Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * binfmt_misc.c | |
3 | * | |
96de0e25 | 4 | * Copyright (C) 1997 Richard Günther |
1da177e4 LT |
5 | * |
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> | |
e8edc6e0 | 21 | #include <linux/sched.h> |
b502bd11 | 22 | #include <linux/magic.h> |
1da177e4 LT |
23 | #include <linux/binfmts.h> |
24 | #include <linux/slab.h> | |
25 | #include <linux/ctype.h> | |
8d82e180 | 26 | #include <linux/string_helpers.h> |
1da177e4 LT |
27 | #include <linux/file.h> |
28 | #include <linux/pagemap.h> | |
29 | #include <linux/namei.h> | |
30 | #include <linux/mount.h> | |
31 | #include <linux/syscalls.h> | |
6e2c10a1 | 32 | #include <linux/fs.h> |
1da177e4 LT |
33 | |
34 | #include <asm/uaccess.h> | |
35 | ||
36 | enum { | |
37 | VERBOSE_STATUS = 1 /* make it zero to save 400 bytes kernel memory */ | |
38 | }; | |
39 | ||
40 | static LIST_HEAD(entries); | |
41 | static int enabled = 1; | |
42 | ||
43 | enum {Enabled, Magic}; | |
44 | #define MISC_FMT_PRESERVE_ARGV0 (1<<31) | |
45 | #define MISC_FMT_OPEN_BINARY (1<<30) | |
46 | #define MISC_FMT_CREDENTIALS (1<<29) | |
47 | ||
48 | typedef struct { | |
49 | struct list_head list; | |
50 | unsigned long flags; /* type, status, etc. */ | |
51 | int offset; /* offset of magic */ | |
52 | int size; /* size of magic/mask */ | |
53 | char *magic; /* magic or filename extension */ | |
54 | char *mask; /* mask, NULL for exact match */ | |
55 | char *interpreter; /* filename of interpreter */ | |
56 | char *name; | |
57 | struct dentry *dentry; | |
58 | } Node; | |
59 | ||
60 | static DEFINE_RWLOCK(entries_lock); | |
1f5ce9e9 | 61 | static struct file_system_type bm_fs_type; |
1da177e4 LT |
62 | static struct vfsmount *bm_mnt; |
63 | static int entry_count; | |
64 | ||
bbaecc08 MF |
65 | /* |
66 | * Max length of the register string. Determined by: | |
67 | * - 7 delimiters | |
68 | * - name: ~50 bytes | |
69 | * - type: 1 byte | |
70 | * - offset: 3 bytes (has to be smaller than BINPRM_BUF_SIZE) | |
71 | * - magic: 128 bytes (512 in escaped form) | |
72 | * - mask: 128 bytes (512 in escaped form) | |
73 | * - interp: ~50 bytes | |
74 | * - flags: 5 bytes | |
75 | * Round that up a bit, and then back off to hold the internal data | |
76 | * (like struct Node). | |
77 | */ | |
78 | #define MAX_REGISTER_LENGTH 1920 | |
79 | ||
80 | /* | |
1da177e4 LT |
81 | * Check if we support the binfmt |
82 | * if we do, return the node, else NULL | |
83 | * locking is done in load_misc_binary | |
84 | */ | |
85 | static Node *check_file(struct linux_binprm *bprm) | |
86 | { | |
87 | char *p = strrchr(bprm->interp, '.'); | |
88 | struct list_head *l; | |
89 | ||
90 | list_for_each(l, &entries) { | |
91 | Node *e = list_entry(l, Node, list); | |
92 | char *s; | |
93 | int j; | |
94 | ||
95 | if (!test_bit(Enabled, &e->flags)) | |
96 | continue; | |
97 | ||
98 | if (!test_bit(Magic, &e->flags)) { | |
99 | if (p && !strcmp(e->magic, p + 1)) | |
100 | return e; | |
101 | continue; | |
102 | } | |
103 | ||
104 | s = bprm->buf + e->offset; | |
105 | if (e->mask) { | |
106 | for (j = 0; j < e->size; j++) | |
107 | if ((*s++ ^ e->magic[j]) & e->mask[j]) | |
108 | break; | |
109 | } else { | |
