1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * binfmt_misc.c
4 *
5 * Copyright (C) 1997 Richard Günther
6 *
7 * binfmt_misc detects binaries via a magic or filename extension and invokes
8 * a specified wrapper. See Documentation/admin-guide/binfmt-misc.rst for more details.
9 */
10
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/sched/mm.h>
17 #include <linux/magic.h>
18 #include <linux/binfmts.h>
19 #include <linux/slab.h>
20 #include <linux/ctype.h>
21 #include <linux/string_helpers.h>
22 #include <linux/file.h>
23 #include <linux/pagemap.h>
24 #include <linux/namei.h>
25 #include <linux/mount.h>
26 #include <linux/fs_context.h>
27 #include <linux/syscalls.h>
28 #include <linux/fs.h>
29 #include <linux/uaccess.h>
30
31 #include "internal.h"
32
33 #ifdef DEBUG
34 # define USE_DEBUG 1
35 #else
36 # define USE_DEBUG 0
37 #endif
38
39 enum {
40 VERBOSE_STATUS = 1 /* make it zero to save 400 bytes kernel memory */
41 };
42
43 static LIST_HEAD(entries);
44 static int enabled = 1;
45
46 enum {Enabled, Magic};
47 #define MISC_FMT_PRESERVE_ARGV0 (1 << 31)
48 #define MISC_FMT_OPEN_BINARY (1 << 30)
49 #define MISC_FMT_CREDENTIALS (1 << 29)
50 #define MISC_FMT_OPEN_FILE (1 << 28)
51
52 typedef struct {
53 struct list_head list;
54 unsigned long flags; /* type, status, etc. */
55 int offset; /* offset of magic */
56 int size; /* size of magic/mask */
57 char *magic; /* magic or filename extension */
58 char *mask; /* mask, NULL for exact match */
59 const char *interpreter; /* filename of interpreter */
60 char *name;
61 struct dentry *dentry;
62 struct file *interp_file;
63 } Node;
64
65 static DEFINE_RWLOCK(entries_lock);
66 static struct file_system_type bm_fs_type;
67 static struct vfsmount *bm_mnt;
68 static int entry_count;
69
70 /*
71 * Max length of the register string. Determined by:
72 * - 7 delimiters
73 * - name: ~50 bytes
74 * - type: 1 byte
75 * - offset: 3 bytes (has to be smaller than BINPRM_BUF_SIZE)
76 * - magic: 128 bytes (512 in escaped form)
77 * - mask: 128 bytes (512 in escaped form)
78 * - interp: ~50 bytes
79 * - flags: 5 bytes
80 * Round that up a bit, and then back off to hold the internal data
81 * (like struct Node).
82 */
83 #define MAX_REGISTER_LENGTH 1920
84
85 /*
86 * Check if we support the binfmt
87 * if we do, return the node, else NULL
88 * locking is done in load_misc_binary
89 */
check_file(struct linux_binprm * bprm)90 static Node *check_file(struct linux_binprm *bprm)
91 {
92 char *p = strrchr(bprm->interp, '.');
93 struct list_head *l;
94
95 /* Walk all the registered handlers. */
96 list_for_each(l, &entries) {
97 Node *e = list_entry(l, Node, list);
98 char *s;
99 int j;
100
101 /* Make sure this one is currently enabled. */
102 if (!test_bit(Enabled, &e->flags))
103 continue;
104
105 /* Do matching based on extension if applicable. */
106 if (!test_bit(Magic, &e->flags)) {
107 if (p && !strcmp(e->magic, p + 1))
108 return e;
109 continue;
110 }
111
112 /* Do matching based on magic & mask. */
113 s = bprm->buf + e->offset;
114 if (e->mask) {
115 for (j = 0; j < e->size; j++)
116 if ((*s++ ^ e->magic[j]) & e->mask[j])
117 break;
