]>
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> |
7c0f6ba6 | 22 | #include <linux/uaccess.h> |
1da177e4 | 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> |
3f6d078d | 33 | #include <linux/compat.h> |
1da177e4 | 34 | |
e81e3f4d EP |
35 | #include "internal.h" |
36 | ||
7744c33f SJR |
37 | #define CREATE_TRACE_POINTS |
38 | #include <trace/events/fs.h> | |
39 | ||
4a30131e N |
40 | int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs, |
41 | struct file *filp) | |
1da177e4 | 42 | { |
939a9421 | 43 | int ret; |
1da177e4 LT |
44 | struct iattr newattrs; |
45 | ||
46 | /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */ | |
47 | if (length < 0) | |
48 | return -EINVAL; | |
49 | ||
50 | newattrs.ia_size = length; | |
4a30131e | 51 | newattrs.ia_valid = ATTR_SIZE | time_attrs; |
cc4e69de MS |
52 | if (filp) { |
53 | newattrs.ia_file = filp; | |
54 | newattrs.ia_valid |= ATTR_FILE; | |
55 | } | |
1da177e4 | 56 | |
45f147a1 JK |
57 | /* Remove suid, sgid, and file capabilities on truncate too */ |
58 | ret = dentry_needs_remove_privs(dentry); | |
59 | if (ret < 0) | |
60 | return ret; | |
939a9421 AW |
61 | if (ret) |
62 | newattrs.ia_valid |= ret | ATTR_FORCE; | |
7b82dc0e | 63 | |
5955102c | 64 | inode_lock(dentry->d_inode); |
27ac0ffe BF |
65 | /* Note any delegations or leases have already been broken: */ |
66 | ret = notify_change(dentry, &newattrs, NULL); | |
5955102c | 67 | inode_unlock(dentry->d_inode); |
939a9421 | 68 | return ret; |
1da177e4 | 69 | } |
c088e31d | 70 | EXPORT_SYMBOL_GPL(do_truncate); |
1da177e4 | 71 | |
7df818b2 | 72 | long vfs_truncate(const struct path *path, loff_t length) |
1da177e4 | 73 | { |
2d8f3038 | 74 | struct inode *inode; |
4d0c5ba2 | 75 | struct dentry *upperdentry; |
a02de960 | 76 | long error; |
1da177e4 | 77 | |
a02de960 | 78 | inode = path->dentry->d_inode; |
1da177e4 LT |
79 | |
80 | /* For directories it's -EISDIR, for other non-regulars - -EINVAL */ | |
1da177e4 | 81 | if (S_ISDIR(inode->i_mode)) |
a02de960 | 82 | return -EISDIR; |
1da177e4 | 83 | if (!S_ISREG(inode->i_mode)) |
a02de960 | 84 | return -EINVAL; |
1da177e4 | 85 | |
a02de960 | 86 | error = mnt_want_write(path->mnt); |
1da177e4 | 87 | if (error) |
a02de960 | 88 | goto out; |
1da177e4 | 89 | |
256984a8 | 90 | error = inode_permission(inode, MAY_WRITE); |
9ac9b847 DH |
91 | if (error) |
92 | goto mnt_drop_write_and_out; | |
1da177e4 LT |
93 | |
94 | error = -EPERM; | |
c82e42da | 95 | if (IS_APPEND(inode)) |
9ac9b847 | 96 | goto mnt_drop_write_and_out; |
1da177e4 | 97 | |
4d0c5ba2 MS |
98 | /* |
99 | * If this is an overlayfs then do as if opening the file so we get | |
100 | * write access on the upper inode, not on the overlay inode. For | |
101 | * non-overlay filesystems d_real() is an identity function. | |
102 | */ | |
495e6429 | 103 | upperdentry = d_real(path->dentry, NULL, O_WRONLY, 0); |
4d0c5ba2 MS |
104 | error = PTR_ERR(upperdentry); |
105 | if (IS_ERR(upperdentry)) | |
106 | goto mnt_drop_write_and_out; | |
107 | ||
108 | error = get_write_access(upperdentry->d_inode); | |
1da177e4 | 109 | if (error) |
9ac9b847 | 110 | goto mnt_drop_write_and_out; |
1da177e4 | 111 | |
9700382c | 112 | /* |
113 | * Make sure that there are no leases. get_write_access() protects | |
114 | * against the truncate racing with a lease-granting setlease(). | |
115 | */ | |
8737c930 | 116 | error = break_lease(inode, O_WRONLY); |
1da177e4 | 117 | if (error) |
9700382c | 118 | goto put_write_and_out; |
1da177e4 LT |
119 | |
120 | error = locks_verify_truncate(inode, NULL, length); | |
be6d3e56 | 121 | if (!error) |
a02de960 | 122 | error = security_path_truncate(path); |
907f4554 | 123 | if (!error) |
a02de960 | 124 | error = do_truncate(path->dentry, length, 0, NULL); |
1da177e4 | 125 | |
9700382c | 126 | put_write_and_out: |
4d0c5ba2 | 127 | put_write_access(upperdentry->d_inode); |
9ac9b847 | 128 | mnt_drop_write_and_out: |
a02de960 | 129 | mnt_drop_write(path->mnt); |
1da177e4 LT |
130 | out: |
131 | return error; | |
132 | } | |
a02de960 DH |
133 | EXPORT_SYMBOL_GPL(vfs_truncate); |
134 | ||
135 | static long do_sys_truncate(const char __user *pathname, loff_t length) | |
136 | { | |
48f7530d | 137 | unsigned int lookup_flags = LOOKUP_FOLLOW; |
a02de960 DH |
138 | struct path path; |
139 | int error; | |
140 | ||
141 | if (length < 0) /* sorry, but loff_t says... */ | |
142 | return -EINVAL; | |
143 | ||
48f7530d JL |
144 | retry: |
145 | error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path); | |
a02de960 DH |
146 | if (!error) { |
147 | error = vfs_truncate(&path, length); | |
148 | path_put(&path); | |
149 | } | |
48f7530d JL |
150 | if (retry_estale(error, lookup_flags)) { |
151 | lookup_flags |= LOOKUP_REVAL; | |
152 | goto retry; | |
153 | } | |
a02de960 DH |
154 | return error; |
155 | } | |
1da177e4 | 156 | |
4fd8da8d | 157 | SYSCALL_DEFINE2(truncate, const char __user *, path, long, length) |
1da177e4 | 158 | { |
4fd8da8d | 159 | return do_sys_truncate(path, length); |
1da177e4 LT |
160 | } |
161 | ||
3f6d078d AV |
162 | #ifdef CONFIG_COMPAT |
163 | COMPAT_SYSCALL_DEFINE2(truncate, const char __user *, path, compat_off_t, length) | |
164 | { | |
165 | return do_sys_truncate(path, length); | |
166 | } | |
167 | #endif | |
168 | ||
b01ec0ef | 169 | static long do_sys_ftruncate(unsigned int fd, loff_t length, int small) |
1da177e4 | 170 | { |
bf2965d5 | 171 | struct inode *inode; |
1da177e4 | 172 | struct dentry *dentry; |
2903ff01 | 173 | struct fd f; |
1da177e4 LT |
174 | int error; |
175 | ||
176 | error = -EINVAL; | |
177 | if (length < 0) | |
178 | goto out; | |
179 | error = -EBADF; | |
2903ff01 AV |
180 | f = fdget(fd); |
181 | if (!f.file) | |
1da177e4 LT |
182 | goto out; |
183 | ||
184 | /* explicitly opened as large or we are on 64-bit box */ | |
2903ff01 | 185 | if (f.file->f_flags & O_LARGEFILE) |
