1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/init.h> 3 #include <linux/async.h> 4 #include <linux/fs.h> 5 #include <linux/slab.h> 6 #include <linux/types.h> 7 #include <linux/fcntl.h> 8 #include <linux/delay.h> 9 #include <linux/string.h> 10 #include <linux/dirent.h> 11 #include <linux/syscalls.h> 12 #include <linux/utime.h> 13 #include <linux/file.h> 14 #include <linux/memblock.h> 15 #include <linux/mm.h> 16 #include <linux/namei.h> 17 #include <linux/init_syscalls.h> 18 #include <linux/umh.h> 19 20 static ssize_t __init xwrite(struct file *file, const char *p, size_t count, 21 loff_t *pos) 22 { 23 ssize_t out = 0; 24 25 /* sys_write only can write MAX_RW_COUNT aka 2G-4K bytes at most */ 26 while (count) { 27 ssize_t rv = kernel_write(file, p, count, pos); 28 29 if (rv < 0) { 30 if (rv == -EINTR || rv == -EAGAIN) 31 continue; 32 return out ? out : rv; 33 } else if (rv == 0) 34 break; 35 36 p += rv; 37 out += rv; 38 count -= rv; 39 } 40 41 return out; 42 } 43 44 static __initdata char *message; 45 static void __init error(char *x) 46 { 47 if (!message) 48 message = x; 49 } 50 51 static void panic_show_mem(const char *fmt, ...) 52 { 53 va_list args; 54 55 show_mem(0, NULL); 56 va_start(args, fmt); 57 panic(fmt, args); 58 va_end(args); 59 } 60 61 /* link hash */ 62 63 #define N_ALIGN(len) ((((len) + 1) & ~3) + 2) 64 65 static __initdata struct hash { 66 int ino, minor, major; 67 umode_t mode; 68 struct hash *next; 69 char name[N_ALIGN(PATH_MAX)]; 70 } *head[32]; 71 72 static inline int hash(int major, int minor, int ino) 73 { 74 unsigned long tmp = ino + minor + (major << 3); 75 tmp += tmp >> 5; 76 return tmp & 31; 77 } 78 79 static char __init *find_link(int major, int minor, int ino, 80 umode_t mode, char *name) 81 { 82 struct hash **p, *q; 83 for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) { 84 if ((*p)->ino != ino) 85 continue; 86 if ((*p)->minor != minor) 87 continue; 88 if ((*p)->major != major) 89 continue; 90 if (((*p)->mode ^ mode) & S_IFMT) 91 continue; 92 return (*p)->name; 93 } 94 q = kmalloc(sizeof(struct hash), GFP_KERNEL); 95 if (!q) 96 panic_show_mem("can't allocate link hash entry"); 97 q->major = major; 98 q->minor = minor; 99 q->ino = ino; 100 q->mode = mode; 101 strcpy(q->name, name); 102 q->next = NULL; 103 *p = q; 104 return NULL; 105 } 106 107 static void __init free_hash(void) 108 { 109 struct hash **p, *q; 110 for (p = head; p < head + 32; p++) { 111 while (*p) { 112 q = *p; 113 *p = q->next; 114 kfree(q); 115 } 116 } 117 } 118 119 static long __init do_utime(char *filename, time64_t mtime) 120 { 121 struct timespec64 t[2]; 122 123 t[0].tv_sec = mtime; 124 t[0].tv_nsec = 0; 125 t[1].tv_sec = mtime; 126 t[1].tv_nsec = 0; 127 return init_utimes(filename, t); 128 } 129 130 static __initdata LIST_HEAD(dir_list); 131 struct dir_entry { 132 struct list_head list; 133 char *name; 134 time64_t mtime; 135 }; 136 137 static void __init dir_add(const char *name, time64_t mtime) 138 { 139 struct dir_entry *de = kmalloc(sizeof(struct dir_entry), GFP_KERNEL); 140 if (!de) 141 panic_show_mem("can't allocate dir_entry buffer"); 142 INIT_LIST_HEAD(&de->list); 143 de->name = kstrdup(name, GFP_KERNEL); 144 de->mtime = mtime; 145 list_add(&de->list, &dir_list); 146 } 147 148 static void __init dir_utime(void) 149 { 150 struct dir_entry *de, *tmp; 151 list_for_each_entry_safe(de, tmp, &dir_list, list) { 152 list_del(&de->list); 153 do_utime(de->name, de->mtime); 154 kfree(de->name); 155 kfree(de); 156 } 157 } 158 159 static __initdata time64_t mtime; 160 161 /* cpio header parsing */ 162 163 static __initdata unsigned long ino, major, minor, nlink; 164 static __initdata umode_t mode; 165 static __initdata unsigned long body_len, name_len; 166 