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