Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0-only
2 : /*
3 : * linux/fs/open.c
4 : *
5 : * Copyright (C) 1991, 1992 Linus Torvalds
6 : */
7 :
8 : #include <linux/string.h>
9 : #include <linux/mm.h>
10 : #include <linux/file.h>
11 : #include <linux/fdtable.h>
12 : #include <linux/fsnotify.h>
13 : #include <linux/module.h>
14 : #include <linux/tty.h>
15 : #include <linux/namei.h>
16 : #include <linux/backing-dev.h>
17 : #include <linux/capability.h>
18 : #include <linux/securebits.h>
19 : #include <linux/security.h>
20 : #include <linux/mount.h>
21 : #include <linux/fcntl.h>
22 : #include <linux/slab.h>
23 : #include <linux/uaccess.h>
24 : #include <linux/fs.h>
25 : #include <linux/personality.h>
26 : #include <linux/pagemap.h>
27 : #include <linux/syscalls.h>
28 : #include <linux/rcupdate.h>
29 : #include <linux/audit.h>
30 : #include <linux/falloc.h>
31 : #include <linux/fs_struct.h>
32 : #include <linux/ima.h>
33 : #include <linux/dnotify.h>
34 : #include <linux/compat.h>
35 :
36 : #include "internal.h"
37 :
38 61 : int do_truncate(struct user_namespace *mnt_userns, struct dentry *dentry,
39 : loff_t length, unsigned int time_attrs, struct file *filp)
40 : {
41 61 : int ret;
42 61 : struct iattr newattrs;
43 :
44 : /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */
45 61 : if (length < 0)
46 : return -EINVAL;
47 :
48 61 : newattrs.ia_size = length;
49 61 : newattrs.ia_valid = ATTR_SIZE | time_attrs;
50 61 : if (filp) {
51 61 : newattrs.ia_file = filp;
52 61 : newattrs.ia_valid |= ATTR_FILE;
53 : }
54 :
55 : /* Remove suid, sgid, and file capabilities on truncate too */
56 61 : ret = dentry_needs_remove_privs(dentry);
57 61 : if (ret < 0)
58 : return ret;
59 61 : if (ret)
60 0 : newattrs.ia_valid |= ret | ATTR_FORCE;
61 :
62 61 : inode_lock(dentry->d_inode);
63 : /* Note any delegations or leases have already been broken: */
64 61 : ret = notify_change(mnt_userns, dentry, &newattrs, NULL);
65 61 : inode_unlock(dentry->d_inode);
66 61 : return ret;
67 : }
68 :
69 0 : long vfs_truncate(const struct path *path, loff_t length)
70 : {
71 0 : struct user_namespace *mnt_userns;
72 0 : struct inode *inode;
73 0 : long error;
74 :
75 0 : inode = path->dentry->d_inode;
76 :
77 : /* For directories it's -EISDIR, for other non-regulars - -EINVAL */
78 0 : if (S_ISDIR(inode->i_mode))
79 : return -EISDIR;
80 0 : if (!S_ISREG(inode->i_mode))
81 : return -EINVAL;
82 :
83 0 : error = mnt_want_write(path->mnt);
84 0 : if (error)
85 0 : goto out;
86 :
87 0 : mnt_userns = mnt_user_ns(path->mnt);
88 0 : error = inode_permission(mnt_userns, inode, MAY_WRITE);
89 0 : if (error)
90 0 : goto mnt_drop_write_and_out;
91 :
92 0 : error = -EPERM;
93 0 : if (IS_APPEND(inode))
94 0 : goto mnt_drop_write_and_out;
95 :
96 0 : error = get_write_access(inode);
97 0 : if (error)
98 0 : goto mnt_drop_write_and_out;
99 :
100 : /*
101 : * Make sure that there are no leases. get_write_access() protects
102 : * against the truncate racing with a lease-granting setlease().