static __initdata uid_t uid; 167 static __initdata gid_t gid; 168 static __initdata unsigned rdev; 169 170 static void __init parse_header(char *s) 171 { 172 unsigned long parsed[12]; 173 char buf[9]; 174 int i; 175 176 buf[8] = '\0'; 177 for (i = 0, s += 6; i < 12; i++, s += 8) { 178 memcpy(buf, s, 8); 179 parsed[i] = simple_strtoul(buf, NULL, 16); 180 } 181 ino = parsed[0]; 182 mode = parsed[1]; 183 uid = parsed[2]; 184 gid = parsed[3]; 185 nlink = parsed[4]; 186 mtime = parsed[5]; /* breaks in y2106 */ 187 body_len = parsed[6]; 188 major = parsed[7]; 189 minor = parsed[8]; 190 rdev = new_encode_dev(MKDEV(parsed[9], parsed[10])); 191 name_len = parsed[11]; 192 } 193 194 /* FSM */ 195 196 static __initdata enum state { 197 Start, 198 Collect, 199 GotHeader, 200 SkipIt, 201 GotName, 202 CopyFile, 203 GotSymlink, 204 Reset 205 } state, next_state; 206 207 static __initdata char *victim; 208 static unsigned long byte_count __initdata; 209 static __initdata loff_t this_header, next_header; 210 211 static inline void __init eat(unsigned n) 212 { 213 victim += n; 214 this_header += n; 215 byte_count -= n; 216 } 217 218 static __initdata char *collected; 219 static long remains __initdata; 220 static __initdata char *collect; 221 222 static void __init read_into(char *buf, unsigned size, enum state next) 223 { 224 if (byte_count >= size) { 225 collected = victim; 226 eat(size); 227 state = next; 228 } else { 229 collect = collected = buf; 230 remains = size; 231 next_state = next; 232 state = Collect; 233 } 234 } 235 236 static __initdata char *header_buf, *symlink_buf, *name_buf; 237 238 static int __init do_start(void) 239 { 240 read_into(header_buf, 110, GotHeader); 241 return 0; 242 } 243 244 static int __init do_collect(void) 245 { 246 unsigned long n = remains; 247 if (byte_count < n) 248 n = byte_count; 249 memcpy(collect, victim, n); 250 eat(n); 251 collect += n; 252 if ((remains -= n) != 0) 253 return 1; 254 state = next_state; 255 return 0; 256 } 257 258 static int __init do_header(void) 259 { 260 if (memcmp(collected, "070707", 6)==0) { 261 error("incorrect cpio method used: use -H newc option"); 262 return 1; 263 } 264 if (memcmp(collected, "070701", 6)) { 265 error("no cpio magic"); 266 return 1; 267 } 268 parse_header(collected); 269 next_header = this_header + N_ALIGN(name_len) + body_len; 270 next_header = (next_header + 3) & ~3; 271 state = SkipIt; 272 if (name_len <= 0 || name_len > PATH_MAX) 273 return 0; 274 if (S_ISLNK(mode)) { 275 if (body_len > PATH_MAX) 276 return 0; 277 collect = collected = symlink_buf; 278 remains = N_ALIGN(name_len) + body_len; 279 next_state = GotSymlink; 280 state = Collect; 281 return 0; 282 } 283 if (S_ISREG(mode) || !body_len) 284 read_into(name_buf, N_ALIGN(name_len), GotName); 285 return 0; 286 } 287 288 static int __init do_skip(void) 289 { 290 if (this_header + byte_count < next_header) { 291 eat(byte_count); 292 return 1; 293 } else { 294 eat(next_header - this_header); 295 state = next_state; 296 return 0; 297 } 298 } 299 300 static int __init do_reset(void) 301 { 302 while (byte_count && *victim == '\0') 303 eat(1); 304 if (byte_count && (this_header & 3)) 305 error("broken padding"); 306 return 1; 307 } 308 309 static void __init clean_path(char *path, umode_t fmode) 310 { 311 struct kstat st; 312 313 if (!init_stat(path, &st, AT_SYMLINK_NOFOLLOW) && 314 (st.mode ^ fmode) & S_IFMT) { 315 if (S_ISDIR(st.mode)) 316 init_rmdir(path); 317 else 318 init_unlink(path); 319 } 320 } 321 322 static int __init maybe_link(void) 323 { 324 if (nlink >= 2) { 325 char *old = find_link(major, minor, ino, mode, collected); 326 if (old) { 327 clean_path(collected, 0); 328 return (init_link(old, collected) < 0) ? -1 : 1; 329 } 330 } 331 