blob: 1befe2ec8186768a7b7baebc4a4c4d20418cfc14 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * binfmt_misc.c
3 *
Jan Engelhardt96de0e22007-10-19 23:21:04 +02004 * Copyright (C) 1997 Richard Günther
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 *
6 * binfmt_misc detects binaries via a magic or filename extension and invokes
7 * a specified wrapper. This should obsolete binfmt_java, binfmt_em86 and
8 * binfmt_mz.
9 *
10 * 1997-04-25 first version
11 * [...]
12 * 1997-05-19 cleanup
13 * 1997-06-26 hpa: pass the real filename rather than argv[0]
14 * 1997-06-30 minor cleanup
15 * 1997-08-09 removed extension stripping, locking cleanup
16 * 2001-02-28 AV: rewritten into something that resembles C. Original didn't.
17 */
18
19#include <linux/module.h>
20#include <linux/init.h>
Alexey Dobriyane8edc6e2007-05-21 01:22:52 +040021#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <linux/binfmts.h>
23#include <linux/slab.h>
24#include <linux/ctype.h>
25#include <linux/file.h>
26#include <linux/pagemap.h>
27#include <linux/namei.h>
28#include <linux/mount.h>
29#include <linux/syscalls.h>
Akinobu Mita6e2c10a2008-07-23 21:29:15 -070030#include <linux/fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
32#include <asm/uaccess.h>
33
34enum {
35 VERBOSE_STATUS = 1 /* make it zero to save 400 bytes kernel memory */
36};
37
38static LIST_HEAD(entries);
39static int enabled = 1;
40
41enum {Enabled, Magic};
42#define MISC_FMT_PRESERVE_ARGV0 (1<<31)
43#define MISC_FMT_OPEN_BINARY (1<<30)
44#define MISC_FMT_CREDENTIALS (1<<29)
45
46typedef struct {
47 struct list_head list;
48 unsigned long flags; /* type, status, etc. */
49 int offset; /* offset of magic */
50 int size; /* size of magic/mask */
51 char *magic; /* magic or filename extension */
52 char *mask; /* mask, NULL for exact match */
53 char *interpreter; /* filename of interpreter */
54 char *name;
55 struct dentry *dentry;
56} Node;
57
58static DEFINE_RWLOCK(entries_lock);
Trond Myklebust1f5ce9e2006-06-09 09:34:16 -040059static struct file_system_type bm_fs_type;
Linus Torvalds1da177e2005-04-16 15:20:36 -070060static struct vfsmount *bm_mnt;
61static int entry_count;
62
63/*
64 * Check if we support the binfmt
65 * if we do, return the node, else NULL
66 * locking is done in load_misc_binary
67 */
68static Node *check_file(struct linux_binprm *bprm)
69{
70 char *p = strrchr(bprm->interp, '.');
71 struct list_head *l;
72
73 list_for_each(l, &entries) {
74 Node *e = list_entry(l, Node, list);
75 char *s;
76 int j;
77
78 if (!test_bit(Enabled, &e->flags))
79 continue;
80
81 if (!test_bit(Magic, &e->flags)) {
82 if (p && !strcmp(e->magic, p + 1))
83 return e;
84 continue;
85 }
86
87 s = bprm->buf + e->offset;
88 if (e->mask) {
89 for (j = 0; j < e->size; j++)
90 if ((*s++ ^ e->magic[j]) & e->mask[j])
91 break;
92 } else {
93 for (j = 0; j < e->size; j++)
94 if ((*s++ ^ e->magic[j]))
95 break;
96 }
97 if (j == e->size)
98 return e;
99 }
100 return NULL;
101}
102
103/*
104 * the loader itself
105 */
106static int load_misc_binary(struct linux_binprm *bprm, struct pt_regs *regs)
107{
108 Node *fmt;
109 struct file * interp_file = NULL;
110 char iname[BINPRM_BUF_SIZE];
David Howellsd7627462010-08-17 23:52:56 +0100111 const char *iname_addr = iname;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 int retval;
113 int fd_binary = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
115 retval = -ENOEXEC;
116 if (!enabled)
117 goto _ret;
118