110 | for (j = 0; j < e->size; j++) | |
111 | if ((*s++ ^ e->magic[j])) | |
112 | break; | |
113 | } | |
114 | if (j == e->size) | |
115 | return e; | |
116 | } | |
117 | return NULL; | |
118 | } | |
119 | ||
120 | /* | |
121 | * the loader itself | |
122 | */ | |
71613c3b | 123 | static int load_misc_binary(struct linux_binprm *bprm) |
1da177e4 LT |
124 | { |
125 | Node *fmt; | |
126 | struct file * interp_file = NULL; | |
127 | char iname[BINPRM_BUF_SIZE]; | |
d7627467 | 128 | const char *iname_addr = iname; |
1da177e4 LT |
129 | int retval; |
130 | int fd_binary = -1; | |
1da177e4 LT |
131 | |
132 | retval = -ENOEXEC; | |
133 | if (!enabled) | |
134 | goto _ret; | |
135 | ||
136 | /* to keep locking time low, we copy the interpreter string */ | |
137 | read_lock(&entries_lock); | |
138 | fmt = check_file(bprm); | |
139 | if (fmt) | |
140 | strlcpy(iname, fmt->interpreter, BINPRM_BUF_SIZE); | |
141 | read_unlock(&entries_lock); | |
142 | if (!fmt) | |
143 | goto _ret; | |
144 | ||
145 | if (!(fmt->flags & MISC_FMT_PRESERVE_ARGV0)) { | |
b6a2fea3 OW |
146 | retval = remove_arg_zero(bprm); |
147 | if (retval) | |
148 | goto _ret; | |
1da177e4 LT |
149 | } |
150 | ||
151 | if (fmt->flags & MISC_FMT_OPEN_BINARY) { | |
152 | ||
1da177e4 LT |
153 | /* if the binary should be opened on behalf of the |
154 | * interpreter than keep it open and assign descriptor | |
155 | * to it */ | |
156 | fd_binary = get_unused_fd(); | |
157 | if (fd_binary < 0) { | |
158 | retval = fd_binary; | |
fd8328be | 159 | goto _ret; |
1da177e4 LT |
160 | } |
161 | fd_install(fd_binary, bprm->file); | |
162 | ||
163 | /* if the binary is not readable than enforce mm->dumpable=0 | |
164 | regardless of the interpreter's permissions */ | |
1b5d783c | 165 | would_dump(bprm, bprm->file); |
1da177e4 LT |
166 | |
167 | allow_write_access(bprm->file); | |
168 | bprm->file = NULL; | |
169 | ||
170 | /* mark the bprm that fd should be passed to interp */ | |
171 | bprm->interp_flags |= BINPRM_FLAGS_EXECFD; | |
172 | bprm->interp_data = fd_binary; | |
173 | ||
174 | } else { | |
175 | allow_write_access(bprm->file); | |
176 | fput(bprm->file); | |
177 | bprm->file = NULL; | |
178 | } | |
179 | /* make argv[1] be the path to the binary */ | |
180 | retval = copy_strings_kernel (1, &bprm->interp, bprm); | |
181 | if (retval < 0) | |
182 | goto _error; | |
183 | bprm->argc++; | |
184 | ||
185 | /* add the interp as argv[0] */ | |
186 | retval = copy_strings_kernel (1, &iname_addr, bprm); | |
187 | if (retval < 0) | |
188 | goto _error; | |
189 | bprm->argc ++; | |
190 | ||
b66c5984 KC |
191 | /* Update interp in case binfmt_script needs it. */ |
192 | retval = bprm_change_interp(iname, bprm); | |
193 | if (retval < 0) | |
194 | goto _error; | |
1da177e4 LT |
195 | |
196 | interp_file = open_exec (iname); | |
197 | retval = PTR_ERR (interp_file); | |
198 | if (IS_ERR (interp_file)) | |
199 | goto _error; | |
200 | ||
201 | bprm->file = interp_file; | |
202 | if (fmt->flags & MISC_FMT_CREDENTIALS) { | |
203 | /* | |
204 | * No need to call prepare_binprm(), it's already been | |
205 | * done. bprm->buf is stale, update from interp_file. | |
206 | */ | |
207 | memset(bprm->buf, 0, BINPRM_BUF_SIZE); | |