103 : */
104 0 : error = break_lease(inode, O_WRONLY);
105 0 : if (error)
106 0 : goto put_write_and_out;
107 :
108 0 : error = locks_verify_truncate(inode, NULL, length);
109 0 : if (!error)
110 0 : error = security_path_truncate(path);
111 0 : if (!error)
112 0 : error = do_truncate(mnt_userns, path->dentry, length, 0, NULL);
113 :
114 0 : put_write_and_out:
115 0 : put_write_access(inode);
116 0 : mnt_drop_write_and_out:
117 0 : mnt_drop_write(path->mnt);
118 : out:
119 : return error;
120 : }
121 : EXPORT_SYMBOL_GPL(vfs_truncate);
122 :
123 0 : long do_sys_truncate(const char __user *pathname, loff_t length)
124 : {
125 0 : unsigned int lookup_flags = LOOKUP_FOLLOW;
126 0 : struct path path;
127 0 : int error;
128 :
129 0 : if (length < 0) /* sorry, but loff_t says... */
130 : return -EINVAL;
131 :
132 0 : retry:
133 0 : error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
134 0 : if (!error) {
135 0 : error = vfs_truncate(&path, length);
136 0 : path_put(&path);
137 : }
138 0 : if (retry_estale(error, lookup_flags)) {
139 0 : lookup_flags |= LOOKUP_REVAL;
140 0 : goto retry;
141 : }
142 : return error;
143 : }
144 :
145 0 : SYSCALL_DEFINE2(truncate, const char __user *, path, long, length)
146 : {
147 0 : return do_sys_truncate(path, length);
148 : }
149 :
150 : #ifdef CONFIG_COMPAT
151 0 : COMPAT_SYSCALL_DEFINE2(truncate, const char __user *, path, compat_off_t, length)
152 : {
153 0 : return do_sys_truncate(path, length);
154 : }
155 : #endif
156 :
157 51 : long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
158 : {
159 51 : struct inode *inode;
160 51 : struct dentry *dentry;
161 51 : struct fd f;
162 51 : int error;
163 :
164 51 : error = -EINVAL;
165 51 : if (length < 0)
166 0 : goto out;
167 51 : error = -EBADF;
168 51 : f = fdget(fd);
169 51 : if (!f.file)
170 0 : goto out;
171 :
172 : /* explicitly opened as large or we are on 64-bit box */
173 51 : if (f.file->f_flags & O_LARGEFILE)
174 51 : small = 0;
175 :
176 51 : dentry = f.file->f_path.dentry;
177 51 : inode = dentry->d_inode;
178 51 : error = -EINVAL;
179 51 : if (!S_ISREG(inode->i_mode) || !(f.file->f_mode & FMODE_WRITE))
180 0 : goto out_putf;
181 :
182 51 : error = -EINVAL;
183 : /* Cannot ftruncate over 2^31 bytes without large file support */
184 51 : if (small && length > MAX_NON_LFS)
185 0 : goto out_putf;
186 :
187 51 : error = -EPERM;
188 : /* Check IS_APPEND on real upper inode */
189 51 : if (IS_APPEND(file_inode(f.file)))
190 0 : goto out_putf;
191 51 : sb_start_write(inode->i_sb);
192 51 : error = locks_verify_truncate(inode, f.file, length);
193 51 : if (!error)
194 51 : error = security_path_truncate(&f.file->f_path);
195 51 : if (!error)
196 51 : error = do_truncate(file_mnt_user_ns(f.file), dentry, length,
197 : ATTR_MTIME | ATTR_CTIME, f.file);
198 51 : sb_end_write(inode->i_sb);
199 51 : out_putf:
200 51 : fdput(f);
201 51 : out:
202 51 : return error;
203 : }
204 :
205 102 : SYSCALL_DEFINE2(ftruncate, unsigned int, fd, unsigned long, length)
206 : {
207 51 : return do_sys_ftruncate(fd, length, 1);
208 : }
209 :
210 : #ifdef CONFIG_COMPAT
211 0 : COMPAT_SYSCALL_DEFINE2(ftruncate, unsigned int, fd, compat_ulong_t, length)
212 : {
213 0 : return do_sys_ftruncate(fd, length, 1);