118 } else {
119 for (j = 0; j < e->size; j++)
120 if ((*s++ ^ e->magic[j]))
121 break;
122 }
123 if (j == e->size)
124 return e;
125 }
126 return NULL;
127 }
128
129 /*
130 * the loader itself
131 */
load_misc_binary(struct linux_binprm * bprm)132 static int load_misc_binary(struct linux_binprm *bprm)
133 {
134 Node *fmt;
135 struct file *interp_file = NULL;
136 int retval;
137
138 retval = -ENOEXEC;
139 if (!enabled)
140 return retval;
141
142 /* to keep locking time low, we copy the interpreter string */
143 read_lock(&entries_lock);
144 fmt = check_file(bprm);
145 if (fmt)
146 dget(fmt->dentry);
147 read_unlock(&entries_lock);
148 if (!fmt)
149 return retval;
150
151 /* Need to be able to load the file after exec */
152 retval = -ENOENT;
153 if (bprm->interp_flags & BINPRM_FLAGS_PATH_INACCESSIBLE)
154 goto ret;
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 bprm->have_execfd = 1;
164
165 /* make argv[1] be the path to the binary */
166 retval = copy_string_kernel(bprm->interp, bprm);
167 if (retval < 0)
168 goto ret;
169 bprm->argc++;
170
171 /* add the interp as argv[0] */
172 retval = copy_string_kernel(fmt->interpreter, bprm);
173 if (retval < 0)
174 goto ret;
175 bprm->argc++;
176
177 /* Update interp in case binfmt_script needs it. */
178 retval = bprm_change_interp(fmt->interpreter, bprm);
179 if (retval < 0)
180 goto ret;
181
182 if (fmt->flags & MISC_FMT_OPEN_FILE) {
183 interp_file = file_clone_open(fmt->interp_file);
184 if (!IS_ERR(interp_file))
185 deny_write_access(interp_file);
186 } else {
187 interp_file = open_exec(fmt->interpreter);
188 }
189 retval = PTR_ERR(interp_file);
190 if (IS_ERR(interp_file))
191 goto ret;
192
193 bprm->interpreter = interp_file;
194 if (fmt->flags & MISC_FMT_CREDENTIALS)
195 bprm->execfd_creds = 1;
196
197 retval = 0;
198 ret:
199 dput(fmt->dentry);
200 return retval;
201 }
202
203 /* Command parsers */
204
205 /*
206 * parses and copies one argument enclosed in del from *sp to *dp,
207 * recognising the \x special.
208 * returns pointer to the copied argument or NULL in case of an
209 * error (and sets err) or null argument length.
210 */
scanarg(char * s,char del)211 static char *scanarg(char *s, char del)
212 {
213 char c;
214
215 while ((c = *s++) != del) {
216 if (c == '\\' && *s == 'x') {
217 s++;
218 if (!isxdigit(*s++))
219 return NULL;
220 if (!isxdigit(*s++))
221 return NULL;
222 }
223 }
224 s[-1] ='\0';
225 return s;
226 }
227
check_special_flags(char * sfs,Node * e)228 static char *check_special_flags(char *sfs, Node *e)
229 {
230 char *p = sfs;
231 int cont = 1;
232
233 /* special flags */
234 while (cont) {
235 switch (*p) {
236 case 'P':
237 pr_debug("register: flag: P (preserve argv0)\n");
238 p++;
239 e->flags |= MISC_FMT_PRESERVE_ARGV0;
240 break;
241 case 'O':
242 pr_debug("register: flag: O (open binary)\n");
243 p++;
244 e->flags |= MISC_FMT_OPEN_BINARY;
245 break;
246 case 'C':
247 pr_debug("register: flag: C (preserve creds)\n");
248 p++;
249 /* this flags also implies the
250 open-binary flag */
251 e->flags |= (MISC_FMT_CREDENTIALS |
252 MISC_FMT_OPEN_BINARY);
253 break;
254 case 'F':
