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/umh.h> 20 21 #include "do_mounts.h" 22 23 static __initdata bool csum_present; 24 static __initdata u32 io_csum; 25 26 static ssize_t __init xwrite(struct file *file, const unsigned char *p, 27 size_t count, loff_t *pos) 28 { 29 ssize_t out = 0; 30 31 /* sys_write only can write MAX_RW_COUNT aka 2G-4K bytes at most */ 32 while (count) { 33 ssize_t rv = kernel_write(file, p, count, pos); 34 35 if (rv < 0) { 36 if (rv == -EINTR || rv == -EAGAIN) 37 continue; 38 return out ? out : rv; 39 } else if (rv == 0) 40 break; 41 42 if (csum_present) { 43 ssize_t i; 44 45 for (i = 0; i < rv; i++) 46 io_csum += p[i]; 47 } 48 49 p += rv; 50 out += rv; 51 count -= rv; 52 } 53 54 return out; 55 } 56 57 static __initdata char *message; 58 static void __init error(char *x) 59 { 60 if (!message) 61 message = x; 62 } 63 64 #define panic_show_mem(fmt, ...) \ 65 ({ show_mem(); panic(fmt, ##__VA_ARGS__); }) 66 67 /* link hash */ 68 69 #define N_ALIGN(len) ((((len) + 1) & ~3) + 2) 70 71 static __initdata struct hash { 72 int ino, minor, major; 73 umode_t mode; 74 struct hash *next; 75 char name[N_ALIGN(PATH_MAX)]; 76 } *head[32]; 77 78 static inline int hash(int major, int minor, int ino) 79 { 80 unsigned long tmp = ino + minor + (major << 3); 81 tmp += tmp >> 5; 82 return tmp & 31; 83 } 84 85 static char __init *find_link(int major, int minor, int ino, 86 umode_t mode, char *name) 87 { 88 struct hash **p, *q; 89 for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) { 90 if ((*p)->ino != ino) 91 continue; 92 if ((*p)->minor != minor) 93 continue; 94 if ((*p)->major != major) 95 continue; 96 if (((*p)->mode ^ mode) & S_IFMT) 97 continue; 98 return (*p)->name; 99 } 100 q = kmalloc(sizeof(struct hash), GFP_KERNEL); 101 if (!q) 102 panic_show_mem("can't allocate link hash entry"); 103 q->major = major; 104 q->minor = minor; 105 q->ino = ino; 106 q->mode = mode; 107 strcpy(q->name, name); 108 q->next = NULL; 109 *p = q; 110 return NULL; 111 } 112 113 static void __init free_hash(void) 114 { 115 struct hash **p, *q; 116 for (p = head; p < head + 32; p++) { 117 while (*p) { 118 q = *p; 119 *p = q->next; 120 kfree(q); 121 } 122 } 123 } 124 125 #ifdef CONFIG_INITRAMFS_PRESERVE_MTIME 126 static void __init do_utime(char *filename, time64_t mtime) 127 { 128 struct timespec64 t[2] = { { .tv_sec = mtime }, { .tv_sec = mtime } }; 129 init_utimes(filename, t); 130 } 131 132 static void __init do_utime_path(const struct path *path, time64_t mtime) 133 { 134 struct timespec64 t[2] = { { .tv_sec = mtime }, { .tv_sec = mtime } }; 135 vfs_utimes(path, t); 136 } 137 138 static __initdata LIST_HEAD(dir_list); 139 struct dir_entry { 140 struct list_head list; 141 time64_t mtime; 142 char name[]; 143 }; 144 145 static void __init dir_add(const char *name, time64_t mtime) 146 { 147 size_t nlen = strlen(name) + 1; 148 struct dir_entry *de; 149 150 de = kmalloc(sizeof(struct dir_entry) + nlen, GFP_KERNEL); 151 if (!de) 152 panic_show_mem("can't allocate dir_entry buffer"); 153 INIT_LIST_HEAD(&de->list); 154 strscpy(de->name, name, nlen); 155 de->mtime = mtime; 156 list_add(&de->list, &dir_list); 157 } 158 159 static void __init dir_utime(void) 160 { 161 struct dir_entry *de, *tmp; 162 