214 : }
215 : #endif
216 :
217 : /* LFS versions of truncate are only needed on 32 bit machines */
218 : #if BITS_PER_LONG == 32
219 : SYSCALL_DEFINE2(truncate64, const char __user *, path, loff_t, length)
220 : {
221 : return do_sys_truncate(path, length);
222 : }
223 :
224 : SYSCALL_DEFINE2(ftruncate64, unsigned int, fd, loff_t, length)
225 : {
226 : return do_sys_ftruncate(fd, length, 0);
227 : }
228 : #endif /* BITS_PER_LONG == 32 */
229 :
230 :
231 2 : int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
232 : {
233 2 : struct inode *inode = file_inode(file);
234 2 : long ret;
235 :
236 2 : if (offset < 0 || len <= 0)
237 : return -EINVAL;
238 :
239 : /* Return error if mode is not supported */
240 2 : if (mode & ~FALLOC_FL_SUPPORTED_MASK)
241 : return -EOPNOTSUPP;
242 :
243 : /* Punch hole and zero range are mutually exclusive */
244 2 : if ((mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) ==
245 : (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE))
246 : return -EOPNOTSUPP;
247 :
248 : /* Punch hole must have keep size set */
249 2 : if ((mode & FALLOC_FL_PUNCH_HOLE) &&
250 : !(mode & FALLOC_FL_KEEP_SIZE))
251 : return -EOPNOTSUPP;
252 :
253 : /* Collapse range should only be used exclusively. */
254 2 : if ((mode & FALLOC_FL_COLLAPSE_RANGE) &&
255 0 : (mode & ~FALLOC_FL_COLLAPSE_RANGE))
256 : return -EINVAL;
257 :
258 : /* Insert range should only be used exclusively. */
259 2 : if ((mode & FALLOC_FL_INSERT_RANGE) &&
260 0 : (mode & ~FALLOC_FL_INSERT_RANGE))
261 : return -EINVAL;
262 :
263 : /* Unshare range should only be used with allocate mode. */
264 2 : if ((mode & FALLOC_FL_UNSHARE_RANGE) &&
265 0 : (mode & ~(FALLOC_FL_UNSHARE_RANGE | FALLOC_FL_KEEP_SIZE)))
266 : return -EINVAL;
267 :
268 2 : if (!(file->f_mode & FMODE_WRITE))
269 : return -EBADF;
270 :
271 : /*
272 : * We can only allow pure fallocate on append only files
273 : */
274 2 : if ((mode & ~FALLOC_FL_KEEP_SIZE) && IS_APPEND(inode))
275 : return -EPERM;
276 :
277 2 : if (IS_IMMUTABLE(inode))
278 : return -EPERM;
279 :
280 : /*
281 : * We cannot allow any fallocate operation on an active swapfile
282 : */
283 2 : if (IS_SWAPFILE(inode))
284 : return -ETXTBSY;
285 :
286 : /*
287 : * Revalidate the write permissions, in case security policy has
288 : * changed since the files were opened.
289 : */
290 2 : ret = security_file_permission(file, MAY_WRITE);
291 2 : if (ret)
292 : return ret;
293 :
294 2 : if (S_ISFIFO(inode->i_mode))
295 : return -ESPIPE;
296 :
297 2 : if (S_ISDIR(inode->i_mode))
298 : return -EISDIR;
299 :
300 2 : if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))
301 : return -ENODEV;
302 :
303 : /* Check for wrap through zero too */
304 2 : if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0))
305 : return -EFBIG;
306 :
307 2 : if (!file->f_op->fallocate)
308 : return -EOPNOTSUPP;
309 :
310 2 : file_start_write(file);
311 2 : ret = file->f_op->fallocate(file, mode, offset, len);
312 :
313 : /*
314 : * Create inotify and fanotify events.
315 : *
316 : * To keep the logic simple always create events if fallocate succeeds.
317 : * This implies that events are even created if the file size remains
318 : * unchanged, e.g. when using flag FALLOC_FL_KEEP_SIZE.