1da177e4 LT |
186 | small = 0; |
187 | ||
2903ff01 | 188 | dentry = f.file->f_path.dentry; |
1da177e4 LT |
189 | inode = dentry->d_inode; |
190 | error = -EINVAL; | |
2903ff01 | 191 | if (!S_ISREG(inode->i_mode) || !(f.file->f_mode & FMODE_WRITE)) |
1da177e4 LT |
192 | goto out_putf; |
193 | ||
194 | error = -EINVAL; | |
195 | /* Cannot ftruncate over 2^31 bytes without large file support */ | |
196 | if (small && length > MAX_NON_LFS) | |
197 | goto out_putf; | |
198 | ||
199 | error = -EPERM; | |
78757af6 AG |
200 | /* Check IS_APPEND on real upper inode */ |
201 | if (IS_APPEND(file_inode(f.file))) | |
1da177e4 LT |
202 | goto out_putf; |
203 | ||
14da9200 | 204 | sb_start_write(inode->i_sb); |
2903ff01 | 205 | error = locks_verify_truncate(inode, f.file, length); |
be6d3e56 | 206 | if (!error) |
2903ff01 | 207 | error = security_path_truncate(&f.file->f_path); |
1da177e4 | 208 | if (!error) |
2903ff01 | 209 | error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, f.file); |
14da9200 | 210 | sb_end_write(inode->i_sb); |
1da177e4 | 211 | out_putf: |
2903ff01 | 212 | fdput(f); |
1da177e4 LT |
213 | out: |
214 | return error; | |
215 | } | |
216 | ||
bdc480e3 | 217 | SYSCALL_DEFINE2(ftruncate, unsigned int, fd, unsigned long, length) |
1da177e4 | 218 | { |
2cf09666 | 219 | return do_sys_ftruncate(fd, length, 1); |
1da177e4 LT |
220 | } |
221 | ||
3f6d078d AV |
222 | #ifdef CONFIG_COMPAT |
223 | COMPAT_SYSCALL_DEFINE2(ftruncate, unsigned int, fd, compat_ulong_t, length) | |
224 | { | |
225 | return do_sys_ftruncate(fd, length, 1); | |
226 | } | |
227 | #endif | |
228 | ||
1da177e4 LT |
229 | /* LFS versions of truncate are only needed on 32 bit machines */ |
230 | #if BITS_PER_LONG == 32 | |
4a0fd5bf | 231 | SYSCALL_DEFINE2(truncate64, const char __user *, path, loff_t, length) |
1da177e4 LT |
232 | { |
233 | return do_sys_truncate(path, length); | |
234 | } | |
235 | ||
4a0fd5bf | 236 | SYSCALL_DEFINE2(ftruncate64, unsigned int, fd, loff_t, length) |
1da177e4 | 237 | { |
2cf09666 | 238 | return do_sys_ftruncate(fd, length, 0); |
1da177e4 | 239 | } |
6673e0c3 | 240 | #endif /* BITS_PER_LONG == 32 */ |
1da177e4 | 241 | |
3e63cbb1 | 242 | |
72c72bdf | 243 | int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len) |
97ac7350 | 244 | { |
496ad9aa | 245 | struct inode *inode = file_inode(file); |
3e63cbb1 | 246 | long ret; |
97ac7350 AA |
247 | |
248 | if (offset < 0 || len <= 0) | |
3e63cbb1 | 249 | return -EINVAL; |
97ac7350 AA |
250 | |
251 | /* Return error if mode is not supported */ | |
dd46c787 | 252 | if (mode & ~FALLOC_FL_SUPPORTED_MASK) |
409332b6 LC |
253 | return -EOPNOTSUPP; |
254 | ||
255 | /* Punch hole and zero range are mutually exclusive */ | |
256 | if ((mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) == | |
257 | (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) | |
79124f18 JB |
258 | return -EOPNOTSUPP; |
259 | ||
260 | /* Punch hole must have keep size set */ | |
261 | if ((mode & FALLOC_FL_PUNCH_HOLE) && | |
262 | !(mode & FALLOC_FL_KEEP_SIZE)) | |
3e63cbb1 | 263 | return -EOPNOTSUPP; |
97ac7350 | 264 | |
00f5e619 NJ |
265 | /* Collapse range should only be used exclusively. */ |
266 | if ((mode & FALLOC_FL_COLLAPSE_RANGE) && | |
267 | (mode & ~FALLOC_FL_COLLAPSE_RANGE)) | |
268 | return -EINVAL; | |
269 | ||
dd46c787 NJ |
270 | /* Insert range should only be used exclusively. */ |
271 | if ((mode & FALLOC_FL_INSERT_RANGE) && | |
272 | (mode & ~FALLOC_FL_INSERT_RANGE)) | |
273 | return -EINVAL; | |
274 | ||
71be6b49 DW |
275 | /* Unshare range should only be used with allocate mode. */ |
276 | if ((mode & FALLOC_FL_UNSHARE_RANGE) && | |
277 | (mode & ~(FALLOC_FL_UNSHARE_RANGE | FALLOC_FL_KEEP_SIZE))) | |
278 | return -EINVAL; | |
279 | ||
97ac7350 | 280 | if (!(file->f_mode & FMODE_WRITE)) |
3e63cbb1 | 281 | return -EBADF; |
1ca551c6 | 282 | |
00f5e619 | 283 | /* |
8fc61d92 | 284 | * We can only allow pure fallocate on append only files |
00f5e619 | 285 | */ |
8fc61d92 | 286 | if ((mode & ~FALLOC_FL_KEEP_SIZE) && IS_APPEND(inode)) |
1ca551c6 MS |
287 | return -EPERM; |
288 | ||
289 | if (IS_IMMUTABLE(inode)) | |
290 | return -EPERM; | |
291 | ||
0790b31b | 292 | /* |
6d2b6170 | 293 | * We cannot allow any fallocate operation on an active swapfile |
0790b31b LC |
294 | */ |
295 | if (IS_SWAPFILE(inode)) | |
6d2b6170 | 296 | return -ETXTBSY; |
0790b31b | 297 | |
97ac7350 AA |
298 | /* |
299 | * Revalidate the write permissions, in case security policy has | |
300 | * changed since the files were opened. | |
301 | */ | |
302 | ret = security_file_permission(file, MAY_WRITE); | |
303 | if (ret) | |
3e63cbb1 | 304 | return ret; |
97ac7350 | 305 | |
97ac7350 | 306 | if (S_ISFIFO(inode->i_mode)) |
3e63cbb1 | 307 | return -ESPIPE; |
97ac7350 | 308 | |
9e79b132 AG |
309 | if (S_ISDIR(inode->i_mode)) |
310 | return -EISDIR; | |
311 | ||
312 | if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) | |
3e63cbb1 | 313 | return -ENODEV; |
97ac7350 | 314 | |
97ac7350 AA |
315 | /* Check for wrap through zero too */ |
316 | if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0)) | |
3e63cbb1 | 317 | return -EFBIG; |
97ac7350 | 318 | |
2fe17c10 | 319 | if (!file->f_op->fallocate) |
3e63cbb1 | 320 | return -EOPNOTSUPP; |
97ac7350 | 321 | |
bfe219d3 | 322 | file_start_write(file); |
14da9200 | 323 | ret = file->f_op->fallocate(file, mode, offset, len); |
820c12d5 HS |
324 | |
325 | /* | |
326 | * Create inotify and fanotify events. | |
327 | * | |
328 | * To keep the logic simple always create events if fallocate succeeds. | |
329 | * This implies that events are even created if the file size remains | |
330 | * unchanged, e.g. when using flag FALLOC_FL_KEEP_SIZE. | |
331 | */ | |
332 | if (ret == 0) | |
333 | fsnotify_modify(file); | |
334 | ||
bfe219d3 | 335 | file_end_write(file); |