Pavel Emelyanov3a2e7f42008-04-29 00:59:24 -0700119 retval = -ENOEXEC;
Kirill A. Shutemovbf2a9a32008-10-15 22:02:39 -0700120 if (bprm->recursion_depth > BINPRM_MAX_RECURSION)
Pavel Emelyanov3a2e7f42008-04-29 00:59:24 -0700121 goto _ret;
122
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123 /* to keep locking time low, we copy the interpreter string */
124 read_lock(&entries_lock);
125 fmt = check_file(bprm);
126 if (fmt)
127 strlcpy(iname, fmt->interpreter, BINPRM_BUF_SIZE);
128 read_unlock(&entries_lock);
129 if (!fmt)
130 goto _ret;
131
132 if (!(fmt->flags & MISC_FMT_PRESERVE_ARGV0)) {
Ollie Wildb6a2fea2007-07-19 01:48:16 -0700133 retval = remove_arg_zero(bprm);
134 if (retval)
135 goto _ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 }
137
138 if (fmt->flags & MISC_FMT_OPEN_BINARY) {
139
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 /* if the binary should be opened on behalf of the
141 * interpreter than keep it open and assign descriptor
142 * to it */
143 fd_binary = get_unused_fd();
144 if (fd_binary < 0) {
145 retval = fd_binary;
Al Virofd8328b2008-04-22 05:11:59 -0400146 goto _ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 }
148 fd_install(fd_binary, bprm->file);
149
150 /* if the binary is not readable than enforce mm->dumpable=0
151 regardless of the interpreter's permissions */
Christoph Hellwig8c744fb2005-11-08 21:35:04 -0800152 if (file_permission(bprm->file, MAY_READ))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
154
155 allow_write_access(bprm->file);
156 bprm->file = NULL;
157
158 /* mark the bprm that fd should be passed to interp */
159 bprm->interp_flags |= BINPRM_FLAGS_EXECFD;
160 bprm->interp_data = fd_binary;
161
162 } else {
163 allow_write_access(bprm->file);
164 fput(bprm->file);
165 bprm->file = NULL;
166 }
167 /* make argv[1] be the path to the binary */
168 retval = copy_strings_kernel (1, &bprm->interp, bprm);
169 if (retval < 0)
170 goto _error;
171 bprm->argc++;
172
173 /* add the interp as argv[0] */
174 retval = copy_strings_kernel (1, &iname_addr, bprm);
175 if (retval < 0)
176 goto _error;
177 bprm->argc ++;
178
179 bprm->interp = iname; /* for binfmt_script */
180
181 interp_file = open_exec (iname);
182 retval = PTR_ERR (interp_file);
183 if (IS_ERR (interp_file))
184 goto _error;
185
186 bprm->file = interp_file;
187 if (fmt->flags & MISC_FMT_CREDENTIALS) {
188 /*
189 * No need to call prepare_binprm(), it's already been
190 * done. bprm->buf is stale, update from interp_file.
191 */
192 memset(bprm->buf, 0, BINPRM_BUF_SIZE);
193 retval = kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE);
194 } else
195 retval = prepare_binprm (bprm);
196
197 if (retval < 0)
198 goto _error;
199
Kirill A. Shutemovbf2a9a32008-10-15 22:02:39 -0700200 bprm->recursion_depth++;
Pavel Emelyanovff9bc512008-08-20 14:09:10 -0700201
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 retval = search_binary_handler (bprm, regs);
203 if (retval < 0)
204 goto _error;
205
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206_ret:
207 return retval;
208_error:
209 if (fd_binary > 0)
210 sys_close(fd_binary);
211 bprm->interp_flags = 0;
212 bprm->interp_data = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 goto _ret;
214}
215
216/* Command parsers */
217
218/*
219 * parses and copies one argument enclosed in del from *sp to *dp,
220 * recognising the \x special.
221 * returns pointer to the copied argument or NULL in case of an
222 * error (and sets err) or null argument length.
