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/task_work.h> 19 #include <linux/umh.h> 20 21 static __initdata bool csum_present; 22 static __initdata u32 io_csum; 23 24 static ssize_t __init xwrite(struct file *file, const unsigned char *p, 25 size_t count, loff_t *pos) 26 { 27 ssize_t out = 0; 28 29 /* sys_write only can write MAX_RW_COUNT aka 2G-4K bytes at most */ 30 while (count) { 31 ssize_t rv = kernel_write(file, p, count, pos); 32 33 if (rv < 0) { 34 if (rv == -EINTR || rv == -EAGAIN) 35 continue; 36 return out ? out : rv; 37 } else if (rv == 0) 38 break; 39 40 if (csum_present) { 41 ssize_t i; 42 43 for (i = 0; i < rv; i++) 44 io_csum += p[i]; 45 } 46 47 p += rv; 48 out += rv; 49 count -= rv; 50 } 51 52 return out; 53 } 54 55 static __initdata char *message; 56 static void __init error(char *x) 57 { 58 if (!message) 59 message = x; 60 } 61 62 static void panic_show_mem(const char *fmt, ...) 63 { 64 va_list args; 65 66 show_mem(0, NULL); 67 va_start(args, fmt); 68 panic(fmt, args); 69 va_end(args); 70 } 71 72 /* link hash */ 73 74 #define N_ALIGN(len) ((((len) + 1) & ~3) + 2) 75 76 static __initdata struct hash { 77 int ino, minor, major; 78 umode_t mode; 79 struct hash *next; 80 char name[N_ALIGN(PATH_MAX)]; 81 } *head[32]; 82 83 static inline int hash(int major, int minor, int ino) 84 { 85 unsigned long tmp = ino + minor + (major << 3); 86 tmp += tmp >> 5; 87 return tmp & 31; 88 } 89 90 static char __init *find_link(int major, int minor, int ino, 91 umode_t mode, char *name) 92 { 93 struct hash **p, *q; 94 for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) { 95 if ((*p)->ino != ino) 96 continue; 97 if ((*p)->minor != minor) 98 continue; 99 if ((*p)->major != major) 100 continue; 101 if (((*p)->mode ^ mode) & S_IFMT) 102 continue; 103 return (*p)->name; 104 } 105 q = kmalloc(sizeof(struct hash), GFP_KERNEL); 106 if (!q) 107 panic_show_mem("can't allocate link hash entry"); 108 q->major = major; 109 q->minor = minor; 110 q->ino = ino; 111 q->mode = mode; 112 strcpy(q->name, name); 113 q->next = NULL; 114 *p = q; 115 return NULL; 116 } 117 118 static void __init free_hash(void) 119 { 120 struct hash **p, *q; 121 for (p = head; p < head + 32; p++) { 122 while (*p) { 123 q = *p; 124 *p = q->next; 125 kfree(q); 126 } 127 } 128 } 129 130 #ifdef CONFIG_INITRAMFS_PRESERVE_MTIME 131 static void __init do_utime(char *filename, time64_t mtime) 132 { 133 struct timespec64 t[2] = { { .tv_sec = mtime }, { .tv_sec = mtime } }; 134 init_utimes(filename, t); 135 } 136 137 static void __init do_utime_path(const struct path *path, time64_t mtime) 138 { 139 struct timespec64 t[2] = { { .tv_sec = mtime }, { .tv_sec = mtime } }; 140 vfs_utimes(path, t); 141 } 142 143 static __initdata LIST_HEAD(dir_list); 144 struct dir_entry { 145 struct list_head list; 146 time64_t mtime; 147 char name[]; 148 }; 149 150 static void __init dir_add(const char *name, time64_t mtime) 151 { 152 size_t nlen = strlen(name) + 1; 153 struct dir_entry *de; 154 155 de = kmalloc(sizeof(struct dir_entry) + nlen, GFP_KERNEL); 156 if (!de) 157 panic_show_mem("can't allocate dir_entry buffer"); 158 INIT_LIST_HEAD(&de->list); 159 strscpy(de->name, name, nlen); 160 de->mtime = mtime; 161 list_add(&de->list, &dir_list); 162 } 163 164 static void __init dir_utime(void) 165 { 166 struct dir_entry *de, *tmp; 167 list_for_each_entry_safe(de, tmp, &dir_list, list) { 