14da9200 | 336 | return ret; |
3e63cbb1 | 337 | } |
72c72bdf | 338 | EXPORT_SYMBOL_GPL(vfs_fallocate); |
3e63cbb1 | 339 | |
4a0fd5bf | 340 | SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len) |
3e63cbb1 | 341 | { |
2903ff01 | 342 | struct fd f = fdget(fd); |
3e63cbb1 AJ |
343 | int error = -EBADF; |
344 | ||
2903ff01 | 345 | if (f.file) { |
72c72bdf | 346 | error = vfs_fallocate(f.file, mode, offset, len); |
2903ff01 | 347 | fdput(f); |
3e63cbb1 | 348 | } |
3e63cbb1 | 349 | return error; |
97ac7350 | 350 | } |
3e63cbb1 | 351 | |
1da177e4 LT |
352 | /* |
353 | * access() needs to use the real uid/gid, not the effective uid/gid. | |
354 | * We do this by temporarily clearing all FS-related capabilities and | |
355 | * switching the fsuid/fsgid around to the real ones. | |
356 | */ | |
6559eed8 | 357 | SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode) |
1da177e4 | 358 | { |
d84f4f99 DH |
359 | const struct cred *old_cred; |
360 | struct cred *override_cred; | |
2d8f3038 | 361 | struct path path; |
256984a8 | 362 | struct inode *inode; |
1da177e4 | 363 | int res; |
87fa5595 | 364 | unsigned int lookup_flags = LOOKUP_FOLLOW; |
1da177e4 LT |
365 | |
366 | if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */ | |
367 | return -EINVAL; | |
368 | ||
d84f4f99 DH |
369 | override_cred = prepare_creds(); |
370 | if (!override_cred) | |
371 | return -ENOMEM; | |
1da177e4 | 372 | |
d84f4f99 DH |
373 | override_cred->fsuid = override_cred->uid; |
374 | override_cred->fsgid = override_cred->gid; | |
1da177e4 | 375 | |
086f7316 | 376 | if (!issecure(SECURE_NO_SETUID_FIXUP)) { |
1cdcbec1 | 377 | /* Clear the capabilities if we switch to a non-root user */ |
18815a18 EB |
378 | kuid_t root_uid = make_kuid(override_cred->user_ns, 0); |
379 | if (!uid_eq(override_cred->uid, root_uid)) | |
d84f4f99 | 380 | cap_clear(override_cred->cap_effective); |
086f7316 | 381 | else |
d84f4f99 DH |
382 | override_cred->cap_effective = |
383 | override_cred->cap_permitted; | |
086f7316 | 384 | } |
1da177e4 | 385 | |
84e96ba9 LT |
386 | /* |
387 | * The new set of credentials can *only* be used in | |
388 | * task-synchronous circumstances, and does not need | |
389 | * RCU freeing, unless somebody then takes a separate | |
390 | * reference to it. | |
391 | * | |
392 | * NOTE! This is _only_ true because this credential | |
393 | * is used purely for override_creds() that installs | |
394 | * it as the subjective cred. Other threads will be | |
395 | * accessing ->real_cred, not the subjective cred. | |
396 | * | |
397 | * If somebody _does_ make a copy of this (using the | |
398 | * 'get_current_cred()' function), that will clear the | |
399 | * non_rcu field, because now that other user may be | |
400 | * expecting RCU freeing. But normal thread-synchronous | |
401 | * cred accesses will keep things non-RCY. | |
402 | */ | |
403 | override_cred->non_rcu = 1; | |
404 | ||
d84f4f99 | 405 | old_cred = override_creds(override_cred); |
87fa5595 JL |
406 | retry: |
407 | res = user_path_at(dfd, filename, lookup_flags, &path); | |
6902d925 DH |
408 | if (res) |
409 | goto out; | |
410 | ||
63afdfc7 | 411 | inode = d_backing_inode(path.dentry); |
256984a8 AV |
412 | |
413 | if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) { | |
30524472 AV |
414 | /* |
415 | * MAY_EXEC on regular files is denied if the fs is mounted | |
416 | * with the "noexec" flag. | |
417 | */ | |
418 | res = -EACCES; | |
90f8572b | 419 | if (path_noexec(&path)) |
30524472 AV |
420 | goto out_path_release; |
421 | } | |
422 | ||
256984a8 | 423 | res = inode_permission(inode, mode | MAY_ACCESS); |
6902d925 | 424 | /* SuS v2 requires we report a read only fs too */ |
256984a8 | 425 | if (res || !(mode & S_IWOTH) || special_file(inode->i_mode)) |
6902d925 | 426 | goto out_path_release; |
2f676cbc DH |
427 | /* |
428 | * This is a rare case where using __mnt_is_readonly() | |
429 | * is OK without a mnt_want/drop_write() pair. Since | |
430 | * no actual write to the fs is performed here, we do | |
431 | * not need to telegraph to that to anyone. | |
432 | * | |
433 | * By doing this, we accept that this access is | |
434 | * inherently racy and know that the fs may change | |
435 | * state before we even see this result. | |
436 | */ | |
2d8f3038 | 437 | if (__mnt_is_readonly(path.mnt)) |
6902d925 | 438 | res = -EROFS; |
1da177e4 | 439 | |
6902d925 | 440 | out_path_release: |
2d8f3038 | 441 | path_put(&path); |
87fa5595 JL |
442 | if (retry_estale(res, lookup_flags)) { |
443 | lookup_flags |= LOOKUP_REVAL; | |
444 | goto retry; | |
445 | } | |
6902d925 | 446 | out: |
d84f4f99 DH |
447 | revert_creds(old_cred); |
448 | put_cred(override_cred); | |
1da177e4 LT |
449 | return res; |
450 | } | |
451 | ||
ca013e94 | 452 | SYSCALL_DEFINE2(access, const char __user *, filename, int, mode) |
5590ff0d UD |
453 | { |
454 | return sys_faccessat(AT_FDCWD, filename, mode); | |
455 | } | |
456 | ||
3cdad428 | 457 | SYSCALL_DEFINE1(chdir, const char __user *, filename) |
1da177e4 | 458 | { |
2d8f3038 | 459 | struct path path; |
1da177e4 | 460 | int error; |
0291c0a5 JL |
461 | unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY; |
462 | retry: | |
463 | error = user_path_at(AT_FDCWD, filename, lookup_flags, &path); | |
1da177e4 LT |
464 | if (error) |
465 | goto out; | |
466 | ||
9cfcac81 | 467 | error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR); |
1da177e4 LT |
468 | if (error) |
469 | goto dput_and_out; | |
470 | ||
2d8f3038 | 471 | set_fs_pwd(current->fs, &path); |
1da177e4 LT |
472 | |
473 | dput_and_out: | |
2d8f3038 | 474 | path_put(&path); |
0291c0a5 JL |
475 | if (retry_estale(error, lookup_flags)) { |
476 | lookup_flags |= LOOKUP_REVAL; | |
477 | goto retry; | |
478 | } | |
1da177e4 LT |
479 | out: |
480 | return error; | |
481 | } | |
482 | ||