319 : */
320 2 : if (ret == 0)
321 2 : fsnotify_modify(file);
322 :
323 2 : file_end_write(file);
324 2 : return ret;
325 : }
326 : EXPORT_SYMBOL_GPL(vfs_fallocate);
327 :
328 2 : int ksys_fallocate(int fd, int mode, loff_t offset, loff_t len)
329 : {
330 2 : struct fd f = fdget(fd);
331 2 : int error = -EBADF;
332 :
333 2 : if (f.file) {
334 2 : error = vfs_fallocate(f.file, mode, offset, len);
335 2 : fdput(f);
336 : }
337 2 : return error;
338 : }
339 :
340 4 : SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len)
341 : {
342 2 : return ksys_fallocate(fd, mode, offset, len);
343 : }
344 :
345 : /*
346 : * access() needs to use the real uid/gid, not the effective uid/gid.
347 : * We do this by temporarily clearing all FS-related capabilities and
348 : * switching the fsuid/fsgid around to the real ones.
349 : */
350 3381 : static const struct cred *access_override_creds(void)
351 : {
352 3381 : const struct cred *old_cred;
353 3381 : struct cred *override_cred;
354 :
355 3381 : override_cred = prepare_creds();
356 3381 : if (!override_cred)
357 : return NULL;
358 :
359 3381 : override_cred->fsuid = override_cred->uid;
360 3381 : override_cred->fsgid = override_cred->gid;
361 :
362 3381 : if (!issecure(SECURE_NO_SETUID_FIXUP)) {
363 : /* Clear the capabilities if we switch to a non-root user */
364 3381 : kuid_t root_uid = make_kuid(override_cred->user_ns, 0);
365 3381 : if (!uid_eq(override_cred->uid, root_uid))
366 31 : cap_clear(override_cred->cap_effective);
367 : else
368 3350 : override_cred->cap_effective =
369 : override_cred->cap_permitted;
370 : }
371 :
372 : /*
373 : * The new set of credentials can *only* be used in
374 : * task-synchronous circumstances, and does not need
375 : * RCU freeing, unless somebody then takes a separate
376 : * reference to it.
377 : *
378 : * NOTE! This is _only_ true because this credential
379 : * is used purely for override_creds() that installs
380 : * it as the subjective cred. Other threads will be
381 : * accessing ->real_cred, not the subjective cred.
382 : *
383 : * If somebody _does_ make a copy of this (using the
384 : * 'get_current_cred()' function), that will clear the
385 : * non_rcu field, because now that other user may be
386 : * expecting RCU freeing. But normal thread-synchronous
387 : * cred accesses will keep things non-RCY.
388 : */
389 3381 : override_cred->non_rcu = 1;
390 :
391 3381 : old_cred = override_creds(override_cred);
392 :
393 : /* override_cred() gets its own ref */
394 3381 : put_cred(override_cred);
395 :
396 3381 : return old_cred;
397 : }
398 :
399 3381 : static long do_faccessat(int dfd, const char __user *filename, int mode, int flags)
400 : {
401 3381 : struct path path;
402 3381 : struct inode *inode;
403 3381 : int res;
404 3381 : unsigned int lookup_flags = LOOKUP_FOLLOW;
405 3381 : const struct cred *old_cred = NULL;
406 :
407 3381 : if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */
408 : return -EINVAL;
409 :
410 3381 : if (flags & ~(AT_EACCESS | AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH))
411 : return -EINVAL;
412 :
413 3381 : if (flags & AT_SYMLINK_NOFOLLOW)
414 0 : lookup_flags &= ~LOOKUP_FOLLOW;
415 3381 : if (flags & AT_EMPTY_PATH)
416 0 : lookup_flags |= LOOKUP_EMPTY;
417 :
418 3381 : if (!(flags & AT_EACCESS)) {
419 3381 : old_cred = access_override_creds();
420 3381 : if (!old_cred)
421 : return -ENOMEM;
422 : }
423 :
424 3381 : retry:
425 3381 : res = user_path_at(dfd, filename, lookup_flags, &path);
426 3381 : if (res)
427 2129 : goto out;
428 :
429 1252 : inode = d_backing_inode(path.dentry);
430 :
431 1252 : if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) {
432 : /*
433 : * MAY_EXEC on regular files is denied if the fs is mounted
434 : * with the "noexec" flag.
