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/kstrtox.h> 15 #include <linux/memblock.h> 16 #include <linux/mm.h> 17 #include <linux/namei.h> 18 #include <linux/init_syscalls.h> 19 #include <linux/task_work.h> 20 #include <linux/umh.h> 21 22 static __initdata bool csum_present; 23 static __initdata u32 io_csum; 24 25 static ssize_t __init xwrite(struct file *file, const unsigned char *p, 26 size_t count, loff_t *pos) 27 { 28 ssize_t out = 0; 29 30 /* sys_write only can write MAX_RW_COUNT aka 2G-4K bytes at most */ 31 while (count) { 32 ssize_t rv = kernel_write(file, p, count, pos); 33 34 if (rv < 0) { 35 if (rv == -EINTR || rv == -EAGAIN) 36 continue; 37 return out ? out : rv; 38 } else if (rv == 0) 39 break; 40 41 if (csum_present) { 42 ssize_t i; 43 44 for (i = 0; i < rv; i++) 45 io_csum += p[i]; 46 } 47 48 p += rv; 49 out += rv; 50 count -= rv; 51 } 52 53 return out; 54 } 55 56 static __initdata char *message; 57 static void __init error(char *x) 58 { 59 if (!message) 60 message = x; 61 } 62 63 static void panic_show_mem(const char *fmt, ...) 64 { 65 va_list args; 66 67 show_mem(0, NULL); 68 va_start(args, fmt); 69 panic(fmt, args); 70 va_end(args); 71 } 72 73 /* link hash */ 74 75 #define N_ALIGN(len) ((((len) + 1) & ~3) + 2) 76 77 static __initdata struct hash { 78 int ino, minor, major; 79 umode_t mode; 80 struct hash *next; 81 char name[N_ALIGN(PATH_MAX)]; 82 } *head[32]; 83 84 static inline int hash(int major, int minor, int ino) 85 { 86 unsigned long tmp = ino + minor + (major << 3); 87 tmp += tmp >> 5; 88 return tmp & 31; 89 } 90 91 static char __init *find_link(int major, int minor, int ino, 92 umode_t mode, char *name) 93 { 94 struct hash **p, *q; 95 for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) { 96 if ((*p)->ino != ino) 97 continue; 98 if ((*p)->minor != minor) 99 continue; 100 if ((*p)->major != major) 101 continue; 102 if (((*p)->mode ^ mode) & S_IFMT) 103 continue; 104 return (*p)->name; 105 } 106 q = kmalloc(sizeof(struct hash), GFP_KERNEL); 107 if (!q) 108 panic_show_mem("can't allocate link hash entry"); 109 q->major = major; 110 q->minor = minor; 111 q->ino = ino; 112 q->mode = mode; 113 strcpy(q->name, name); 114 q->next = NULL; 115 *p = q; 116 return NULL; 117 } 118 119 static void __init free_hash(void) 120 { 121 struct hash **p, *q; 122 for (p = head; p < head + 32; p++) { 123 while (*p) { 124 q = *p; 125 *p = q->next; 126 kfree(q); 127 } 128 } 129 } 130 131 #ifdef CONFIG_INITRAMFS_PRESERVE_MTIME 132 static void __init do_utime(char *filename, time64_t mtime) 133 { 134 struct timespec64 t[2] = { { .tv_sec = mtime }, { .tv_sec = mtime } }; 135 init_utimes(filename, t); 136 } 137 138 static void __init do_utime_path(const struct path *path, time64_t mtime) 139 { 140 struct timespec64 t[2] = { { .tv_sec = mtime }, { .tv_sec = mtime } }; 141 vfs_utimes(path, t); 142 } 143 144 static __initdata LIST_HEAD(dir_list); 145 struct dir_entry { 146 struct list_head list; 147 time64_t mtime; 148 char name[]; 149 }; 150 151 static void __init dir_add(const char *name, time64_t mtime) 152 { 153 size_t nlen = strlen(name) + 1; 154 struct dir_entry *de; 155 156 de = kmalloc(sizeof(struct dir_entry) + nlen, GFP_KERNEL); 157 if (!de) 158 panic_show_mem("can't allocate dir_entry buffer"); 159 INIT_LIST_HEAD(&de->list); 160 strscpy(de->name, name, nlen); 161 de->mtime = mtime; 162 list_add(&de->list, &dir_list); 163 } 164 165 static void __init dir_utime(void) 166 { 167 struct dir_entry *de, *tmp; 168 list_for_each_entry_safe(de, tmp, &dir_list, list) { 169 list_del(&de->list); 170 do_utime(de->name, de->mtime); 171 kfree(de); 172 } 173 } 174 #else 175 static void __init do_utime(char *filename, time64_t mtime) {} 176 static void __init do_utime_path(const struct path *path, time64_t mtime) {} 177 static void __init dir_add(const char *name, time64_t mtime) {} 178 