208 | retval = kernel_read(bprm->file, 0, bprm->buf, BINPRM_BUF_SIZE); | |
209 | } else | |
210 | retval = prepare_binprm (bprm); | |
211 | ||
212 | if (retval < 0) | |
213 | goto _error; | |
214 | ||
3c456bfc | 215 | retval = search_binary_handler(bprm); |
1da177e4 LT |
216 | if (retval < 0) |
217 | goto _error; | |
218 | ||
1da177e4 LT |
219 | _ret: |
220 | return retval; | |
221 | _error: | |
222 | if (fd_binary > 0) | |
223 | sys_close(fd_binary); | |
224 | bprm->interp_flags = 0; | |
225 | bprm->interp_data = 0; | |
1da177e4 LT |
226 | goto _ret; |
227 | } | |
228 | ||
229 | /* Command parsers */ | |
230 | ||
231 | /* | |
232 | * parses and copies one argument enclosed in del from *sp to *dp, | |
233 | * recognising the \x special. | |
234 | * returns pointer to the copied argument or NULL in case of an | |
235 | * error (and sets err) or null argument length. | |
236 | */ | |
237 | static char *scanarg(char *s, char del) | |
238 | { | |
239 | char c; | |
240 | ||
241 | while ((c = *s++) != del) { | |
242 | if (c == '\\' && *s == 'x') { | |
243 | s++; | |
244 | if (!isxdigit(*s++)) | |
245 | return NULL; | |
246 | if (!isxdigit(*s++)) | |
247 | return NULL; | |
248 | } | |
249 | } | |
250 | return s; | |
251 | } | |
252 | ||
858119e1 | 253 | static char * check_special_flags (char * sfs, Node * e) |
1da177e4 LT |
254 | { |
255 | char * p = sfs; | |
256 | int cont = 1; | |
257 | ||
258 | /* special flags */ | |
259 | while (cont) { | |
260 | switch (*p) { | |
261 | case 'P': | |
262 | p++; | |
263 | e->flags |= MISC_FMT_PRESERVE_ARGV0; | |
264 | break; | |
265 | case 'O': | |
266 | p++; | |
267 | e->flags |= MISC_FMT_OPEN_BINARY; | |
268 | break; | |
269 | case 'C': | |
270 | p++; | |
271 | /* this flags also implies the | |
272 | open-binary flag */ | |
273 | e->flags |= (MISC_FMT_CREDENTIALS | | |
274 | MISC_FMT_OPEN_BINARY); | |
275 | break; | |
276 | default: | |
277 | cont = 0; | |
278 | } | |
279 | } | |
280 | ||
281 | return p; | |
282 | } | |
283 | /* | |
284 | * This registers a new binary format, it recognises the syntax | |
285 | * ':name:type:offset:magic:mask:interpreter:flags' | |
286 | * where the ':' is the IFS, that can be chosen with the first char | |
287 | */ | |
288 | static Node *create_entry(const char __user *buffer, size_t count) | |
289 | { | |
290 | Node *e; | |
291 | int memsize, err; | |
292 | char *buf, *p; | |
293 | char del; | |
294 | ||
295 | /* some sanity checks */ | |
296 | err = -EINVAL; | |
bbaecc08 | 297 | if ((count < 11) || (count > MAX_REGISTER_LENGTH)) |
1da177e4 LT |
298 | goto out; |
299 | ||
300 | err = -ENOMEM; | |
301 | memsize = sizeof(Node) + count + 8; | |
5cbded58 | 302 | e = kmalloc(memsize, GFP_USER); |
1da177e4 LT |
303 | if (!e) |
304 | goto out; | |
305 | ||
306 | p = buf = (char *)e + sizeof(Node); | |
307 | ||
308 | memset(e, 0, sizeof(Node)); | |
309 | if (copy_from_user(buf, buffer, count)) | |
310 | goto Efault; | |
311 | ||
312 | del = *p++; /* delimeter */ | |
313 | ||
314 | memset(buf+count, del, 8); | |
315 | ||
316 | e->name = p; | |
317 | p = strchr(p, del); | |
318 | if (!p) | |
319 | goto Einval; | |
320 | *p++ = '\0'; | |
321 | if (!e->name[0] || | |
322 | !strcmp(e->name, ".") || | |