168 list_del(&de->list); 169 do_utime(de->name, de->mtime); 170 kfree(de); 171 } 172 } 173 #else 174 static void __init do_utime(char *filename, time64_t mtime) {} 175 static void __init do_utime_path(const struct path *path, time64_t mtime) {} 176 static void __init dir_add(const char *name, time64_t mtime) {} 177 static void __init dir_utime(void) {} 178 #endif 179 180 static __initdata time64_t mtime; 181 182 /* cpio header parsing */ 183 184 static __initdata unsigned long ino, major, minor, nlink; 185 static __initdata umode_t mode; 186 static __initdata unsigned long body_len, name_len; 187 static __initdata uid_t uid; 188 static __initdata gid_t gid; 189 static __initdata unsigned rdev; 190 static __initdata u32 hdr_csum; 191 192 static void __init parse_header(char *s) 193 { 194 unsigned long parsed[13]; 195 char buf[9]; 196 int i; 197 198 buf[8] = '\0'; 199 for (i = 0, s += 6; i < 13; i++, s += 8) { 200 memcpy(buf, s, 8); 201 parsed[i] = simple_strtoul(buf, NULL, 16); 202 } 203 ino = parsed[0]; 204 mode = parsed[1]; 205 uid = parsed[2]; 206 gid = parsed[3]; 207 nlink = parsed[4]; 208 mtime = parsed[5]; /* breaks in y2106 */ 209 body_len = parsed[6]; 210 major = parsed[7]; 211 minor = parsed[8]; 212 rdev = new_encode_dev(MKDEV(parsed[9], parsed[10])); 213 name_len = parsed[11]; 214 hdr_csum = parsed[12]; 215 } 216 217 /* FSM */ 218 219 static __initdata enum state { 220 Start, 221 Collect, 222 GotHeader, 223 SkipIt, 224 GotName, 225 CopyFile, 226 GotSymlink, 227 Reset 228 } state, next_state; 229 230 static __initdata char *victim; 231 static unsigned long byte_count __initdata; 232 static __initdata loff_t this_header, next_header; 233 234 static inline void __init eat(unsigned n) 235 { 236 victim += n; 237 this_header += n; 238 byte_count -= n; 239 } 240 241 static __initdata char *collected; 242 static long remains __initdata; 243 static __initdata char *collect; 244 245 static void __init read_into(char *buf, unsigned size, enum state next) 246 { 247 if (byte_count >= size) { 248 collected = victim; 249 eat(size); 250 state = next; 251 } else { 252 collect = collected = buf; 253 remains = size; 254 next_state = next; 255 state = Collect; 256 } 257 } 258 259 static __initdata char *header_buf, *symlink_buf, *name_buf; 260 261 static int __init do_start(void) 262 { 263 read_into(header_buf, 110, GotHeader); 264 return 0; 265 } 266 267 static int __init do_collect(void) 268 { 269 unsigned long n = remains; 270 if (byte_count < n) 271 n = byte_count; 272 memcpy(collect, victim, n); 273 eat(n); 274 collect += n; 275 if ((remains -= n) != 0) 276 return 1; 277 state = next_state; 278 return 0; 279 } 280 281 static int __init do_header(void) 282 { 283 if (!memcmp(collected, "070701", 6)) { 284 csum_present = false; 285 } else if (!memcmp(collected, "070702", 6)) { 286 csum_present = true; 287 } else { 288 if (memcmp(collected, "070707", 6) == 0) 289 error("incorrect cpio method used: use -H newc option"); 290 else 291 error("no cpio magic"); 292 return 1; 293 } 294 parse_header(collected); 295 next_header = this_header + N_ALIGN(name_len) + body_len; 296 next_header = (next_header + 3) & ~3; 297 state = SkipIt; 298 if (name_len <= 0 || name_len > PATH_MAX) 299 return 0; 300 if (S_ISLNK(mode)) { 301 if (body_len > PATH_MAX) 302 return 0; 303 collect = collected = symlink_buf; 