Commit | Line | Data |
---|---|---|
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> | |
1da177e4 | 9 | #include <linux/file.h> |
9f3acc31 | 10 | #include <linux/fdtable.h> |
0eeca283 | 11 | #include <linux/fsnotify.h> |
1da177e4 | 12 | #include <linux/module.h> |
1da177e4 LT |
13 | #include <linux/tty.h> |
14 | #include <linux/namei.h> | |
15 | #include <linux/backing-dev.h> | |
16f7e0fe | 16 | #include <linux/capability.h> |
086f7316 | 17 | #include <linux/securebits.h> |
1da177e4 LT |
18 | #include <linux/security.h> |
19 | #include <linux/mount.h> | |
5590ff0d | 20 | #include <linux/fcntl.h> |
5a0e3ad6 | 21 | #include <linux/slab.h> |
1da177e4 LT |
22 | #include <asm/uaccess.h> |
23 | #include <linux/fs.h> | |
ef3daeda | 24 | #include <linux/personality.h> |
1da177e4 LT |
25 | #include <linux/pagemap.h> |
26 | #include <linux/syscalls.h> | |
ab2af1f5 | 27 | #include <linux/rcupdate.h> |
73241ccc | 28 | #include <linux/audit.h> |
97ac7350 | 29 | #include <linux/falloc.h> |
5ad4e53b | 30 | #include <linux/fs_struct.h> |
b65a9cfc | 31 | #include <linux/ima.h> |
2dfc1cae | 32 | #include <linux/dnotify.h> |
1da177e4 | 33 | |
e81e3f4d EP |
34 | #include "internal.h" |
35 | ||
4a30131e N |
36 | int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs, |
37 | struct file *filp) | |
1da177e4 | 38 | { |
939a9421 | 39 | int ret; |
1da177e4 LT |
40 | struct iattr newattrs; |
41 | ||
42 | /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */ | |
43 | if (length < 0) | |
44 | return -EINVAL; | |
45 | ||
46 | newattrs.ia_size = length; | |
4a30131e | 47 | newattrs.ia_valid = ATTR_SIZE | time_attrs; |
cc4e69de MS |
48 | if (filp) { |
49 | newattrs.ia_file = filp; | |
50 | newattrs.ia_valid |= ATTR_FILE; | |
51 | } | |
1da177e4 | 52 | |
7b82dc0e | 53 | /* Remove suid/sgid on truncate too */ |
939a9421 AW |
54 | ret = should_remove_suid(dentry); |
55 | if (ret) | |
56 | newattrs.ia_valid |= ret | ATTR_FORCE; | |
7b82dc0e | 57 | |
1b1dcc1b | 58 | mutex_lock(&dentry->d_inode->i_mutex); |
939a9421 | 59 | ret = notify_change(dentry, &newattrs); |
1b1dcc1b | 60 | mutex_unlock(&dentry->d_inode->i_mutex); |
939a9421 | 61 | return ret; |
1da177e4 LT |
62 | } |
63 | ||
2d8f3038 | 64 | static long do_sys_truncate(const char __user *pathname, loff_t length) |
1da177e4 | 65 | { |
2d8f3038 AV |
66 | struct path path; |
67 | struct inode *inode; | |
1da177e4 LT |
68 | int error; |
69 | ||
70 | error = -EINVAL; | |
71 | if (length < 0) /* sorry, but loff_t says... */ | |
72 | goto out; | |
73 | ||
2d8f3038 | 74 | error = user_path(pathname, &path); |
1da177e4 LT |
75 | if (error) |
76 | goto out; | |
2d8f3038 | 77 | inode = path.dentry->d_inode; |
1da177e4 LT |
78 | |
79 | /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ | |
80 | error = -EISDIR; | |
81 | if (S_ISDIR(inode->i_mode)) | |
82 | goto dput_and_out; | |
83 | ||
84 | error = -EINVAL; | |
85 | if (!S_ISREG(inode->i_mode)) | |
86 | goto dput_and_out; | |
87 | ||
2d8f3038 | 88 | error = mnt_want_write(path.mnt); |
1da177e4 LT |
89 | if (error) |
90 | goto dput_and_out; | |
91 | ||
256984a8 | 92 | error = inode_permission(inode, MAY_WRITE); |
9ac9b847 DH |
93 | if (error) |
94 | goto mnt_drop_write_and_out; | |
1da177e4 LT |
95 | |
96 | error = -EPERM; | |
c82e42da | 97 | if (IS_APPEND(inode)) |
9ac9b847 | 98 | goto mnt_drop_write_and_out; |
1da177e4 | 99 | |
9700382c | 100 | error = get_write_access(inode); |
1da177e4 | 101 | if (error) |
9ac9b847 | 102 | goto mnt_drop_write_and_out; |
1da177e4 | 103 | |
9700382c | 104 | /* |
105 | * Make sure that there are no leases. get_write_access() protects | |
106 | * against the truncate racing with a lease-granting setlease(). | |
107 | */ | |
8737c930 | 108 | error = break_lease(inode, O_WRONLY); |
1da177e4 | 109 | if (error) |
9700382c | 110 | goto put_write_and_out; |
1da177e4 LT |
111 | |
112 | error = locks_verify_truncate(inode, NULL, length); | |
be6d3e56 | 113 | if (!error) |
ea0d3ab2 | 114 | error = security_path_truncate(&path); |
907f4554 | 115 | if (!error) |
2d8f3038 | 116 | error = do_truncate(path.dentry, length, 0, NULL); |
1da177e4 | 117 | |
9700382c | 118 | put_write_and_out: |
119 | put_write_access(inode); | |
9ac9b847 | 120 | mnt_drop_write_and_out: |
2d8f3038 | 121 | mnt_drop_write(path.mnt); |
1da177e4 | 122 | dput_and_out: |
2d8f3038 | 123 | path_put(&path); |
1da177e4 LT |
124 | out: |
125 | return error; | |
126 | } | |
127 | ||
4fd8da8d | 128 | SYSCALL_DEFINE2(truncate, const char __user *, path, long, length) |
1da177e4 | 129 | { |
4fd8da8d | 130 | return do_sys_truncate(path, length); |
1da177e4 LT |
131 | } |
132 | ||
b01ec0ef | 133 | static long do_sys_ftruncate(unsigned int fd, loff_t length, int small) |
1da177e4 LT |
134 | { |
135 | struct inode * inode; | |
136 | struct dentry *dentry; | |
137 | struct file * file; | |
138 | int error; | |
139 | ||
140 | error = -EINVAL; | |
141 | if (length < 0) | |
142 | goto out; | |
143 | error = -EBADF; | |
144 | file = fget(fd); | |
145 | if (!file) | |
146 | goto out; | |
147 | ||