223 */
224static char *scanarg(char *s, char del)
225{
226 char c;
227
228 while ((c = *s++) != del) {
229 if (c == '\\' && *s == 'x') {
230 s++;
231 if (!isxdigit(*s++))
232 return NULL;
233 if (!isxdigit(*s++))
234 return NULL;
235 }
236 }
237 return s;
238}
239
240static int unquote(char *from)
241{
242 char c = 0, *s = from, *p = from;
243
244 while ((c = *s++) != '\0') {
245 if (c == '\\' && *s == 'x') {
246 s++;
247 c = toupper(*s++);
248 *p = (c - (isdigit(c) ? '0' : 'A' - 10)) << 4;
249 c = toupper(*s++);
250 *p++ |= c - (isdigit(c) ? '0' : 'A' - 10);
251 continue;
252 }
253 *p++ = c;
254 }
255 return p - from;
256}
257
Arjan van de Ven858119e2006-01-14 13:20:43 -0800258static char * check_special_flags (char * sfs, Node * e)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259{
260 char * p = sfs;
261 int cont = 1;
262
263 /* special flags */
264 while (cont) {
265 switch (*p) {
266 case 'P':
267 p++;
268 e->flags |= MISC_FMT_PRESERVE_ARGV0;
269 break;
270 case 'O':
271 p++;
272 e->flags |= MISC_FMT_OPEN_BINARY;
273 break;
274 case 'C':
275 p++;
276 /* this flags also implies the
277 open-binary flag */
278 e->flags |= (MISC_FMT_CREDENTIALS |
279 MISC_FMT_OPEN_BINARY);
280 break;
281 default:
282 cont = 0;
283 }
284 }
285
286 return p;
287}
288/*
289 * This registers a new binary format, it recognises the syntax
290 * ':name:type:offset:magic:mask:interpreter:flags'
291 * where the ':' is the IFS, that can be chosen with the first char
292 */
293static Node *create_entry(const char __user *buffer, size_t count)
294{
295 Node *e;
296 int memsize, err;
297 char *buf, *p;
298 char del;
299
300 /* some sanity checks */
301 err = -EINVAL;
302 if ((count < 11) || (count > 256))
303 goto out;
304
305 err = -ENOMEM;
306 memsize = sizeof(Node) + count + 8;
Robert P. J. Day5cbded52006-12-13 00:35:56 -0800307 e = kmalloc(memsize, GFP_USER);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 if (!e)
309 goto out;
310
311 p = buf = (char *)e + sizeof(Node);
312
313 memset(e, 0, sizeof(Node));
314 if (copy_from_user(buf, buffer, count))
315 goto Efault;
316
317 del = *p++; /* delimeter */
318
319 memset(buf+count, del, 8);
320
321 e->name = p;
322 p = strchr(p, del);
323 if (!p)
324 goto Einval;
325 *p++ = '\0';
326 if (!e->name[0] ||
327 !strcmp(e->name, ".") ||
328 !strcmp(e->name, "..") ||
329 strchr(e->name, '/'))
330 goto Einval;
331 switch (*p++) {
332 case 'E': e->flags = 1<<Enabled; break;
333 case 'M': e->flags = (1<<Enabled) | (1<<Magic); break;
334 default: goto Einval;
335 }
336 if (*p++ != del)
337 goto Einval;
338 if (test_bit(Magic, &e->flags)) {
339 char *s = strchr(p, del);
340 if (!s)
341 goto Einval;
342 *s++ = '\0';
343 e->offset = simple_strtoul(p, &p, 10);
344 if (*p++)
345 goto Einval;
346 e->magic = p;
347 p = scanarg(p, del);
348 if (!p)
349 goto Einval;
350 p[-1] = '\0';
351 if (!e->magic[0])
352 goto Einval;
353 e->mask = p;
354 p = scanarg(p, del);
355 if (!p)
356 goto Einval;
357 p[-1] = '\0';
358 if (!e->mask[0])
359 e->mask = NULL;
360 e->size = unquote(e->magic);
361 if (e->mask && unquote(e->mask) != e->size)
362 goto Einval;
363 if (e->size + e->offset > BINPRM_BUF_SIZE)
364 goto Einval;
365 } else {
366 p = strchr(p, del);
367 if (!p)
368 goto Einval;
369 *p++ = '\0';
370 e->magic = p;
371 p = strchr(p, del);
372 if (!p)
373 goto Einval;
374 *p++ = '\0';
375 if (!e->magic[0] || strchr(e->magic, '/'))
376 goto Einval;
377 p = strchr(p, del);
378 if (!p)
379 goto Einval;
380 *p++ = '\0';
381 }
382 e->interpreter = p;
383 p = strchr(p, del);
384 if (!p)
385 goto Einval;
386 *p++ = '\0';
387 if (!e->interpreter[0])
388 goto Einval;
389
390
391 p = check_special_flags (p, e);
392
393 if (*p == '\n')
394 p++;
