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