255 pr_debug("register: flag: F: open interpreter file now\n");
256 p++;
257 e->flags |= MISC_FMT_OPEN_FILE;
258 break;
259 default:
260 cont = 0;
261 }
262 }
263
264 return p;
265 }
266
267 /*
268 * This registers a new binary format, it recognises the syntax
269 * ':name:type:offset:magic:mask:interpreter:flags'
270 * where the ':' is the IFS, that can be chosen with the first char
271 */
create_entry(const char __user * buffer,size_t count)272 static Node *create_entry(const char __user *buffer, size_t count)
273 {
274 Node *e;
275 int memsize, err;
276 char *buf, *p;
277 char del;
278
279 pr_debug("register: received %zu bytes\n", count);
280
281 /* some sanity checks */
282 err = -EINVAL;
283 if ((count < 11) || (count > MAX_REGISTER_LENGTH))
284 goto out;
285
286 err = -ENOMEM;
287 memsize = sizeof(Node) + count + 8;
288 e = kmalloc(memsize, GFP_KERNEL);
289 if (!e)
290 goto out;
291
292 p = buf = (char *)e + sizeof(Node);
293
294 memset(e, 0, sizeof(Node));
295 if (copy_from_user(buf, buffer, count))
296 goto efault;
297
298 del = *p++; /* delimeter */
299
300 pr_debug("register: delim: %#x {%c}\n", del, del);
301
302 /* Pad the buffer with the delim to simplify parsing below. */
303 memset(buf + count, del, 8);
304
305 /* Parse the 'name' field. */
306 e->name = p;
307 p = strchr(p, del);
308 if (!p)
309 goto einval;
310 *p++ = '\0';
311 if (!e->name[0] ||
312 !strcmp(e->name, ".") ||
313 !strcmp(e->name, "..") ||
314 strchr(e->name, '/'))
315 goto einval;
316
317 pr_debug("register: name: {%s}\n", e->name);
318
319 /* Parse the 'type' field. */
320 switch (*p++) {
321 case 'E':
322 pr_debug("register: type: E (extension)\n");
323 e->flags = 1 << Enabled;
324 break;
325 case 'M':
326 pr_debug("register: type: M (magic)\n");
327 e->flags = (1 << Enabled) | (1 << Magic);
328 break;
329 default:
330 goto einval;
331 }
332 if (*p++ != del)
333 goto einval;
334
335 if (test_bit(Magic, &e->flags)) {
336 /* Handle the 'M' (magic) format. */
337 char *s;
338
339 /* Parse the 'offset' field. */
340 s = strchr(p, del);
341 if (!s)
342 goto einval;
343 *s = '\0';
344 if (p != s) {
345 int r = kstrtoint(p, 10, &e->offset);
346 if (r != 0 || e->offset < 0)
347 goto einval;
348 }
349 p = s;
350 if (*p++)
351 goto einval;
352 pr_debug("register: offset: %#x\n", e->offset);
353
354 /* Parse the 'magic' field. */
355 e->magic = p;
356 p = scanarg(p, del);
357 if (!p)
358 goto einval;
359 if (!e->magic[0])
360 goto einval;
361 if (USE_DEBUG)
362 print_hex_dump_bytes(
363 KBUILD_MODNAME ": register: magic[raw]: ",
364 DUMP_PREFIX_NONE, e->magic, p - e->magic);
365
366 /* Parse the 'mask' field. */
367 e->mask = p;
368 p = scanarg(p, del);
369 if (!p)
370 goto einval;
371 if (!e->mask[0]) {
372 e->mask = NULL;
373 pr_debug("register: mask[raw]: none\n");
374 } else if (USE_DEBUG)
375 print_hex_dump_bytes(
376 KBUILD_MODNAME ": register: mask[raw]: ",
377 DUMP_PREFIX_NONE, e->mask, p - e->mask);
378
379 /*
380 * Decode the magic & mask fields.
381 * Note: while we might have accepted embedded NUL bytes from
382 * above, the unescape helpers here will stop at the first one
383 * it encounters.