return 0; 332 } 333 334 static __initdata struct file *wfile; 335 static __initdata loff_t wfile_pos; 336 337 static int __init do_name(void) 338 { 339 state = SkipIt; 340 next_state = Reset; 341 if (strcmp(collected, "TRAILER!!!") == 0) { 342 free_hash(); 343 return 0; 344 } 345 clean_path(collected, mode); 346 if (S_ISREG(mode)) { 347 int ml = maybe_link(); 348 if (ml >= 0) { 349 int openflags = O_WRONLY|O_CREAT; 350 if (ml != 1) 351 openflags |= O_TRUNC; 352 wfile = filp_open(collected, openflags, mode); 353 if (IS_ERR(wfile)) 354 return 0; 355 wfile_pos = 0; 356 357 vfs_fchown(wfile, uid, gid); 358 vfs_fchmod(wfile, mode); 359 if (body_len) 360 vfs_truncate(&wfile->f_path, body_len); 361 state = CopyFile; 362 } 363 } else if (S_ISDIR(mode)) { 364 init_mkdir(collected, mode); 365 init_chown(collected, uid, gid, 0); 366 init_chmod(collected, mode); 367 dir_add(collected, mtime); 368 } else if (S_ISBLK(mode) || S_ISCHR(mode) || 369 S_ISFIFO(mode) || S_ISSOCK(mode)) { 370 if (maybe_link() == 0) { 371 init_mknod(collected, mode, rdev); 372 init_chown(collected, uid, gid, 0); 373 init_chmod(collected, mode); 374 do_utime(collected, mtime); 375 } 376 } 377 return 0; 378 } 379 380 static int __init do_copy(void) 381 { 382 if (byte_count >= body_len) { 383 struct timespec64 t[2] = { }; 384 if (xwrite(wfile, victim, body_len, &wfile_pos) != body_len) 385 error("write error"); 386 387 t[0].tv_sec = mtime; 388 t[1].tv_sec = mtime; 389 vfs_utimes(&wfile->f_path, t); 390 391 fput(wfile); 392 eat(body_len); 393 state = SkipIt; 394 return 0; 395 } else { 396 if (xwrite(wfile, victim, byte_count, &wfile_pos) != byte_count) 397 error("write error"); 398 body_len -= byte_count; 399 eat(byte_count); 400 return 1; 401 } 402 } 403 404 static int __init do_symlink(void) 405 { 406 collected[N_ALIGN(name_len) + body_len] = '\0'; 407 clean_path(collected, 0); 408 init_symlink(collected + N_ALIGN(name_len), collected); 409 init_chown(collected, uid, gid, AT_SYMLINK_NOFOLLOW); 410 do_utime(collected, mtime); 411 state = SkipIt; 412 next_state = Reset; 413 return 0; 414 } 415 416 static __initdata int (*actions[])(void) = { 417 [Start] = do_start, 418 [Collect] = do_collect, 419 [GotHeader] = do_header, 420 [SkipIt] = do_skip, 421 [GotName] = do_name, 422 [CopyFile] = do_copy, 423 [GotSymlink] = do_symlink, 424 [Reset] = do_reset, 425 }; 426 427 static long __init write_buffer(char *buf, unsigned long len) 428 { 429 byte_count = len; 430 victim = buf; 431 432 while (!actions[state]()) 433 ; 434 return len - byte_count; 435 } 436 437 static long __init flush_buffer(void *bufv, unsigned long len) 438 { 439 char *buf = (char *) bufv; 440 long written; 441 long origLen = len; 442 if (message) 443 return -1; 444 while ((written = write_buffer(buf, len)) < len && !message) { 445 char c = buf[written]; 446 if (c == '0') { 447 buf += written; 448 len -= written; 449 state = Start; 450 } else if (c == 0) { 451 buf += written; 452 len -= written; 453 state = Reset; 454 } else 455 error("junk within compressed archive"); 456 } 457 return origLen; 458 } 459 460 static unsigned long my_inptr; /* index of next byte to be processed in inbuf */ 461 462 #include <linux/decompress/generic.h> 463 464 static char * __init unpack_to_rootfs(char *buf, unsigned long len) 465 { 466 long written; 467 decompress_fn decompress; 468 const char *compress_name; 469 static __initdata char msg_buf[64]; 470 471 header_buf = kmalloc(110, GFP_KERNEL); 472 symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL); 473 name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL); 474 475 if (!header_buf || !symlink_buf || !name_buf) 476 panic_show_mem("can't allocate buffers"); 477 478 state = Start; 479 this_header = 0; 480 message = NULL; 481 while (!message && len) { 482 loff_t saved_offset = this_header; 483 if (*buf == '0' && !