148 | /* explicitly opened as large or we are on 64-bit box */ | |
149 | if (file->f_flags & O_LARGEFILE) | |
150 | small = 0; | |
151 | ||
0f7fc9e4 | 152 | dentry = file->f_path.dentry; |
1da177e4 LT |
153 | inode = dentry->d_inode; |
154 | error = -EINVAL; | |
155 | if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE)) | |
156 | goto out_putf; | |
157 | ||
158 | error = -EINVAL; | |
159 | /* Cannot ftruncate over 2^31 bytes without large file support */ | |
160 | if (small && length > MAX_NON_LFS) | |
161 | goto out_putf; | |
162 | ||
163 | error = -EPERM; | |
164 | if (IS_APPEND(inode)) | |
165 | goto out_putf; | |
166 | ||
14da9200 | 167 | sb_start_write(inode->i_sb); |
1da177e4 | 168 | error = locks_verify_truncate(inode, file, length); |
be6d3e56 | 169 | if (!error) |
ea0d3ab2 | 170 | error = security_path_truncate(&file->f_path); |
1da177e4 | 171 | if (!error) |
6e656be8 | 172 | error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, file); |
14da9200 | 173 | sb_end_write(inode->i_sb); |
1da177e4 LT |
174 | out_putf: |
175 | fput(file); | |
176 | out: | |
177 | return error; | |
178 | } | |
179 | ||
bdc480e3 | 180 | SYSCALL_DEFINE2(ftruncate, unsigned int, fd, unsigned long, length) |
1da177e4 | 181 | { |
0a489cb3 | 182 | long ret = do_sys_ftruncate(fd, length, 1); |
385910f2 | 183 | /* avoid REGPARM breakage on x86: */ |
54a01510 | 184 | asmlinkage_protect(2, ret, fd, length); |
0a489cb3 | 185 | return ret; |
1da177e4 LT |
186 | } |
187 | ||
188 | /* LFS versions of truncate are only needed on 32 bit machines */ | |
189 | #if BITS_PER_LONG == 32 | |
6673e0c3 | 190 | SYSCALL_DEFINE(truncate64)(const char __user * path, loff_t length) |
1da177e4 LT |
191 | { |
192 | return do_sys_truncate(path, length); | |
193 | } | |
6673e0c3 HC |
194 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
195 | asmlinkage long SyS_truncate64(long path, loff_t length) | |
196 | { | |
197 | return SYSC_truncate64((const char __user *) path, length); | |
198 | } | |
199 | SYSCALL_ALIAS(sys_truncate64, SyS_truncate64); | |
200 | #endif | |
1da177e4 | 201 | |
6673e0c3 | 202 | SYSCALL_DEFINE(ftruncate64)(unsigned int fd, loff_t length) |
1da177e4 | 203 | { |
0a489cb3 | 204 | long ret = do_sys_ftruncate(fd, length, 0); |
385910f2 | 205 | /* avoid REGPARM breakage on x86: */ |
54a01510 | 206 | asmlinkage_protect(2, ret, fd, length); |
0a489cb3 | 207 | return ret; |
1da177e4 | 208 | } |
6673e0c3 HC |
209 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
210 | asmlinkage long SyS_ftruncate64(long fd, loff_t length) | |
211 | { | |
212 | return SYSC_ftruncate64((unsigned int) fd, length); | |
213 | } | |
214 | SYSCALL_ALIAS(sys_ftruncate64, SyS_ftruncate64); | |
1da177e4 | 215 | #endif |
6673e0c3 | 216 | #endif /* BITS_PER_LONG == 32 */ |
1da177e4 | 217 | |
3e63cbb1 AJ |
218 | |
219 | int do_fallocate(struct file *file, int mode, loff_t offset, loff_t len) | |
97ac7350 | 220 | { |
3e63cbb1 AJ |
221 | struct inode *inode = file->f_path.dentry->d_inode; |
222 | long ret; | |
97ac7350 AA |
223 | |
224 | if (offset < 0 || len <= 0) | |
3e63cbb1 | 225 | return -EINVAL; |
97ac7350 AA |
226 | |
227 | /* Return error if mode is not supported */ | |
79124f18 JB |
228 | if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) |
229 | return -EOPNOTSUPP; | |
230 | ||
231 | /* Punch hole must have keep size set */ | |
232 | if ((mode & FALLOC_FL_PUNCH_HOLE) && | |
233 | !(mode & FALLOC_FL_KEEP_SIZE)) | |
3e63cbb1 | 234 | return -EOPNOTSUPP; |
97ac7350 | 235 | |
97ac7350 | 236 | if (!(file->f_mode & FMODE_WRITE)) |
3e63cbb1 | 237 | return -EBADF; |
1ca551c6 MS |
238 | |
239 | /* It's not possible punch hole on append only file */ | |
240 | if (mode & FALLOC_FL_PUNCH_HOLE && IS_APPEND(inode)) | |
241 | return -EPERM; | |
242 | ||
243 | if (IS_IMMUTABLE(inode)) | |
244 | return -EPERM; | |
245 | ||
97ac7350 AA |
246 | /* |
247 | * Revalidate the write permissions, in case security policy has | |
248 | * changed since the files were opened. | |
249 | */ | |
250 | ret = security_file_permission(file, MAY_WRITE); | |
251 | if (ret) | |
3e63cbb1 | 252 | return ret; |
97ac7350 | 253 | |
97ac7350 | 254 | if (S_ISFIFO(inode->i_mode)) |
3e63cbb1 | 255 | return -ESPIPE; |
97ac7350 | 256 | |
97ac7350 AA |
257 | /* |
258 | * Let individual file system decide if it supports preallocation | |
259 | * for directories or not. | |
260 | */ | |
261 | if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode)) | |
3e63cbb1 | 262 | return -ENODEV; |
97ac7350 | 263 | |
97ac7350 AA |
264 | /* Check for wrap through zero too */ |
265 | if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0)) | |
3e63cbb1 | 266 | return -EFBIG; |
97ac7350 | 267 | |
2fe17c10 | 268 | if (!file->f_op->fallocate) |
3e63cbb1 | 269 | return -EOPNOTSUPP; |
97ac7350 | 270 | |
14da9200 JK |
271 | sb_start_write(inode->i_sb); |
272 | ret = file->f_op->fallocate(file, mode, offset, len); | |
273 | sb_end_write(inode->i_sb); | |
274 | return ret; | |
3e63cbb1 AJ |
275 | } |
276 | ||
277 | SYSCALL_DEFINE(fallocate)(int fd, int mode, loff_t offset, loff_t len) | |