static void __init dir_utime(void) {} 179 #endif 180 181 static __initdata time64_t mtime; 182 183 /* cpio header parsing */ 184 185 static __initdata unsigned long ino, major, minor, nlink; 186 static __initdata umode_t mode; 187 static __initdata unsigned long body_len, name_len; 188 static __initdata uid_t uid; 189 static __initdata gid_t gid; 190 static __initdata unsigned rdev; 191 static __initdata u32 hdr_csum; 192 193 static void __init parse_header(char *s) 194 { 195 unsigned long parsed[13]; 196 char buf[9]; 197 int i; 198 199 buf[8] = '\0'; 200 for (i = 0, s += 6; i < 13; i++, s += 8) { 201 memcpy(buf, s, 8); 202 parsed[i] = simple_strtoul(buf, NULL, 16); 203 } 204 ino = parsed[0]; 205 mode = parsed[1]; 206 uid = parsed[2]; 207 gid = parsed[3]; 208 nlink = parsed[4]; 209 mtime = parsed[5]; /* breaks in y2106 */ 210 body_len = parsed[6]; 211 major = parsed[7]; 212 minor = parsed[8]; 213 rdev = new_encode_dev(MKDEV(parsed[9], parsed[10])); 214 name_len = parsed[11]; 215 hdr_csum = parsed[12]; 216 } 217 218 /* FSM */ 219 220 static __initdata enum state { 221 Start, 222 Collect, 223 GotHeader, 224 SkipIt, 225 GotName, 226 CopyFile, 227 GotSymlink, 228 Reset 229 } state, next_state; 230 231 static __initdata char *victim; 232 static unsigned long byte_count __initdata; 233 static __initdata loff_t this_header, next_header; 234 235 static inline void __init eat(unsigned n) 236 { 237 victim += n; 238 this_header += n; 239 byte_count -= n; 240 } 241 242 static __initdata char *collected; 243 static long remains __initdata; 244 static __initdata char *collect; 245 246 static void __init read_into(char *buf, unsigned size, enum state next) 247 { 248 if (byte_count >= size) { 249 collected = victim; 250 eat(size); 251 state = next; 252 } else { 253 collect = collected = buf; 254 remains = size; 255 next_state = next; 256 state = Collect; 257 } 258 } 259 260 static __initdata char *header_buf, *symlink_buf, *name_buf; 261 262 static int __init do_start(void) 263 { 264 read_into(header_buf, 110, GotHeader); 265 return 0; 266 } 267 268 static int __init do_collect(void) 269 { 270 unsigned long n = remains; 271 if (byte_count < n) 272 n = byte_count; 273 memcpy(collect, victim, n); 274 eat(n); 275 collect += n; 276 if ((remains -= n) != 0) 277 return 1; 278 state = next_state; 279 return 0; 280 } 281 282 static int __init do_header(void) 283 { 284 if (!memcmp(collected, "070701", 6)) { 285 csum_present = false; 286 } else if (!memcmp(collected, "070702", 6)) { 287 csum_present = true; 288 } else { 289 if (memcmp(collected, "070707", 6) == 0) 290 error("incorrect cpio method used: use -H newc option"); 291 else 292 error("no cpio magic"); 293 return 1; 294 } 295 parse_header(collected); 296 next_header = this_header + N_ALIGN(name_len) + body_len; 297 next_header = (next_header + 3) & ~3; 298 state = SkipIt; 299 if (name_len <= 0 || name_len > PATH_MAX) 300 return 0; 301 if (S_ISLNK(mode)) { 302 if (body_len > PATH_MAX) 303 return 0; 304 collect = collected = symlink_buf; 305 remains = N_ALIGN(name_len) + body_len; 306 next_state = GotSymlink; 307 state = Collect; 308 return 0; 309 } 310 if (S_ISREG(mode) || !body_len) 311 read_into(name_buf, N_ALIGN(name_len), GotName); 312 return 0; 313 } 314 315 static int __init do_skip(void) 316 { 317 if (this_header + byte_count < next_header) { 318 eat(byte_count); 319 return 1; 320 } else { 321 eat(next_header - this_header); 322 state = next_state; 323 return 0; 324 } 325 } 326 327 static int __init do_reset(void) 328 { 329 while (byte_count && *victim == '\0') 330 eat(1); 331 if (byte_count && (this_header & 3)) 332 error("broken padding"); 333 return 1; 334 } 335 336 static void __init clean_path(char *path, umode_t fmode) 337 { 338 struct kstat st; 339 340 if (!init_stat(path, &st, AT_SYMLINK_NOFOLLOW) && 341 (st.mode ^ fmode) & S_IFMT) { 342 