3cdad428 | 483 | SYSCALL_DEFINE1(fchdir, unsigned int, fd) |
1da177e4 | 484 | { |
2903ff01 | 485 | struct fd f = fdget_raw(fd); |
159b0956 | 486 | int error; |
1da177e4 LT |
487 | |
488 | error = -EBADF; | |
2903ff01 | 489 | if (!f.file) |
1da177e4 LT |
490 | goto out; |
491 | ||
1da177e4 | 492 | error = -ENOTDIR; |
159b0956 | 493 | if (!d_can_lookup(f.file->f_path.dentry)) |
1da177e4 LT |
494 | goto out_putf; |
495 | ||
159b0956 | 496 | error = inode_permission(file_inode(f.file), MAY_EXEC | MAY_CHDIR); |
1da177e4 | 497 | if (!error) |
2903ff01 | 498 | set_fs_pwd(current->fs, &f.file->f_path); |
1da177e4 | 499 | out_putf: |
2903ff01 | 500 | fdput(f); |
1da177e4 LT |
501 | out: |
502 | return error; | |
503 | } | |
504 | ||
3480b257 | 505 | SYSCALL_DEFINE1(chroot, const char __user *, filename) |
1da177e4 | 506 | { |
2d8f3038 | 507 | struct path path; |
1da177e4 | 508 | int error; |
2771261e JL |
509 | unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY; |
510 | retry: | |
511 | error = user_path_at(AT_FDCWD, filename, lookup_flags, &path); | |
1da177e4 LT |
512 | if (error) |
513 | goto out; | |
514 | ||
9cfcac81 | 515 | error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR); |
1da177e4 LT |
516 | if (error) |
517 | goto dput_and_out; | |
518 | ||
519 | error = -EPERM; | |
c7b96acf | 520 | if (!ns_capable(current_user_ns(), CAP_SYS_CHROOT)) |
1da177e4 | 521 | goto dput_and_out; |
8b8efb44 TH |
522 | error = security_path_chroot(&path); |
523 | if (error) | |
524 | goto dput_and_out; | |
1da177e4 | 525 | |
2d8f3038 | 526 | set_fs_root(current->fs, &path); |
1da177e4 LT |
527 | error = 0; |
528 | dput_and_out: | |
2d8f3038 | 529 | path_put(&path); |
2771261e JL |
530 | if (retry_estale(error, lookup_flags)) { |
531 | lookup_flags |= LOOKUP_REVAL; | |
532 | goto retry; | |
533 | } | |
1da177e4 LT |
534 | out: |
535 | return error; | |
536 | } | |
537 | ||
be01f9f2 | 538 | static int chmod_common(const struct path *path, umode_t mode) |
1da177e4 | 539 | { |
e57712eb | 540 | struct inode *inode = path->dentry->d_inode; |
27ac0ffe | 541 | struct inode *delegated_inode = NULL; |
1da177e4 | 542 | struct iattr newattrs; |
e57712eb | 543 | int error; |
1da177e4 | 544 | |
e57712eb AV |
545 | error = mnt_want_write(path->mnt); |
546 | if (error) | |
547 | return error; | |
27ac0ffe | 548 | retry_deleg: |
5955102c | 549 | inode_lock(inode); |
cdcf116d | 550 | error = security_path_chmod(path, mode); |
e57712eb | 551 | if (error) |
fe542cf5 | 552 | goto out_unlock; |
1da177e4 LT |
553 | newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO); |
554 | newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; | |
27ac0ffe | 555 | error = notify_change(path->dentry, &newattrs, &delegated_inode); |
fe542cf5 | 556 | out_unlock: |
5955102c | 557 | inode_unlock(inode); |
27ac0ffe BF |
558 | if (delegated_inode) { |
559 | error = break_deleg_wait(&delegated_inode); | |
560 | if (!error) | |
561 | goto retry_deleg; | |
562 | } | |
e57712eb AV |
563 | mnt_drop_write(path->mnt); |
564 | return error; | |
565 | } | |
566 | ||
49f0a076 | 567 | SYSCALL_DEFINE2(fchmod, unsigned int, fd, umode_t, mode) |
e57712eb | 568 | { |
173c8401 | 569 | struct fd f = fdget(fd); |
e57712eb AV |
570 | int err = -EBADF; |
571 | ||
173c8401 | 572 | if (f.file) { |
9f45f5bf | 573 | audit_file(f.file); |
173c8401 AV |
574 | err = chmod_common(&f.file->f_path, mode); |
575 | fdput(f); | |
e57712eb | 576 | } |
1da177e4 LT |
577 | return err; |
578 | } | |
579 | ||
49f0a076 | 580 | SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, umode_t, mode) |
1da177e4 | 581 | { |
2d8f3038 | 582 | struct path path; |
1da177e4 | 583 | int error; |
14ff690c JL |
584 | unsigned int lookup_flags = LOOKUP_FOLLOW; |
585 | retry: | |
586 | error = user_path_at(dfd, filename, lookup_flags, &path); | |
e57712eb AV |
587 | if (!error) { |
588 | error = chmod_common(&path, mode); | |
589 | path_put(&path); | |
14ff690c JL |
590 | if (retry_estale(error, lookup_flags)) { |
591 | lookup_flags |= LOOKUP_REVAL; | |
592 | goto retry; | |
593 | } | |
e57712eb | 594 | } |
1da177e4 LT |
595 | return error; |
596 | } | |
597 | ||
49f0a076 | 598 | SYSCALL_DEFINE2(chmod, const char __user *, filename, umode_t, mode) |
5590ff0d UD |
599 | { |
600 | return sys_fchmodat(AT_FDCWD, filename, mode); | |
601 | } | |
602 | ||
7fd25dac | 603 | static int chown_common(const struct path *path, uid_t user, gid_t group) |
1da177e4 | 604 | { |
fe542cf5 | 605 | struct inode *inode = path->dentry->d_inode; |
27ac0ffe | 606 | struct inode *delegated_inode = NULL; |
1da177e4 LT |
607 | int error; |
608 | struct iattr newattrs; | |
52137abe EB |
609 | kuid_t uid; |
610 | kgid_t gid; | |
611 | ||
612 | uid = make_kuid(current_user_ns(), user); | |
613 | gid = make_kgid(current_user_ns(), group); | |
1da177e4 | 614 | |
c1b8940b | 615 | retry_deleg: |
1da177e4 LT |
616 | newattrs.ia_valid = ATTR_CTIME; |
617 | if (user != (uid_t) -1) { | |
52137abe EB |
618 | if (!uid_valid(uid)) |
619 | return -EINVAL; | |
1da177e4 | 620 | newattrs.ia_valid |= ATTR_UID; |
52137abe | 621 | newattrs.ia_uid = uid; |
1da177e4 LT |
622 | } |
623 | if (group != (gid_t) -1) { | |
52137abe EB |
624 | if (!gid_valid(gid)) |
625 | return -EINVAL; | |
1da177e4 | 626 | newattrs.ia_valid |= ATTR_GID; |
52137abe | 627 | newattrs.ia_gid = gid; |
1da177e4 LT |
628 | } |
629 | if (!S_ISDIR(inode->i_mode)) | |
b5376771 SH |
630 | newattrs.ia_valid |= |
631 | ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; | |
5955102c | 632 | inode_lock(inode); |
d2b31ca6 | 633 | error = security_path_chown(path, uid, gid); |
fe542cf5 | 634 | if (!error) |
27ac0ffe | 635 | error = notify_change(path->dentry, &newattrs, &delegated_inode); |
5955102c | 636 | inode_unlock(inode); |
27ac0ffe BF |
637 | if (delegated_inode) { |
638 | error = break_deleg_wait(&delegated_inode); | |
