1 /* 2 * binfmt_misc.c 3 * 4 * Copyright (C) 1997 Richard Günther 5 * 6 * binfmt_misc detects binaries via a magic or filename extension and invokes 7 * a specified wrapper. See Documentation/binfmt_misc.txt for more details. 8 */ 9 10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 11 12 #include <linux/kernel.h> 13 #include <linux/module.h> 14 #include <linux/init.h> 15 #include <linux/sched/mm.h> 16 #include <linux/magic.h> 17 #include <linux/binfmts.h> 18 #include <linux/slab.h> 19 #include <linux/ctype.h> 20 #include <linux/string_helpers.h> 21 #include <linux/file.h> 22 #include <linux/pagemap.h> 23 #include <linux/namei.h> 24 #include <linux/mount.h> 25 #include <linux/syscalls.h> 26 #include <linux/fs.h> 27 #include <linux/uaccess.h> 28 29 #include "internal.h" 30 31 #ifdef DEBUG 32 # define USE_DEBUG 1 33 #else 34 # define USE_DEBUG 0 35 #endif 36 37 enum { 38 VERBOSE_STATUS = 1 /* make it zero to save 400 bytes kernel memory */ 39 }; 40 41 static LIST_HEAD(entries); 42 static int enabled = 1; 43 44 enum {Enabled, Magic}; 45 #define MISC_FMT_PRESERVE_ARGV0 (1 << 31) 46 #define MISC_FMT_OPEN_BINARY (1 << 30) 47 #define MISC_FMT_CREDENTIALS (1 << 29) 48 #define MISC_FMT_OPEN_FILE (1 << 28) 49 50 typedef struct { 51 struct list_head list; 52 unsigned long flags; /* type, status, etc. */ 53 int offset; /* offset of magic */ 54 int size; /* size of magic/mask */ 55 char *magic; /* magic or filename extension */ 56 char *mask; /* mask, NULL for exact match */ 57 char *interpreter; /* filename of interpreter */ 58 char *name; 59 struct dentry *dentry; 60 struct file *interp_file; 61 } Node; 62 63 static DEFINE_RWLOCK(entries_lock); 64 static struct file_system_type bm_fs_type; 65 static struct vfsmount *bm_mnt; 66 static int entry_count; 67 68 /* 69 * Max length of the register string. Determined by: 70 * - 7 delimiters 71 * - name: ~50 bytes 72 * - type: 1 byte 73 * - offset: 3 bytes (has to be smaller than BINPRM_BUF_SIZE) 74 * - magic: 128 bytes (512 in escaped form) 75 * - mask: 128 bytes (512 in escaped form) 76 * - interp: ~50 bytes 77 * - flags: 5 bytes 78 * Round that up a bit, and then back off to hold the internal data 79 * (like struct Node). 80 */ 81 #define MAX_REGISTER_LENGTH 1920 82 83 /* 84 * Check if we support the binfmt 85 * if we do, return the node, else NULL 86 * locking is done in load_misc_binary 87 */ 88 static Node *check_file(struct linux_binprm *bprm) 89 { 90 char *p = strrchr(bprm->interp, '.'); 91 struct list_head *l; 92 93 /* Walk all the registered handlers. */ 94 list_for_each(l, &entries) { 95 Node *e = list_entry(l, Node, list); 96 char *s; 97 int j; 98 99 /* Make sure this one is currently enabled. */ 100 if (!test_bit(Enabled, &e->flags)) 101 continue; 102 103 /* Do matching based on extension if applicable. */ 104 if (!test_bit(Magic, &e->flags)) { 105 if (p && !strcmp(e->magic, p + 1)) 106 return e; 107 continue; 108 } 109 110 /* Do matching based on magic & mask. */ 111 s = bprm->buf + e->offset; 112 if (e->mask) { 113 for (j = 0; j < e->size; j++) 114 if ((*s++ ^ e->magic[j]) & e->mask[j]) 115 break; 116 } else { 117 for (j = 0; j < e->size; j++) 118 if ((*s++ ^ e->magic[j])) 119 break; 120 } 121 if (j == e->size) 122 return e; 123 } 124 return NULL; 125 } 126 127 /* 128 * the loader itself 129 */ 130 static int load_misc_binary(struct linux_binprm *bprm) 131 { 132 Node *fmt; 133 struct file *interp_file = NULL; 134 char iname[BINPRM_BUF_SIZE]; 135 const char *iname_addr = iname; 136 int retval; 137 int fd_binary = -1; 138 139 retval = -ENOEXEC; 140 if (!enabled) 141 goto ret; 142 143 /* to keep locking time low, we copy the interpreter string */ 144 read_lock(&entries_lock); 145 fmt = check_file(bprm); 146 if (fmt) 147 strlcpy(iname, fmt->interpreter, BINPRM_BUF_SIZE); 148 read_unlock(&entries_lock); 149 if (!fmt) 150 goto ret; 151 152 /* Need to be able to load the file after exec */ 153 if (bprm->interp_flags & BINPRM_FLAGS_PATH_INACCESSIBLE) 154 return -ENOENT; 155 156 if (!(fmt->flags & MISC_FMT_PRESERVE_ARGV0)) { 157 retval = remove_arg_zero(bprm); 158 if (retval) 159 goto ret; 160 } 161 162 if (fmt->flags & MISC_FMT_OPEN_BINARY) { 163 164 /* if the binary should be opened on behalf of the 165 * interpreter than keep it open and assign descriptor 166 * to it 167 */ 168 fd_binary = get_unused_fd_flags(0); 169 if (fd_binary < 0) { 170 retval = fd_binary; 171 goto ret; 172 } 173 fd_install(fd_binary, bprm->file); 174 175 /* if the binary is not readable than enforce mm->dumpable=0 176 regardless of the interpreter's permissions */ 177 would_dump(bprm, bprm->file); 178 179 allow_write_access(bprm->file); 180 bprm->file = NULL; 181 182 /* mark the bprm that fd should be passed to interp */ 183 bprm->interp_flags |= BINPRM_FLAGS_EXECFD; 184 bprm->interp_data = fd_binary; 185 186 } else { 187 allow_write_access(bprm->file); 188 fput(bprm->file); 189 bprm->file = NULL; 190 } 191 /* make argv[1] be the path to the binary */ 192 retval = copy_strings_kernel(1, &bprm->interp, bprm); 193 if (retval < 0) 194 goto error; 195 bprm->argc++; 196 197 /* add the interp as argv[0] */ 198 retval = copy_strings_kernel(1, &iname_addr, bprm); 199 if (retval < 0) 200 goto error; 201 bprm->argc++; 202 203 /* Update interp in case binfmt_script needs it. */ 204 retval = bprm_change_interp(iname, bprm); 205 if (retval < 0) 206 goto error; 207 208 if (fmt->flags & MISC_FMT_OPEN_FILE && fmt->interp_file) { 209 interp_file = filp_clone_open(fmt->interp_file); 210 if (!IS_ERR(interp_file)) 211 deny_write_access(interp_file); 212 } else { 213 interp_file = open_exec(iname); 214 } 215 retval = PTR_ERR(interp_file); 216 if (IS_ERR(interp_file)) 217 goto error; 218 219 bprm->file = interp_file; 220 if (fmt->flags & MISC_FMT_CREDENTIALS) { 221 loff_t pos = 0; 222 223 /* 224 * No need to call prepare_binprm(), it's already been 225 * done. bprm->buf is stale, update from interp_file. 226 */ 227 memset(bprm->buf, 0, BINPRM_BUF_SIZE); 228 retval = kernel_read(bprm->file, bprm->buf, BINPRM_BUF_SIZE, 229 &pos); 230 } else 231 retval = prepare_binprm(bprm); 232 233 if (retval < 0) 234 goto error; 235 236 retval = search_binary_handler(bprm); 237 if (retval < 0) 238 goto error; 239 240 ret: 241 return retval; 242 error: 243 if (fd_binary > 0) 244 sys_close(fd_binary); 245 bprm->interp_flags = 0; 246 bprm->interp_data = 0; 247 goto ret; 248 } 249 250 /* Command parsers */ 251 252 /* 253 * parses and copies one argument enclosed in del from *sp to *dp, 254 * recognising the \x special. 255 * returns pointer to the copied argument or NULL in case of an 256 * error (and sets err) or null argument length. 