if (S_ISDIR(st.mode)) 343 init_rmdir(path); 344 else 345 init_unlink(path); 346 } 347 } 348 349 static int __init maybe_link(void) 350 { 351 if (nlink >= 2) { 352 char *old = find_link(major, minor, ino, mode, collected); 353 if (old) { 354 clean_path(collected, 0); 355 return (init_link(old, collected) < 0) ? -1 : 1; 356 } 357 } 358 return 0; 359 } 360 361 static __initdata struct file *wfile; 362 static __initdata loff_t wfile_pos; 363 364 static int __init do_name(void) 365 { 366 state = SkipIt; 367 next_state = Reset; 368 if (strcmp(collected, "TRAILER!!!") == 0) { 369 free_hash(); 370 return 0; 371 } 372 clean_path(collected, mode); 373 if (S_ISREG(mode)) { 374 int ml = maybe_link(); 375 if (ml >= 0) { 376 int openflags = O_WRONLY|O_CREAT; 377 if (ml != 1) 378 openflags |= O_TRUNC; 379 wfile = filp_open(collected, openflags, mode); 380 if (IS_ERR(wfile)) 381 return 0; 382 wfile_pos = 0; 383 io_csum = 0; 384 385 vfs_fchown(wfile, uid, gid); 386 vfs_fchmod(wfile, mode); 387 if (body_len) 388 vfs_truncate(&wfile->f_path, body_len); 389 state = CopyFile; 390 } 391 } else if (S_ISDIR(mode)) { 392 init_mkdir(collected, mode); 393 init_chown(collected, uid, gid, 0); 394 init_chmod(collected, mode); 395 dir_add(collected, mtime); 396 } else if (S_ISBLK(mode) || S_ISCHR(mode) || 397 S_ISFIFO(mode) || S_ISSOCK(mode)) { 398 if (maybe_link() == 0) { 399 init_mknod(collected, mode, rdev); 400 init_chown(collected, uid, gid, 0); 401 init_chmod(collected, mode); 402 do_utime(collected, mtime); 403 } 404 } 405 return 0; 406 } 407 408 static int __init do_copy(void) 409 { 410 if (byte_count >= body_len) { 411 if (xwrite(wfile, victim, body_len, &wfile_pos) != body_len) 412 error("write error"); 413 414 do_utime_path(&wfile->f_path, mtime); 415 fput(wfile); 416 if (csum_present && io_csum != hdr_csum) 417 error("bad data checksum"); 418 eat(body_len); 419 state = SkipIt; 420 return 0; 421 } else { 422 if (xwrite(wfile, victim, byte_count, &wfile_pos) != byte_count) 423 error("write error"); 424 body_len -= byte_count; 425 eat(byte_count); 426 return 1; 427 } 428 } 429 430 static int __init do_symlink(void) 431 { 432 collected[N_ALIGN(name_len) + body_len] = '\0'; 433 clean_path(collected, 0); 434 init_symlink(collected + N_ALIGN(name_len), collected); 435 init_chown(collected, uid, gid, AT_SYMLINK_NOFOLLOW); 436 do_utime(collected, mtime); 437 state = SkipIt; 438 next_state = Reset; 439 return 0; 440 } 441 442 static __initdata int (*actions[])(void) = { 443 [Start] = do_start, 444 [Collect] = do_collect, 445 [GotHeader] = do_header, 446 [SkipIt] = do_skip, 447 [GotName] = do_name, 448 [CopyFile] = do_copy, 449 [GotSymlink] = do_symlink, 450 [Reset] = do_reset, 451 }; 452 453 static long __init write_buffer(char *buf, unsigned long len) 454 { 455 byte_count = len; 456 victim = buf; 457 458 while (!actions[state]()) 459 ; 460 return len - byte_count; 461 } 462 463 static long __init flush_buffer(void *bufv, unsigned long len) 464 { 465 char *buf = bufv; 466 long written; 467 long origLen = len; 468 if (message) 469 return -1; 470 while ((written = write_buffer(buf, len)) < len && !message) { 471 char c = buf[written]; 472 if (c == '0') { 473 buf += written; 474 len -= written; 475 state = Start; 476 } else if (c == 0) { 477 buf += written; 478 len -= written; 479 state = Reset; 480 } else 481 error("junk within compressed archive"); 482 } 483 return origLen; 484 } 485 486 static unsigned long my_inptr __initdata; /* index of next byte to be processed in inbuf */ 487 488 #include <linux/decompress/generic.h> 489 490 static char * __init unpack_to_rootfs(char *buf, unsigned long len) 491 { 492 long written; 493 decompress_fn decompress; 494 const char *compress_name; 495 static __initdata char msg_buf[64]; 496 497 header_buf = kmalloc(110, GFP_KERNEL); 498 symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL); 499 name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL); 500 501 if (!header_buf || !symlink_buf || !name_buf) 502 panic_show_mem("can't allocate buffers"); 503 504 state = Start; 505 this_header = 0; 506 message = NULL; 507 while (!message && len) { 508 loff_t saved_offset = this_header; 509 if (*buf == '0' && !