list_for_each_entry_safe(de, tmp, &dir_list, list) { 163 list_del(&de->list); 164 do_utime(de->name, de->mtime); 165 kfree(de); 166 } 167 } 168 #else 169 static void __init do_utime(char *filename, time64_t mtime) {} 170 static void __init do_utime_path(const struct path *path, time64_t mtime) {} 171 static void __init dir_add(const char *name, time64_t mtime) {} 172 static void __init dir_utime(void) {} 173 #endif 174 175 static __initdata time64_t mtime; 176 177 /* cpio header parsing */ 178 179 static __initdata unsigned long ino, major, minor, nlink; 180 static __initdata umode_t mode; 181 static __initdata unsigned long body_len, name_len; 182 static __initdata uid_t uid; 183 static __initdata gid_t gid; 184 static __initdata unsigned rdev; 185 static __initdata u32 hdr_csum; 186 187 static void __init parse_header(char *s) 188 { 189 unsigned long parsed[13]; 190 char buf[9]; 191 int i; 192 193 buf[8] = '\0'; 194 for (i = 0, s += 6; i < 13; i++, s += 8) { 195 memcpy(buf, s, 8); 196 parsed[i] = simple_strtoul(buf, NULL, 16); 197 } 198 ino = parsed[0]; 199 mode = parsed[1]; 200 uid = parsed[2]; 201 gid = parsed[3]; 202 nlink = parsed[4]; 203 mtime = parsed[5]; /* breaks in y2106 */ 204 body_len = parsed[6]; 205 major = parsed[7]; 206 minor = parsed[8]; 207 rdev = new_encode_dev(MKDEV(parsed[9], parsed[10])); 208 name_len = parsed[11]; 209 hdr_csum = parsed[12]; 210 } 211 212 /* FSM */ 213 214 static __initdata enum state { 215 Start, 216 Collect, 217 GotHeader, 218 SkipIt, 219 GotName, 220 CopyFile, 221 GotSymlink, 222 Reset 223 } state, next_state; 224 225 static __initdata char *victim; 226 static unsigned long byte_count __initdata; 227 static __initdata loff_t this_header, next_header; 228 229 static inline void __init eat(unsigned n) 230 { 231 victim += n; 232 this_header += n; 233 byte_count -= n; 234 } 235 236 static __initdata char *collected; 237 static long remains __initdata; 238 static __initdata char *collect; 239 240 static void __init read_into(char *buf, unsigned size, enum state next) 241 { 242 if (byte_count >= size) { 243 collected = victim; 244 eat(size); 245 state = next; 246 } else { 247 collect = collected = buf; 248 remains = size; 249 next_state = next; 250 state = Collect; 251 } 252 } 253 254 static __initdata char *header_buf, *symlink_buf, *name_buf; 255 256 static int __init do_start(void) 257 { 258 read_into(header_buf, 110, GotHeader); 259 return 0; 260 } 261 262 static int __init do_collect(void) 263 { 264 unsigned long n = remains; 265 if (byte_count < n) 266 n = byte_count; 267 memcpy(collect, victim, n); 268 eat(n); 269 collect += n; 270 if ((remains -= n) != 0) 271 return 1; 272 state = next_state; 273 return 0; 274 } 275 276 static int __init do_header(void) 277 { 278 if (!memcmp(collected, "070701", 6)) { 279 csum_present = false; 280 } else if (!memcmp(collected, "070702", 6)) { 281 csum_present = true; 282 } else { 283 if (memcmp(collected, "070707", 6) == 0) 284 error("incorrect cpio method used: use -H newc option"); 285 else 286 error("no cpio magic"); 287 return 1; 288 } 289 parse_header(collected); 290 next_header = this_header + N_ALIGN(name_len) + body_len; 291 next_header = (next_header + 3) & ~3; 292 state = SkipIt; 293 if (name_len <= 0 || name_len > PATH_MAX) 294 return 0; 295 if (S_ISLNK(mode)) { 296 if (body_len > PATH_MAX) 297 return 0; 298 collect = collected = symlink_buf; 299 remains = N_ALIGN(name_len) + body_len; 300 next_state = GotSymlink; 301 state = Collect; 302 return 0; 303 } 304 if (S_ISREG(mode) || !body_len) 305 read_into(name_buf, N_ALIGN(name_len), GotName); 306 return 0; 307 } 308 309 static int __init do_skip(void) 310 { 311 if (this_header + byte_count < next_header) { 312 eat(byte_count); 313 return 1; 314 } else { 315 eat(next_header - this_header); 316 state = next_state; 317 return 0; 318 } 319 } 320 321 static int __init do_reset(void) 322 { 323 while (byte_count && *victim == '\0') 324 eat(1); 325 if (byte_count && (this_header & 3)) 326 error("broken padding"); 327 return 1; 328 } 329 330 static void __init clean_path(char *path, umode_t fmode) 331 { 332 struct kstat st; 333 334 if (!init_stat(path, &st, AT_SYMLINK_NOFOLLOW) && 335 (st.mode ^ fmode) & S_IFMT) { 336 if (S_ISDIR(st.mode)) 337 init_rmdir(path); 338 else 339 init_unlink(path); 340 } 341 } 342 343 static int __init maybe_link(void) 344 { 345 if (nlink >= 2) { 346 char *old = find_link(major, minor, ino, mode, collected); 347 if (old) { 348 clean_path(collected, 0); 349 return (init_link(old, collected) < 0) ? -1 : 1; 350 } 351 } 352 return 0; 353 } 354 355 static __initdata struct file *wfile; 356 static __initdata loff_t wfile_pos; 357 358 static int __init do_name(void) 359 { 360 state = SkipIt; 361 next_state = Reset; 362 if (strcmp(collected, "TRAILER!!!") == 0) { 363 free_hash(); 364 return 0; 365 } 366 clean_path(collected, mode); 367 if (S_ISREG(mode)) { 368 int ml = maybe_link(); 369 if (ml >= 0) { 370 int openflags = O_WRONLY|O_CREAT|O_LARGEFILE; 371 if (ml != 1) 372 openflags |= O_TRUNC; 373 wfile = filp_open(collected, openflags, mode); 374 if (IS_ERR(wfile)) 375 return 0; 376 wfile_pos = 0; 377 io_csum = 0; 378 379 vfs_fchown(wfile, uid, gid); 380 vfs_fchmod(wfile, mode); 381 if (body_len) 382 vfs_truncate(&wfile->f_path, body_len); 383 state = CopyFile; 384 } 385 } else if (S_ISDIR(mode)) { 386 init_mkdir(collected, mode); 387 init_chown(collected, uid, gid, 0); 388 init_chmod(collected, mode); 389 dir_add(collected, mtime); 390 } else if (S_ISBLK(mode) || S_ISCHR(mode) || 391 S_ISFIFO(mode) || S_ISSOCK(mode)) { 392 if (maybe_link() == 0) { 393 init_mknod(collected, mode, rdev); 394 init_chown(collected, uid, gid, 0); 395 init_chmod(collected, mode); 396 do_utime(collected, mtime); 397 } 398 } 399 return 0; 400 } 401 402 static int __init do_copy(void) 403 { 404 if (byte_count >= body_len) { 405 if (xwrite(wfile, victim, body_len, &wfile_pos) != body_len) 406 error("write error"); 407 408 do_utime_path(&wfile->f_path, mtime); 409 fput(wfile); 410 if (csum_present && io_csum != hdr_csum) 411 error("bad data checksum"); 412 eat(body_len); 413 state = SkipIt; 414 return 0; 415 } else { 416 if (xwrite(wfile, victim, byte_count, &wfile_pos) != byte_count) 417 error("write error"); 418 body_len -= byte_count; 419 eat(byte_count); 420 return 1; 421 } 422 } 423 424 static int __init do_symlink(void) 425 { 426 collected[N_ALIGN(name_len) + body_len] = '\0'; 427 clean_path(collected, 0); 428 init_symlink(collected + N_ALIGN(name_len), collected); 429 