278 | { | |
279 | struct file *file; | |
280 | int error = -EBADF; | |
281 | ||
282 | file = fget(fd); | |
283 | if (file) { | |
284 | error = do_fallocate(file, mode, offset, len); | |
285 | fput(file); | |
286 | } | |
287 | ||
288 | return error; | |
97ac7350 | 289 | } |
3e63cbb1 | 290 | |
6673e0c3 HC |
291 | #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS |
292 | asmlinkage long SyS_fallocate(long fd, long mode, loff_t offset, loff_t len) | |
293 | { | |
294 | return SYSC_fallocate((int)fd, (int)mode, offset, len); | |
295 | } | |
296 | SYSCALL_ALIAS(sys_fallocate, SyS_fallocate); | |
297 | #endif | |
97ac7350 | 298 | |
1da177e4 LT |
299 | /* |
300 | * access() needs to use the real uid/gid, not the effective uid/gid. | |
301 | * We do this by temporarily clearing all FS-related capabilities and | |
302 | * switching the fsuid/fsgid around to the real ones. | |
303 | */ | |
6559eed8 | 304 | SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode) |
1da177e4 | 305 | { |
d84f4f99 DH |
306 | const struct cred *old_cred; |
307 | struct cred *override_cred; | |
2d8f3038 | 308 | struct path path; |
256984a8 | 309 | struct inode *inode; |
1da177e4 LT |
310 | int res; |
311 | ||
312 | if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ | |
313 | return -EINVAL; | |
314 | ||
d84f4f99 DH |
315 | override_cred = prepare_creds(); |
316 | if (!override_cred) | |
317 | return -ENOMEM; | |
1da177e4 | 318 | |
d84f4f99 DH |
319 | override_cred->fsuid = override_cred->uid; |
320 | override_cred->fsgid = override_cred->gid; | |
1da177e4 | 321 | |
086f7316 | 322 | if (!issecure(SECURE_NO_SETUID_FIXUP)) { |
1cdcbec1 | 323 | /* Clear the capabilities if we switch to a non-root user */ |
18815a18 EB |
324 | kuid_t root_uid = make_kuid(override_cred->user_ns, 0); |
325 | if (!uid_eq(override_cred->uid, root_uid)) | |
d84f4f99 | 326 | cap_clear(override_cred->cap_effective); |
086f7316 | 327 | else |
d84f4f99 DH |
328 | override_cred->cap_effective = |
329 | override_cred->cap_permitted; | |
086f7316 | 330 | } |
1da177e4 | 331 | |
d84f4f99 DH |
332 | old_cred = override_creds(override_cred); |
333 | ||
2d8f3038 | 334 | res = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path); |
6902d925 DH |
335 | if (res) |
336 | goto out; | |
337 | ||
2d8f3038 | 338 | inode = path.dentry->d_inode; |
256984a8 AV |
339 | |
340 | if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) { | |
30524472 AV |
341 | /* |
342 | * MAY_EXEC on regular files is denied if the fs is mounted | |
343 | * with the "noexec" flag. | |
344 | */ | |
345 | res = -EACCES; | |
2d8f3038 | 346 | if (path.mnt->mnt_flags & MNT_NOEXEC) |
30524472 AV |
347 | goto out_path_release; |
348 | } | |
349 | ||
256984a8 | 350 | res = inode_permission(inode, mode | MAY_ACCESS); |
6902d925 | 351 | /* SuS v2 requires we report a read only fs too */ |
256984a8 | 352 | if (res || !(mode & S_IWOTH) || special_file(inode->i_mode)) |
6902d925 | 353 | goto out_path_release; |
2f676cbc DH |
354 | /* |
355 | * This is a rare case where using __mnt_is_readonly() | |
356 | * is OK without a mnt_want/drop_write() pair. Since | |
357 | * no actual write to the fs is performed here, we do | |
358 | * not need to telegraph to that to anyone. | |
359 | * | |
360 | * By doing this, we accept that this access is | |
361 | * inherently racy and know that the fs may change | |
362 | * state before we even see this result. | |
363 | */ | |
2d8f3038 | 364 | if (__mnt_is_readonly(path.mnt)) |
6902d925 | 365 | res = -EROFS; |
1da177e4 | 366 | |
6902d925 | 367 | out_path_release: |
2d8f3038 | 368 | path_put(&path); |
6902d925 | 369 | out: |
d84f4f99 DH |
370 | revert_creds(old_cred); |
371 | put_cred(override_cred); | |
1da177e4 LT |
372 | return res; |
373 | } | |
374 | ||
ca013e94 | 375 | SYSCALL_DEFINE2(access, const char __user *, filename, int, mode) |
5590ff0d UD |
376 | { |
377 | return sys_faccessat(AT_FDCWD, filename, mode); | |
378 | } | |
379 | ||
3cdad428 | 380 | SYSCALL_DEFINE1(chdir, const char __user *, filename) |
1da177e4 | 381 | { |
2d8f3038 | 382 | struct path path; |
1da177e4 LT |
383 | int error; |
384 | ||
2d8f3038 | 385 | error = user_path_dir(filename, &path); |
1da177e4 LT |
386 | if (error) |
387 | goto out; | |
388 | ||
9cfcac81 | 389 | error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR); |
1da177e4 LT |
390 | if (error) |
391 | goto dput_and_out; | |
392 | ||
2d8f3038 | 393 | set_fs_pwd(current->fs, &path); |
1da177e4 LT |
394 | |
395 | dput_and_out: | |
2d8f3038 | 396 | path_put(&path); |
1da177e4 LT |
397 | out: |
398 | return error; | |
399 | } | |
400 | ||
3cdad428 | 401 | SYSCALL_DEFINE1(fchdir, unsigned int, fd) |
1da177e4 LT |
402 | { |
403 | struct file *file; | |
1da177e4 | 404 | struct inode *inode; |
332a2e12 | 405 | int error, fput_needed; |
1da177e4 LT |
406 | |
407 | error = -EBADF; | |
332a2e12 | 408 | file = fget_raw_light(fd, &fput_needed); |
1da177e4 LT |
409 | if (!file) |
410 | goto out; | |
411 | ||
ac748a09 | 412 | inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