257 */ 258 static char *scanarg(char *s, char del) 259 { 260 char c; 261 262 while ((c = *s++) != del) { 263 if (c == '\\' && *s == 'x') { 264 s++; 265 if (!isxdigit(*s++)) 266 return NULL; 267 if (!isxdigit(*s++)) 268 return NULL; 269 } 270 } 271 s[-1] ='\0'; 272 return s; 273 } 274 275 static char *check_special_flags(char *sfs, Node *e) 276 { 277 char *p = sfs; 278 int cont = 1; 279 280 /* special flags */ 281 while (cont) { 282 switch (*p) { 283 case 'P': 284 pr_debug("register: flag: P (preserve argv0)\n"); 285 p++; 286 e->flags |= MISC_FMT_PRESERVE_ARGV0; 287 break; 288 case 'O': 289 pr_debug("register: flag: O (open binary)\n"); 290 p++; 291 e->flags |= MISC_FMT_OPEN_BINARY; 292 break; 293 case 'C': 294 pr_debug("register: flag: C (preserve creds)\n"); 295 p++; 296 /* this flags also implies the 297 open-binary flag */ 298 e->flags |= (MISC_FMT_CREDENTIALS | 299 MISC_FMT_OPEN_BINARY); 300 break; 301 case 'F': 302 pr_debug("register: flag: F: open interpreter file now\n"); 303 p++; 304 e->flags |= MISC_FMT_OPEN_FILE; 305 break; 306 default: 307 cont = 0; 308 } 309 } 310 311 return p; 312 } 313 314 /* 315 * This registers a new binary format, it recognises the syntax 316 * ':name:type:offset:magic:mask:interpreter:flags' 317 * where the ':' is the IFS, that can be chosen with the first char 318 */ 319 static Node *create_entry(const char __user *buffer, size_t count) 320 { 321 Node *e; 322 int memsize, err; 323 char *buf, *p; 324 char del; 325 326 pr_debug("register: received %zu bytes\n", count); 327 328 /* some sanity checks */ 329 err = -EINVAL; 330 if ((count < 11) || (count > MAX_REGISTER_LENGTH)) 331 goto out; 332 333 err = -ENOMEM; 334 memsize = sizeof(Node) + count + 8; 335 e = kmalloc(memsize, GFP_KERNEL); 336 if (!e) 337 goto out; 338 339 p = buf = (char *)e + sizeof(Node); 340 341 memset(e, 0, sizeof(Node)); 342 if (copy_from_user(buf, buffer, count)) 343 goto efault; 344 345 del = *p++; /* delimeter */ 346 347 pr_debug("register: delim: %#x {%c}\n", del, del); 348 349 /* Pad the buffer with the delim to simplify parsing below. */ 350 memset(buf + count, del, 8); 351 352 /* Parse the 'name' field. */ 353 e->name = p; 354 p = strchr(p, del); 355 if (!p) 356 goto einval; 357 *p++ = '\0'; 358 if (!e->name[0] || 359 !strcmp(e->name, ".") || 360 !strcmp(e->name, "..") || 361 strchr(e->name, '/')) 362 goto einval; 363 364 pr_debug("register: name: {%s}\n", e->name); 365 366 /* Parse the 'type' field. */ 367 switch (*p++) { 368 case 'E': 369 pr_debug("register: type: E (extension)\n"); 370 e->flags = 1 << Enabled; 371 break; 372 case 'M': 373 pr_debug("register: type: M (magic)\n"); 374 e->flags = (1 << Enabled) | (1 << Magic); 375 break; 376 default: 377 goto einval; 378 } 379 if (*p++ != del) 380 goto einval; 381 382 if (test_bit(Magic, &e->flags)) { 383 /* Handle the 'M' (magic) format. */ 384 char *s; 385 386 /* Parse the 'offset' field. */ 387 s = strchr(p, del); 388 if (!s) 389 goto einval; 390 *s++ = '\0'; 391 e->offset = simple_strtoul(p, &p, 10); 392 if (*p++) 393 goto einval; 394 pr_debug("register: offset: %#x\n", e->offset); 395 396 /* Parse the 'magic' field. */ 397 e->magic = p; 398 p = scanarg(p, del); 399 if (!p) 400 goto einval; 401 if (!e->magic[0]) 402 goto einval; 403 if (USE_DEBUG) 404 print_hex_dump_bytes( 405 KBUILD_MODNAME ": register: magic[raw]: ", 406 DUMP_PREFIX_NONE, e->magic, p - e->magic); 407 408 /* Parse the 'mask' field. */ 409 e->mask = p; 410 p = scanarg(p, del); 411 if (!p) 412 goto einval; 413 if (!e->mask[0]) { 414 e->mask = NULL; 415 pr_debug("register: mask[raw]: none\n"); 416 } else if (USE_DEBUG) 417 print_hex_dump_bytes( 418 KBUILD_MODNAME ": register: mask[raw]: ", 419 DUMP_PREFIX_NONE, e->mask, p - e->mask); 420 421 /* 422 * Decode the magic & mask fields. 