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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/fs/open.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | */ | |
6 | ||
7 | #include <linux/string.h> | |
8 | #include <linux/mm.h> | |
9 | #include <linux/utime.h> | |
10 | #include <linux/file.h> | |
11 | #include <linux/smp_lock.h> | |
12 | #include <linux/quotaops.h> | |
0eeca283 | 13 | #include <linux/fsnotify.h> |
1da177e4 LT |
14 | #include <linux/module.h> |
15 | #include <linux/slab.h> | |
16 | #include <linux/tty.h> | |
17 | #include <linux/namei.h> | |
18 | #include <linux/backing-dev.h> | |
16f7e0fe | 19 | #include <linux/capability.h> |
1da177e4 LT |
20 | #include <linux/security.h> |
21 | #include <linux/mount.h> | |
22 | #include <linux/vfs.h> | |
5590ff0d | 23 | #include <linux/fcntl.h> |
1da177e4 LT |
24 | #include <asm/uaccess.h> |
25 | #include <linux/fs.h> | |
ef3daeda | 26 | #include <linux/personality.h> |
1da177e4 LT |
27 | #include <linux/pagemap.h> |
28 | #include <linux/syscalls.h> | |
ab2af1f5 | 29 | #include <linux/rcupdate.h> |
73241ccc | 30 | #include <linux/audit.h> |
1da177e4 LT |
31 | |
32 | #include <asm/unistd.h> | |
33 | ||
34 | int vfs_statfs(struct super_block *sb, struct kstatfs *buf) | |
35 | { | |
36 | int retval = -ENODEV; | |
37 | ||
38 | if (sb) { | |
39 | retval = -ENOSYS; | |
40 | if (sb->s_op->statfs) { | |
41 | memset(buf, 0, sizeof(*buf)); | |
42 | retval = security_sb_statfs(sb); | |
43 | if (retval) | |
44 | return retval; | |
45 | retval = sb->s_op->statfs(sb, buf); | |
46 | if (retval == 0 && buf->f_frsize == 0) | |
47 | buf->f_frsize = buf->f_bsize; | |
48 | } | |
49 | } | |
50 | return retval; | |
51 | } | |
52 | ||
53 | EXPORT_SYMBOL(vfs_statfs); | |
54 | ||
55 | static int vfs_statfs_native(struct super_block *sb, struct statfs *buf) | |
56 | { | |
57 | struct kstatfs st; | |
58 | int retval; | |
59 | ||
60 | retval = vfs_statfs(sb, &st); | |
61 | if (retval) | |
62 | return retval; | |
63 | ||
64 | if (sizeof(*buf) == sizeof(st)) | |
65 | memcpy(buf, &st, sizeof(st)); | |
66 | else { | |
67 | if (sizeof buf->f_blocks == 4) { | |
68 | if ((st.f_blocks | st.f_bfree | st.f_bavail) & | |
69 | 0xffffffff00000000ULL) | |
70 | return -EOVERFLOW; | |
71 | /* | |
72 | * f_files and f_ffree may be -1; it's okay to stuff | |
73 | * that into 32 bits | |
74 | */ | |
75 | if (st.f_files != -1 && | |
76 | (st.f_files & 0xffffffff00000000ULL)) | |
77 | return -EOVERFLOW; | |
78 | if (st.f_ffree != -1 && | |
79 | (st.f_ffree & 0xffffffff00000000ULL)) | |
80 | return -EOVERFLOW; | |
81 | } | |
82 | ||
83 | buf->f_type = st.f_type; | |
84 | buf->f_bsize = st.f_bsize; | |
85 | buf->f_blocks = st.f_blocks; | |
86 | buf->f_bfree = st.f_bfree; | |
87 | buf->f_bavail = st.f_bavail; | |
88 | buf->f_files = st.f_files; | |
89 | buf->f_ffree = st.f_ffree; | |
90 | buf->f_fsid = st.f_fsid; | |
91 | buf->f_namelen = st.f_namelen; | |
92 | buf->f_frsize = st.f_frsize; | |
93 | memset(buf->f_spare, 0, sizeof(buf->f_spare)); | |
94 | } | |
95 | return 0; | |
96 | } | |
97 | ||
98 | static int vfs_statfs64(struct super_block *sb, struct statfs64 *buf) | |
99 | { | |
100 | struct kstatfs st; | |
101 | int retval; | |
102 | ||
103 | retval = vfs_statfs(sb, &st); | |
104 | if (retval) | |
105 | return retval; | |
106 | ||
107 | if (sizeof(*buf) == sizeof(st)) | |
108 | memcpy(buf, &st, sizeof(st)); | |
109 | else { | |
110 | buf->f_type = st.f_type; | |
111 | buf->f_bsize = st.f_bsize; | |
112 | buf->f_blocks = st.f_blocks; | |
113 | buf->f_bfree = st.f_bfree; | |
114 | buf->f_bavail = st.f_bavail; | |
115 | buf->f_files = st.f_files; | |
116 | buf->f_ffree = st.f_ffree; | |
117 | buf->f_fsid = st.f_fsid; | |
118 | buf->f_namelen = st.f_namelen; | |
119 | buf->f_frsize = st.f_frsize; | |
120 | memset(buf->f_spare, 0, sizeof(buf->f_spare)); | |
121 | } | |
122 | return 0; | |
123 | } | |
124 | ||
125 | asmlinkage long sys_statfs(const char __user * path, struct statfs __user * buf) | |
126 | { | |
127 | struct nameidata nd; | |
128 | int error; | |
129 | ||
130 | error = user_path_walk(path, &nd); | |
131 | if (!error) { | |
132 | struct statfs tmp; | |
133 | error = vfs_statfs_native(nd.dentry->d_inode->i_sb, &tmp); | |
134 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) | |
135 | error = -EFAULT; | |
136 | path_release(&nd); | |
137 | } | |
138 | return error; | |
139 | } | |
140 | ||
141 | ||
142 | asmlinkage long sys_statfs64(const char __user *path, size_t sz, struct statfs64 __user *buf) | |
143 | { | |
144 | struct nameidata nd; | |
145 | long error; | |
146 | ||
147 | if (sz != sizeof(*buf)) | |
148 | return -EINVAL; | |
149 | error = user_path_walk(path, &nd); | |
150 | if (!error) { | |
151 | struct statfs64 tmp; | |
152 | error = vfs_statfs64(nd.dentry->d_inode->i_sb, &tmp); | |
153 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) | |
154 | error = -EFAULT; | |
155 | path_release(&nd); | |
156 | } | |
157 | return error; | |
158 | } | |
159 | ||
160 | ||
161 | asmlinkage long sys_fstatfs(unsigned int fd, struct statfs __user * buf) | |