639 | if (!error) | |
640 | goto retry_deleg; | |
641 | } | |
1da177e4 LT |
642 | return error; |
643 | } | |
644 | ||
6559eed8 HC |
645 | SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user, |
646 | gid_t, group, int, flag) | |
5590ff0d | 647 | { |
2d8f3038 | 648 | struct path path; |
5590ff0d | 649 | int error = -EINVAL; |
65cfc672 | 650 | int lookup_flags; |
5590ff0d | 651 | |
65cfc672 | 652 | if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0) |
5590ff0d UD |
653 | goto out; |
654 | ||
65cfc672 AV |
655 | lookup_flags = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW; |
656 | if (flag & AT_EMPTY_PATH) | |
657 | lookup_flags |= LOOKUP_EMPTY; | |
99a5df37 | 658 | retry: |
65cfc672 | 659 | error = user_path_at(dfd, filename, lookup_flags, &path); |
6902d925 DH |
660 | if (error) |
661 | goto out; | |
2d8f3038 | 662 | error = mnt_want_write(path.mnt); |
2af482a7 DH |
663 | if (error) |
664 | goto out_release; | |
fe542cf5 | 665 | error = chown_common(&path, user, group); |
2d8f3038 | 666 | mnt_drop_write(path.mnt); |
2af482a7 | 667 | out_release: |
2d8f3038 | 668 | path_put(&path); |
99a5df37 JL |
669 | if (retry_estale(error, lookup_flags)) { |
670 | lookup_flags |= LOOKUP_REVAL; | |
671 | goto retry; | |
672 | } | |
5590ff0d UD |
673 | out: |
674 | return error; | |
675 | } | |
676 | ||
55e4def0 | 677 | SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group) |
1da177e4 | 678 | { |
55e4def0 DH |
679 | return sys_fchownat(AT_FDCWD, filename, user, group, 0); |
680 | } | |
1da177e4 | 681 | |
55e4def0 DH |
682 | SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group) |
683 | { | |
684 | return sys_fchownat(AT_FDCWD, filename, user, group, | |
685 | AT_SYMLINK_NOFOLLOW); | |
1da177e4 LT |
686 | } |
687 | ||
ca013e94 | 688 | SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group) |
1da177e4 | 689 | { |
2903ff01 | 690 | struct fd f = fdget(fd); |
1da177e4 LT |
691 | int error = -EBADF; |
692 | ||
2903ff01 | 693 | if (!f.file) |
6902d925 DH |
694 | goto out; |
695 | ||
7c6893e3 | 696 | error = mnt_want_write_file_path(f.file); |
2af482a7 DH |
697 | if (error) |
698 | goto out_fput; | |
9f45f5bf | 699 | audit_file(f.file); |
2903ff01 | 700 | error = chown_common(&f.file->f_path, user, group); |
7c6893e3 | 701 | mnt_drop_write_file_path(f.file); |
2af482a7 | 702 | out_fput: |
2903ff01 | 703 | fdput(f); |
6902d925 | 704 | out: |
1da177e4 LT |
705 | return error; |
706 | } | |
707 | ||
90ad1a8e MS |
708 | int open_check_o_direct(struct file *f) |
709 | { | |
710 | /* NB: we're sure to have correct a_ops only after f_op->open */ | |
711 | if (f->f_flags & O_DIRECT) { | |
e748dcd0 | 712 | if (!f->f_mapping->a_ops || !f->f_mapping->a_ops->direct_IO) |
90ad1a8e | 713 | return -EINVAL; |
90ad1a8e MS |
714 | } |
715 | return 0; | |
716 | } | |
c088e31d | 717 | EXPORT_SYMBOL_GPL(open_check_o_direct); |
90ad1a8e | 718 | |
02e5180d | 719 | static int do_dentry_open(struct file *f, |
4bacc9c9 | 720 | struct inode *inode, |
96b7e579 AV |
721 | int (*open)(struct inode *, struct file *), |
722 | const struct cred *cred) | |
1da177e4 | 723 | { |
1abf0c71 | 724 | static const struct file_operations empty_fops = {}; |
1da177e4 LT |
725 | int error; |
726 | ||
5300990c | 727 | f->f_mode = OPEN_FMODE(f->f_flags) | FMODE_LSEEK | |
a1a5b3d9 | 728 | FMODE_PREAD | FMODE_PWRITE; |
1abf0c71 | 729 | |
b5bcdda3 | 730 | path_get(&f->f_path); |
4bacc9c9 | 731 | f->f_inode = inode; |
1da177e4 | 732 | f->f_mapping = inode->i_mapping; |
1da177e4 | 733 | |
5660e13d JL |
734 | /* Ensure that we skip any errors that predate opening of the file */ |
735 | f->f_wb_err = filemap_sample_wb_err(f->f_mapping); | |
736 | ||
3f4d5a00 AV |
737 | if (unlikely(f->f_flags & O_PATH)) { |
738 | f->f_mode = FMODE_PATH; | |
1abf0c71 | 739 | f->f_op = &empty_fops; |
96b7e579 | 740 | return 0; |
1abf0c71 AV |
741 | } |
742 | ||
8cb2f70c TH |
743 | /* Any file opened for execve()/uselib() has to be a regular file. */ |
744 | if (unlikely(f->f_flags & FMODE_EXEC && !S_ISREG(inode->i_mode))) { | |
745 | error = -EACCES; | |
746 | goto cleanup_file; | |
747 | } | |
748 | ||
dd20908a | 749 | if (f->f_mode & FMODE_WRITE && !special_file(inode->i_mode)) { |
0ccb2863 | 750 | error = get_write_access(inode); |
3f4d5a00 | 751 | if (unlikely(error)) |
1da177e4 | 752 | goto cleanup_file; |
0ccb2863 | 753 | error = __mnt_want_write(f->f_path.mnt); |
3f4d5a00 | 754 | if (unlikely(error)) { |
0ccb2863 AV |
755 | put_write_access(inode); |
756 | goto cleanup_file; | |
757 | } | |
83f936c7 | 758 | f->f_mode |= FMODE_WRITER; |
1da177e4 LT |
759 | } |
760 | ||
9c225f26 | 761 | /* POSIX.1-2008/SUSv4 Section XSI 2.9.7 */ |
63b6df14 | 762 | if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)) |
9c225f26 LT |
763 | f->f_mode |= FMODE_ATOMIC_POS; |
764 | ||
1abf0c71 | 765 | f->f_op = fops_get(inode->i_fop); |
72c2d531 AV |
766 | if (unlikely(WARN_ON(!f->f_op))) { |
767 | error = -ENODEV; | |
768 | goto cleanup_all; | |
769 | } | |
1abf0c71 | 770 | |
83d49856 | 771 | error = security_file_open(f, cred); |
788e7dd4 YN |
772 | if (error) |
773 | goto cleanup_all; | |
774 | ||
c568d683 | 775 | error = break_lease(locks_inode(f), f->f_flags); |
f3c7691e BF |
776 | if (error) |
777 | goto cleanup_all; | |
778 | ||
72c2d531 | 779 | if (!open) |
834f2a4a TM |
780 | open = f->f_op->open; |
781 | if (open) { | |
782 | error = open(inode, f); | |
1da177e4 LT |
783 | if (error) |
784 | goto cleanup_all; | |
785 | } | |
890275b5 MZ |
786 | if ((f->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) |
787 | i_readcount_inc(inode); | |
293bc982 | 788 | if ((f->f_mode & FMODE_READ) && |
84363182 | 789 | likely(f->f_op->read || f->f_op->read_iter)) |
7f7f25e8 | 790 | f->f_mode |= FMODE_CAN_READ; |
293bc982 | 791 | if ((f->f_mode & FMODE_WRITE) && |