423 * Note: while we might have accepted embedded NUL bytes from 424 * above, the unescape helpers here will stop at the first one 425 * it encounters. 426 */ 427 e->size = string_unescape_inplace(e->magic, UNESCAPE_HEX); 428 if (e->mask && 429 string_unescape_inplace(e->mask, UNESCAPE_HEX) != e->size) 430 goto einval; 431 if (e->size + e->offset > BINPRM_BUF_SIZE) 432 goto einval; 433 pr_debug("register: magic/mask length: %i\n", e->size); 434 if (USE_DEBUG) { 435 print_hex_dump_bytes( 436 KBUILD_MODNAME ": register: magic[decoded]: ", 437 DUMP_PREFIX_NONE, e->magic, e->size); 438 439 if (e->mask) { 440 int i; 441 char *masked = kmalloc(e->size, GFP_KERNEL); 442 443 print_hex_dump_bytes( 444 KBUILD_MODNAME ": register: mask[decoded]: ", 445 DUMP_PREFIX_NONE, e->mask, e->size); 446 447 if (masked) { 448 for (i = 0; i < e->size; ++i) 449 masked[i] = e->magic[i] & e->mask[i]; 450 print_hex_dump_bytes( 451 KBUILD_MODNAME ": register: magic[masked]: ", 452 DUMP_PREFIX_NONE, masked, e->size); 453 454 kfree(masked); 455 } 456 } 457 } 458 } else { 459 /* Handle the 'E' (extension) format. */ 460 461 /* Skip the 'offset' field. */ 462 p = strchr(p, del); 463 if (!p) 464 goto einval; 465 *p++ = '\0'; 466 467 /* Parse the 'magic' field. */ 468 e->magic = p; 469 p = strchr(p, del); 470 if (!p) 471 goto einval; 472 *p++ = '\0'; 473 if (!e->magic[0] || strchr(e->magic, '/')) 474 goto einval; 475 pr_debug("register: extension: {%s}\n", e->magic); 476 477 /* Skip the 'mask' field. */ 478 p = strchr(p, del); 479 if (!p) 480 goto einval; 481 *p++ = '\0'; 482 } 483 484 /* Parse the 'interpreter' field. */ 485 e->interpreter = p; 486 p = strchr(p, del); 487 if (!p) 488 goto einval; 489 *p++ = '\0'; 490 if (!e->interpreter[0]) 491 goto einval; 492 pr_debug("register: interpreter: {%s}\n", e->interpreter); 493 494 /* Parse the 'flags' field. */ 495 p = check_special_flags(p, e); 496 if (*p == '\n') 497 p++; 498 if (p != buf + count) 499 goto einval; 500 501 return e; 502 503 out: 504 return ERR_PTR(err); 505 506 efault: 507 kfree(e); 508 return ERR_PTR(-EFAULT); 509 einval: 510 kfree(e); 511 return ERR_PTR(-EINVAL); 512 } 513 514 /* 515 * Set status of entry/binfmt_misc: 516 * '1' enables, '0' disables and '-1' clears entry/binfmt_misc 517 */ 518 static int parse_command(const char __user *buffer, size_t count) 519 { 520 char s[4]; 521 522 if (count > 3) 523 return -EINVAL; 524 if (copy_from_user(s, buffer, count)) 525 return -EFAULT; 526 if (!count) 527 return 0; 528 if (s[count - 1] == '\n') 529 count--; 530 if (count == 1 && s[0] == '0') 531 return 1; 532 if (count == 1 && s[0] == '1') 533 return 2; 534 if (count == 2 && s[0] == '-' && s[1] == '1') 535 return 3; 536 return -EINVAL; 537 } 538 539 /* generic stuff */ 540 541 static void entry_status(Node *e, char *page) 542 { 543 char *dp = page; 544 const char *status = "disabled"; 545 546 if (test_bit(Enabled, &e->flags)) 547 status = "enabled"; 548 549 if (!VERBOSE_STATUS) { 550 sprintf(page, "%s\n", status); 551 return; 552 } 553 554 dp += sprintf(dp, "%s\ninterpreter %s\n", status, e->interpreter); 555 556 /* print the special flags */ 557 dp += sprintf(dp, "flags: "); 558 if (e->flags & MISC_FMT_PRESERVE_ARGV0) 559 *dp++ = 'P'; 560 if (e->flags & MISC_FMT_OPEN_BINARY) 561 *dp++ = 'O'; 562 if (e->flags & MISC_FMT_CREDENTIALS) 563 *dp++ = 'C'; 564 if (e->flags & MISC_FMT_OPEN_FILE) 565 *dp++ = 'F'; 566 *dp++ = '\n'; 567 568 if (!test_bit(Magic, &e->flags)) { 569 sprintf(dp, "extension .