323 | !strcmp(e->name, "..") || | |
324 | strchr(e->name, '/')) | |
325 | goto Einval; | |
326 | switch (*p++) { | |
327 | case 'E': e->flags = 1<<Enabled; break; | |
328 | case 'M': e->flags = (1<<Enabled) | (1<<Magic); break; | |
329 | default: goto Einval; | |
330 | } | |
331 | if (*p++ != del) | |
332 | goto Einval; | |
333 | if (test_bit(Magic, &e->flags)) { | |
334 | char *s = strchr(p, del); | |
335 | if (!s) | |
336 | goto Einval; | |
337 | *s++ = '\0'; | |
338 | e->offset = simple_strtoul(p, &p, 10); | |
339 | if (*p++) | |
340 | goto Einval; | |
341 | e->magic = p; | |
342 | p = scanarg(p, del); | |
343 | if (!p) | |
344 | goto Einval; | |
345 | p[-1] = '\0'; | |
346 | if (!e->magic[0]) | |
347 | goto Einval; | |
348 | e->mask = p; | |
349 | p = scanarg(p, del); | |
350 | if (!p) | |
351 | goto Einval; | |
352 | p[-1] = '\0'; | |
353 | if (!e->mask[0]) | |
354 | e->mask = NULL; | |
8d82e180 AS |
355 | e->size = string_unescape_inplace(e->magic, UNESCAPE_HEX); |
356 | if (e->mask && | |
357 | string_unescape_inplace(e->mask, UNESCAPE_HEX) != e->size) | |
1da177e4 LT |
358 | goto Einval; |
359 | if (e->size + e->offset > BINPRM_BUF_SIZE) | |
360 | goto Einval; | |
361 | } else { | |
362 | p = strchr(p, del); | |
363 | if (!p) | |
364 | goto Einval; | |
365 | *p++ = '\0'; | |
366 | e->magic = p; | |
367 | p = strchr(p, del); | |
368 | if (!p) | |
369 | goto Einval; | |
370 | *p++ = '\0'; | |
371 | if (!e->magic[0] || strchr(e->magic, '/')) | |
372 | goto Einval; | |
373 | p = strchr(p, del); | |
374 | if (!p) | |
375 | goto Einval; | |
376 | *p++ = '\0'; | |
377 | } | |
378 | e->interpreter = p; | |
379 | p = strchr(p, del); | |
380 | if (!p) | |
381 | goto Einval; | |
382 | *p++ = '\0'; | |
383 | if (!e->interpreter[0]) | |
384 | goto Einval; | |
385 | ||
386 | ||
387 | p = check_special_flags (p, e); | |
388 | ||
389 | if (*p == '\n') | |
390 | p++; | |
391 | if (p != buf + count) | |
392 | goto Einval; | |
393 | return e; | |
394 | ||
395 | out: | |
396 | return ERR_PTR(err); | |
397 | ||
398 | Efault: | |
399 | kfree(e); | |
400 | return ERR_PTR(-EFAULT); | |
401 | Einval: | |
402 | kfree(e); | |
403 | return ERR_PTR(-EINVAL); | |
404 | } | |
405 | ||
406 | /* | |
407 | * Set status of entry/binfmt_misc: | |
408 | * '1' enables, '0' disables and '-1' clears entry/binfmt_misc | |
409 | */ | |
410 | static int parse_command(const char __user *buffer, size_t count) | |
411 | { | |
412 | char s[4]; | |
413 | ||
1da177e4 LT |
414 | if (count > 3) |
415 | return -EINVAL; | |
416 | if (copy_from_user(s, buffer, count)) | |
417 | return -EFAULT; | |
de8288b1 AB |
418 | if (!count) |
419 | return 0; | |
1da177e4 LT |
420 | if (s[count-1] == '\n') |
421 | count--; | |
422 | if (count == 1 && s[0] == '0') | |
423 | return 1; | |
424 | if (count == 1 && s[0] == '1') | |
425 | return 2; | |
426 | if (count == 2 && s[0] == '-' && s[1] == '1') | |
427 | return 3; | |
428 | return -EINVAL; | |
429 | } | |
430 | ||
431 | /* generic stuff */ | |
432 | ||
433 | static void entry_status(Node *e, char *page) | |
434 | { | |
435 | char *dp; | |
436 | char *status = "disabled"; | |
437 | const char * flags = "flags: "; | |
438 | ||
439 | if (test_bit(Enabled, &e->flags)) | |