162 | { | |
163 | struct file * file; | |
164 | struct statfs tmp; | |
165 | int error; | |
166 | ||
167 | error = -EBADF; | |
168 | file = fget(fd); | |
169 | if (!file) | |
170 | goto out; | |
171 | error = vfs_statfs_native(file->f_dentry->d_inode->i_sb, &tmp); | |
172 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) | |
173 | error = -EFAULT; | |
174 | fput(file); | |
175 | out: | |
176 | return error; | |
177 | } | |
178 | ||
179 | asmlinkage long sys_fstatfs64(unsigned int fd, size_t sz, struct statfs64 __user *buf) | |
180 | { | |
181 | struct file * file; | |
182 | struct statfs64 tmp; | |
183 | int error; | |
184 | ||
185 | if (sz != sizeof(*buf)) | |
186 | return -EINVAL; | |
187 | ||
188 | error = -EBADF; | |
189 | file = fget(fd); | |
190 | if (!file) | |
191 | goto out; | |
192 | error = vfs_statfs64(file->f_dentry->d_inode->i_sb, &tmp); | |
193 | if (!error && copy_to_user(buf, &tmp, sizeof(tmp))) | |
194 | error = -EFAULT; | |
195 | fput(file); | |
196 | out: | |
197 | return error; | |
198 | } | |
199 | ||
4a30131e N |
200 | int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs, |
201 | struct file *filp) | |
1da177e4 LT |
202 | { |
203 | int err; | |
204 | struct iattr newattrs; | |
205 | ||
206 | /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */ | |
207 | if (length < 0) | |
208 | return -EINVAL; | |
209 | ||
210 | newattrs.ia_size = length; | |
4a30131e | 211 | newattrs.ia_valid = ATTR_SIZE | time_attrs; |
cc4e69de MS |
212 | if (filp) { |
213 | newattrs.ia_file = filp; | |
214 | newattrs.ia_valid |= ATTR_FILE; | |
215 | } | |
1da177e4 | 216 | |
1b1dcc1b | 217 | mutex_lock(&dentry->d_inode->i_mutex); |
1da177e4 | 218 | err = notify_change(dentry, &newattrs); |
1b1dcc1b | 219 | mutex_unlock(&dentry->d_inode->i_mutex); |
1da177e4 LT |
220 | return err; |
221 | } | |
222 | ||
b01ec0ef | 223 | static long do_sys_truncate(const char __user * path, loff_t length) |
1da177e4 LT |
224 | { |
225 | struct nameidata nd; | |
226 | struct inode * inode; | |
227 | int error; | |
228 | ||
229 | error = -EINVAL; | |
230 | if (length < 0) /* sorry, but loff_t says... */ | |
231 | goto out; | |
232 | ||
233 | error = user_path_walk(path, &nd); | |
234 | if (error) | |
235 | goto out; | |
236 | inode = nd.dentry->d_inode; | |
237 | ||
238 | /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ | |
239 | error = -EISDIR; | |
240 | if (S_ISDIR(inode->i_mode)) | |
241 | goto dput_and_out; | |
242 | ||
243 | error = -EINVAL; | |
244 | if (!S_ISREG(inode->i_mode)) | |
245 | goto dput_and_out; | |
246 | ||
e4543edd | 247 | error = vfs_permission(&nd, MAY_WRITE); |
1da177e4 LT |
248 | if (error) |
249 | goto dput_and_out; | |
250 | ||
251 | error = -EROFS; | |
252 | if (IS_RDONLY(inode)) | |
253 | goto dput_and_out; | |
254 | ||
255 | error = -EPERM; | |
256 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
257 | goto dput_and_out; | |
258 | ||
259 | /* | |
260 | * Make sure that there are no leases. | |
261 | */ | |
262 | error = break_lease(inode, FMODE_WRITE); | |
263 | if (error) | |
264 | goto dput_and_out; | |
265 | ||
266 | error = get_write_access(inode); | |
267 | if (error) | |
268 | goto dput_and_out; | |
269 | ||
270 | error = locks_verify_truncate(inode, NULL, length); | |
271 | if (!error) { | |
272 | DQUOT_INIT(inode); | |
4a30131e | 273 | error = do_truncate(nd.dentry, length, 0, NULL); |
1da177e4 LT |
274 | } |
275 | put_write_access(inode); | |
276 | ||
277 | dput_and_out: | |
278 | path_release(&nd); | |
279 | out: | |
280 | return error; | |
281 | } | |
282 | ||
283 | asmlinkage long sys_truncate(const char __user * path, unsigned long length) | |
284 | { | |
285 | /* on 32-bit boxen it will cut the range 2^31--2^32-1 off */ | |
286 | return do_sys_truncate(path, (long)length); | |
287 | } | |
288 | ||
b01ec0ef | 289 | static long do_sys_ftruncate(unsigned int fd, loff_t length, int small) |
1da177e4 LT |
290 | { |
291 | struct inode * inode; | |
292 | struct dentry *dentry; | |
293 | struct file * file; | |
294 | int error; | |
295 | ||
296 | error = -EINVAL; | |
297 | if (length < 0) | |
298 | goto out; | |
299 | error = -EBADF; | |
300 | file = fget(fd); | |
301 | if (!file) | |
302 | goto out; | |
303 | ||
304 | /* explicitly opened as large or we are on 64-bit box */ | |
305 | if (file->f_flags & O_LARGEFILE) | |
306 | small = 0; | |
307 | ||
308 | dentry = file->f_dentry; | |
309 | inode = dentry->d_inode; | |
310 | error = -EINVAL; | |
311 | if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE)) | |
312 | goto out_putf; | |
313 | ||
314 | error = -EINVAL; | |
315 | /* Cannot ftruncate over 2^31 bytes without large file support */ | |
316 | if (small && length > MAX_NON_LFS) | |
317 | goto out_putf; | |
318 | ||
319 | error = -EPERM; | |
320 | if (IS_APPEND(inode)) | |
321 | goto out_putf; | |
322 | ||
323 | error = locks_verify_truncate(inode, file, length); | |
324 | if (!error) | |
4a30131e | 325 | error = do_truncate(dentry, length, 0, file); |
1da177e4 LT |
326 | out_putf: |
327 | fput(file); | |