413 | |
414 | error = -ENOTDIR; | |
415 | if (!S_ISDIR(inode->i_mode)) | |
416 | goto out_putf; | |
417 | ||
9cfcac81 | 418 | error = inode_permission(inode, MAY_EXEC | MAY_CHDIR); |
1da177e4 | 419 | if (!error) |
ac748a09 | 420 | set_fs_pwd(current->fs, &file->f_path); |
1da177e4 | 421 | out_putf: |
332a2e12 | 422 | fput_light(file, fput_needed); |
1da177e4 LT |
423 | out: |
424 | return error; | |
425 | } | |
426 | ||
3480b257 | 427 | SYSCALL_DEFINE1(chroot, const char __user *, filename) |
1da177e4 | 428 | { |
2d8f3038 | 429 | struct path path; |
1da177e4 LT |
430 | int error; |
431 | ||
2d8f3038 | 432 | error = user_path_dir(filename, &path); |
1da177e4 LT |
433 | if (error) |
434 | goto out; | |
435 | ||
9cfcac81 | 436 | error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR); |
1da177e4 LT |
437 | if (error) |
438 | goto dput_and_out; | |
439 | ||
440 | error = -EPERM; | |
441 | if (!capable(CAP_SYS_CHROOT)) | |
442 | goto dput_and_out; | |
8b8efb44 TH |
443 | error = security_path_chroot(&path); |
444 | if (error) | |
445 | goto dput_and_out; | |
1da177e4 | 446 | |
2d8f3038 | 447 | set_fs_root(current->fs, &path); |
1da177e4 LT |
448 | error = 0; |
449 | dput_and_out: | |
2d8f3038 | 450 | path_put(&path); |
1da177e4 LT |
451 | out: |
452 | return error; | |
453 | } | |
454 | ||
e57712eb | 455 | static int chmod_common(struct path *path, umode_t mode) |
1da177e4 | 456 | { |
e57712eb | 457 | struct inode *inode = path->dentry->d_inode; |
1da177e4 | 458 | struct iattr newattrs; |
e57712eb | 459 | int error; |
1da177e4 | 460 | |
e57712eb AV |
461 | error = mnt_want_write(path->mnt); |
462 | if (error) | |
463 | return error; | |
fe542cf5 | 464 | mutex_lock(&inode->i_mutex); |
cdcf116d | 465 | error = security_path_chmod(path, mode); |
e57712eb | 466 | if (error) |
fe542cf5 | 467 | goto out_unlock; |
1da177e4 LT |
468 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); |
469 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | |
e57712eb | 470 | error = notify_change(path->dentry, &newattrs); |
fe542cf5 | 471 | out_unlock: |
1b1dcc1b | 472 | mutex_unlock(&inode->i_mutex); |
e57712eb AV |
473 | mnt_drop_write(path->mnt); |
474 | return error; | |
475 | } | |
476 | ||
49f0a076 | 477 | SYSCALL_DEFINE2(fchmod, unsigned int, fd, umode_t, mode) |
e57712eb AV |
478 | { |
479 | struct file * file; | |
480 | int err = -EBADF; | |
481 | ||
482 | file = fget(fd); | |
483 | if (file) { | |
484 | audit_inode(NULL, file->f_path.dentry); | |
485 | err = chmod_common(&file->f_path, mode); | |
486 | fput(file); | |
487 | } | |
1da177e4 LT |
488 | return err; |
489 | } | |
490 | ||
49f0a076 | 491 | SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, umode_t, mode) |
1da177e4 | 492 | { |
2d8f3038 | 493 | struct path path; |
1da177e4 | 494 | int error; |
1da177e4 | 495 | |
2d8f3038 | 496 | error = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path); |
e57712eb AV |
497 | if (!error) { |
498 | error = chmod_common(&path, mode); | |
499 | path_put(&path); | |
500 | } | |
1da177e4 LT |
501 | return error; |
502 | } | |
503 | ||
49f0a076 | 504 | SYSCALL_DEFINE2(chmod, const char __user *, filename, umode_t, mode) |
5590ff0d UD |
505 | { |
506 | return sys_fchmodat(AT_FDCWD, filename, mode); | |
507 | } | |
508 | ||
fe542cf5 | 509 | static int chown_common(struct path *path, uid_t user, gid_t group) |
1da177e4 | 510 | { |
fe542cf5 | 511 | struct inode *inode = path->dentry->d_inode; |
1da177e4 LT |
512 | int error; |
513 | struct iattr newattrs; | |
52137abe EB |
514 | kuid_t uid; |
515 | kgid_t gid; | |
516 | ||
517 | uid = make_kuid(current_user_ns(), user); | |
518 | gid = make_kgid(current_user_ns(), group); | |
1da177e4 | 519 | |
1da177e4 LT |
520 | newattrs.ia_valid = ATTR_CTIME; |
521 | if (user != (uid_t) -1) { | |
52137abe EB |
522 | if (!uid_valid(uid)) |
523 | return -EINVAL; | |
1da177e4 | 524 | newattrs.ia_valid |= ATTR_UID; |
52137abe | 525 | newattrs.ia_uid = uid; |
1da177e4 LT |
526 | } |
527 | if (group != (gid_t) -1) { | |
52137abe EB |
528 | if (!gid_valid(gid)) |
529 | return -EINVAL; | |
1da177e4 | 530 | newattrs.ia_valid |= ATTR_GID; |
52137abe | 531 | newattrs.ia_gid = gid; |
1da177e4 LT |
532 | } |
533 | if (!S_ISDIR(inode->i_mode)) | |
b5376771 SH |
534 | newattrs.ia_valid |= |
535 | ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; | |
1b1dcc1b | 536 | mutex_lock(&inode->i_mutex); |
fe542cf5 TH |
537 | error = security_path_chown(path, user, group); |
538 | if (!error) | |
539 | error = notify_change(path->dentry, &newattrs); | |
1b1dcc1b | 540 | mutex_unlock(&inode->i_mutex); |
beb29e05 | 541 | |
1da177e4 LT |
542 | return error; |
543 | } | |
544 | ||
6559eed8 HC |
545 | SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user, |
546 | gid_t, group, int, flag) | |
5590ff0d | 547 | { |
2d8f3038 | 548 | struct path path; |
5590ff0d | 549 | int error = -EINVAL; |
65cfc672 | 550 | int lookup_flags; |
5590ff0d | 551 | |
65cfc672 | 552 | if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0) |
5590ff0d UD |
553 | goto out; |
554 | ||