440 | status = "enabled"; | |
441 | ||
442 | if (!VERBOSE_STATUS) { | |
443 | sprintf(page, "%s\n", status); | |
444 | return; | |
445 | } | |
446 | ||
447 | sprintf(page, "%s\ninterpreter %s\n", status, e->interpreter); | |
448 | dp = page + strlen(page); | |
449 | ||
450 | /* print the special flags */ | |
451 | sprintf (dp, "%s", flags); | |
452 | dp += strlen (flags); | |
453 | if (e->flags & MISC_FMT_PRESERVE_ARGV0) { | |
454 | *dp ++ = 'P'; | |
455 | } | |
456 | if (e->flags & MISC_FMT_OPEN_BINARY) { | |
457 | *dp ++ = 'O'; | |
458 | } | |
459 | if (e->flags & MISC_FMT_CREDENTIALS) { | |
460 | *dp ++ = 'C'; | |
461 | } | |
462 | *dp ++ = '\n'; | |
463 | ||
464 | ||
465 | if (!test_bit(Magic, &e->flags)) { | |
466 | sprintf(dp, "extension .%s\n", e->magic); | |
467 | } else { | |
468 | int i; | |
469 | ||
470 | sprintf(dp, "offset %i\nmagic ", e->offset); | |
471 | dp = page + strlen(page); | |
472 | for (i = 0; i < e->size; i++) { | |
473 | sprintf(dp, "%02x", 0xff & (int) (e->magic[i])); | |
474 | dp += 2; | |
475 | } | |
476 | if (e->mask) { | |
477 | sprintf(dp, "\nmask "); | |
478 | dp += 6; | |
479 | for (i = 0; i < e->size; i++) { | |
480 | sprintf(dp, "%02x", 0xff & (int) (e->mask[i])); | |
481 | dp += 2; | |
482 | } | |
483 | } | |
484 | *dp++ = '\n'; | |
485 | *dp = '\0'; | |
486 | } | |
487 | } | |
488 | ||
489 | static struct inode *bm_get_inode(struct super_block *sb, int mode) | |
490 | { | |
491 | struct inode * inode = new_inode(sb); | |
492 | ||
493 | if (inode) { | |
85fe4025 | 494 | inode->i_ino = get_next_ino(); |
1da177e4 | 495 | inode->i_mode = mode; |
1da177e4 LT |
496 | inode->i_atime = inode->i_mtime = inode->i_ctime = |
497 | current_fs_time(inode->i_sb); | |
498 | } | |
499 | return inode; | |
500 | } | |
501 | ||
b57922d9 | 502 | static void bm_evict_inode(struct inode *inode) |
1da177e4 | 503 | { |
dbd5768f | 504 | clear_inode(inode); |
8e18e294 | 505 | kfree(inode->i_private); |
1da177e4 LT |
506 | } |
507 | ||
508 | static void kill_node(Node *e) | |
509 | { | |
510 | struct dentry *dentry; | |
511 | ||
512 | write_lock(&entries_lock); | |
513 | dentry = e->dentry; | |
514 | if (dentry) { | |
515 | list_del_init(&e->list); | |
516 | e->dentry = NULL; | |
517 | } | |
518 | write_unlock(&entries_lock); | |
519 | ||
520 | if (dentry) { | |
6d6b77f1 | 521 | drop_nlink(dentry->d_inode); |
1da177e4 LT |
522 | d_drop(dentry); |
523 | dput(dentry); | |
524 | simple_release_fs(&bm_mnt, &entry_count); | |
525 | } | |
526 | } | |
527 | ||
528 | /* /<entry> */ | |
529 | ||
530 | static ssize_t | |
531 | bm_entry_read(struct file * file, char __user * buf, size_t nbytes, loff_t *ppos) | |
532 | { | |
496ad9aa | 533 | Node *e = file_inode(file)->i_private; |
1da177e4 LT |
534 | ssize_t res; |
535 | char *page; | |
1da177e4 LT |
536 | |
537 | if (!(page = (char*) __get_free_page(GFP_KERNEL))) | |
538 | return -ENOMEM; | |
539 | ||
540 | entry_status(e, page); | |
1da177e4 | 541 | |
6e2c10a1 AM |
542 | res = simple_read_from_buffer(buf, nbytes, ppos, page, strlen(page)); |
543 | ||
1da177e4 LT |
544 | free_page((unsigned long) page); |
545 | return res; | |
546 | } | |
547 | ||
548 | static ssize_t bm_entry_write(struct file *file, const char __user *buffer, | |