init_chown(collected, uid, gid, AT_SYMLINK_NOFOLLOW); 430 do_utime(collected, mtime); 431 state = SkipIt; 432 next_state = Reset; 433 return 0; 434 } 435 436 static __initdata int (*actions[])(void) = { 437 [Start] = do_start, 438 [Collect] = do_collect, 439 [GotHeader] = do_header, 440 [SkipIt] = do_skip, 441 [GotName] = do_name, 442 [CopyFile] = do_copy, 443 [GotSymlink] = do_symlink, 444 [Reset] = do_reset, 445 }; 446 447 static long __init write_buffer(char *buf, unsigned long len) 448 { 449 byte_count = len; 450 victim = buf; 451 452 while (!actions[state]()) 453 ; 454 return len - byte_count; 455 } 456 457 static long __init flush_buffer(void *bufv, unsigned long len) 458 { 459 char *buf = bufv; 460 long written; 461 long origLen = len; 462 if (message) 463 return -1; 464 while ((written = write_buffer(buf, len)) < len && !message) { 465 char c = buf[written]; 466 if (c == '0') { 467 buf += written; 468 len -= written; 469 state = Start; 470 } else if (c == 0) { 471 buf += written; 472 len -= written; 473 state = Reset; 474 } else 475 error("junk within compressed archive"); 476 } 477 return origLen; 478 } 479 480 static unsigned long my_inptr __initdata; /* index of next byte to be processed in inbuf */ 481 482 #include <linux/decompress/generic.h> 483 484 static char * __init unpack_to_rootfs(char *buf, unsigned long len) 485 { 486 long written; 487 decompress_fn decompress; 488 const char *compress_name; 489 static __initdata char msg_buf[64]; 490 491 header_buf = kmalloc(110, GFP_KERNEL); 492 symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL); 493 name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL); 494 495 if (!header_buf || !symlink_buf || !name_buf) 496 panic_show_mem("can't allocate buffers"); 497 498 state = Start; 499 this_header = 0; 500 message = NULL; 501 while (!message && len) { 502 loff_t saved_offset = this_header; 503 if (*buf == '0' && !(this_header & 3)) { 504 state = Start; 505 written = write_buffer(buf, len); 506 buf += written; 507 len -= written; 508 continue; 509 } 510 if (!*buf) { 511 buf++; 512 len--; 513 this_header++; 514 continue; 515 } 516 this_header = 0; 517 decompress = decompress_method(buf, len, &compress_name); 518 pr_debug("Detected %s compressed data\n", compress_name); 519 if (decompress) { 520 int res = decompress(buf, len, NULL, flush_buffer, NULL, 521 &my_inptr, error); 522 if (res) 523 error("decompressor failed"); 524 } else if (compress_name) { 525 if (!message) { 526 snprintf(msg_buf, sizeof msg_buf, 527 "compression method %s not configured", 528 compress_name); 529 message = msg_buf; 530 } 531 } else 532 error("invalid magic at start of compressed archive"); 533 if (state != Reset) 534 error("junk at the end of compressed archive"); 535 this_header = saved_offset + my_inptr; 536 buf += my_inptr; 537 len -= my_inptr; 538 } 539 dir_utime(); 540 kfree(name_buf); 541 kfree(symlink_buf); 542 kfree(header_buf); 543 return message; 544 } 545 546 static int __initdata do_retain_initrd; 547 548 static int __init retain_initrd_param(char *str) 549 { 550 if (*str) 551 return 0; 552 do_retain_initrd = 1; 553 return 1; 554 } 555 __setup("retain_initrd", retain_initrd_param); 556 557 #ifdef CONFIG_ARCH_HAS_KEEPINITRD 558 static int __init