304 remains = N_ALIGN(name_len) + body_len; 305 next_state = GotSymlink; 306 state = Collect; 307 return 0; 308 } 309 if (S_ISREG(mode) || !body_len) 310 read_into(name_buf, N_ALIGN(name_len), GotName); 311 return 0; 312 } 313 314 static int __init do_skip(void) 315 { 316 if (this_header + byte_count < next_header) { 317 eat(byte_count); 318 return 1; 319 } else { 320 eat(next_header - this_header); 321 state = next_state; 322 return 0; 323 } 324 } 325 326 static int __init do_reset(void) 327 { 328 while (byte_count && *victim == '\0') 329 eat(1); 330 if (byte_count && (this_header & 3)) 331 error("broken padding"); 332 return 1; 333 } 334 335 static void __init clean_path(char *path, umode_t fmode) 336 { 337 struct kstat st; 338 339 if (!init_stat(path, &st, AT_SYMLINK_NOFOLLOW) && 340 (st.mode ^ fmode) & S_IFMT) { 341 if (S_ISDIR(st.mode)) 342 init_rmdir(path); 343 else 344 init_unlink(path); 345 } 346 } 347 348 static int __init maybe_link(void) 349 { 350 if (nlink >= 2) { 351 char *old = find_link(major, minor, ino, mode, collected); 352 if (old) { 353 clean_path(collected, 0); 354 return (init_link(old, collected) < 0) ? -1 : 1; 355 } 356 } 357 return 0; 358 } 359 360 static __initdata struct file *wfile; 361 static __initdata loff_t wfile_pos; 362 363 static int __init do_name(void) 364 { 365 state = SkipIt; 366 next_state = Reset; 367 if (strcmp(collected, "TRAILER!!!") == 0) { 368 free_hash(); 369 return 0; 370 } 371 clean_path(collected, mode); 372 if (S_ISREG(mode)) { 373 int ml = maybe_link(); 374 if (ml >= 0) { 375 int openflags = O_WRONLY|O_CREAT; 376 if (ml != 1) 377 openflags |= O_TRUNC; 378 wfile = filp_open(collected, openflags, mode); 379 if (IS_ERR(wfile)) 380 return 0; 381 wfile_pos = 0; 382 io_csum = 0; 383 384 vfs_fchown(wfile, uid, gid); 385 vfs_fchmod(wfile, mode); 386 if (body_len) 387 vfs_truncate(&wfile->f_path, body_len); 388 state = CopyFile; 389 } 390 } else if (S_ISDIR(mode)) { 391 init_mkdir(collected, mode); 392 init_chown(collected, uid, gid, 0); 393 init_chmod(collected, mode); 394 dir_add(collected, mtime); 395 } else if (S_ISBLK(mode) || S_ISCHR(mode) || 396 S_ISFIFO(mode) || S_ISSOCK(mode)) { 397 if (maybe_link() == 0) { 398 init_mknod(collected, mode, rdev); 399 init_chown(collected, uid, gid, 0); 400 init_chmod(collected, mode); 401 do_utime(collected, mtime); 402 } 403 } 404 return 0; 405 } 406 407 static int __init do_copy(void) 408 { 409 if (byte_count >= body_len) { 410 if (xwrite(wfile, victim, body_len, &wfile_pos) != body_len) 411 error("write error"); 412 413 do_utime_path(&wfile->f_path, mtime); 414 fput(wfile); 415 if (csum_present && io_csum != hdr_csum) 416 error("bad data checksum"); 417 eat(body_len); 418 state = SkipIt; 419 return 0; 420 } else { 421 if (xwrite(wfile, victim, byte_count, &wfile_pos) != byte_count) 422 error("write error"); 423 body_len -= byte_count; 424 eat(byte_count); 425 return 1; 426 } 427 } 428 429 static int __init do_symlink(void) 430 { 431 collected[N_ALIGN(name_len) + body_len] = '\0'; 432 clean_path(collected, 0); 433 init_symlink(collected + N_ALIGN(name_len), collected); 434 init_chown(collected, uid, gid, AT_SYMLINK_NOFOLLOW); 435 do_utime(collected, mtime); 436 state = SkipIt; 437 next_state = Reset; 438 return 0; 439 } 440 441 static __initdata int (*actions[])(void) = { 442 [Start] = do_start, 443 [Collect] = do_collect, 