84363182 | 792 | likely(f->f_op->write || f->f_op->write_iter)) |
7f7f25e8 | 793 | f->f_mode |= FMODE_CAN_WRITE; |
834f2a4a | 794 | |
c75b1d94 | 795 | f->f_write_hint = WRITE_LIFE_NOT_SET; |
1da177e4 LT |
796 | f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC); |
797 | ||
798 | file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping); | |
799 | ||
96b7e579 | 800 | return 0; |
1da177e4 LT |
801 | |
802 | cleanup_all: | |
803 | fops_put(f->f_op); | |
83f936c7 | 804 | if (f->f_mode & FMODE_WRITER) { |
1da177e4 | 805 | put_write_access(inode); |
83f936c7 | 806 | __mnt_drop_write(f->f_path.mnt); |
4a3fd211 | 807 | } |
1da177e4 | 808 | cleanup_file: |
02e5180d AV |
809 | path_put(&f->f_path); |
810 | f->f_path.mnt = NULL; | |
811 | f->f_path.dentry = NULL; | |
dd37978c | 812 | f->f_inode = NULL; |
96b7e579 | 813 | return error; |
1da177e4 LT |
814 | } |
815 | ||
d18e9008 MS |
816 | /** |
817 | * finish_open - finish opening a file | |
0854d450 | 818 | * @file: file pointer |
d18e9008 MS |
819 | * @dentry: pointer to dentry |
820 | * @open: open callback | |
0854d450 | 821 | * @opened: state of open |
d18e9008 MS |
822 | * |
823 | * This can be used to finish opening a file passed to i_op->atomic_open(). | |
824 | * | |
825 | * If the open callback is set to NULL, then the standard f_op->open() | |
826 | * filesystem callback is substituted. | |
0854d450 MS |
827 | * |
828 | * NB: the dentry reference is _not_ consumed. If, for example, the dentry is | |
829 | * the return value of d_splice_alias(), then the caller needs to perform dput() | |
830 | * on it after finish_open(). | |
831 | * | |
832 | * On successful return @file is a fully instantiated open file. After this, if | |
833 | * an error occurs in ->atomic_open(), it needs to clean up with fput(). | |
834 | * | |
835 | * Returns zero on success or -errno if the open failed. | |
d18e9008 | 836 | */ |
30d90494 AV |
837 | int finish_open(struct file *file, struct dentry *dentry, |
838 | int (*open)(struct inode *, struct file *), | |
839 | int *opened) | |
d18e9008 | 840 | { |
96b7e579 | 841 | int error; |
3d8a00d2 | 842 | BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */ |
d18e9008 | 843 | |
b5bcdda3 | 844 | file->f_path.dentry = dentry; |
4bacc9c9 DH |
845 | error = do_dentry_open(file, d_backing_inode(dentry), open, |
846 | current_cred()); | |
96b7e579 | 847 | if (!error) |
47237687 | 848 | *opened |= FILE_OPENED; |
d18e9008 | 849 | |
96b7e579 | 850 | return error; |
d18e9008 MS |
851 | } |
852 | EXPORT_SYMBOL(finish_open); | |
853 | ||
854 | /** | |
855 | * finish_no_open - finish ->atomic_open() without opening the file | |
856 | * | |
0854d450 | 857 | * @file: file pointer |
d18e9008 MS |
858 | * @dentry: dentry or NULL (as returned from ->lookup()) |
859 | * | |
860 | * This can be used to set the result of a successful lookup in ->atomic_open(). | |
0854d450 MS |
861 | * |
862 | * NB: unlike finish_open() this function does consume the dentry reference and | |
863 | * the caller need not dput() it. | |
864 | * | |
865 | * Returns "1" which must be the return value of ->atomic_open() after having | |
866 | * called this function. | |
d18e9008 | 867 | */ |
e45198a6 | 868 | int finish_no_open(struct file *file, struct dentry *dentry) |
d18e9008 | 869 | { |
30d90494 | 870 | file->f_path.dentry = dentry; |
e45198a6 | 871 | return 1; |
d18e9008 MS |
872 | } |
873 | EXPORT_SYMBOL(finish_no_open); | |
874 | ||
9bf39ab2 MS |
875 | char *file_path(struct file *filp, char *buf, int buflen) |
876 | { | |
877 | return d_path(&filp->f_path, buf, buflen); | |
878 | } | |
879 | EXPORT_SYMBOL(file_path); | |
880 | ||
4bacc9c9 DH |
881 | /** |
882 | * vfs_open - open the file at the given path | |
883 | * @path: path to open | |
884 | * @file: newly allocated file with f_flag initialized | |
885 | * @cred: credentials to use | |
886 | */ | |
887 | int vfs_open(const struct path *path, struct file *file, | |
888 | const struct cred *cred) | |
889 | { | |
495e6429 | 890 | struct dentry *dentry = d_real(path->dentry, NULL, file->f_flags, 0); |
4bacc9c9 | 891 | |
2d902671 MS |
892 | if (IS_ERR(dentry)) |
893 | return PTR_ERR(dentry); | |
4bacc9c9 | 894 | |
54d5ca87 | 895 | file->f_path = *path; |
2d902671 | 896 | return do_dentry_open(file, d_backing_inode(dentry), NULL, cred); |
4bacc9c9 DH |
897 | } |
898 | ||
765927b2 | 899 | struct file *dentry_open(const struct path *path, int flags, |
745ca247 | 900 | const struct cred *cred) |
a1a5b3d9 PS |
901 | { |
902 | int error; | |
903 | struct file *f; | |
904 | ||
e0e81739 DH |
905 | validate_creds(cred); |
906 | ||
c212f9aa | 907 | /* We must always pass in a valid mount pointer. */ |
765927b2 | 908 | BUG_ON(!path->mnt); |
322ee5b3 | 909 | |
a1a5b3d9 | 910 | f = get_empty_filp(); |
1afc99be AV |
911 | if (!IS_ERR(f)) { |
912 | f->f_flags = flags; | |
4aa7c634 | 913 | error = vfs_open(path, f, cred); |
1afc99be AV |
914 | if (!error) { |
915 | /* from now on we need fput() to dispose of f */ | |
916 | error = open_check_o_direct(f); | |
917 | if (error) { | |
918 | fput(f); | |
919 | f = ERR_PTR(error); | |
920 | } | |
921 | } else { | |
922 | put_filp(f); | |
2a027e7a AV |
923 | f = ERR_PTR(error); |
924 | } | |
2a027e7a AV |
925 | } |
926 | return f; | |
a1a5b3d9 | 927 | } |
1da177e4 LT |
928 | EXPORT_SYMBOL(dentry_open); |
929 | ||
a218d0fd | 930 | static inline int build_open_flags(int flags, umode_t mode, struct open_flags *op) |
47c805dc AV |
931 | { |
932 | int lookup_flags = 0; | |
62fb4a15 | 933 | int acc_mode = ACC_MODE(flags); |
47c805dc | 934 | |
629e014b CH |
935 | /* |
936 | * Clear out all open flags we don't know about so that we don't report | |
937 | * them in fcntl(F_GETFD) or similar interfaces. | |
938 | */ | |
939 | flags &= VALID_OPEN_FLAGS; | |
940 | ||
e305f48b | 941 | if (flags & (O_CREAT | __O_TMPFILE)) |