65cfc672 AV |
555 | lookup_flags = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; |
556 | if (flag & AT_EMPTY_PATH) | |
557 | lookup_flags |= LOOKUP_EMPTY; | |
558 | error = user_path_at(dfd, filename, lookup_flags, &path); | |
6902d925 DH |
559 | if (error) |
560 | goto out; | |
2d8f3038 | 561 | error = mnt_want_write(path.mnt); |
2af482a7 DH |
562 | if (error) |
563 | goto out_release; | |
fe542cf5 | 564 | error = chown_common(&path, user, group); |
2d8f3038 | 565 | mnt_drop_write(path.mnt); |
2af482a7 | 566 | out_release: |
2d8f3038 | 567 | path_put(&path); |
5590ff0d UD |
568 | out: |
569 | return error; | |
570 | } | |
571 | ||
55e4def0 | 572 | SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group) |
1da177e4 | 573 | { |
55e4def0 DH |
574 | return sys_fchownat(AT_FDCWD, filename, user, group, 0); |
575 | } | |
1da177e4 | 576 | |
55e4def0 DH |
577 | SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group) |
578 | { | |
579 | return sys_fchownat(AT_FDCWD, filename, user, group, | |
580 | AT_SYMLINK_NOFOLLOW); | |
1da177e4 LT |
581 | } |
582 | ||
ca013e94 | 583 | SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group) |
1da177e4 LT |
584 | { |
585 | struct file * file; | |
586 | int error = -EBADF; | |
6902d925 | 587 | struct dentry * dentry; |
1da177e4 LT |
588 | |
589 | file = fget(fd); | |
6902d925 DH |
590 | if (!file) |
591 | goto out; | |
592 | ||
96029c4e | 593 | error = mnt_want_write_file(file); |
2af482a7 DH |
594 | if (error) |
595 | goto out_fput; | |
0f7fc9e4 | 596 | dentry = file->f_path.dentry; |
5a190ae6 | 597 | audit_inode(NULL, dentry); |
fe542cf5 | 598 | error = chown_common(&file->f_path, user, group); |
2a79f17e | 599 | mnt_drop_write_file(file); |
2af482a7 | 600 | out_fput: |
6902d925 DH |
601 | fput(file); |
602 | out: | |
1da177e4 LT |
603 | return error; |
604 | } | |
605 | ||
4a3fd211 DH |
606 | /* |
607 | * You have to be very careful that these write | |
608 | * counts get cleaned up in error cases and | |
609 | * upon __fput(). This should probably never | |
610 | * be called outside of __dentry_open(). | |
611 | */ | |
612 | static inline int __get_file_write_access(struct inode *inode, | |
613 | struct vfsmount *mnt) | |
614 | { | |
615 | int error; | |
616 | error = get_write_access(inode); | |
617 | if (error) | |
618 | return error; | |
619 | /* | |
620 | * Do not take mount writer counts on | |
621 | * special files since no writes to | |
622 | * the mount itself will occur. | |
623 | */ | |
624 | if (!special_file(inode->i_mode)) { | |
625 | /* | |
626 | * Balanced in __fput() | |
627 | */ | |
eb04c282 | 628 | error = __mnt_want_write(mnt); |
4a3fd211 DH |
629 | if (error) |
630 | put_write_access(inode); | |
631 | } | |
632 | return error; | |
633 | } | |
634 | ||
90ad1a8e MS |
635 | int open_check_o_direct(struct file *f) |
636 | { | |
637 | /* NB: we're sure to have correct a_ops only after f_op->open */ | |
638 | if (f->f_flags & O_DIRECT) { | |
639 | if (!f->f_mapping->a_ops || | |
640 | ((!f->f_mapping->a_ops->direct_IO) && | |
641 | (!f->f_mapping->a_ops->get_xip_mem))) { | |
642 | return -EINVAL; | |
643 | } | |
644 | } | |
645 | return 0; | |
646 | } | |
647 | ||
02e5180d | 648 | static int do_dentry_open(struct file *f, |
96b7e579 AV |
649 | int (*open)(struct inode *, struct file *), |
650 | const struct cred *cred) | |
1da177e4 | 651 | { |
1abf0c71 | 652 | static const struct file_operations empty_fops = {}; |
1da177e4 LT |
653 | struct inode *inode; |
654 | int error; | |
655 | ||
5300990c | 656 | f->f_mode = OPEN_FMODE(f->f_flags) | FMODE_LSEEK | |
a1a5b3d9 | 657 | FMODE_PREAD | FMODE_PWRITE; |
1abf0c71 AV |
658 | |
659 | if (unlikely(f->f_flags & O_PATH)) | |
660 | f->f_mode = FMODE_PATH; | |
661 | ||
b5bcdda3 | 662 | path_get(&f->f_path); |
02e5180d | 663 | inode = f->f_path.dentry->d_inode; |
1da177e4 | 664 | if (f->f_mode & FMODE_WRITE) { |
02e5180d | 665 | error = __get_file_write_access(inode, f->f_path.mnt); |
1da177e4 LT |
666 | if (error) |
667 | goto cleanup_file; | |
ad775f5a DH |
668 | if (!special_file(inode->i_mode)) |
669 | file_take_write(f); | |
1da177e4 LT |
670 | } |
671 | ||
672 | f->f_mapping = inode->i_mapping; | |
1da177e4 | 673 | f->f_pos = 0; |
ee2ffa0d | 674 | file_sb_list_add(f, inode->i_sb); |
1da177e4 | 675 | |
1abf0c71 AV |
676 | if (unlikely(f->f_mode & FMODE_PATH)) { |
677 | f->f_op = &empty_fops; | |
96b7e579 | 678 | return 0; |
1abf0c71 AV |
679 | } |
680 | ||
681 | f->f_op = fops_get(inode->i_fop); | |
682 | ||
83d49856 | 683 | error = security_file_open(f, cred); |
788e7dd4 YN |
684 | if (error) |
685 | goto cleanup_all; | |
686 | ||
f3c7691e BF |
687 | error = break_lease(inode, f->f_flags); |
688 | if (error) | |
689 | goto cleanup_all; | |
690 | ||
834f2a4a TM |
691 | if (!open && f->f_op) |
692 | open = f->f_op->open; | |
693 | if (open) { | |
694 | error = open(inode, f); | |
1da177e4 LT |
695 | if (error) |
696 | goto cleanup_all; | |
697 | } | |
890275b5 MZ |
698 | if ((f->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) |