549 | size_t count, loff_t *ppos) | |
550 | { | |
551 | struct dentry *root; | |
496ad9aa | 552 | Node *e = file_inode(file)->i_private; |
1da177e4 LT |
553 | int res = parse_command(buffer, count); |
554 | ||
555 | switch (res) { | |
556 | case 1: clear_bit(Enabled, &e->flags); | |
557 | break; | |
558 | case 2: set_bit(Enabled, &e->flags); | |
559 | break; | |
d8c9584e | 560 | case 3: root = dget(file->f_path.dentry->d_sb->s_root); |
1b1dcc1b | 561 | mutex_lock(&root->d_inode->i_mutex); |
1da177e4 LT |
562 | |
563 | kill_node(e); | |
564 | ||
1b1dcc1b | 565 | mutex_unlock(&root->d_inode->i_mutex); |
1da177e4 LT |
566 | dput(root); |
567 | break; | |
568 | default: return res; | |
569 | } | |
570 | return count; | |
571 | } | |
572 | ||
4b6f5d20 | 573 | static const struct file_operations bm_entry_operations = { |
1da177e4 LT |
574 | .read = bm_entry_read, |
575 | .write = bm_entry_write, | |
6038f373 | 576 | .llseek = default_llseek, |
1da177e4 LT |
577 | }; |
578 | ||
579 | /* /register */ | |
580 | ||
581 | static ssize_t bm_register_write(struct file *file, const char __user *buffer, | |
582 | size_t count, loff_t *ppos) | |
583 | { | |
584 | Node *e; | |
585 | struct inode *inode; | |
586 | struct dentry *root, *dentry; | |
d8c9584e | 587 | struct super_block *sb = file->f_path.dentry->d_sb; |
1da177e4 LT |
588 | int err = 0; |
589 | ||
590 | e = create_entry(buffer, count); | |
591 | ||
592 | if (IS_ERR(e)) | |
593 | return PTR_ERR(e); | |
594 | ||
595 | root = dget(sb->s_root); | |
1b1dcc1b | 596 | mutex_lock(&root->d_inode->i_mutex); |
1da177e4 LT |
597 | dentry = lookup_one_len(e->name, root, strlen(e->name)); |
598 | err = PTR_ERR(dentry); | |
599 | if (IS_ERR(dentry)) | |
600 | goto out; | |
601 | ||
602 | err = -EEXIST; | |
603 | if (dentry->d_inode) | |
604 | goto out2; | |
605 | ||
606 | inode = bm_get_inode(sb, S_IFREG | 0644); | |
607 | ||
608 | err = -ENOMEM; | |
609 | if (!inode) | |
610 | goto out2; | |
611 | ||
1f5ce9e9 | 612 | err = simple_pin_fs(&bm_fs_type, &bm_mnt, &entry_count); |
1da177e4 LT |
613 | if (err) { |
614 | iput(inode); | |
615 | inode = NULL; | |
616 | goto out2; | |
617 | } | |
618 | ||
619 | e->dentry = dget(dentry); | |
8e18e294 | 620 | inode->i_private = e; |
1da177e4 LT |
621 | inode->i_fop = &bm_entry_operations; |
622 | ||
623 | d_instantiate(dentry, inode); | |
624 | write_lock(&entries_lock); | |
625 | list_add(&e->list, &entries); | |
626 | write_unlock(&entries_lock); | |
627 | ||
628 | err = 0; | |
629 | out2: | |
630 | dput(dentry); | |
631 | out: | |
1b1dcc1b | 632 | mutex_unlock(&root->d_inode->i_mutex); |
1da177e4 LT |
633 | dput(root); |
634 | ||
635 | if (err) { | |
636 | kfree(e); | |
637 | return -EINVAL; | |
638 | } | |
639 | return count; | |
640 | } | |
641 | ||
4b6f5d20 | 642 | static const struct file_operations bm_register_operations = { |
1da177e4 | 643 | .write = bm_register_write, |
6038f373 | 644 | .llseek = noop_llseek, |
1da177e4 LT |
645 | }; |
646 | ||
647 | /* /status */ | |
648 | ||
649 | static ssize_t | |
650 | bm_status_read(struct file *file, char __user *buf, size_t nbytes, loff_t *ppos) | |
651 | { | |
87113e80 | 652 | char *s = enabled ? "enabled\n" : "disabled\n"; |