keepinitrd_setup(char *__unused) 559 { 560 do_retain_initrd = 1; 561 return 1; 562 } 563 __setup("keepinitrd", keepinitrd_setup); 564 #endif 565 566 static bool __initdata initramfs_async = true; 567 static int __init initramfs_async_setup(char *str) 568 { 569 return kstrtobool(str, &initramfs_async) == 0; 570 } 571 __setup("initramfs_async=", initramfs_async_setup); 572 573 extern char __initramfs_start[]; 574 extern unsigned long __initramfs_size; 575 #include <linux/initrd.h> 576 #include <linux/kexec.h> 577 578 static ssize_t raw_read(struct file *file, struct kobject *kobj, 579 struct bin_attribute *attr, char *buf, 580 loff_t pos, size_t count) 581 { 582 memcpy(buf, attr->private + pos, count); 583 return count; 584 } 585 586 static BIN_ATTR(initrd, 0440, raw_read, NULL, 0); 587 588 void __init reserve_initrd_mem(void) 589 { 590 phys_addr_t start; 591 unsigned long size; 592 593 /* Ignore the virtul address computed during device tree parsing */ 594 initrd_start = initrd_end = 0; 595 596 if (!phys_initrd_size) 597 return; 598 /* 599 * Round the memory region to page boundaries as per free_initrd_mem() 600 * This allows us to detect whether the pages overlapping the initrd 601 * are in use, but more importantly, reserves the entire set of pages 602 * as we don't want these pages allocated for other purposes. 603 */ 604 start = round_down(phys_initrd_start, PAGE_SIZE); 605 size = phys_initrd_size + (phys_initrd_start - start); 606 size = round_up(size, PAGE_SIZE); 607 608 if (!memblock_is_region_memory(start, size)) { 609 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region", 610 (u64)start, size); 611 goto disable; 612 } 613 614 if (memblock_is_region_reserved(start, size)) { 615 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region\n", 616 (u64)start, size); 617 goto disable; 618 } 619 620 memblock_reserve(start, size); 621 /* Now convert initrd to virtual addresses */ 622 initrd_start = (unsigned long)__va(phys_initrd_start); 623 initrd_end = initrd_start + phys_initrd_size; 624 initrd_below_start_ok = 1; 625 626 return; 627 disable: 628 pr_cont(" - disabling initrd\n"); 629 initrd_start = 0; 630 initrd_end = 0; 631 } 632 633 void __weak __init free_initrd_mem(unsigned long start, unsigned long end) 634 { 635 #ifdef CONFIG_ARCH_KEEP_MEMBLOCK 636 unsigned long aligned_start = ALIGN_DOWN(start, PAGE_SIZE); 637 unsigned long aligned_end = ALIGN(end, PAGE_SIZE); 638 639 memblock_free((void *)aligned_start, aligned_end - aligned_start); 640 #endif 641 642 free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM, 643 "initrd"); 644 } 645 646 #ifdef CONFIG_CRASH_RESERVE 647 static bool __init kexec_free_initrd(void) 648 { 649 unsigned long crashk_start = (unsigned long)__va(crashk_res.start); 650 unsigned long crashk_end = (unsigned long)__va(crashk_res.end); 651 652 /* 653 * If the initrd region is overlapped with crashkernel reserved region, 654 * free only memory that is not part of crashkernel region. 