%s\n", e->magic); 570 } else { 571 dp += sprintf(dp, "offset %i\nmagic ", e->offset); 572 dp = bin2hex(dp, e->magic, e->size); 573 if (e->mask) { 574 dp += sprintf(dp, "\nmask "); 575 dp = bin2hex(dp, e->mask, e->size); 576 } 577 *dp++ = '\n'; 578 *dp = '\0'; 579 } 580 } 581 582 static struct inode *bm_get_inode(struct super_block *sb, int mode) 583 { 584 struct inode *inode = new_inode(sb); 585 586 if (inode) { 587 inode->i_ino = get_next_ino(); 588 inode->i_mode = mode; 589 inode->i_atime = inode->i_mtime = inode->i_ctime = 590 current_time(inode); 591 } 592 return inode; 593 } 594 595 static void bm_evict_inode(struct inode *inode) 596 { 597 clear_inode(inode); 598 kfree(inode->i_private); 599 } 600 601 static void kill_node(Node *e) 602 { 603 struct dentry *dentry; 604 605 write_lock(&entries_lock); 606 dentry = e->dentry; 607 if (dentry) { 608 list_del_init(&e->list); 609 e->dentry = NULL; 610 } 611 write_unlock(&entries_lock); 612 613 if ((e->flags & MISC_FMT_OPEN_FILE) && e->interp_file) { 614 filp_close(e->interp_file, NULL); 615 e->interp_file = NULL; 616 } 617 618 if (dentry) { 619 drop_nlink(d_inode(dentry)); 620 d_drop(dentry); 621 dput(dentry); 622 simple_release_fs(&bm_mnt, &entry_count); 623 } 624 } 625 626 /* /<entry> */ 627 628 static ssize_t 629 bm_entry_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) 630 { 631 Node *e = file_inode(file)->i_private; 632 ssize_t res; 633 char *page; 634 635 page = (char *) __get_free_page(GFP_KERNEL); 636 if (!page) 637 return -ENOMEM; 638 639 entry_status(e, page); 640 641 res = simple_read_from_buffer(buf, nbytes, ppos, page, strlen(page)); 642 643 free_page((unsigned long) page); 644 return res; 645 } 646 647 static ssize_t bm_entry_write(struct file *file, const char __user *buffer, 648 size_t count, loff_t *ppos) 649 { 650 struct dentry *root; 651 Node *e = file_inode(file)->i_private; 652 int res = parse_command(buffer, count); 653 654 switch (res) { 655 case 1: 656 /* Disable this handler. */ 657 clear_bit(Enabled, &e->flags); 658 break; 659 case 2: 660 /* Enable this handler. */ 661 set_bit(Enabled, &e->flags); 662 break; 663 case 3: 664 /* Delete this handler. */ 665 root = file_inode(file)->i_sb->s_root; 666 inode_lock(d_inode(root)); 667 668 kill_node(e); 669 670 inode_unlock(d_inode(root)); 671 break; 672 default: 673 return res; 674 } 675 676 return count; 677 } 678 679 static const struct file_operations bm_entry_operations = { 680 .read = bm_entry_read, 681 .write = bm_entry_write, 682 .llseek = default_llseek, 683 }; 684 685 /* /register */ 686 687 static ssize_t bm_register_write(struct file *file, const char __user *buffer, 688 size_t count, loff_t *ppos) 689 { 690 Node *e; 691 struct inode *inode; 692 struct super_block *sb = file_inode(file)->i_sb; 693 struct dentry *root = sb->s_root, *dentry; 694 int err = 0; 695 696 e = create_entry(buffer, count); 697 698 if (IS_ERR(e)) 699 return PTR_ERR(e); 700 701 inode_lock(d_inode(root)); 702 dentry = lookup_one_len(e->name, root, strlen(e->name)); 703 err = PTR_ERR(dentry); 704 if (IS_ERR(dentry)) 705 goto out; 706 707 err = -EEXIST; 708 if (d_really_is_positive(dentry)) 709 goto out2; 710 711 inode = bm_get_inode(sb, S_IFREG | 0644); 712 713 err = -ENOMEM; 714 if (!inode) 715 goto out2; 716 717 err = simple_pin_fs(&bm_fs_type, &bm_mnt, &entry_count); 718 if (err) { 719 iput(inode); 720 inode = NULL; 721 goto out2; 722 } 723 724 if (e->flags & MISC_FMT_OPEN_FILE) { 725 