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