(this_header & 3)) { 484 state = Start; 485 written = write_buffer(buf, len); 486 buf += written; 487 len -= written; 488 continue; 489 } 490 if (!*buf) { 491 buf++; 492 len--; 493 this_header++; 494 continue; 495 } 496 this_header = 0; 497 decompress = decompress_method(buf, len, &compress_name); 498 pr_debug("Detected %s compressed data\n", compress_name); 499 if (decompress) { 500 int res = decompress(buf, len, NULL, flush_buffer, NULL, 501 &my_inptr, error); 502 if (res) 503 error("decompressor failed"); 504 } else if (compress_name) { 505 if (!message) { 506 snprintf(msg_buf, sizeof msg_buf, 507 "compression method %s not configured", 508 compress_name); 509 message = msg_buf; 510 } 511 } else 512 error("invalid magic at start of compressed archive"); 513 if (state != Reset) 514 error("junk at the end of compressed archive"); 515 this_header = saved_offset + my_inptr; 516 buf += my_inptr; 517 len -= my_inptr; 518 } 519 dir_utime(); 520 kfree(name_buf); 521 kfree(symlink_buf); 522 kfree(header_buf); 523 return message; 524 } 525 526 static int __initdata do_retain_initrd; 527 528 static int __init retain_initrd_param(char *str) 529 { 530 if (*str) 531 return 0; 532 do_retain_initrd = 1; 533 return 1; 534 } 535 __setup("retain_initrd", retain_initrd_param); 536 537 #ifdef CONFIG_ARCH_HAS_KEEPINITRD 538 static int __init keepinitrd_setup(char *__unused) 539 { 540 do_retain_initrd = 1; 541 return 1; 542 } 543 __setup("keepinitrd", keepinitrd_setup); 544 #endif 545 546 static bool __initdata initramfs_async = true; 547 static int __init initramfs_async_setup(char *str) 548 { 549 strtobool(str, &initramfs_async); 550 return 1; 551 } 552 __setup("initramfs_async=", initramfs_async_setup); 553 554 extern char __initramfs_start[]; 555 extern unsigned long __initramfs_size; 556 #include <linux/initrd.h> 557 #include <linux/kexec.h> 558 559 void __init reserve_initrd_mem(void) 560 { 561 phys_addr_t start; 562 unsigned long size; 563 564 /* Ignore the virtul address computed during device tree parsing */ 565 initrd_start = initrd_end = 0; 566 567 if (!phys_initrd_size) 568 return; 569 /* 570 * Round the memory region to page boundaries as per free_initrd_mem() 571 * This allows us to detect whether the pages overlapping the initrd 572 * are in use, but more importantly, reserves the entire set of pages 573 * as we don't want these pages allocated for other purposes. 574 */ 575 start = round_down(phys_initrd_start, PAGE_SIZE); 576 size = phys_initrd_size + (phys_initrd_start - start); 577 size = round_up(size, PAGE_SIZE); 578 579 if (!memblock_is_region_memory(start, size)) { 580 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region", 581 (u64)start, size); 582 goto disable; 583 } 584 585 if (memblock_is_region_reserved(start, size)) { 586 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region\n", 587 (u64)start, size); 588 goto disable; 589 } 590 591 memblock_reserve(start, size); 592 /* Now convert initrd to virtual addresses */ 593 initrd_start = (unsigned long)__va(phys_initrd_start); 594 initrd_end = initrd_start + phys_initrd_size; 595 initrd_below_start_ok = 1; 596 597 return; 598 disable: 599 pr_cont(" - disabling initrd\n"); 600 initrd_start = 0; 601 initrd_end = 0; 602 } 603 604 void __weak __init free_initrd_mem(unsigned long start, unsigned long end) 605 { 606 #ifdef CONFIG_ARCH_KEEP_MEMBLOCK 607 unsigned long aligned_start = ALIGN_DOWN(start, PAGE_SIZE); 608 unsigned long aligned_end = ALIGN(end, PAGE_SIZE); 609 610 memblock_free((void *)aligned_start, aligned_end - aligned_start); 611 #endif 612 613 free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM, 614 "initrd"); 615 } 616 617 #ifdef CONFIG_KEXEC_CORE 618 static bool __init kexec_free_initrd(void) 619 { 620 unsigned long crashk_start = (unsigned long)__va(crashk_res.start); 621 unsigned long crashk_end = (unsigned long)__va(crashk_res.end); 622 623 /* 624 * If the initrd region is overlapped with crashkernel reserved region, 625 * free only memory that is not part of crashkernel region. 