395 if (p != buf + count)
396 goto Einval;
397 return e;
398
399out:
400 return ERR_PTR(err);
401
402Efault:
403 kfree(e);
404 return ERR_PTR(-EFAULT);
405Einval:
406 kfree(e);
407 return ERR_PTR(-EINVAL);
408}
409
410/*
411 * Set status of entry/binfmt_misc:
412 * '1' enables, '0' disables and '-1' clears entry/binfmt_misc
413 */
414static int parse_command(const char __user *buffer, size_t count)
415{
416 char s[4];
417
418 if (!count)
419 return 0;
420 if (count > 3)
421 return -EINVAL;
422 if (copy_from_user(s, buffer, count))
423 return -EFAULT;
424 if (s[count-1] == '\n')
425 count--;
426 if (count == 1 && s[0] == '0')
427 return 1;
428 if (count == 1 && s[0] == '1')
429 return 2;
430 if (count == 2 && s[0] == '-' && s[1] == '1')
431 return 3;
432 return -EINVAL;
433}
434
435/* generic stuff */
436
437static void entry_status(Node *e, char *page)
438{
439 char *dp;
440 char *status = "disabled";
441 const char * flags = "flags: ";
442
443 if (test_bit(Enabled, &e->flags))
444 status = "enabled";
445
446 if (!VERBOSE_STATUS) {
447 sprintf(page, "%s\n", status);
448 return;
449 }
450
451 sprintf(page, "%s\ninterpreter %s\n", status, e->interpreter);
452 dp = page + strlen(page);
453
454 /* print the special flags */
455 sprintf (dp, "%s", flags);
456 dp += strlen (flags);
457 if (e->flags & MISC_FMT_PRESERVE_ARGV0) {
458 *dp ++ = 'P';
459 }
460 if (e->flags & MISC_FMT_OPEN_BINARY) {
461 *dp ++ = 'O';
462 }
463 if (e->flags & MISC_FMT_CREDENTIALS) {
464 *dp ++ = 'C';
465 }
466 *dp ++ = '\n';
467
468
469 if (!test_bit(Magic, &e->flags)) {
470 sprintf(dp, "extension .%s\n", e->magic);
471 } else {
472 int i;
473
474 sprintf(dp, "offset %i\nmagic ", e->offset);
475 dp = page + strlen(page);
476 for (i = 0; i < e->size; i++) {
477 sprintf(dp, "%02x", 0xff & (int) (e->magic[i]));
478 dp += 2;
479 }
480 if (e->mask) {
481 sprintf(dp, "\nmask ");
482 dp += 6;
483 for (i = 0; i < e->size; i++) {
484 sprintf(dp, "%02x", 0xff & (int) (e->mask[i]));
485 dp += 2;
486 }
487 }
488 *dp++ = '\n';
489 *dp = '\0';
490 }
491}
492
493static struct inode *bm_get_inode(struct super_block *sb, int mode)
494{
495 struct inode * inode = new_inode(sb);
496
497 if (inode) {
Christoph Hellwig85fe4022010-10-23 11:19:54 -0400498 inode->i_ino = get_next_ino();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 inode->i_mode = mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 inode->i_atime = inode->i_mtime = inode->i_ctime =
501 current_fs_time(inode->i_sb);
502 }
503 return inode;
504}
505
Al Virob57922d2010-06-07 14:34:48 -0400506static void bm_evict_inode(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507{
Al Virob57922d2010-06-07 14:34:48 -0400508 end_writeback(inode);
Theodore Ts'o8e18e292006-09-27 01:50:46 -0700509 kfree(inode->i_private);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510}
511
512static void kill_node(Node *e)
513{
514 struct dentry *dentry;
515
516 write_lock(&entries_lock);
517 dentry = e->dentry;
518 if (dentry) {
519 list_del_init(&e->list);
520 e->dentry = NULL;
521 }
522 write_unlock(&entries_lock);
523
524 if (dentry) {
525 dentry->d_inode->i_nlink--;
526 d_drop(dentry);
527 dput(dentry);
528 simple_release_fs(&bm_mnt, &entry_count);
529 }
530}
531
532/* /<entry> */
533
534static ssize_t
535bm_entry_read(struct file * file, char __user * buf, size_t nbytes, loff_t *ppos)
536{
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800537 Node *e = file->f_path.dentry->d_inode->i_private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 ssize_t res;
539 char *page;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540
541 if (!(page = (char*) __get_free_page(GFP_KERNEL)))
542 return -ENOMEM;
543
544 entry_status(e, page);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545