328 | out: | |
329 | return error; | |
330 | } | |
331 | ||
332 | asmlinkage long sys_ftruncate(unsigned int fd, unsigned long length) | |
333 | { | |
334 | return do_sys_ftruncate(fd, length, 1); | |
335 | } | |
336 | ||
337 | /* LFS versions of truncate are only needed on 32 bit machines */ | |
338 | #if BITS_PER_LONG == 32 | |
339 | asmlinkage long sys_truncate64(const char __user * path, loff_t length) | |
340 | { | |
341 | return do_sys_truncate(path, length); | |
342 | } | |
343 | ||
344 | asmlinkage long sys_ftruncate64(unsigned int fd, loff_t length) | |
345 | { | |
346 | return do_sys_ftruncate(fd, length, 0); | |
347 | } | |
348 | #endif | |
349 | ||
350 | #ifdef __ARCH_WANT_SYS_UTIME | |
351 | ||
352 | /* | |
353 | * sys_utime() can be implemented in user-level using sys_utimes(). | |
354 | * Is this for backwards compatibility? If so, why not move it | |
355 | * into the appropriate arch directory (for those architectures that | |
356 | * need it). | |
357 | */ | |
358 | ||
359 | /* If times==NULL, set access and modification to current time, | |
360 | * must be owner or have write permission. | |
361 | * Else, update from *times, must be owner or super user. | |
362 | */ | |
363 | asmlinkage long sys_utime(char __user * filename, struct utimbuf __user * times) | |
364 | { | |
365 | int error; | |
366 | struct nameidata nd; | |
367 | struct inode * inode; | |
368 | struct iattr newattrs; | |
369 | ||
370 | error = user_path_walk(filename, &nd); | |
371 | if (error) | |
372 | goto out; | |
373 | inode = nd.dentry->d_inode; | |
374 | ||
375 | error = -EROFS; | |
376 | if (IS_RDONLY(inode)) | |
377 | goto dput_and_out; | |
378 | ||
379 | /* Don't worry, the checks are done in inode_change_ok() */ | |
380 | newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME; | |
381 | if (times) { | |
382 | error = -EPERM; | |
383 | if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) | |
384 | goto dput_and_out; | |
385 | ||
386 | error = get_user(newattrs.ia_atime.tv_sec, ×->actime); | |
387 | newattrs.ia_atime.tv_nsec = 0; | |
5590ff0d | 388 | if (!error) |
1da177e4 LT |
389 | error = get_user(newattrs.ia_mtime.tv_sec, ×->modtime); |
390 | newattrs.ia_mtime.tv_nsec = 0; | |
391 | if (error) | |
392 | goto dput_and_out; | |
393 | ||
394 | newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET; | |
395 | } else { | |
396 | error = -EACCES; | |
397 | if (IS_IMMUTABLE(inode)) | |
398 | goto dput_and_out; | |
399 | ||
400 | if (current->fsuid != inode->i_uid && | |
e4543edd | 401 | (error = vfs_permission(&nd, MAY_WRITE)) != 0) |
1da177e4 LT |
402 | goto dput_and_out; |
403 | } | |
1b1dcc1b | 404 | mutex_lock(&inode->i_mutex); |
1da177e4 | 405 | error = notify_change(nd.dentry, &newattrs); |
1b1dcc1b | 406 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
407 | dput_and_out: |
408 | path_release(&nd); | |
409 | out: | |
410 | return error; | |
411 | } | |
412 | ||
413 | #endif | |
414 | ||
415 | /* If times==NULL, set access and modification to current time, | |
416 | * must be owner or have write permission. | |
417 | * Else, update from *times, must be owner or super user. | |
418 | */ | |
5590ff0d | 419 | long do_utimes(int dfd, char __user *filename, struct timeval *times) |
1da177e4 LT |
420 | { |
421 | int error; | |
422 | struct nameidata nd; | |
423 | struct inode * inode; | |
424 | struct iattr newattrs; | |
425 | ||
5590ff0d | 426 | error = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd); |
1da177e4 LT |
427 | |
428 | if (error) | |
429 | goto out; | |
430 | inode = nd.dentry->d_inode; | |
431 | ||
432 | error = -EROFS; | |
433 | if (IS_RDONLY(inode)) | |
434 | goto dput_and_out; | |
435 | ||
436 | /* Don't worry, the checks are done in inode_change_ok() */ | |
437 | newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME; | |
438 | if (times) { | |
439 | error = -EPERM; | |
440 | if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) | |
441 | goto dput_and_out; | |
442 | ||
443 | newattrs.ia_atime.tv_sec = times[0].tv_sec; | |
444 | newattrs.ia_atime.tv_nsec = times[0].tv_usec * 1000; | |
445 | newattrs.ia_mtime.tv_sec = times[1].tv_sec; | |
446 | newattrs.ia_mtime.tv_nsec = times[1].tv_usec * 1000; | |
447 | newattrs.ia_valid |= ATTR_ATIME_SET | ATTR_MTIME_SET; | |
448 | } else { | |
449 | error = -EACCES; | |
450 | if (IS_IMMUTABLE(inode)) | |
451 | goto dput_and_out; | |
452 | ||
453 | if (current->fsuid != inode->i_uid && | |
e4543edd | 454 | (error = vfs_permission(&nd, MAY_WRITE)) != 0) |
1da177e4 LT |
455 | goto dput_and_out; |
456 | } | |
1b1dcc1b | 457 | mutex_lock(&inode->i_mutex); |
1da177e4 | 458 | error = notify_change(nd.dentry, &newattrs); |
1b1dcc1b | 459 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
460 | dput_and_out: |
461 | path_release(&nd); | |
462 | out: | |
463 | return error; | |
464 | } | |
465 | ||
5590ff0d | 466 | asmlinkage long sys_futimesat(int dfd, char __user *filename, struct timeval __user *utimes) |
1da177e4 LT |
467 | { |
468 | struct timeval times[2]; | |
469 | ||