384 */
385 e->size = string_unescape_inplace(e->magic, UNESCAPE_HEX);
386 if (e->mask &&
387 string_unescape_inplace(e->mask, UNESCAPE_HEX) != e->size)
388 goto einval;
389 if (e->size > BINPRM_BUF_SIZE ||
390 BINPRM_BUF_SIZE - e->size < e->offset)
391 goto einval;
392 pr_debug("register: magic/mask length: %i\n", e->size);
393 if (USE_DEBUG) {
394 print_hex_dump_bytes(
395 KBUILD_MODNAME ": register: magic[decoded]: ",
396 DUMP_PREFIX_NONE, e->magic, e->size);
397
398 if (e->mask) {
399 int i;
400 char *masked = kmalloc(e->size, GFP_KERNEL);
401
402 print_hex_dump_bytes(
403 KBUILD_MODNAME ": register: mask[decoded]: ",
404 DUMP_PREFIX_NONE, e->mask, e->size);
405
406 if (masked) {
407 for (i = 0; i < e->size; ++i)
408 masked[i] = e->magic[i] & e->mask[i];
409 print_hex_dump_bytes(
410 KBUILD_MODNAME ": register: magic[masked]: ",
411 DUMP_PREFIX_NONE, masked, e->size);
412
413 kfree(masked);
414 }
415 }
416 }
417 } else {
418 /* Handle the 'E' (extension) format. */
419
420 /* Skip the 'offset' field. */
421 p = strchr(p, del);
422 if (!p)
423 goto einval;
424 *p++ = '\0';
425
426 /* Parse the 'magic' field. */
427 e->magic = p;
428 p = strchr(p, del);
429 if (!p)
430 goto einval;
431 *p++ = '\0';
432 if (!e->magic[0] || strchr(e->magic, '/'))
433 goto einval;
434 pr_debug("register: extension: {%s}\n", e->magic);
435
436 /* Skip the 'mask' field. */
437 p = strchr(p, del);
438 if (!p)
439 goto einval;
440 *p++ = '\0';
441 }
442
443 /* Parse the 'interpreter' field. */
444 e->interpreter = p;
445 p = strchr(p, del);
446 if (!p)
447 goto einval;
448 *p++ = '\0';
449 if (!e->interpreter[0])
450 goto einval;
451 pr_debug("register: interpreter: {%s}\n", e->interpreter);
452
453 /* Parse the 'flags' field. */
454 p = check_special_flags(p, e);
455 if (*p == '\n')
456 p++;
457 if (p != buf + count)
458 goto einval;
459
460 return e;
461
462 out:
463 return ERR_PTR(err);
464
465 efault:
466 kfree(e);
467 return ERR_PTR(-EFAULT);
468 einval:
469 kfree(e);
470 return ERR_PTR(-EINVAL);
471 }
472
473 /*
474 * Set status of entry/binfmt_misc:
475 * '1' enables, '0' disables and '-1' clears entry/binfmt_misc
476 */
parse_command(const char __user * buffer,size_t count)477 static int parse_command(const char __user *buffer, size_t count)
478 {
479 char s[4];
480
481 if (count > 3)
482 return -EINVAL;
483 if (copy_from_user(s, buffer, count))
484 return -EFAULT;
485 if (!count)
486 return 0;
487 if (s[count - 1] == '\n')
488 count--;
489 if (count == 1 && s[0] == '0')
490 return 1;
491 if (count == 1 && s[0] == '1')
492 return 2;
493 if (count == 2 && s[0] == '-' && s[1] == '1')
494 return 3;
495 return -EINVAL;
496 }
497
498 /* generic stuff */
499
entry_status(Node * e,char * page)500 static void entry_status(Node *e, char *page)
501 {
502 char *dp = page;
503 const char *status = "disabled";
504
505 if (test_bit(Enabled, &e->flags))
506 status = "enabled";
507
508 if (!VERBOSE_STATUS) {
509 sprintf(page, "%s\n", status);
510 return;
511 }
512
513 dp += sprintf(dp, "%s\ninterpreter %s\n", status, e->interpreter);
514
515 /* print the special flags */
516 dp += sprintf(dp, "flags: ");
517 if (e->flags & MISC_FMT_PRESERVE_ARGV0)
518 *dp++ = 'P';
519 if (e->flags & MISC_FMT_OPEN_BINARY)
520 *dp++ = 'O';
521 if (e->flags & MISC_FMT_CREDENTIALS)
522 *dp++ = 'C';
523 if (e->flags & MISC_FMT_OPEN_FILE)
524 *dp++ = 'F';
525 *dp++ = '\n';
526
527 if (!test_bit(Magic, &e->flags)) {
528 sprintf(dp, "extension .%s\n", e->magic);
529 } else {
530 dp += sprintf(dp, "offset %i\nmagic ", e->offset);
531 dp = bin2hex(dp, e->magic, e->size);
532 if (e->mask) {
533 dp += sprintf(dp, "\nmask ");
534 dp = bin2hex(dp, e->mask, e->size);
535 }
536 *dp++ = '\n';
537 *dp = '\0';
538 }
539 }