Akinobu Mita6e2c10a2008-07-23 21:29:15 -0700546 res = simple_read_from_buffer(buf, nbytes, ppos, page, strlen(page));
547
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 free_page((unsigned long) page);
549 return res;
550}
551
552static ssize_t bm_entry_write(struct file *file, const char __user *buffer,
553 size_t count, loff_t *ppos)
554{
555 struct dentry *root;
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800556 Node *e = file->f_path.dentry->d_inode->i_private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 int res = parse_command(buffer, count);
558
559 switch (res) {
560 case 1: clear_bit(Enabled, &e->flags);
561 break;
562 case 2: set_bit(Enabled, &e->flags);
563 break;
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800564 case 3: root = dget(file->f_path.mnt->mnt_sb->s_root);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800565 mutex_lock(&root->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566
567 kill_node(e);
568
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800569 mutex_unlock(&root->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 dput(root);
571 break;
572 default: return res;
573 }
574 return count;
575}
576
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800577static const struct file_operations bm_entry_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 .read = bm_entry_read,
579 .write = bm_entry_write,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200580 .llseek = default_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581};
582
583/* /register */
584
585static ssize_t bm_register_write(struct file *file, const char __user *buffer,
586 size_t count, loff_t *ppos)
587{
588 Node *e;
589 struct inode *inode;
590 struct dentry *root, *dentry;
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800591 struct super_block *sb = file->f_path.mnt->mnt_sb;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 int err = 0;
593
594 e = create_entry(buffer, count);
595
596 if (IS_ERR(e))
597 return PTR_ERR(e);
598
599 root = dget(sb->s_root);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800600 mutex_lock(&root->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 dentry = lookup_one_len(e->name, root, strlen(e->name));
602 err = PTR_ERR(dentry);
603 if (IS_ERR(dentry))
604 goto out;
605
606 err = -EEXIST;
607 if (dentry->d_inode)
608 goto out2;
609
610 inode = bm_get_inode(sb, S_IFREG | 0644);
611
612 err = -ENOMEM;
613 if (!inode)
614 goto out2;
615
Trond Myklebust1f5ce9e2006-06-09 09:34:16 -0400616 err = simple_pin_fs(&bm_fs_type, &bm_mnt, &entry_count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 if (err) {
618 iput(inode);
619 inode = NULL;
620 goto out2;
621 }
622
623 e->dentry = dget(dentry);
Theodore Ts'o8e18e292006-09-27 01:50:46 -0700624 inode->i_private = e;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625 inode->i_fop = &bm_entry_operations;
626
627 d_instantiate(dentry, inode);
628 write_lock(&entries_lock);
629 list_add(&e->list, &entries);
630 write_unlock(&entries_lock);
631
632 err = 0;
633out2:
634 dput(dentry);
635out:
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800636 mutex_unlock(&root->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 dput(root);
638
639 if (err) {
640 kfree(e);
641 return -EINVAL;
642 }
643 return count;
644}
645
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800646static const struct file_operations bm_register_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647 .write = bm_register_write,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200648 .llseek = noop_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649};
650
651/* /status */
652