435 : */
436 89 : res = -EACCES;
437 89 : if (path_noexec(&path))
438 0 : goto out_path_release;
439 : }
440 :
441 1252 : res = inode_permission(mnt_user_ns(path.mnt), inode, mode | MAY_ACCESS);
442 : /* SuS v2 requires we report a read only fs too */
443 1252 : if (res || !(mode & S_IWOTH) || special_file(inode->i_mode))
444 1235 : goto out_path_release;
445 : /*
446 : * This is a rare case where using __mnt_is_readonly()
447 : * is OK without a mnt_want/drop_write() pair. Since
448 : * no actual write to the fs is performed here, we do
449 : * not need to telegraph to that to anyone.
450 : *
451 : * By doing this, we accept that this access is
452 : * inherently racy and know that the fs may change
453 : * state before we even see this result.
454 : */
455 17 : if (__mnt_is_readonly(path.mnt))
456 0 : res = -EROFS;
457 :
458 17 : out_path_release:
459 1252 : path_put(&path);
460 2504 : if (retry_estale(res, lookup_flags)) {
461 0 : lookup_flags |= LOOKUP_REVAL;
462 0 : goto retry;
463 : }
464 1252 : out:
465 3381 : if (old_cred)
466 3381 : revert_creds(old_cred);
467 :
468 3381 : return res;
469 : }
470 :
471 122 : SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode)
472 : {
473 61 : return do_faccessat(dfd, filename, mode, 0);
474 : }
475 :
476 0 : SYSCALL_DEFINE4(faccessat2, int, dfd, const char __user *, filename, int, mode,
477 : int, flags)
478 : {
479 0 : return do_faccessat(dfd, filename, mode, flags);
480 : }
481 :
482 6640 : SYSCALL_DEFINE2(access, const char __user *, filename, int, mode)
483 : {
484 3320 : return do_faccessat(AT_FDCWD, filename, mode, 0);
485 : }
486 :
487 2716 : SYSCALL_DEFINE1(chdir, const char __user *, filename)
488 : {
489 1358 : struct path path;
490 1358 : int error;
491 1358 : unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
492 1358 : retry:
493 1358 : error = user_path_at(AT_FDCWD, filename, lookup_flags, &path);
494 1358 : if (error)
495 0 : goto out;
496 :
497 1358 : error = path_permission(&path, MAY_EXEC | MAY_CHDIR);
498 1358 : if (error)
499 0 : goto dput_and_out;
500 :
501 1358 : set_fs_pwd(current->fs, &path);
502 :
503 1358 : dput_and_out:
504 1358 : path_put(&path);
505 2716 : if (retry_estale(error, lookup_flags)) {
506 0 : lookup_flags |= LOOKUP_REVAL;
507 0 : goto retry;
508 : }
509 1358 : out:
510 1358 : return error;
511 : }
512 :
513 688 : SYSCALL_DEFINE1(fchdir, unsigned int, fd)
514 : {
515 344 : struct fd f = fdget_raw(fd);
516 344 : int error;
517 :
518 344 : error = -EBADF;
519 344 : if (!f.file)
520 0 : goto out;
521 :
522 344 : error = -ENOTDIR;
523 344 : if (!d_can_lookup(f.file->f_path.dentry))
524 0 : goto out_putf;
525 :
526 344 : error = file_permission(f.file, MAY_EXEC | MAY_CHDIR);
527 344 : if (!error)
528 344 : set_fs_pwd(current->fs, &f.file->f_path);
529 0 : out_putf:
530 344 : fdput(f);
531 344 : out:
532 344 : return error;
533 : }
534 :
535 18 : SYSCALL_DEFINE1(chroot, const char __user *, filename)
536 : {
537 9 : struct path path;
538 9 : int error;
539 9 : unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
540 9 : retry:
541 9 : error = user_path_at(AT_FDCWD, filename, lookup_flags, &path);
542 9 : if (error)
543 0 : goto out;
544 :
545 9 : error = path_permission(&path, MAY_EXEC | MAY_CHDIR);
546 9 : if (error)
547 0 : goto dput_and_out;
548 :
549 9 : error = -EPERM;
550 9 : if (!ns_capable(current_user_ns(), CAP_SYS_CHROOT))
551 0 : goto dput_and_out;
552 9 : error = security_path_chroot(&path);