(this_header & 3)) { 510 state = Start; 511 written = write_buffer(buf, len); 512 buf += written; 513 len -= written; 514 continue; 515 } 516 if (!*buf) { 517 buf++; 518 len--; 519 this_header++; 520 continue; 521 } 522 this_header = 0; 523 decompress = decompress_method(buf, len, &compress_name); 524 pr_debug("Detected %s compressed data\n", compress_name); 525 if (decompress) { 526 int res = decompress(buf, len, NULL, flush_buffer, NULL, 527 &my_inptr, error); 528 if (res) 529 error("decompressor failed"); 530 } else if (compress_name) { 531 if (!message) { 532 snprintf(msg_buf, sizeof msg_buf, 533 "compression method %s not configured", 534 compress_name); 535 message = msg_buf; 536 } 537 } else 538 error("invalid magic at start of compressed archive"); 539 if (state != Reset) 540 error("junk at the end of compressed archive"); 541 this_header = saved_offset + my_inptr; 542 buf += my_inptr; 543 len -= my_inptr; 544 } 545 dir_utime(); 546 kfree(name_buf); 547 kfree(symlink_buf); 548 kfree(header_buf); 549 return message; 550 } 551 552 static int __initdata do_retain_initrd; 553 554 static int __init retain_initrd_param(char *str) 555 { 556 if (*str) 557 return 0; 558 do_retain_initrd = 1; 559 return 1; 560 } 561 __setup("retain_initrd", retain_initrd_param); 562 563 #ifdef CONFIG_ARCH_HAS_KEEPINITRD 564 static int __init keepinitrd_setup(char *__unused) 565 { 566 do_retain_initrd = 1; 567 return 1; 568 } 569 __setup("keepinitrd", keepinitrd_setup); 570 #endif 571 572 static bool __initdata initramfs_async = true; 573 static int __init initramfs_async_setup(char *str) 574 { 575 return kstrtobool(str, &initramfs_async) == 0; 576 } 577 __setup("initramfs_async=", initramfs_async_setup); 578 579 extern char __initramfs_start[]; 580 extern unsigned long __initramfs_size; 581 #include <linux/initrd.h> 582 #include <linux/kexec.h> 583 584 void __init reserve_initrd_mem(void) 585 { 586 phys_addr_t start; 587 unsigned long size; 588 589 /* Ignore the virtul address computed during device tree parsing */ 590 initrd_start = initrd_end = 0; 591 592 if (!phys_initrd_size) 593 return; 594 /* 595 * Round the memory region to page boundaries as per free_initrd_mem() 596 * This allows us to detect whether the pages overlapping the initrd 597 * are in use, but more importantly, reserves the entire set of pages 598 * as we don't want these pages allocated for other purposes. 599 */ 600 start = round_down(phys_initrd_start, PAGE_SIZE); 601 size = phys_initrd_size + (phys_initrd_start - start); 602 size = round_up(size, PAGE_SIZE); 603 604 if (!memblock_is_region_memory(start, size)) { 605 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region", 606 (u64)start, size); 607 goto disable; 608 } 609 610 if (memblock_is_region_reserved(start, size)) { 611 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region\n", 612 (u64)start, size); 613 goto disable; 614 } 615 616 memblock_reserve(start, size); 617 /* Now convert initrd to virtual addresses */ 618 initrd_start = (unsigned long)__va(phys_initrd_start); 619 initrd_end = initrd_start + phys_initrd_size; 620 initrd_below_start_ok = 1; 621 622 return; 623 disable: 624 pr_cont(" - disabling initrd\n"); 625 initrd_start = 0; 626 initrd_end = 0; 627 } 628 629 void __weak __init free_initrd_mem(unsigned long start, unsigned long end) 630 { 631 #ifdef CONFIG_ARCH_KEEP_MEMBLOCK 632 unsigned long aligned_start = ALIGN_DOWN(start, PAGE_SIZE); 633 unsigned long aligned_end = ALIGN(end, PAGE_SIZE); 634 635 memblock_free((void *)aligned_start, aligned_end - aligned_start); 636 #endif 637 638 free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM, 639 "initrd"); 640 } 641 642 #ifdef CONFIG_KEXEC_CORE 643 static bool __init kexec_free_initrd(void) 644 { 645 unsigned long crashk_start = (unsigned long)__va(crashk_res.start); 646 unsigned long crashk_end = (unsigned long)__va(crashk_res.end); 647 648 /* 649 * If the initrd region is overlapped with crashkernel reserved region, 650 * free only memory that is not part of crashkernel region. 