e68726ff MS |
942 | op->mode = (mode & S_IALLUGO) | S_IFREG; |
943 | else | |
944 | op->mode = 0; | |
47c805dc AV |
945 | |
946 | /* Must never be set by userspace */ | |
c6f3d811 | 947 | flags &= ~FMODE_NONOTIFY & ~O_CLOEXEC; |
47c805dc AV |
948 | |
949 | /* | |
950 | * O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only | |
951 | * check for O_DSYNC if the need any syncing at all we enforce it's | |
952 | * always set instead of having to deal with possibly weird behaviour | |
953 | * for malicious applications setting only __O_SYNC. | |
954 | */ | |
955 | if (flags & __O_SYNC) | |
956 | flags |= O_DSYNC; | |
957 | ||
bb458c64 AV |
958 | if (flags & __O_TMPFILE) { |
959 | if ((flags & O_TMPFILE_MASK) != O_TMPFILE) | |
60545d0d | 960 | return -EINVAL; |
ba57ea64 AV |
961 | if (!(acc_mode & MAY_WRITE)) |
962 | return -EINVAL; | |
60545d0d AV |
963 | } else if (flags & O_PATH) { |
964 | /* | |
965 | * If we have O_PATH in the open flag. Then we | |
966 | * cannot have anything other than the below set of flags | |
967 | */ | |
1abf0c71 AV |
968 | flags &= O_DIRECTORY | O_NOFOLLOW | O_PATH; |
969 | acc_mode = 0; | |
1abf0c71 | 970 | } |
47c805dc | 971 | |
1abf0c71 | 972 | op->open_flag = flags; |
47c805dc AV |
973 | |
974 | /* O_TRUNC implies we need access checks for write permissions */ | |
975 | if (flags & O_TRUNC) | |
976 | acc_mode |= MAY_WRITE; | |
977 | ||
978 | /* Allow the LSM permission hook to distinguish append | |
979 | access from general write access. */ | |
980 | if (flags & O_APPEND) | |
981 | acc_mode |= MAY_APPEND; | |
982 | ||
983 | op->acc_mode = acc_mode; | |
984 | ||
1abf0c71 AV |
985 | op->intent = flags & O_PATH ? 0 : LOOKUP_OPEN; |
986 | ||
47c805dc AV |
987 | if (flags & O_CREAT) { |
988 | op->intent |= LOOKUP_CREATE; | |
989 | if (flags & O_EXCL) | |
990 | op->intent |= LOOKUP_EXCL; | |
991 | } | |
992 | ||
993 | if (flags & O_DIRECTORY) | |
994 | lookup_flags |= LOOKUP_DIRECTORY; | |
995 | if (!(flags & O_NOFOLLOW)) | |
996 | lookup_flags |= LOOKUP_FOLLOW; | |
f9652e10 AV |
997 | op->lookup_flags = lookup_flags; |
998 | return 0; | |
47c805dc AV |
999 | } |
1000 | ||
669abf4e JL |
1001 | /** |
1002 | * file_open_name - open file and return file pointer | |
1003 | * | |
1004 | * @name: struct filename containing path to open | |
1005 | * @flags: open flags as per the open(2) second argument | |
1006 | * @mode: mode for the new file if O_CREAT is set, else ignored | |
1007 | * | |
1008 | * This is the helper to open a file from kernelspace if you really | |
1009 | * have to. But in generally you should not do this, so please move | |
1010 | * along, nothing to see here.. | |
1011 | */ | |
1012 | struct file *file_open_name(struct filename *name, int flags, umode_t mode) | |
1013 | { | |
1014 | struct open_flags op; | |
f9652e10 AV |
1015 | int err = build_open_flags(flags, mode, &op); |
1016 | return err ? ERR_PTR(err) : do_filp_open(AT_FDCWD, name, &op); | |
669abf4e JL |
1017 | } |
1018 | ||
47c805dc AV |
1019 | /** |
1020 | * filp_open - open file and return file pointer | |
1021 | * | |
1022 | * @filename: path to open | |
1023 | * @flags: open flags as per the open(2) second argument | |
1024 | * @mode: mode for the new file if O_CREAT is set, else ignored | |
1025 | * | |
1026 | * This is the helper to open a file from kernelspace if you really | |
1027 | * have to. But in generally you should not do this, so please move | |
1028 | * along, nothing to see here.. | |
1029 | */ | |
a218d0fd | 1030 | struct file *filp_open(const char *filename, int flags, umode_t mode) |
47c805dc | 1031 | { |
51689104 PM |
1032 | struct filename *name = getname_kernel(filename); |
1033 | struct file *file = ERR_CAST(name); | |
1034 | ||
1035 | if (!IS_ERR(name)) { | |
1036 | file = file_open_name(name, flags, mode); | |
1037 | putname(name); | |
1038 | } | |
1039 | return file; | |
47c805dc AV |
1040 | } |
1041 | EXPORT_SYMBOL(filp_open); | |
1042 | ||
73d049a4 | 1043 | struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt, |
378c6520 | 1044 | const char *filename, int flags, umode_t mode) |
73d049a4 AV |
1045 | { |
1046 | struct open_flags op; | |
378c6520 | 1047 | int err = build_open_flags(flags, mode, &op); |
f9652e10 AV |
1048 | if (err) |
1049 | return ERR_PTR(err); | |
f9652e10 | 1050 | return do_file_open_root(dentry, mnt, filename, &op); |
73d049a4 AV |
1051 | } |
1052 | EXPORT_SYMBOL(file_open_root); | |
1053 | ||
9a08c352 JB |
1054 | struct file *filp_clone_open(struct file *oldfile) |
1055 | { | |
1056 | struct file *file; | |
1057 | int retval; | |
1058 | ||
1059 | file = get_empty_filp(); | |
1060 | if (IS_ERR(file)) | |
1061 | return file; | |
1062 | ||
1063 | file->f_flags = oldfile->f_flags; | |
1064 | retval = vfs_open(&oldfile->f_path, file, oldfile->f_cred); | |
1065 | if (retval) { | |
1066 | put_filp(file); | |
1067 | return ERR_PTR(retval); | |
1068 | } | |
1069 | ||
1070 | return file; | |
1071 | } | |
1072 | EXPORT_SYMBOL(filp_clone_open); | |
1073 | ||
a218d0fd | 1074 | long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode) |
1da177e4 | 1075 | { |
47c805dc | 1076 | struct open_flags op; |
f9652e10 AV |
1077 | int fd = build_open_flags(flags, mode, &op); |
1078 | struct filename *tmp; | |
1079 | ||
1080 | if (fd) | |
1081 | return fd; | |
1082 | ||
1083 | tmp = getname(filename); | |
1084 | if (IS_ERR(tmp)) | |
1085 | return PTR_ERR(tmp); | |
1086 | ||
1087 | fd = get_unused_fd_flags(flags); | |
1088 | if (fd >= 0) { | |
1089 | struct file *f = do_filp_open(dfd, tmp, &op); | |
1090 | if (IS_ERR(f)) { | |
1091 | put_unused_fd(fd); | |
1092 | fd = PTR_ERR(f); | |
1093 | } else { | |
1094 | fsnotify_open(f); | |
1095 | fd_install(fd, f); | |
7744c33f | 1096 | trace_do_sys_open(tmp->name, flags, mode); |
1da177e4 | 1097 | } |
1da177e4 | 1098 | } |
f9652e10 | 1099 | putname(tmp); |