655 */ 656 if (initrd_start >= crashk_end || initrd_end <= crashk_start) 657 return false; 658 659 /* 660 * Initialize initrd memory region since the kexec boot does not do. 661 */ 662 memset((void *)initrd_start, 0, initrd_end - initrd_start); 663 if (initrd_start < crashk_start) 664 free_initrd_mem(initrd_start, crashk_start); 665 if (initrd_end > crashk_end) 666 free_initrd_mem(crashk_end, initrd_end); 667 return true; 668 } 669 #else 670 static inline bool kexec_free_initrd(void) 671 { 672 return false; 673 } 674 #endif /* CONFIG_KEXEC_CORE */ 675 676 #ifdef CONFIG_BLK_DEV_RAM 677 static void __init populate_initrd_image(char *err) 678 { 679 ssize_t written; 680 struct file *file; 681 loff_t pos = 0; 682 683 printk(KERN_INFO "rootfs image is not initramfs (%s); looks like an initrd\n", 684 err); 685 file = filp_open("/initrd.image", O_WRONLY|O_CREAT|O_LARGEFILE, 0700); 686 if (IS_ERR(file)) 687 return; 688 689 written = xwrite(file, (char *)initrd_start, initrd_end - initrd_start, 690 &pos); 691 if (written != initrd_end - initrd_start) 692 pr_err("/initrd.image: incomplete write (%zd != %ld)\n", 693 written, initrd_end - initrd_start); 694 fput(file); 695 } 696 #endif /* CONFIG_BLK_DEV_RAM */ 697 698 static void __init do_populate_rootfs(void *unused, async_cookie_t cookie) 699 { 700 /* Load the built in initramfs */ 701 char *err = unpack_to_rootfs(__initramfs_start, __initramfs_size); 702 if (err) 703 panic_show_mem("%s", err); /* Failed to decompress INTERNAL initramfs */ 704 705 if (!initrd_start || IS_ENABLED(CONFIG_INITRAMFS_FORCE)) 706 goto done; 707 708 if (IS_ENABLED(CONFIG_BLK_DEV_RAM)) 709 printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n"); 710 else 711 printk(KERN_INFO "Unpacking initramfs...\n"); 712 713 err = unpack_to_rootfs((char *)initrd_start, initrd_end - initrd_start); 714 if (err) { 715 #ifdef CONFIG_BLK_DEV_RAM 716 populate_initrd_image(err); 717 #else 718 printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err); 719 #endif 720 } 721 722 done: 723 /* 724 * If the initrd region is overlapped with crashkernel reserved region, 725 * free only memory that is not part of crashkernel region. 726 */ 727 if (!do_retain_initrd && initrd_start && !kexec_free_initrd()) { 728 free_initrd_mem(initrd_start, initrd_end); 729 } else if (do_retain_initrd && initrd_start) { 730 bin_attr_initrd.size = initrd_end - initrd_start; 731 bin_attr_initrd.private = (void *)initrd_start; 732 if (sysfs_create_bin_file(firmware_kobj, &bin_attr_initrd)) 733 pr_err("Failed to create initrd sysfs file"); 734 } 735 initrd_start = 0; 736 initrd_end = 0; 737 738 init_flush_fput(); 739 } 740 741 static ASYNC_DOMAIN_EXCLUSIVE(initramfs_domain); 742 static async_cookie_t initramfs_cookie; 743 744 void wait_for_initramfs(void) 745 { 746 if (!initramfs_cookie) { 747 /* 748 * Something before rootfs_initcall wants to access 749 * the filesystem/initramfs. Probably a bug. Make a 750 * note, avoid deadlocking the machine, and let the 751 * caller's access fail as it used to. 752 */ 753 pr_warn_once("wait_for_initramfs() called before rootfs_initcalls\n"); 754 return; 755 } 756 async_synchronize_cookie_domain(initramfs_cookie + 1, &initramfs_domain); 757 } 758 EXPORT_SYMBOL_GPL(wait_for_initramfs); 759 760 static int __init populate_rootfs(void) 761 { 762 initramfs_cookie = async_schedule_domain(do_populate_rootfs, NULL, 763 &initramfs_domain); 764 usermodehelper_enable(); 765 if (!initramfs_async) 766 wait_for_initramfs(); 767 return 0; 768 } 769 rootfs_initcall(populate_rootfs); 770