699 | i_readcount_inc(inode); | |
834f2a4a | 700 | |
1da177e4 LT |
701 | f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); |
702 | ||
703 | file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); | |
704 | ||
96b7e579 | 705 | return 0; |
1da177e4 LT |
706 | |
707 | cleanup_all: | |
708 | fops_put(f->f_op); | |
c3c4f694 | 709 | file_sb_list_del(f); |
4a3fd211 | 710 | if (f->f_mode & FMODE_WRITE) { |
1da177e4 | 711 | put_write_access(inode); |
ad775f5a DH |
712 | if (!special_file(inode->i_mode)) { |
713 | /* | |
714 | * We don't consider this a real | |
715 | * mnt_want/drop_write() pair | |
716 | * because it all happenend right | |
717 | * here, so just reset the state. | |
718 | */ | |
719 | file_reset_write(f); | |
02e5180d | 720 | mnt_drop_write(f->f_path.mnt); |
ad775f5a | 721 | } |
4a3fd211 | 722 | } |
1da177e4 | 723 | cleanup_file: |
02e5180d AV |
724 | path_put(&f->f_path); |
725 | f->f_path.mnt = NULL; | |
726 | f->f_path.dentry = NULL; | |
96b7e579 | 727 | return error; |
1da177e4 LT |
728 | } |
729 | ||
d18e9008 MS |
730 | /** |
731 | * finish_open - finish opening a file | |
732 | * @od: opaque open data | |
733 | * @dentry: pointer to dentry | |
734 | * @open: open callback | |
735 | * | |
736 | * This can be used to finish opening a file passed to i_op->atomic_open(). | |
737 | * | |
738 | * If the open callback is set to NULL, then the standard f_op->open() | |
739 | * filesystem callback is substituted. | |
740 | */ | |
30d90494 AV |
741 | int finish_open(struct file *file, struct dentry *dentry, |
742 | int (*open)(struct inode *, struct file *), | |
743 | int *opened) | |
d18e9008 | 744 | { |
96b7e579 | 745 | int error; |
3d8a00d2 | 746 | BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */ |
d18e9008 | 747 | |
b5bcdda3 | 748 | file->f_path.dentry = dentry; |
02e5180d | 749 | error = do_dentry_open(file, open, current_cred()); |
96b7e579 | 750 | if (!error) |
47237687 | 751 | *opened |= FILE_OPENED; |
d18e9008 | 752 | |
96b7e579 | 753 | return error; |
d18e9008 MS |
754 | } |
755 | EXPORT_SYMBOL(finish_open); | |
756 | ||
757 | /** | |
758 | * finish_no_open - finish ->atomic_open() without opening the file | |
759 | * | |
760 | * @od: opaque open data | |
761 | * @dentry: dentry or NULL (as returned from ->lookup()) | |
762 | * | |
763 | * This can be used to set the result of a successful lookup in ->atomic_open(). | |
764 | * The filesystem's atomic_open() method shall return NULL after calling this. | |
765 | */ | |
e45198a6 | 766 | int finish_no_open(struct file *file, struct dentry *dentry) |
d18e9008 | 767 | { |
30d90494 | 768 | file->f_path.dentry = dentry; |
e45198a6 | 769 | return 1; |
d18e9008 MS |
770 | } |
771 | EXPORT_SYMBOL(finish_no_open); | |
772 | ||
765927b2 | 773 | struct file *dentry_open(const struct path *path, int flags, |
745ca247 | 774 | const struct cred *cred) |
a1a5b3d9 PS |
775 | { |
776 | int error; | |
777 | struct file *f; | |
778 | ||
e0e81739 DH |
779 | validate_creds(cred); |
780 | ||
c212f9aa | 781 | /* We must always pass in a valid mount pointer. */ |
765927b2 | 782 | BUG_ON(!path->mnt); |
322ee5b3 | 783 | |
a1a5b3d9 PS |
784 | error = -ENFILE; |
785 | f = get_empty_filp(); | |
765927b2 | 786 | if (f == NULL) |
a1a5b3d9 PS |
787 | return ERR_PTR(error); |
788 | ||
482928d5 | 789 | f->f_flags = flags; |
765927b2 | 790 | f->f_path = *path; |
02e5180d | 791 | error = do_dentry_open(f, NULL, cred); |
2a027e7a AV |
792 | if (!error) { |
793 | error = open_check_o_direct(f); | |
794 | if (error) { | |
795 | fput(f); | |
796 | f = ERR_PTR(error); | |
797 | } | |
798 | } else { | |
799 | put_filp(f); | |
800 | f = ERR_PTR(error); | |
801 | } | |
802 | return f; | |
a1a5b3d9 | 803 | } |
1da177e4 LT |
804 | EXPORT_SYMBOL(dentry_open); |
805 | ||
b01ec0ef | 806 | static void __put_unused_fd(struct files_struct *files, unsigned int fd) |
1da177e4 | 807 | { |
badf1662 | 808 | struct fdtable *fdt = files_fdtable(files); |
1dce27c5 | 809 | __clear_open_fd(fd, fdt); |
0c9e63fd ED |
810 | if (fd < files->next_fd) |
811 | files->next_fd = fd; | |
1da177e4 LT |
812 | } |
813 | ||
fc9b52cd | 814 | void put_unused_fd(unsigned int fd) |
1da177e4 LT |
815 | { |
816 | struct files_struct *files = current->files; | |
817 | spin_lock(&files->file_lock); | |
818 | __put_unused_fd(files, fd); | |
819 | spin_unlock(&files->file_lock); | |
820 | } | |
821 | ||
822 | EXPORT_SYMBOL(put_unused_fd); | |
823 | ||
824 | /* | |
5590ff0d | 825 | * Install a file pointer in the fd array. |
1da177e4 LT |
826 | * |
827 | * The VFS is full of places where we drop the files lock between | |
828 | * setting the open_fds bitmap and installing the file in the file | |
829 | * array. At any such point, we are vulnerable to a dup2() race | |
830 | * installing a file in the array before us. We need to detect this and | |
831 | * fput() the struct file we are about to overwrite in this case. | |
832 | * | |
833 | * It should never happen - if we allow dup2() do it, _really_ bad things | |
834 | * will follow. | |
835 | */ | |
836 | ||