470 | if (utimes && copy_from_user(×, utimes, sizeof(times))) | |
471 | return -EFAULT; | |
5590ff0d UD |
472 | return do_utimes(dfd, filename, utimes ? times : NULL); |
473 | } | |
474 | ||
475 | asmlinkage long sys_utimes(char __user *filename, struct timeval __user *utimes) | |
476 | { | |
477 | return sys_futimesat(AT_FDCWD, filename, utimes); | |
1da177e4 LT |
478 | } |
479 | ||
480 | ||
481 | /* | |
482 | * access() needs to use the real uid/gid, not the effective uid/gid. | |
483 | * We do this by temporarily clearing all FS-related capabilities and | |
484 | * switching the fsuid/fsgid around to the real ones. | |
485 | */ | |
5590ff0d | 486 | asmlinkage long sys_faccessat(int dfd, const char __user *filename, int mode) |
1da177e4 LT |
487 | { |
488 | struct nameidata nd; | |
489 | int old_fsuid, old_fsgid; | |
490 | kernel_cap_t old_cap; | |
491 | int res; | |
492 | ||
493 | if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ | |
494 | return -EINVAL; | |
495 | ||
496 | old_fsuid = current->fsuid; | |
497 | old_fsgid = current->fsgid; | |
498 | old_cap = current->cap_effective; | |
499 | ||
500 | current->fsuid = current->uid; | |
501 | current->fsgid = current->gid; | |
502 | ||
503 | /* | |
504 | * Clear the capabilities if we switch to a non-root user | |
505 | * | |
506 | * FIXME: There is a race here against sys_capset. The | |
507 | * capabilities can change yet we will restore the old | |
508 | * value below. We should hold task_capabilities_lock, | |
509 | * but we cannot because user_path_walk can sleep. | |
510 | */ | |
511 | if (current->uid) | |
512 | cap_clear(current->cap_effective); | |
513 | else | |
514 | current->cap_effective = current->cap_permitted; | |
515 | ||
5590ff0d | 516 | res = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW|LOOKUP_ACCESS, &nd); |
1da177e4 | 517 | if (!res) { |
e4543edd | 518 | res = vfs_permission(&nd, mode); |
1da177e4 LT |
519 | /* SuS v2 requires we report a read only fs too */ |
520 | if(!res && (mode & S_IWOTH) && IS_RDONLY(nd.dentry->d_inode) | |
521 | && !special_file(nd.dentry->d_inode->i_mode)) | |
522 | res = -EROFS; | |
523 | path_release(&nd); | |
524 | } | |
525 | ||
526 | current->fsuid = old_fsuid; | |
527 | current->fsgid = old_fsgid; | |
528 | current->cap_effective = old_cap; | |
529 | ||
530 | return res; | |
531 | } | |
532 | ||
5590ff0d UD |
533 | asmlinkage long sys_access(const char __user *filename, int mode) |
534 | { | |
535 | return sys_faccessat(AT_FDCWD, filename, mode); | |
536 | } | |
537 | ||
1da177e4 LT |
538 | asmlinkage long sys_chdir(const char __user * filename) |
539 | { | |
540 | struct nameidata nd; | |
541 | int error; | |
542 | ||
543 | error = __user_walk(filename, LOOKUP_FOLLOW|LOOKUP_DIRECTORY, &nd); | |
544 | if (error) | |
545 | goto out; | |
546 | ||
e4543edd | 547 | error = vfs_permission(&nd, MAY_EXEC); |
1da177e4 LT |
548 | if (error) |
549 | goto dput_and_out; | |
550 | ||
551 | set_fs_pwd(current->fs, nd.mnt, nd.dentry); | |
552 | ||
553 | dput_and_out: | |
554 | path_release(&nd); | |
555 | out: | |
556 | return error; | |
557 | } | |
558 | ||
559 | asmlinkage long sys_fchdir(unsigned int fd) | |
560 | { | |
561 | struct file *file; | |
562 | struct dentry *dentry; | |
563 | struct inode *inode; | |
564 | struct vfsmount *mnt; | |
565 | int error; | |
566 | ||
567 | error = -EBADF; | |
568 | file = fget(fd); | |
569 | if (!file) | |
570 | goto out; | |
571 | ||
572 | dentry = file->f_dentry; | |
573 | mnt = file->f_vfsmnt; | |
574 | inode = dentry->d_inode; | |
575 | ||
576 | error = -ENOTDIR; | |
577 | if (!S_ISDIR(inode->i_mode)) | |
578 | goto out_putf; | |
579 | ||
8c744fb8 | 580 | error = file_permission(file, MAY_EXEC); |
1da177e4 LT |
581 | if (!error) |
582 | set_fs_pwd(current->fs, mnt, dentry); | |
583 | out_putf: | |
584 | fput(file); | |
585 | out: | |
586 | return error; | |
587 | } | |
588 | ||
589 | asmlinkage long sys_chroot(const char __user * filename) | |
590 | { | |
591 | struct nameidata nd; | |
592 | int error; | |
593 | ||
594 | error = __user_walk(filename, LOOKUP_FOLLOW | LOOKUP_DIRECTORY | LOOKUP_NOALT, &nd); | |
595 | if (error) | |
596 | goto out; | |
597 | ||
e4543edd | 598 | error = vfs_permission(&nd, MAY_EXEC); |
1da177e4 LT |
599 | if (error) |
600 | goto dput_and_out; | |
601 | ||
602 | error = -EPERM; | |
603 | if (!capable(CAP_SYS_CHROOT)) | |
604 | goto dput_and_out; | |
605 | ||
606 | set_fs_root(current->fs, nd.mnt, nd.dentry); | |
607 | set_fs_altroot(); | |
608 | error = 0; | |
609 | dput_and_out: | |
610 | path_release(&nd); | |
611 | out: | |
612 | return error; | |
613 | } | |
614 | ||
615 | asmlinkage long sys_fchmod(unsigned int fd, mode_t mode) | |
616 | { | |
617 | struct inode * inode; | |
618 | struct dentry * dentry; | |
619 | struct file * file; | |
620 | int err = -EBADF; | |
621 | struct iattr newattrs; | |
622 | ||
623 | file = fget(fd); | |
624 | if (!file) | |
625 | goto out; | |
626 | ||
627 | dentry = file->f_dentry; | |
628 | inode = dentry->d_inode; | |
629 | ||
73241ccc AG |
630 | audit_inode(NULL, inode, 0); |
631 | ||