444 [GotHeader] = do_header, 445 [SkipIt] = do_skip, 446 [GotName] = do_name, 447 [CopyFile] = do_copy, 448 [GotSymlink] = do_symlink, 449 [Reset] = do_reset, 450 }; 451 452 static long __init write_buffer(char *buf, unsigned long len) 453 { 454 byte_count = len; 455 victim = buf; 456 457 while (!actions[state]()) 458 ; 459 return len - byte_count; 460 } 461 462 static long __init flush_buffer(void *bufv, unsigned long len) 463 { 464 char *buf = bufv; 465 long written; 466 long origLen = len; 467 if (message) 468 return -1; 469 while ((written = write_buffer(buf, len)) < len && !message) { 470 char c = buf[written]; 471 if (c == '0') { 472 buf += written; 473 len -= written; 474 state = Start; 475 } else if (c == 0) { 476 buf += written; 477 len -= written; 478 state = Reset; 479 } else 480 error("junk within compressed archive"); 481 } 482 return origLen; 483 } 484 485 static unsigned long my_inptr __initdata; /* index of next byte to be processed in inbuf */ 486 487 #include <linux/decompress/generic.h> 488 489 static char * __init unpack_to_rootfs(char *buf, unsigned long len) 490 { 491 long written; 492 decompress_fn decompress; 493 const char *compress_name; 494 static __initdata char msg_buf[64]; 495 496 header_buf = kmalloc(110, GFP_KERNEL); 497 symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL); 498 name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL); 499 500 if (!header_buf || !symlink_buf || !name_buf) 501 panic_show_mem("can't allocate buffers"); 502 503 state = Start; 504 this_header = 0; 505 message = NULL; 506 while (!message && len) { 507 loff_t saved_offset = this_header; 508 if (*buf == '0' && !(this_header & 3)) { 509 state = Start; 510 written = write_buffer(buf, len); 511 buf += written; 512 len -= written; 513 continue; 514 } 515 if (!*buf) { 516 buf++; 517 len--; 518 this_header++; 519 continue; 520 } 521 this_header = 0; 522 decompress = decompress_method(buf, len, &compress_name); 523 pr_debug("Detected %s compressed data\n", compress_name); 524 if (decompress) { 525 int res = decompress(buf, len, NULL, flush_buffer, NULL, 526 &my_inptr, error); 527 if (res) 528 error("decompressor failed"); 529 } else if (compress_name) { 530 if (!message) { 531 snprintf(msg_buf, sizeof msg_buf, 532 "compression method %s not configured", 533 compress_name); 534 message = msg_buf; 535 } 536 } else 537 error("invalid magic at start of compressed archive"); 538 if (state != Reset) 539 error("junk at the end of compressed archive"); 540 this_header = saved_offset + my_inptr; 541 buf += my_inptr; 542 len -= my_inptr; 543 } 544 dir_utime(); 545 kfree(name_buf); 546 kfree(symlink_buf); 547 kfree(header_buf); 548 return message; 549 } 550 551 static int __initdata do_retain_initrd; 552 553 static int __init retain_initrd_param(char *str) 554 { 555 if (*str) 556 return 0; 557 do_retain_initrd = 1; 558 return 1; 559 } 560 __setup("retain_initrd", retain_initrd_param); 561 562 #ifdef CONFIG_ARCH_HAS_KEEPINITRD 563 static int __init keepinitrd_setup(char *__unused) 564 { 565 do_retain_initrd = 1; 566 return 1; 567 } 568 __setup("keepinitrd", keepinitrd_setup); 569 #endif 570 571 static bool __initdata initramfs_async = true; 572 static int __init initramfs_async_setup(char *str) 573 { 574 strtobool(str, &initramfs_async); 575 return 1; 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