fc9b52cd | 837 | void fd_install(unsigned int fd, struct file *file) |
1da177e4 LT |
838 | { |
839 | struct files_struct *files = current->files; | |
badf1662 | 840 | struct fdtable *fdt; |
1da177e4 | 841 | spin_lock(&files->file_lock); |
badf1662 | 842 | fdt = files_fdtable(files); |
ab2af1f5 DS |
843 | BUG_ON(fdt->fd[fd] != NULL); |
844 | rcu_assign_pointer(fdt->fd[fd], file); | |
1da177e4 LT |
845 | spin_unlock(&files->file_lock); |
846 | } | |
847 | ||
848 | EXPORT_SYMBOL(fd_install); | |
849 | ||
a218d0fd | 850 | static inline int build_open_flags(int flags, umode_t mode, struct open_flags *op) |
47c805dc AV |
851 | { |
852 | int lookup_flags = 0; | |
853 | int acc_mode; | |
854 | ||
855 | if (!(flags & O_CREAT)) | |
856 | mode = 0; | |
857 | op->mode = mode; | |
858 | ||
859 | /* Must never be set by userspace */ | |
860 | flags &= ~FMODE_NONOTIFY; | |
861 | ||
862 | /* | |
863 | * O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only | |
864 | * check for O_DSYNC if the need any syncing at all we enforce it's | |
865 | * always set instead of having to deal with possibly weird behaviour | |
866 | * for malicious applications setting only __O_SYNC. | |
867 | */ | |
868 | if (flags & __O_SYNC) | |
869 | flags |= O_DSYNC; | |
870 | ||
1abf0c71 AV |
871 | /* |
872 | * If we have O_PATH in the open flag. Then we | |
873 | * cannot have anything other than the below set of flags | |
874 | */ | |
875 | if (flags & O_PATH) { | |
876 | flags &= O_DIRECTORY | O_NOFOLLOW | O_PATH; | |
877 | acc_mode = 0; | |
878 | } else { | |
879 | acc_mode = MAY_OPEN | ACC_MODE(flags); | |
880 | } | |
47c805dc | 881 | |
1abf0c71 | 882 | op->open_flag = flags; |
47c805dc AV |
883 | |
884 | /* O_TRUNC implies we need access checks for write permissions */ | |
885 | if (flags & O_TRUNC) | |
886 | acc_mode |= MAY_WRITE; | |
887 | ||
888 | /* Allow the LSM permission hook to distinguish append | |
889 | access from general write access. */ | |
890 | if (flags & O_APPEND) | |
891 | acc_mode |= MAY_APPEND; | |
892 | ||
893 | op->acc_mode = acc_mode; | |
894 | ||
1abf0c71 AV |
895 | op->intent = flags & O_PATH ? 0 : LOOKUP_OPEN; |
896 | ||
47c805dc AV |
897 | if (flags & O_CREAT) { |
898 | op->intent |= LOOKUP_CREATE; | |
899 | if (flags & O_EXCL) | |
900 | op->intent |= LOOKUP_EXCL; | |
901 | } | |
902 | ||
903 | if (flags & O_DIRECTORY) | |
904 | lookup_flags |= LOOKUP_DIRECTORY; | |
905 | if (!(flags & O_NOFOLLOW)) | |
906 | lookup_flags |= LOOKUP_FOLLOW; | |
907 | return lookup_flags; | |
908 | } | |
909 | ||
910 | /** | |
911 | * filp_open - open file and return file pointer | |
912 | * | |
913 | * @filename: path to open | |
914 | * @flags: open flags as per the open(2) second argument | |
915 | * @mode: mode for the new file if O_CREAT is set, else ignored | |
916 | * | |
917 | * This is the helper to open a file from kernelspace if you really | |
918 | * have to. But in generally you should not do this, so please move | |
919 | * along, nothing to see here.. | |
920 | */ | |
a218d0fd | 921 | struct file *filp_open(const char *filename, int flags, umode_t mode) |
47c805dc AV |
922 | { |
923 | struct open_flags op; | |
924 | int lookup = build_open_flags(flags, mode, &op); | |
925 | return do_filp_open(AT_FDCWD, filename, &op, lookup); | |
926 | } | |
927 | EXPORT_SYMBOL(filp_open); | |
928 | ||
73d049a4 AV |
929 | struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt, |
930 | const char *filename, int flags) | |
931 | { | |
932 | struct open_flags op; | |
933 | int lookup = build_open_flags(flags, 0, &op); | |
934 | if (flags & O_CREAT) | |
935 | return ERR_PTR(-EINVAL); | |
936 | if (!filename && (flags & O_DIRECTORY)) | |
937 | if (!dentry->d_inode->i_op->lookup) | |
938 | return ERR_PTR(-ENOTDIR); | |
939 | return do_file_open_root(dentry, mnt, filename, &op, lookup); | |
940 | } | |
941 | EXPORT_SYMBOL(file_open_root); | |
942 | ||
a218d0fd | 943 | long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode) |
1da177e4 | 944 | { |
47c805dc AV |
945 | struct open_flags op; |
946 | int lookup = build_open_flags(flags, mode, &op); | |
e922efc3 MS |
947 | char *tmp = getname(filename); |
948 | int fd = PTR_ERR(tmp); | |
1da177e4 | 949 | |
1da177e4 | 950 | if (!IS_ERR(tmp)) { |
f23513e8 | 951 | fd = get_unused_fd_flags(flags); |
1da177e4 | 952 | if (fd >= 0) { |
47c805dc | 953 | struct file *f = do_filp_open(dfd, tmp, &op, lookup); |
fed2fc18 TN |
954 | if (IS_ERR(f)) { |
955 | put_unused_fd(fd); | |
956 | fd = PTR_ERR(f); | |
957 | } else { | |
2a12a9d7 | 958 | fsnotify_open(f); |
fed2fc18 TN |
959 | fd_install(fd, f); |
960 | } | |
1da177e4 | 961 | } |
1da177e4 LT |
962 | putname(tmp); |
963 | } | |
964 | return fd; | |
1da177e4 | 965 | } |
e922efc3 | 966 | |
a218d0fd | 967 | SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode) |
e922efc3 | 968 | { |
385910f2 LT |
969 | long ret; |
970 | ||
e922efc3 MS |
971 | if (force_o_largefile()) |
972 | flags |= O_LARGEFILE; | |
973 | ||
385910f2 LT |
974 | ret = do_sys_open(AT_FDCWD, filename, flags, mode); |
975 | /* avoid REGPARM breakage on x86: */ | |