1da177e4 LT |
632 | err = -EROFS; |
633 | if (IS_RDONLY(inode)) | |
634 | goto out_putf; | |
635 | err = -EPERM; | |
636 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
637 | goto out_putf; | |
1b1dcc1b | 638 | mutex_lock(&inode->i_mutex); |
1da177e4 LT |
639 | if (mode == (mode_t) -1) |
640 | mode = inode->i_mode; | |
641 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); | |
642 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | |
643 | err = notify_change(dentry, &newattrs); | |
1b1dcc1b | 644 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
645 | |
646 | out_putf: | |
647 | fput(file); | |
648 | out: | |
649 | return err; | |
650 | } | |
651 | ||
5590ff0d UD |
652 | asmlinkage long sys_fchmodat(int dfd, const char __user *filename, |
653 | mode_t mode) | |
1da177e4 LT |
654 | { |
655 | struct nameidata nd; | |
656 | struct inode * inode; | |
657 | int error; | |
658 | struct iattr newattrs; | |
659 | ||
5590ff0d | 660 | error = __user_walk_fd(dfd, filename, LOOKUP_FOLLOW, &nd); |
1da177e4 LT |
661 | if (error) |
662 | goto out; | |
663 | inode = nd.dentry->d_inode; | |
664 | ||
665 | error = -EROFS; | |
666 | if (IS_RDONLY(inode)) | |
667 | goto dput_and_out; | |
668 | ||
669 | error = -EPERM; | |
670 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
671 | goto dput_and_out; | |
672 | ||
1b1dcc1b | 673 | mutex_lock(&inode->i_mutex); |
1da177e4 LT |
674 | if (mode == (mode_t) -1) |
675 | mode = inode->i_mode; | |
676 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); | |
677 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | |
678 | error = notify_change(nd.dentry, &newattrs); | |
1b1dcc1b | 679 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
680 | |
681 | dput_and_out: | |
682 | path_release(&nd); | |
683 | out: | |
684 | return error; | |
685 | } | |
686 | ||
5590ff0d UD |
687 | asmlinkage long sys_chmod(const char __user *filename, mode_t mode) |
688 | { | |
689 | return sys_fchmodat(AT_FDCWD, filename, mode); | |
690 | } | |
691 | ||
1da177e4 LT |
692 | static int chown_common(struct dentry * dentry, uid_t user, gid_t group) |
693 | { | |
694 | struct inode * inode; | |
695 | int error; | |
696 | struct iattr newattrs; | |
697 | ||
698 | error = -ENOENT; | |
699 | if (!(inode = dentry->d_inode)) { | |
700 | printk(KERN_ERR "chown_common: NULL inode\n"); | |
701 | goto out; | |
702 | } | |
703 | error = -EROFS; | |
704 | if (IS_RDONLY(inode)) | |
705 | goto out; | |
706 | error = -EPERM; | |
707 | if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) | |
708 | goto out; | |
709 | newattrs.ia_valid = ATTR_CTIME; | |
710 | if (user != (uid_t) -1) { | |
711 | newattrs.ia_valid |= ATTR_UID; | |
712 | newattrs.ia_uid = user; | |
713 | } | |
714 | if (group != (gid_t) -1) { | |
715 | newattrs.ia_valid |= ATTR_GID; | |
716 | newattrs.ia_gid = group; | |
717 | } | |
718 | if (!S_ISDIR(inode->i_mode)) | |
719 | newattrs.ia_valid |= ATTR_KILL_SUID|ATTR_KILL_SGID; | |
1b1dcc1b | 720 | mutex_lock(&inode->i_mutex); |
1da177e4 | 721 | error = notify_change(dentry, &newattrs); |
1b1dcc1b | 722 | mutex_unlock(&inode->i_mutex); |
1da177e4 LT |
723 | out: |
724 | return error; | |
725 | } | |
726 | ||
727 | asmlinkage long sys_chown(const char __user * filename, uid_t user, gid_t group) | |
728 | { | |
729 | struct nameidata nd; | |
730 | int error; | |
731 | ||
732 | error = user_path_walk(filename, &nd); | |
733 | if (!error) { | |
734 | error = chown_common(nd.dentry, user, group); | |
735 | path_release(&nd); | |
736 | } | |
737 | return error; | |
738 | } | |
739 | ||
5590ff0d UD |
740 | asmlinkage long sys_fchownat(int dfd, const char __user *filename, uid_t user, |
741 | gid_t group, int flag) | |
742 | { | |
743 | struct nameidata nd; | |
744 | int error = -EINVAL; | |
745 | int follow; | |
746 | ||
747 | if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0) | |
748 | goto out; | |
749 | ||
750 | follow = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; | |
751 | error = __user_walk_fd(dfd, filename, follow, &nd); | |
752 | if (!error) { | |
753 | error = chown_common(nd.dentry, user, group); | |
754 | path_release(&nd); | |
755 | } | |
756 | out: | |
757 | return error; | |
758 | } | |
759 | ||
1da177e4 LT |
760 | asmlinkage long sys_lchown(const char __user * filename, uid_t user, gid_t group) |
761 | { | |
762 | struct nameidata nd; | |
763 | int error; | |
764 | ||
765 | error = user_path_walk_link(filename, &nd); | |
766 | if (!error) { | |
767 | error = chown_common(nd.dentry, user, group); | |
768 | path_release(&nd); | |
769 | } | |
770 | return error; | |
771 | } | |
772 | ||
773 | ||
774 | asmlinkage long sys_fchown(unsigned int fd, uid_t user, gid_t group) | |
775 | { | |
776 | struct file * file; | |
777 | int error = -EBADF; | |
778 | ||
779 | file = fget(fd); | |
780 | if (file) { | |
73241ccc AG |
781 | struct dentry * dentry; |
782 | dentry = file->f_dentry; | |
783 | audit_inode(NULL, dentry->d_inode, 0); | |
784 | error = chown_common(dentry, user, group); | |
1da177e4 LT |
785 | fput(file); |
786 | } | |