540
bm_get_inode(struct super_block * sb,int mode)541 static struct inode *bm_get_inode(struct super_block *sb, int mode)
542 {
543 struct inode *inode = new_inode(sb);
544
545 if (inode) {
546 inode->i_ino = get_next_ino();
547 inode->i_mode = mode;
548 inode->i_atime = inode->i_mtime = inode->i_ctime =
549 current_time(inode);
550 }
551 return inode;
552 }
553
bm_evict_inode(struct inode * inode)554 static void bm_evict_inode(struct inode *inode)
555 {
556 Node *e = inode->i_private;
557
558 if (e && e->flags & MISC_FMT_OPEN_FILE)
559 filp_close(e->interp_file, NULL);
560
561 clear_inode(inode);
562 kfree(e);
563 }
564
kill_node(Node * e)565 static void kill_node(Node *e)
566 {
567 struct dentry *dentry;
568
569 write_lock(&entries_lock);
570 list_del_init(&e->list);
571 write_unlock(&entries_lock);
572
573 dentry = e->dentry;
574 drop_nlink(d_inode(dentry));
575 d_drop(dentry);
576 dput(dentry);
577 simple_release_fs(&bm_mnt, &entry_count);
578 }
579
580 /* /<entry> */
581
582 static ssize_t
bm_entry_read(struct file * file,char __user * buf,size_t nbytes,loff_t * ppos)583 bm_entry_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
584 {
585 Node *e = file_inode(file)->i_private;
586 ssize_t res;
587 char *page;
588
589 page = (char *) __get_free_page(GFP_KERNEL);
590 if (!page)
591 return -ENOMEM;
592
593 entry_status(e, page);
594
595 res = simple_read_from_buffer(buf, nbytes, ppos, page, strlen(page));
596
597 free_page((unsigned long) page);
598 return res;
599 }
600
bm_entry_write(struct file * file,const char __user * buffer,size_t count,loff_t * ppos)601 static ssize_t bm_entry_write(struct file *file, const char __user *buffer,
602 size_t count, loff_t *ppos)
603 {
604 struct dentry *root;
605 Node *e = file_inode(file)->i_private;
606 int res = parse_command(buffer, count);
607
608 switch (res) {
609 case 1:
610 /* Disable this handler. */
611 clear_bit(Enabled, &e->flags);
612 break;
613 case 2:
614 /* Enable this handler. */
615 set_bit(Enabled, &e->flags);
616 break;
617 case 3:
618 /* Delete this handler. */
619 root = file_inode(file)->i_sb->s_root;
620 inode_lock(d_inode(root));
621
622 if (!list_empty(&e->list))
623 kill_node(e);
624
625 inode_unlock(d_inode(root));
626 break;
627 default:
628 return res;
629 }
630
631 return count;
632 }
633
634 static const struct file_operations bm_entry_operations = {
635 .read = bm_entry_read,
636 .write = bm_entry_write,
637 .llseek = default_llseek,
638 };
639
640 /* /register */
641
bm_register_write(struct file * file,const char __user * buffer,size_t count,loff_t * ppos)642 static ssize_t bm_register_write(struct file *file, const char __user *buffer,
643 size_t count, loff_t *ppos)
644 {
645 Node *e;
646 struct inode *inode;
647 struct super_block *sb = file_inode(file)->i_sb;
648 struct dentry *root = sb->s_root, *dentry;
649 int err = 0;
650
651 e = create_entry(buffer, count);
652
653 if (IS_ERR(e))
654 return PTR_ERR(e);
655
656 inode_lock(d_inode(root));
657 dentry = lookup_one_len(e->name, root, strlen(e->name));
658 err = PTR_ERR(dentry);
659 if (IS_ERR(dentry))
660 goto out;
661
662 err = -EEXIST;
663 if (d_really_is_positive(dentry))
664 goto out2;
665
666 inode = bm_get_inode(sb, S_IFREG | 0644);
667
668 err = -ENOMEM;
669 if (!inode)
670 goto out2;
671
672 err = simple_pin_fs(&bm_fs_type, &bm_mnt, &entry_count);
673 if (err) {
674 iput(inode);
675 inode = NULL;
676 goto out2;
677 }
678
679 if (e->flags & MISC_FMT_OPEN_FILE) {
680 struct file *f;
681
682 f = open_exec(e->interpreter);
683 if (IS_ERR(f)) {
684 err = PTR_ERR(f);
685 pr_notice("register: failed to install interpreter file %s\n", e->interpreter);
686 simple_release_fs(&bm_mnt, &entry_count);
687 iput(inode);
688 inode = NULL;