1da177e4 | 653 | |
92f4c701 | 654 | return simple_read_from_buffer(buf, nbytes, ppos, s, strlen(s)); |
1da177e4 LT |
655 | } |
656 | ||
657 | static ssize_t bm_status_write(struct file * file, const char __user * buffer, | |
658 | size_t count, loff_t *ppos) | |
659 | { | |
660 | int res = parse_command(buffer, count); | |
661 | struct dentry *root; | |
662 | ||
663 | switch (res) { | |
664 | case 1: enabled = 0; break; | |
665 | case 2: enabled = 1; break; | |
d8c9584e | 666 | case 3: root = dget(file->f_path.dentry->d_sb->s_root); |
1b1dcc1b | 667 | mutex_lock(&root->d_inode->i_mutex); |
1da177e4 LT |
668 | |
669 | while (!list_empty(&entries)) | |
670 | kill_node(list_entry(entries.next, Node, list)); | |
671 | ||
1b1dcc1b | 672 | mutex_unlock(&root->d_inode->i_mutex); |
1da177e4 | 673 | dput(root); |
b003f965 | 674 | break; |
1da177e4 LT |
675 | default: return res; |
676 | } | |
677 | return count; | |
678 | } | |
679 | ||
4b6f5d20 | 680 | static const struct file_operations bm_status_operations = { |
1da177e4 LT |
681 | .read = bm_status_read, |
682 | .write = bm_status_write, | |
6038f373 | 683 | .llseek = default_llseek, |
1da177e4 LT |
684 | }; |
685 | ||
686 | /* Superblock handling */ | |
687 | ||
ee9b6d61 | 688 | static const struct super_operations s_ops = { |
1da177e4 | 689 | .statfs = simple_statfs, |
b57922d9 | 690 | .evict_inode = bm_evict_inode, |
1da177e4 LT |
691 | }; |
692 | ||
693 | static int bm_fill_super(struct super_block * sb, void * data, int silent) | |
694 | { | |
695 | static struct tree_descr bm_files[] = { | |
1a1c9bb4 JL |
696 | [2] = {"status", &bm_status_operations, S_IWUSR|S_IRUGO}, |
697 | [3] = {"register", &bm_register_operations, S_IWUSR}, | |
1da177e4 LT |
698 | /* last one */ {""} |
699 | }; | |
b502bd11 | 700 | int err = simple_fill_super(sb, BINFMTFS_MAGIC, bm_files); |
1da177e4 LT |
701 | if (!err) |
702 | sb->s_op = &s_ops; | |
703 | return err; | |
704 | } | |
705 | ||
fc14f2fe AV |
706 | static struct dentry *bm_mount(struct file_system_type *fs_type, |
707 | int flags, const char *dev_name, void *data) | |
1da177e4 | 708 | { |
fc14f2fe | 709 | return mount_single(fs_type, flags, data, bm_fill_super); |
1da177e4 LT |
710 | } |
711 | ||
712 | static struct linux_binfmt misc_format = { | |
713 | .module = THIS_MODULE, | |
714 | .load_binary = load_misc_binary, | |
715 | }; | |
716 | ||
717 | static struct file_system_type bm_fs_type = { | |
718 | .owner = THIS_MODULE, | |
719 | .name = "binfmt_misc", | |
fc14f2fe | 720 | .mount = bm_mount, |
1da177e4 LT |
721 | .kill_sb = kill_litter_super, |
722 | }; | |
7f78e035 | 723 | MODULE_ALIAS_FS("binfmt_misc"); |
1da177e4 LT |
724 | |
725 | static int __init init_misc_binfmt(void) | |
726 | { | |
727 | int err = register_filesystem(&bm_fs_type); | |
8fc3dc5a AV |
728 | if (!err) |
729 | insert_binfmt(&misc_format); | |
1da177e4 LT |
730 | return err; |
731 | } | |
732 | ||
733 | static void __exit exit_misc_binfmt(void) | |
734 | { | |
735 | unregister_binfmt(&misc_format); | |
736 | unregister_filesystem(&bm_fs_type); | |
737 | } | |
738 | ||
739 | core_initcall(init_misc_binfmt); | |
740 | module_exit(exit_misc_binfmt); | |
741 | MODULE_LICENSE("GPL"); |