787 | return error; | |
788 | } | |
789 | ||
a1a5b3d9 | 790 | static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt, |
834f2a4a TM |
791 | int flags, struct file *f, |
792 | int (*open)(struct inode *, struct file *)) | |
1da177e4 | 793 | { |
1da177e4 LT |
794 | struct inode *inode; |
795 | int error; | |
796 | ||
1da177e4 | 797 | f->f_flags = flags; |
a1a5b3d9 PS |
798 | f->f_mode = ((flags+1) & O_ACCMODE) | FMODE_LSEEK | |
799 | FMODE_PREAD | FMODE_PWRITE; | |
1da177e4 LT |
800 | inode = dentry->d_inode; |
801 | if (f->f_mode & FMODE_WRITE) { | |
802 | error = get_write_access(inode); | |
803 | if (error) | |
804 | goto cleanup_file; | |
805 | } | |
806 | ||
807 | f->f_mapping = inode->i_mapping; | |
808 | f->f_dentry = dentry; | |
809 | f->f_vfsmnt = mnt; | |
810 | f->f_pos = 0; | |
811 | f->f_op = fops_get(inode->i_fop); | |
812 | file_move(f, &inode->i_sb->s_files); | |
813 | ||
834f2a4a TM |
814 | if (!open && f->f_op) |
815 | open = f->f_op->open; | |
816 | if (open) { | |
817 | error = open(inode, f); | |
1da177e4 LT |
818 | if (error) |
819 | goto cleanup_all; | |
820 | } | |
834f2a4a | 821 | |
1da177e4 LT |
822 | f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); |
823 | ||
824 | file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); | |
825 | ||
826 | /* NB: we're sure to have correct a_ops only after f_op->open */ | |
827 | if (f->f_flags & O_DIRECT) { | |
ceffc078 CO |
828 | if (!f->f_mapping->a_ops || |
829 | ((!f->f_mapping->a_ops->direct_IO) && | |
830 | (!f->f_mapping->a_ops->get_xip_page))) { | |
1da177e4 LT |
831 | fput(f); |
832 | f = ERR_PTR(-EINVAL); | |
833 | } | |
834 | } | |
835 | ||
836 | return f; | |
837 | ||
838 | cleanup_all: | |
839 | fops_put(f->f_op); | |
840 | if (f->f_mode & FMODE_WRITE) | |
841 | put_write_access(inode); | |
842 | file_kill(f); | |
843 | f->f_dentry = NULL; | |
844 | f->f_vfsmnt = NULL; | |
845 | cleanup_file: | |
846 | put_filp(f); | |
1da177e4 LT |
847 | dput(dentry); |
848 | mntput(mnt); | |
849 | return ERR_PTR(error); | |
850 | } | |
851 | ||
a1a5b3d9 PS |
852 | /* |
853 | * Note that while the flag value (low two bits) for sys_open means: | |
854 | * 00 - read-only | |
855 | * 01 - write-only | |
856 | * 10 - read-write | |
857 | * 11 - special | |
858 | * it is changed into | |
859 | * 00 - no permissions needed | |
860 | * 01 - read-permission | |
861 | * 10 - write-permission | |
862 | * 11 - read-write | |
863 | * for the internal routines (ie open_namei()/follow_link() etc). 00 is | |
864 | * used by symlinks. | |
865 | */ | |
5590ff0d UD |
866 | static struct file *do_filp_open(int dfd, const char *filename, int flags, |
867 | int mode) | |
a1a5b3d9 PS |
868 | { |
869 | int namei_flags, error; | |
870 | struct nameidata nd; | |
a1a5b3d9 PS |
871 | |
872 | namei_flags = flags; | |
873 | if ((namei_flags+1) & O_ACCMODE) | |
874 | namei_flags++; | |
a1a5b3d9 | 875 | |
5590ff0d | 876 | error = open_namei(dfd, filename, namei_flags, mode, &nd); |
a1a5b3d9 | 877 | if (!error) |
834f2a4a | 878 | return nameidata_to_filp(&nd, flags); |
a1a5b3d9 | 879 | |
a1a5b3d9 PS |
880 | return ERR_PTR(error); |
881 | } | |
5590ff0d UD |
882 | |
883 | struct file *filp_open(const char *filename, int flags, int mode) | |
884 | { | |
885 | return do_filp_open(AT_FDCWD, filename, flags, mode); | |
886 | } | |
a1a5b3d9 PS |
887 | EXPORT_SYMBOL(filp_open); |
888 | ||
834f2a4a TM |
889 | /** |
890 | * lookup_instantiate_filp - instantiates the open intent filp | |
891 | * @nd: pointer to nameidata | |
892 | * @dentry: pointer to dentry | |
893 | * @open: open callback | |
894 | * | |
895 | * Helper for filesystems that want to use lookup open intents and pass back | |
896 | * a fully instantiated struct file to the caller. | |
897 | * This function is meant to be called from within a filesystem's | |
898 | * lookup method. | |
9a56c213 OD |
899 | * Beware of calling it for non-regular files! Those ->open methods might block |
900 | * (e.g. in fifo_open), leaving you with parent locked (and in case of fifo, | |
901 | * leading to a deadlock, as nobody can open that fifo anymore, because | |
902 | * another process to open fifo will block on locked parent when doing lookup). | |
834f2a4a TM |
903 | * Note that in case of error, nd->intent.open.file is destroyed, but the |
904 | * path information remains valid. | |
905 | * If the open callback is set to NULL, then the standard f_op->open() | |
906 | * filesystem callback is substituted. | |
907 | */ | |
908 | struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry *dentry, | |
909 | int (*open)(struct inode *, struct file *)) | |
910 | { | |
911 | if (IS_ERR(nd->intent.open.file)) | |
912 | goto out; | |
913 | if (IS_ERR(dentry)) | |
914 | goto out_err; | |
915 | nd->intent.open.file = __dentry_open(dget(dentry), mntget(nd->mnt), | |
916 | nd->intent.open.flags - 1, | |
917 | nd->intent.open.file, | |
918 | open); | |
919 | out: | |
920 | return nd->intent.open.file; | |
921 | out_err: | |
922 | release_open_intent(nd); | |
923 | nd->intent.open.file = (struct file *)dentry; | |
