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