626 */ 627 if (initrd_start >= crashk_end || initrd_end <= crashk_start) 628 return false; 629 630 /* 631 * Initialize initrd memory region since the kexec boot does not do. 632 */ 633 memset((void *)initrd_start, 0, initrd_end - initrd_start); 634 if (initrd_start < crashk_start) 635 free_initrd_mem(initrd_start, crashk_start); 636 if (initrd_end > crashk_end) 637 free_initrd_mem(crashk_end, initrd_end); 638 return true; 639 } 640 #else 641 static inline bool kexec_free_initrd(void) 642 { 643 return false; 644 } 645 #endif /* CONFIG_KEXEC_CORE */ 646 647 #ifdef CONFIG_BLK_DEV_RAM 648 static void __init populate_initrd_image(char *err) 649 { 650 ssize_t written; 651 struct file *file; 652 loff_t pos = 0; 653 654 unpack_to_rootfs(__initramfs_start, __initramfs_size); 655 656 printk(KERN_INFO "rootfs image is not initramfs (%s); looks like an initrd\n", 657 err); 658 file = filp_open("/initrd.image", O_WRONLY | O_CREAT, 0700); 659 if (IS_ERR(file)) 660 return; 661 662 written = xwrite(file, (char *)initrd_start, initrd_end - initrd_start, 663 &pos); 664 if (written != initrd_end - initrd_start) 665 pr_err("/initrd.image: incomplete write (%zd != %ld)\n", 666 written, initrd_end - initrd_start); 667 fput(file); 668 } 669 #endif /* CONFIG_BLK_DEV_RAM */ 670 671 static void __init do_populate_rootfs(void *unused, async_cookie_t cookie) 672 { 673 /* Load the built in initramfs */ 674 char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size); 675 if (err) 676 panic_show_mem("%s", err); /* Failed to decompress INTERNAL initramfs */ 677 678 if (!initrd_start || IS_ENABLED(CONFIG_INITRAMFS_FORCE)) 679 goto done; 680 681 if (IS_ENABLED(CONFIG_BLK_DEV_RAM)) 682 printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n"); 683 else 684 printk(KERN_INFO "Unpacking initramfs...\n"); 685 686 err = unpack_to_rootfs((char *)initrd_start, initrd_end - initrd_start); 687 if (err) { 688 #ifdef CONFIG_BLK_DEV_RAM 689 populate_initrd_image(err); 690 #else 691 printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err); 692 #endif 693 } 694 695 done: 696 /* 697 * If the initrd region is overlapped with crashkernel reserved region, 698 * free only memory that is not part of crashkernel region. 699 */ 700 if (!do_retain_initrd && initrd_start && !kexec_free_initrd()) 701 free_initrd_mem(initrd_start, initrd_end); 702 initrd_start = 0; 703 initrd_end = 0; 704 705 flush_delayed_fput(); 706 } 707 708 static ASYNC_DOMAIN_EXCLUSIVE(initramfs_domain); 709 static async_cookie_t initramfs_cookie; 710 711 void wait_for_initramfs(void) 712 { 713 if (!initramfs_cookie) { 714 /* 715 * Something before rootfs_initcall wants to access 716 * the filesystem/initramfs. Probably a bug. Make a 717 * note, avoid deadlocking the machine, and let the 718 * caller's access fail as it used to. 719 */ 720 pr_warn_once("wait_for_initramfs() called before rootfs_initcalls\n"); 721 return; 722 } 723 async_synchronize_cookie_domain(initramfs_cookie + 1, &initramfs_domain); 724 } 725 EXPORT_SYMBOL_GPL(wait_for_initramfs); 726 727 static int __init populate_rootfs(void) 728 { 729 initramfs_cookie = async_schedule_domain(do_populate_rootfs, NULL, 730 &initramfs_domain); 731 usermodehelper_enable(); 732 if (!initramfs_async) 733 wait_for_initramfs(); 734 return 0; 735 } 736 rootfs_initcall(populate_rootfs); 737