924 | goto out; | |
925 | } | |
926 | EXPORT_SYMBOL_GPL(lookup_instantiate_filp); | |
927 | ||
928 | /** | |
929 | * nameidata_to_filp - convert a nameidata to an open filp. | |
930 | * @nd: pointer to nameidata | |
931 | * @flags: open flags | |
932 | * | |
933 | * Note that this function destroys the original nameidata | |
934 | */ | |
935 | struct file *nameidata_to_filp(struct nameidata *nd, int flags) | |
936 | { | |
937 | struct file *filp; | |
938 | ||
939 | /* Pick up the filp from the open intent */ | |
940 | filp = nd->intent.open.file; | |
941 | /* Has the filesystem initialised the file for us? */ | |
942 | if (filp->f_dentry == NULL) | |
943 | filp = __dentry_open(nd->dentry, nd->mnt, flags, filp, NULL); | |
944 | else | |
945 | path_release(nd); | |
946 | return filp; | |
947 | } | |
948 | ||
6fdcc216 PS |
949 | /* |
950 | * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an | |
951 | * error. | |
952 | */ | |
a1a5b3d9 PS |
953 | struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags) |
954 | { | |
955 | int error; | |
956 | struct file *f; | |
957 | ||
958 | error = -ENFILE; | |
959 | f = get_empty_filp(); | |
6fdcc216 PS |
960 | if (f == NULL) { |
961 | dput(dentry); | |
962 | mntput(mnt); | |
a1a5b3d9 | 963 | return ERR_PTR(error); |
6fdcc216 | 964 | } |
a1a5b3d9 | 965 | |
834f2a4a | 966 | return __dentry_open(dentry, mnt, flags, f, NULL); |
a1a5b3d9 | 967 | } |
1da177e4 LT |
968 | EXPORT_SYMBOL(dentry_open); |
969 | ||
970 | /* | |
971 | * Find an empty file descriptor entry, and mark it busy. | |
972 | */ | |
973 | int get_unused_fd(void) | |
974 | { | |
975 | struct files_struct * files = current->files; | |
976 | int fd, error; | |
badf1662 | 977 | struct fdtable *fdt; |
1da177e4 LT |
978 | |
979 | error = -EMFILE; | |
980 | spin_lock(&files->file_lock); | |
981 | ||
982 | repeat: | |
badf1662 DS |
983 | fdt = files_fdtable(files); |
984 | fd = find_next_zero_bit(fdt->open_fds->fds_bits, | |
985 | fdt->max_fdset, | |
0c9e63fd | 986 | files->next_fd); |
1da177e4 LT |
987 | |
988 | /* | |
989 | * N.B. For clone tasks sharing a files structure, this test | |
990 | * will limit the total number of files that can be opened. | |
991 | */ | |
992 | if (fd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur) | |
993 | goto out; | |
994 | ||
995 | /* Do we need to expand the fd array or fd set? */ | |
996 | error = expand_files(files, fd); | |
997 | if (error < 0) | |
998 | goto out; | |
999 | ||
1000 | if (error) { | |
1001 | /* | |
1002 | * If we needed to expand the fs array we | |
1003 | * might have blocked - try again. | |
1004 | */ | |
1005 | error = -EMFILE; | |
1006 | goto repeat; | |
1007 | } | |
1008 | ||
badf1662 DS |
1009 | FD_SET(fd, fdt->open_fds); |
1010 | FD_CLR(fd, fdt->close_on_exec); | |
0c9e63fd | 1011 | files->next_fd = fd + 1; |
1da177e4 LT |
1012 | #if 1 |
1013 | /* Sanity check */ | |
badf1662 | 1014 | if (fdt->fd[fd] != NULL) { |
1da177e4 | 1015 | printk(KERN_WARNING "get_unused_fd: slot %d not NULL!\n", fd); |
badf1662 | 1016 | fdt->fd[fd] = NULL; |
1da177e4 LT |
1017 | } |
1018 | #endif | |
1019 | error = fd; | |
1020 | ||
1021 | out: | |
1022 | spin_unlock(&files->file_lock); | |
1023 | return error; | |
1024 | } | |
1025 | ||
1026 | EXPORT_SYMBOL(get_unused_fd); | |
1027 | ||
b01ec0ef | 1028 | static void __put_unused_fd(struct files_struct *files, unsigned int fd) |
1da177e4 | 1029 | { |
badf1662 DS |
1030 | struct fdtable *fdt = files_fdtable(files); |
1031 | __FD_CLR(fd, fdt->open_fds); | |
0c9e63fd ED |
1032 | if (fd < files->next_fd) |
1033 | files->next_fd = fd; | |
1da177e4 LT |
1034 | } |
1035 | ||
1036 | void fastcall put_unused_fd(unsigned int fd) | |
1037 | { | |
1038 | struct files_struct *files = current->files; | |
1039 | spin_lock(&files->file_lock); | |
1040 | __put_unused_fd(files, fd); | |
1041 | spin_unlock(&files->file_lock); | |
1042 | } | |
1043 | ||
1044 | EXPORT_SYMBOL(put_unused_fd); | |
1045 | ||
1046 | /* | |
5590ff0d | 1047 | * Install a file pointer in the fd array. |
1da177e4 LT |
1048 | * |
1049 | * The VFS is full of places where we drop the files lock between | |
1050 | * setting the open_fds bitmap and installing the file in the file | |
1051 | * array. At any such point, we are vulnerable to a dup2() race | |
1052 | * installing a file in the array before us. We need to detect this and | |
1053 | * fput() the struct file we are about to overwrite in this case. | |
1054 | * | |
1055 | * It should never happen - if we allow dup2() do it, _really_ bad things | |
1056 | * will follow. | |
1057 | */ | |
1058 | ||
1059 | void fastcall fd_install(unsigned int fd, struct file * file) | |
1060 | { | |
1061 | struct files_struct *files = current->files; | |
badf1662 | 1062 | struct fdtable *fdt; |
1da177e4 | 1063 | spin_lock(&files->file_lock); |
badf1662 | 1064 | fdt = files_fdtable(files); |
ab2af1f5 DS |
1065 | BUG_ON(fdt->fd[fd] != NULL); |
1066 | rcu_assign_pointer(fdt->fd[fd], file); | |
1da177e4 LT |
1067 | spin_unlock(&files->file_lock); |
1068 | } | |
1069 | ||