1da177e4 | 1100 | return fd; |
1da177e4 | 1101 | } |
e922efc3 | 1102 | |
a218d0fd | 1103 | SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode) |
e922efc3 MS |
1104 | { |
1105 | if (force_o_largefile()) | |
1106 | flags |= O_LARGEFILE; | |
1107 | ||
2cf09666 | 1108 | return do_sys_open(AT_FDCWD, filename, flags, mode); |
e922efc3 | 1109 | } |
1da177e4 | 1110 | |
6559eed8 | 1111 | SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags, |
a218d0fd | 1112 | umode_t, mode) |
5590ff0d UD |
1113 | { |
1114 | if (force_o_largefile()) | |
1115 | flags |= O_LARGEFILE; | |
1116 | ||
2cf09666 | 1117 | return do_sys_open(dfd, filename, flags, mode); |
5590ff0d | 1118 | } |
5590ff0d | 1119 | |
e35d49f6 AV |
1120 | #ifdef CONFIG_COMPAT |
1121 | /* | |
1122 | * Exactly like sys_open(), except that it doesn't set the | |
1123 | * O_LARGEFILE flag. | |
1124 | */ | |
1125 | COMPAT_SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode) | |
1126 | { | |
1127 | return do_sys_open(AT_FDCWD, filename, flags, mode); | |
1128 | } | |
1129 | ||
1130 | /* | |
1131 | * Exactly like sys_openat(), except that it doesn't set the | |
1132 | * O_LARGEFILE flag. | |
1133 | */ | |
1134 | COMPAT_SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags, umode_t, mode) | |
1135 | { | |
1136 | return do_sys_open(dfd, filename, flags, mode); | |
1137 | } | |
1138 | #endif | |
1139 | ||
1da177e4 LT |
1140 | #ifndef __alpha__ |
1141 | ||
1142 | /* | |
1143 | * For backward compatibility? Maybe this should be moved | |
1144 | * into arch/i386 instead? | |
1145 | */ | |
a218d0fd | 1146 | SYSCALL_DEFINE2(creat, const char __user *, pathname, umode_t, mode) |
1da177e4 LT |
1147 | { |
1148 | return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode); | |
1149 | } | |
1150 | ||
1151 | #endif | |
1152 | ||
1153 | /* | |
1154 | * "id" is the POSIX thread ID. We use the | |
1155 | * files pointer for this.. | |
1156 | */ | |
1157 | int filp_close(struct file *filp, fl_owner_t id) | |
1158 | { | |
45778ca8 | 1159 | int retval = 0; |
1da177e4 LT |
1160 | |
1161 | if (!file_count(filp)) { | |
1162 | printk(KERN_ERR "VFS: Close: file count is 0\n"); | |
45778ca8 | 1163 | return 0; |
1da177e4 LT |
1164 | } |
1165 | ||
72c2d531 | 1166 | if (filp->f_op->flush) |
75e1fcc0 | 1167 | retval = filp->f_op->flush(filp, id); |
1da177e4 | 1168 | |
1abf0c71 AV |
1169 | if (likely(!(filp->f_mode & FMODE_PATH))) { |
1170 | dnotify_flush(filp, id); | |
1171 | locks_remove_posix(filp, id); | |
1172 | } | |
1da177e4 LT |
1173 | fput(filp); |
1174 | return retval; | |
1175 | } | |
1176 | ||
1177 | EXPORT_SYMBOL(filp_close); | |
1178 | ||
1179 | /* | |
1180 | * Careful here! We test whether the file pointer is NULL before | |
1181 | * releasing the fd. This ensures that one clone task can't release | |
1182 | * an fd while another clone is opening it. | |
1183 | */ | |
ca013e94 | 1184 | SYSCALL_DEFINE1(close, unsigned int, fd) |
1da177e4 | 1185 | { |
483ce1d4 | 1186 | int retval = __close_fd(current->files, fd); |
ee731f4f EP |
1187 | |
1188 | /* can't restart close syscall because file table entry was cleared */ | |
1189 | if (unlikely(retval == -ERESTARTSYS || | |
1190 | retval == -ERESTARTNOINTR || | |
1191 | retval == -ERESTARTNOHAND || | |
1192 | retval == -ERESTART_RESTARTBLOCK)) | |
1193 | retval = -EINTR; | |
1194 | ||
1195 | return retval; | |
1da177e4 | 1196 | } |
1da177e4 LT |
1197 | EXPORT_SYMBOL(sys_close); |
1198 | ||
1199 | /* | |
1200 | * This routine simulates a hangup on the tty, to arrange that users | |
1201 | * are given clean terminals at login time. | |
1202 | */ | |
ca013e94 | 1203 | SYSCALL_DEFINE0(vhangup) |
1da177e4 LT |
1204 | { |
1205 | if (capable(CAP_SYS_TTY_CONFIG)) { | |
2cb5998b | 1206 | tty_vhangup_self(); |
1da177e4 LT |
1207 | return 0; |
1208 | } | |
1209 | return -EPERM; | |
1210 | } | |
1211 | ||
1212 | /* | |
1213 | * Called when an inode is about to be open. | |
1214 | * We use this to disallow opening large files on 32bit systems if | |
1215 | * the caller didn't specify O_LARGEFILE. On 64bit systems we force | |
1216 | * on this flag in sys_open. | |
1217 | */ | |
1218 | int generic_file_open(struct inode * inode, struct file * filp) | |
1219 | { | |
1220 | if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS) | |
a9c62a18 | 1221 | return -EOVERFLOW; |
1da177e4 LT |
1222 | return 0; |
1223 | } | |
1224 | ||
1225 | EXPORT_SYMBOL(generic_file_open); | |
1226 | ||
1227 | /* | |
1228 | * This is used by subsystems that don't want seekable | |
06b1e104 DT |
1229 | * file descriptors. The function is not supposed to ever fail, the only |
1230 | * reason it returns an 'int' and not 'void' is so that it can be plugged | |
1231 | * directly into file_operations structure. | |
1da177e4 LT |
1232 | */ |
1233 | int nonseekable_open(struct inode *inode, struct file *filp) | |
1234 | { | |
1235 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE); | |
1236 | return 0; | |
1237 | } | |
1238 | ||
1239 | EXPORT_SYMBOL(nonseekable_open); | |
6680c082 KS |
1240 | |
1241 | /* | |
1242 | * stream_open is used by subsystems that want stream-like file descriptors. | |
1243 | * Such file descriptors are not seekable and don't have notion of position | |
1244 | * (file.f_pos is always 0). Contrary to file descriptors of other regular | |
1245 | * files, .read() and .write() can run simultaneously. | |
1246 | * | |
1247 | * stream_open never fails and is marked to return int so that it could be | |
1248 | * directly used as file_operations.open . | |
1249 | */ | |
1250 | int stream_open(struct inode *inode, struct file *filp) | |
1251 | { | |
1252 | filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE | FMODE_ATOMIC_POS); | |
1253 | filp->f_mode |= FMODE_STREAM; | |
1254 | return 0; | |
1255 | } | |
1256 | ||
1257 | EXPORT_SYMBOL(stream_open); |