689 goto out2;
690 }
691 e->interp_file = f;
692 }
693
694 e->dentry = dget(dentry);
695 inode->i_private = e;
696 inode->i_fop = &bm_entry_operations;
697
698 d_instantiate(dentry, inode);
699 write_lock(&entries_lock);
700 list_add(&e->list, &entries);
701 write_unlock(&entries_lock);
702
703 err = 0;
704 out2:
705 dput(dentry);
706 out:
707 inode_unlock(d_inode(root));
708
709 if (err) {
710 kfree(e);
711 return err;
712 }
713 return count;
714 }
715
716 static const struct file_operations bm_register_operations = {
717 .write = bm_register_write,
718 .llseek = noop_llseek,
719 };
720
721 /* /status */
722
723 static ssize_t
bm_status_read(struct file * file,char __user * buf,size_t nbytes,loff_t * ppos)724 bm_status_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
725 {
726 char *s = enabled ? "enabled\n" : "disabled\n";
727
728 return simple_read_from_buffer(buf, nbytes, ppos, s, strlen(s));
729 }
730
bm_status_write(struct file * file,const char __user * buffer,size_t count,loff_t * ppos)731 static ssize_t bm_status_write(struct file *file, const char __user *buffer,
732 size_t count, loff_t *ppos)
733 {
734 int res = parse_command(buffer, count);
735 struct dentry *root;
736
737 switch (res) {
738 case 1:
739 /* Disable all handlers. */
740 enabled = 0;
741 break;
742 case 2:
743 /* Enable all handlers. */
744 enabled = 1;
745 break;
746 case 3:
747 /* Delete all handlers. */
748 root = file_inode(file)->i_sb->s_root;
749 inode_lock(d_inode(root));
750
751 while (!list_empty(&entries))
752 kill_node(list_first_entry(&entries, Node, list));
753
754 inode_unlock(d_inode(root));
755 break;
756 default:
757 return res;
758 }
759
760 return count;
761 }
762
763 static const struct file_operations bm_status_operations = {
764 .read = bm_status_read,
765 .write = bm_status_write,
766 .llseek = default_llseek,
767 };
768
769 /* Superblock handling */
770
771 static const struct super_operations s_ops = {
772 .statfs = simple_statfs,
773 .evict_inode = bm_evict_inode,
774 };
775
bm_fill_super(struct super_block * sb,struct fs_context * fc)776 static int bm_fill_super(struct super_block *sb, struct fs_context *fc)
777 {
778 int err;
779 static const struct tree_descr bm_files[] = {
780 [2] = {"status", &bm_status_operations, S_IWUSR|S_IRUGO},
781 [3] = {"register", &bm_register_operations, S_IWUSR},
782 /* last one */ {""}
783 };
784
785 err = simple_fill_super(sb, BINFMTFS_MAGIC, bm_files);
786 if (!err)
787 sb->s_op = &s_ops;
788 return err;
789 }
790
bm_get_tree(struct fs_context * fc)791 static int bm_get_tree(struct fs_context *fc)
792 {
793 return get_tree_single(fc, bm_fill_super);
794 }
795
796 static const struct fs_context_operations bm_context_ops = {
797 .get_tree = bm_get_tree,
798 };
799
bm_init_fs_context(struct fs_context * fc)800 static int bm_init_fs_context(struct fs_context *fc)
801 {
802 fc->ops = &bm_context_ops;
803 return 0;
804 }
805
806 static struct linux_binfmt misc_format = {
807 .module = THIS_MODULE,
808 .load_binary = load_misc_binary,
809 };
810
811 static struct file_system_type bm_fs_type = {
812 .owner = THIS_MODULE,
813 .name = "binfmt_misc",
814 .init_fs_context = bm_init_fs_context,
815 .kill_sb = kill_litter_super,
816 };
817 MODULE_ALIAS_FS("binfmt_misc");
818
init_misc_binfmt(void)819 static int __init init_misc_binfmt(void)
820 {
821 int err = register_filesystem(&bm_fs_type);
822 if (!err)
823 insert_binfmt(&misc_format);
824 return err;
825 }
826
exit_misc_binfmt(void)827 static void __exit exit_misc_binfmt(void)
828 {
829 unregister_binfmt(&misc_format);
830 unregister_filesystem(&bm_fs_type);
831 }
832
833 core_initcall(init_misc_binfmt);
834 module_exit(exit_misc_binfmt);
835 MODULE_LICENSE("GPL");
836