653static ssize_t
654bm_status_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos)
655{
Qinghuang Feng87113e82009-01-06 14:41:38 -0800656 char *s = enabled ? "enabled\n" : "disabled\n";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657
Akinobu Mita92f4c702007-05-09 02:33:32 -0700658 return simple_read_from_buffer(buf, nbytes, ppos, s, strlen(s));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659}
660
661static ssize_t bm_status_write(struct file * file, const char __user * buffer,
662 size_t count, loff_t *ppos)
663{
664 int res = parse_command(buffer, count);
665 struct dentry *root;
666
667 switch (res) {
668 case 1: enabled = 0; break;
669 case 2: enabled = 1; break;
Josef "Jeff" Sipek0f7fc9e2006-12-08 02:36:35 -0800670 case 3: root = dget(file->f_path.mnt->mnt_sb->s_root);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800671 mutex_lock(&root->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672
673 while (!list_empty(&entries))
674 kill_node(list_entry(entries.next, Node, list));
675
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800676 mutex_unlock(&root->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 dput(root);
678 default: return res;
679 }
680 return count;
681}
682
Arjan van de Ven4b6f5d22006-03-28 01:56:42 -0800683static const struct file_operations bm_status_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 .read = bm_status_read,
685 .write = bm_status_write,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200686 .llseek = default_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687};
688
689/* Superblock handling */
690
Josef 'Jeff' Sipekee9b6d62007-02-12 00:55:41 -0800691static const struct super_operations s_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 .statfs = simple_statfs,
Al Virob57922d2010-06-07 14:34:48 -0400693 .evict_inode = bm_evict_inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694};
695
696static int bm_fill_super(struct super_block * sb, void * data, int silent)
697{
698 static struct tree_descr bm_files[] = {
Jeff Layton1a1c9bb2007-05-08 00:32:31 -0700699 [2] = {"status", &bm_status_operations, S_IWUSR|S_IRUGO},
700 [3] = {"register", &bm_register_operations, S_IWUSR},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 /* last one */ {""}
702 };
703 int err = simple_fill_super(sb, 0x42494e4d, bm_files);
704 if (!err)
705 sb->s_op = &s_ops;
706 return err;
707}
708
Al Virofc14f2f2010-07-25 01:48:30 +0400709static struct dentry *bm_mount(struct file_system_type *fs_type,
710 int flags, const char *dev_name, void *data)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711{
Al Virofc14f2f2010-07-25 01:48:30 +0400712 return mount_single(fs_type, flags, data, bm_fill_super);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713}
714
715static struct linux_binfmt misc_format = {
716 .module = THIS_MODULE,
717 .load_binary = load_misc_binary,
718};
719
720static struct file_system_type bm_fs_type = {
721 .owner = THIS_MODULE,
722 .name = "binfmt_misc",
Al Virofc14f2f2010-07-25 01:48:30 +0400723 .mount = bm_mount,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724 .kill_sb = kill_litter_super,
725};
726
727static int __init init_misc_binfmt(void)
728{
729 int err = register_filesystem(&bm_fs_type);
730 if (!err) {
Jan Semberaee3aebd2010-09-09 16:37:54 -0700731 err = insert_binfmt(&misc_format);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732 if (err)
733 unregister_filesystem(&bm_fs_type);
734 }
735 return err;
736}
737
738static void __exit exit_misc_binfmt(void)
739{
740 unregister_binfmt(&misc_format);
741 unregister_filesystem(&bm_fs_type);
742}
743
744core_initcall(init_misc_binfmt);
745module_exit(exit_misc_binfmt);
746MODULE_LICENSE("GPL");