54a01510 | 976 | asmlinkage_protect(3, ret, filename, flags, mode); |
385910f2 | 977 | return ret; |
e922efc3 | 978 | } |
1da177e4 | 979 | |
6559eed8 | 980 | SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags, |
a218d0fd | 981 | umode_t, mode) |
5590ff0d | 982 | { |
385910f2 LT |
983 | long ret; |
984 | ||
5590ff0d UD |
985 | if (force_o_largefile()) |
986 | flags |= O_LARGEFILE; | |
987 | ||
385910f2 LT |
988 | ret = do_sys_open(dfd, filename, flags, mode); |
989 | /* avoid REGPARM breakage on x86: */ | |
54a01510 | 990 | asmlinkage_protect(4, ret, dfd, filename, flags, mode); |
385910f2 | 991 | return ret; |
5590ff0d | 992 | } |
5590ff0d | 993 | |
1da177e4 LT |
994 | #ifndef __alpha__ |
995 | ||
996 | /* | |
997 | * For backward compatibility? Maybe this should be moved | |
998 | * into arch/i386 instead? | |
999 | */ | |
a218d0fd | 1000 | SYSCALL_DEFINE2(creat, const char __user *, pathname, umode_t, mode) |
1da177e4 LT |
1001 | { |
1002 | return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode); | |
1003 | } | |
1004 | ||
1005 | #endif | |
1006 | ||
1007 | /* | |
1008 | * "id" is the POSIX thread ID. We use the | |
1009 | * files pointer for this.. | |
1010 | */ | |
1011 | int filp_close(struct file *filp, fl_owner_t id) | |
1012 | { | |
45778ca8 | 1013 | int retval = 0; |
1da177e4 LT |
1014 | |
1015 | if (!file_count(filp)) { | |
1016 | printk(KERN_ERR "VFS: Close: file count is 0\n"); | |
45778ca8 | 1017 | return 0; |
1da177e4 LT |
1018 | } |
1019 | ||
45778ca8 | 1020 | if (filp->f_op && filp->f_op->flush) |
75e1fcc0 | 1021 | retval = filp->f_op->flush(filp, id); |
1da177e4 | 1022 | |
1abf0c71 AV |
1023 | if (likely(!(filp->f_mode & FMODE_PATH))) { |
1024 | dnotify_flush(filp, id); | |
1025 | locks_remove_posix(filp, id); | |
1026 | } | |
1da177e4 LT |
1027 | fput(filp); |
1028 | return retval; | |
1029 | } | |
1030 | ||
1031 | EXPORT_SYMBOL(filp_close); | |
1032 | ||
1033 | /* | |
1034 | * Careful here! We test whether the file pointer is NULL before | |
1035 | * releasing the fd. This ensures that one clone task can't release | |
1036 | * an fd while another clone is opening it. | |
1037 | */ | |
ca013e94 | 1038 | SYSCALL_DEFINE1(close, unsigned int, fd) |
1da177e4 LT |
1039 | { |
1040 | struct file * filp; | |
1041 | struct files_struct *files = current->files; | |
badf1662 | 1042 | struct fdtable *fdt; |
ee731f4f | 1043 | int retval; |
1da177e4 LT |
1044 | |
1045 | spin_lock(&files->file_lock); | |
badf1662 DS |
1046 | fdt = files_fdtable(files); |
1047 | if (fd >= fdt->max_fds) | |
1da177e4 | 1048 | goto out_unlock; |
badf1662 | 1049 | filp = fdt->fd[fd]; |
1da177e4 LT |
1050 | if (!filp) |
1051 | goto out_unlock; | |
ab2af1f5 | 1052 | rcu_assign_pointer(fdt->fd[fd], NULL); |
1dce27c5 | 1053 | __clear_close_on_exec(fd, fdt); |
1da177e4 LT |
1054 | __put_unused_fd(files, fd); |
1055 | spin_unlock(&files->file_lock); | |
ee731f4f EP |
1056 | retval = filp_close(filp, files); |
1057 | ||
1058 | /* can't restart close syscall because file table entry was cleared */ | |
1059 | if (unlikely(retval == -ERESTARTSYS || | |
1060 | retval == -ERESTARTNOINTR || | |
1061 | retval == -ERESTARTNOHAND || | |
1062 | retval == -ERESTART_RESTARTBLOCK)) | |
1063 | retval = -EINTR; | |
1064 | ||
1065 | return retval; | |
1da177e4 LT |
1066 | |
1067 | out_unlock: | |
1068 | spin_unlock(&files->file_lock); | |
1069 | return -EBADF; | |
1070 | } | |
1da177e4 LT |
1071 | EXPORT_SYMBOL(sys_close); |
1072 | ||
1073 | /* | |
1074 | * This routine simulates a hangup on the tty, to arrange that users | |
1075 | * are given clean terminals at login time. | |
1076 | */ | |
ca013e94 | 1077 | SYSCALL_DEFINE0(vhangup) |
1da177e4 LT |
1078 | { |
1079 | if (capable(CAP_SYS_TTY_CONFIG)) { | |
2cb5998b | 1080 | tty_vhangup_self(); |
1da177e4 LT |
1081 | return 0; |
1082 | } | |
1083 | return -EPERM; | |
1084 | } | |
1085 | ||
1086 | /* | |
1087 | * Called when an inode is about to be open. | |
1088 | * We use this to disallow opening large files on 32bit systems if | |
1089 | * the caller didn't specify O_LARGEFILE. On 64bit systems we force | |
1090 | * on this flag in sys_open. | |
1091 | */ | |
1092 | int generic_file_open(struct inode * inode, struct file * filp) | |
1093 | { | |
1094 | if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) | |
a9c62a18 | 1095 | return -EOVERFLOW; |
1da177e4 LT |
1096 | return 0; |
1097 | } | |
1098 | ||
1099 | EXPORT_SYMBOL(generic_file_open); | |
1100 | ||
1101 | /* | |
1102 | * This is used by subsystems that don't want seekable | |
06b1e104 DT |
1103 | * file descriptors. The function is not supposed to ever fail, the only |
1104 | * reason it returns an 'int' and not 'void' is so that it can be plugged | |
1105 | * directly into file_operations structure. | |
1da177e4 LT |
1106 | */ |
1107 | int nonseekable_open(struct inode *inode, struct file *filp) | |
1108 | { | |
1109 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); | |
1110 | return 0; | |
1111 | } | |
1112 | ||
1113 | EXPORT_SYMBOL(nonseekable_open); |