 #ifndef CONFIG_NUMA 420 VMCOREINFO_SYMBOL(mem_map); 421 VMCOREINFO_SYMBOL(contig_page_data); 422 #endif 423 #ifdef CONFIG_SPARSEMEM 424 VMCOREINFO_SYMBOL_ARRAY(mem_section); 425 VMCOREINFO_LENGTH(mem_section, NR_SECTION_ROOTS); 426 VMCOREINFO_STRUCT_SIZE(mem_section); 427 VMCOREINFO_OFFSET(mem_section, section_mem_map); 428 VMCOREINFO_NUMBER(SECTION_SIZE_BITS); 429 VMCOREINFO_NUMBER(MAX_PHYSMEM_BITS); 430 #endif 431 VMCOREINFO_STRUCT_SIZE(page); 432 VMCOREINFO_STRUCT_SIZE(pglist_data); 433 VMCOREINFO_STRUCT_SIZE(zone); 434 VMCOREINFO_STRUCT_SIZE(free_area); 435 VMCOREINFO_STRUCT_SIZE(list_head); 436 VMCOREINFO_SIZE(nodemask_t); 437 VMCOREINFO_OFFSET(page, flags); 438 VMCOREINFO_OFFSET(page, _refcount); 439 VMCOREINFO_OFFSET(page, mapping); 440 VMCOREINFO_OFFSET(page, lru); 441 VMCOREINFO_OFFSET(page, _mapcount); 442 VMCOREINFO_OFFSET(page, private); 443 VMCOREINFO_OFFSET(page, compound_dtor); 444 VMCOREINFO_OFFSET(page, compound_order); 445 VMCOREINFO_OFFSET(page, compound_head); 446 VMCOREINFO_OFFSET(pglist_data, node_zones); 447 VMCOREINFO_OFFSET(pglist_data, nr_zones); 448 #ifdef CONFIG_FLATMEM 449 VMCOREINFO_OFFSET(pglist_data, node_mem_map); 450 #endif 451 VMCOREINFO_OFFSET(pglist_data, node_start_pfn); 452 VMCOREINFO_OFFSET(pglist_data, node_spanned_pages); 453 VMCOREINFO_OFFSET(pglist_data, node_id); 454 VMCOREINFO_OFFSET(zone, free_area); 455 VMCOREINFO_OFFSET(zone, vm_stat); 456 VMCOREINFO_OFFSET(zone, spanned_pages); 457 VMCOREINFO_OFFSET(free_area, free_list); 458 VMCOREINFO_OFFSET(list_head, next); 459 VMCOREINFO_OFFSET(list_head, prev); 460 VMCOREINFO_OFFSET(vmap_area, va_start); 461 VMCOREINFO_OFFSET(vmap_area, list); 462 VMCOREINFO_LENGTH(zone.free_area, MAX_ORDER); 463 log_buf_vmcoreinfo_setup(); 464 VMCOREINFO_LENGTH(free_area.free_list, MIGRATE_TYPES); 465 VMCOREINFO_NUMBER(NR_FREE_PAGES); 466 VMCOREINFO_NUMBER(PG_lru); 467 VMCOREINFO_NUMBER(PG_private); 468 VMCOREINFO_NUMBER(PG_swapcache); 469 VMCOREINFO_NUMBER(PG_swapbacked); 470 VMCOREINFO_NUMBER(PG_slab); 471 #ifdef CONFIG_MEMORY_FAILURE 472 VMCOREINFO_NUMBER(PG_hwpoison); 473 #endif 474 VMCOREINFO_NUMBER(PG_head_mask); 475 #define PAGE_BUDDY_MAPCOUNT_VALUE (~PG_buddy) 476 VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE); 477 #ifdef CONFIG_HUGETLB_PAGE 478 VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR); 479 #define PAGE_OFFLINE_MAPCOUNT_VALUE (~PG_offline) 480 VMCOREINFO_NUMBER(PAGE_OFFLINE_MAPCOUNT_VALUE); 481 #endif 482 483 arch_crash_save_vmcoreinfo(); 484 update_vmcoreinfo_note(); 485 486 return 0; 487 } 488 489 subsys_initcall(crash_save_vmcoreinfo_init); 490