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