1070 | EXPORT_SYMBOL(fd_install); | |
1071 | ||
5590ff0d | 1072 | long do_sys_open(int dfd, const char __user *filename, int flags, int mode) |
1da177e4 | 1073 | { |
e922efc3 MS |
1074 | char *tmp = getname(filename); |
1075 | int fd = PTR_ERR(tmp); | |
1da177e4 | 1076 | |
1da177e4 LT |
1077 | if (!IS_ERR(tmp)) { |
1078 | fd = get_unused_fd(); | |
1079 | if (fd >= 0) { | |
5590ff0d | 1080 | struct file *f = do_filp_open(dfd, tmp, flags, mode); |
fed2fc18 TN |
1081 | if (IS_ERR(f)) { |
1082 | put_unused_fd(fd); | |
1083 | fd = PTR_ERR(f); | |
1084 | } else { | |
0eeca283 | 1085 | fsnotify_open(f->f_dentry); |
fed2fc18 TN |
1086 | fd_install(fd, f); |
1087 | } | |
1da177e4 | 1088 | } |
1da177e4 LT |
1089 | putname(tmp); |
1090 | } | |
1091 | return fd; | |
1da177e4 | 1092 | } |
e922efc3 MS |
1093 | |
1094 | asmlinkage long sys_open(const char __user *filename, int flags, int mode) | |
1095 | { | |
1096 | if (force_o_largefile()) | |
1097 | flags |= O_LARGEFILE; | |
1098 | ||
5590ff0d | 1099 | return do_sys_open(AT_FDCWD, filename, flags, mode); |
e922efc3 | 1100 | } |
1da177e4 LT |
1101 | EXPORT_SYMBOL_GPL(sys_open); |
1102 | ||
5590ff0d UD |
1103 | asmlinkage long sys_openat(int dfd, const char __user *filename, int flags, |
1104 | int mode) | |
1105 | { | |
1106 | if (force_o_largefile()) | |
1107 | flags |= O_LARGEFILE; | |
1108 | ||
1109 | return do_sys_open(dfd, filename, flags, mode); | |
1110 | } | |
1111 | EXPORT_SYMBOL_GPL(sys_openat); | |
1112 | ||
1da177e4 LT |
1113 | #ifndef __alpha__ |
1114 | ||
1115 | /* | |
1116 | * For backward compatibility? Maybe this should be moved | |
1117 | * into arch/i386 instead? | |
1118 | */ | |
1119 | asmlinkage long sys_creat(const char __user * pathname, int mode) | |
1120 | { | |
1121 | return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode); | |
1122 | } | |
1123 | ||
1124 | #endif | |
1125 | ||
1126 | /* | |
1127 | * "id" is the POSIX thread ID. We use the | |
1128 | * files pointer for this.. | |
1129 | */ | |
1130 | int filp_close(struct file *filp, fl_owner_t id) | |
1131 | { | |
45778ca8 | 1132 | int retval = 0; |
1da177e4 LT |
1133 | |
1134 | if (!file_count(filp)) { | |
1135 | printk(KERN_ERR "VFS: Close: file count is 0\n"); | |
45778ca8 | 1136 | return 0; |
1da177e4 LT |
1137 | } |
1138 | ||
45778ca8 CL |
1139 | if (filp->f_op && filp->f_op->flush) |
1140 | retval = filp->f_op->flush(filp); | |
1da177e4 LT |
1141 | |
1142 | dnotify_flush(filp, id); | |
1143 | locks_remove_posix(filp, id); | |
1144 | fput(filp); | |
1145 | return retval; | |
1146 | } | |
1147 | ||
1148 | EXPORT_SYMBOL(filp_close); | |
1149 | ||
1150 | /* | |
1151 | * Careful here! We test whether the file pointer is NULL before | |
1152 | * releasing the fd. This ensures that one clone task can't release | |
1153 | * an fd while another clone is opening it. | |
1154 | */ | |
1155 | asmlinkage long sys_close(unsigned int fd) | |
1156 | { | |
1157 | struct file * filp; | |
1158 | struct files_struct *files = current->files; | |
badf1662 | 1159 | struct fdtable *fdt; |
1da177e4 LT |
1160 | |
1161 | spin_lock(&files->file_lock); | |
badf1662 DS |
1162 | fdt = files_fdtable(files); |
1163 | if (fd >= fdt->max_fds) | |
1da177e4 | 1164 | goto out_unlock; |
badf1662 | 1165 | filp = fdt->fd[fd]; |
1da177e4 LT |
1166 | if (!filp) |
1167 | goto out_unlock; | |
ab2af1f5 | 1168 | rcu_assign_pointer(fdt->fd[fd], NULL); |
badf1662 | 1169 | FD_CLR(fd, fdt->close_on_exec); |
1da177e4 LT |
1170 | __put_unused_fd(files, fd); |
1171 | spin_unlock(&files->file_lock); | |
1172 | return filp_close(filp, files); | |
1173 | ||
1174 | out_unlock: | |
1175 | spin_unlock(&files->file_lock); | |
1176 | return -EBADF; | |
1177 | } | |
1178 | ||
1179 | EXPORT_SYMBOL(sys_close); | |
1180 | ||
1181 | /* | |
1182 | * This routine simulates a hangup on the tty, to arrange that users | |
1183 | * are given clean terminals at login time. | |
1184 | */ | |
1185 | asmlinkage long sys_vhangup(void) | |
1186 | { | |
1187 | if (capable(CAP_SYS_TTY_CONFIG)) { | |
1188 | tty_vhangup(current->signal->tty); | |
1189 | return 0; | |
1190 | } | |
1191 | return -EPERM; | |
1192 | } | |
1193 | ||
1194 | /* | |
1195 | * Called when an inode is about to be open. | |
1196 | * We use this to disallow opening large files on 32bit systems if | |
1197 | * the caller didn't specify O_LARGEFILE. On 64bit systems we force | |
1198 | * on this flag in sys_open. | |
1199 | */ | |
1200 | int generic_file_open(struct inode * inode, struct file * filp) | |
1201 | { | |
1202 | if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) | |
1203 | return -EFBIG; | |
1204 | return 0; | |
1205 | } | |
1206 | ||
1207 | EXPORT_SYMBOL(generic_file_open); | |
1208 | ||
1209 | /* | |
1210 | * This is used by subsystems that don't want seekable | |
1211 | * file descriptors | |
1212 | */ | |
1213 | int nonseekable_open(struct inode *inode, struct file *filp) | |
1214 | { | |
1215 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); | |
1216 | return 0; | |
1217 | } | |
1218 | ||
1219 | EXPORT_SYMBOL(nonseekable_open); |