651 */ 652 if (initrd_start >= crashk_end || initrd_end <= crashk_start) 653 return false; 654 655 /* 656 * Initialize initrd memory region since the kexec boot does not do. 657 */ 658 memset((void *)initrd_start, 0, initrd_end - initrd_start); 659 if (initrd_start < crashk_start) 660 free_initrd_mem(initrd_start, crashk_start); 661 if (initrd_end > crashk_end) 662 free_initrd_mem(crashk_end, initrd_end); 663 return true; 664 } 665 #else 666 static inline bool kexec_free_initrd(void) 667 { 668 return false; 669 } 670 #endif /* CONFIG_KEXEC_CORE */ 671 672 #ifdef CONFIG_BLK_DEV_RAM 673 static void __init populate_initrd_image(char *err) 674 { 675 ssize_t written; 676 struct file *file; 677 loff_t pos = 0; 678 679 unpack_to_rootfs(__initramfs_start, __initramfs_size); 680 681 printk(KERN_INFO "rootfs image is not initramfs (%s); looks like an initrd\n", 682 err); 683 file = filp_open("/initrd.image", O_WRONLY | O_CREAT, 0700); 684 if (IS_ERR(file)) 685 return; 686 687 written = xwrite(file, (char *)initrd_start, initrd_end - initrd_start, 688 &pos); 689 if (written != initrd_end - initrd_start) 690 pr_err("/initrd.image: incomplete write (%zd != %ld)\n", 691 written, initrd_end - initrd_start); 692 fput(file); 693 } 694 #endif /* CONFIG_BLK_DEV_RAM */ 695 696 static void __init do_populate_rootfs(void *unused, async_cookie_t cookie) 697 { 698 /* Load the built in initramfs */ 699 char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size); 700 if (err) 701 panic_show_mem("%s", err); /* Failed to decompress INTERNAL initramfs */ 702 703 if (!initrd_start || IS_ENABLED(CONFIG_INITRAMFS_FORCE)) 704 goto done; 705 706 if (IS_ENABLED(CONFIG_BLK_DEV_RAM)) 707 printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n"); 708 else 709 printk(KERN_INFO "Unpacking initramfs...\n"); 710 711 err = unpack_to_rootfs((char *)initrd_start, initrd_end - initrd_start); 712 if (err) { 713 #ifdef CONFIG_BLK_DEV_RAM 714 populate_initrd_image(err); 715 #else 716 printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err); 717 #endif 718 } 719 720 done: 721 /* 722 * If the initrd region is overlapped with crashkernel reserved region, 723 * free only memory that is not part of crashkernel region. 724 */ 725 if (!do_retain_initrd && initrd_start && !kexec_free_initrd()) 726 free_initrd_mem(initrd_start, initrd_end); 727 initrd_start = 0; 728 initrd_end = 0; 729 730 flush_delayed_fput(); 731 task_work_run(); 732 } 733 734 static ASYNC_DOMAIN_EXCLUSIVE(initramfs_domain); 735 static async_cookie_t initramfs_cookie; 736 737 void wait_for_initramfs(void) 738 { 739 if (!initramfs_cookie) { 740 /* 741 * Something before rootfs_initcall wants to access 742 * the filesystem/initramfs. Probably a bug. Make a 743 * note, avoid deadlocking the machine, and let the 744 * caller's access fail as it used to. 745 */ 746 pr_warn_once("wait_for_initramfs() called before rootfs_initcalls\n"); 747 return; 748 } 749 async_synchronize_cookie_domain(initramfs_cookie + 1, &initramfs_domain); 750 } 751 EXPORT_SYMBOL_GPL(wait_for_initramfs); 752 753 static int __init populate_rootfs(void) 754 { 755 initramfs_cookie = async_schedule_domain(do_populate_rootfs, NULL, 756 &initramfs_domain); 757 usermodehelper_enable(); 758 if (!initramfs_async) 759 wait_for_initramfs(); 760 return 0; 761 } 762 rootfs_initcall(populate_rootfs); 763