struct file *f; 726 727 f = open_exec(e->interpreter); 728 if (IS_ERR(f)) { 729 err = PTR_ERR(f); 730 pr_notice("register: failed to install interpreter file %s\n", e->interpreter); 731 simple_release_fs(&bm_mnt, &entry_count); 732 iput(inode); 733 inode = NULL; 734 goto out2; 735 } 736 e->interp_file = f; 737 } 738 739 e->dentry = dget(dentry); 740 inode->i_private = e; 741 inode->i_fop = &bm_entry_operations; 742 743 d_instantiate(dentry, inode); 744 write_lock(&entries_lock); 745 list_add(&e->list, &entries); 746 write_unlock(&entries_lock); 747 748 err = 0; 749 out2: 750 dput(dentry); 751 out: 752 inode_unlock(d_inode(root)); 753 754 if (err) { 755 kfree(e); 756 return err; 757 } 758 return count; 759 } 760 761 static const struct file_operations bm_register_operations = { 762 .write = bm_register_write, 763 .llseek = noop_llseek, 764 }; 765 766 /* /status */ 767 768 static ssize_t 769 bm_status_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) 770 { 771 char *s = enabled ? "enabled\n" : "disabled\n"; 772 773 return simple_read_from_buffer(buf, nbytes, ppos, s, strlen(s)); 774 } 775 776 static ssize_t bm_status_write(struct file *file, const char __user *buffer, 777 size_t count, loff_t *ppos) 778 { 779 int res = parse_command(buffer, count); 780 struct dentry *root; 781 782 switch (res) { 783 case 1: 784 /* Disable all handlers. */ 785 enabled = 0; 786 break; 787 case 2: 788 /* Enable all handlers. */ 789 enabled = 1; 790 break; 791 case 3: 792 /* Delete all handlers. */ 793 root = file_inode(file)->i_sb->s_root; 794 inode_lock(d_inode(root)); 795 796 while (!list_empty(&entries)) 797 kill_node(list_entry(entries.next, Node, list)); 798 799 inode_unlock(d_inode(root)); 800 break; 801 default: 802 return res; 803 } 804 805 return count; 806 } 807 808 static const struct file_operations bm_status_operations = { 809 .read = bm_status_read, 810 .write = bm_status_write, 811 .llseek = default_llseek, 812 }; 813 814 /* Superblock handling */ 815 816 static const struct super_operations s_ops = { 817 .statfs = simple_statfs, 818 .evict_inode = bm_evict_inode, 819 }; 820 821 static int bm_fill_super(struct super_block *sb, void *data, int silent) 822 { 823 int err; 824 static const struct tree_descr bm_files[] = { 825 [2] = {"status", &bm_status_operations, S_IWUSR|S_IRUGO}, 826 [3] = {"register", &bm_register_operations, S_IWUSR}, 827 /* last one */ {""} 828 }; 829 830 err = simple_fill_super(sb, BINFMTFS_MAGIC, bm_files); 831 if (!err) 832 sb->s_op = &s_ops; 833 return err; 834 } 835 836 static struct dentry *bm_mount(struct file_system_type *fs_type, 837 int flags, const char *dev_name, void *data) 838 { 839 return mount_single(fs_type, flags, data, bm_fill_super); 840 } 841 842 static struct linux_binfmt misc_format = { 843 .module = THIS_MODULE, 844 .load_binary = load_misc_binary, 845 }; 846 847 static struct file_system_type bm_fs_type = { 848 .owner = THIS_MODULE, 849 .name = "binfmt_misc", 850 .mount = bm_mount, 851 .kill_sb = kill_litter_super, 852 }; 853 MODULE_ALIAS_FS("binfmt_misc"); 854 855 static int __init init_misc_binfmt(void) 856 { 857 int err = register_filesystem(&bm_fs_type); 858 if (!err) 859 insert_binfmt(&misc_format); 860 return err; 861 } 862 863 static void __exit exit_misc_binfmt(void) 864 { 865 unregister_binfmt(&misc_format); 866 unregister_filesystem(&bm_fs_type); 867 } 868 869 core_initcall(init_misc_binfmt); 870 module_exit(exit_misc_binfmt); 871 MODULE_LICENSE("GPL"); 872