553 9 : if (error)
554 0 : goto dput_and_out;
555 :
556 9 : set_fs_root(current->fs, &path);
557 9 : error = 0;
558 9 : dput_and_out:
559 9 : path_put(&path);
560 18 : if (retry_estale(error, lookup_flags)) {
561 0 : lookup_flags |= LOOKUP_REVAL;
562 0 : goto retry;
563 : }
564 9 : out:
565 9 : return error;
566 : }
567 :
568 447 : int chmod_common(const struct path *path, umode_t mode)
569 : {
570 447 : struct inode *inode = path->dentry->d_inode;
571 447 : struct inode *delegated_inode = NULL;
572 447 : struct iattr newattrs;
573 447 : int error;
574 :
575 447 : error = mnt_want_write(path->mnt);
576 447 : if (error)
577 : return error;
578 447 : retry_deleg:
579 447 : inode_lock(inode);
580 447 : error = security_path_chmod(path, mode);
581 447 : if (error)
582 0 : goto out_unlock;
583 447 : newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
584 447 : newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
585 447 : error = notify_change(mnt_user_ns(path->mnt), path->dentry,
586 : &newattrs, &delegated_inode);
587 447 : out_unlock:
588 447 : inode_unlock(inode);
589 447 : if (delegated_inode) {
590 0 : error = break_deleg_wait(&delegated_inode);
591 0 : if (!error)
592 0 : goto retry_deleg;
593 : }
594 447 : mnt_drop_write(path->mnt);
595 447 : return error;
596 : }
597 :
598 256 : int vfs_fchmod(struct file *file, umode_t mode)
599 : {
600 0 : audit_file(file);
601 256 : return chmod_common(&file->f_path, mode);
602 : }
603 :
604 512 : SYSCALL_DEFINE2(fchmod, unsigned int, fd, umode_t, mode)
605 : {
606 256 : struct fd f = fdget(fd);
607 256 : int err = -EBADF;
608 :
609 256 : if (f.file) {
610 256 : err = vfs_fchmod(f.file, mode);
611 256 : fdput(f);
612 : }
613 256 : return err;
614 : }
615 :
616 188 : static int do_fchmodat(int dfd, const char __user *filename, umode_t mode)
617 : {
618 188 : struct path path;
619 188 : int error;
620 188 : unsigned int lookup_flags = LOOKUP_FOLLOW;
621 188 : retry:
622 188 : error = user_path_at(dfd, filename, lookup_flags, &path);
623 188 : if (!error) {
624 188 : error = chmod_common(&path, mode);
625 188 : path_put(&path);
626 376 : if (retry_estale(error, lookup_flags)) {
627 0 : lookup_flags |= LOOKUP_REVAL;
628 0 : goto retry;
629 : }
630 : }
631 188 : return error;
632 : }
633 :
634 10 : SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename,
635 : umode_t, mode)
636 : {
637 5 : return do_fchmodat(dfd, filename, mode);
638 : }
639 :
640 366 : SYSCALL_DEFINE2(chmod, const char __user *, filename, umode_t, mode)
641 : {
642 183 : return do_fchmodat(AT_FDCWD, filename, mode);
643 : }
644 :
645 194 : int chown_common(const struct path *path, uid_t user, gid_t group)
646 : {
647 194 : struct user_namespace *mnt_userns;
648 194 : struct inode *inode = path->dentry->d_inode;
649 194 : struct inode *delegated_inode = NULL;
650 194 : int error;
651 194 : struct iattr newattrs;
652 194 : kuid_t uid;
653 194 : kgid_t gid;
654 :
655 194 : uid = make_kuid(current_user_ns(), user);
656 194 : gid = make_kgid(current_user_ns(), group);
657 :
658 194 : mnt_userns = mnt_user_ns(path->mnt);
659 194 : uid = kuid_from_mnt(mnt_userns, uid);
660 194 : gid = kgid_from_mnt(mnt_userns, gid);
661 :
662 194 : retry_deleg:
663 194 : newattrs.ia_valid = ATTR_CTIME;
664 194 : if (user != (uid_t) -1) {
665 193 : if (!uid_valid(uid))
666 : return -EINVAL;
667 193 : newattrs.ia_valid |= ATTR_UID;
668 193 : newattrs.ia_uid = uid;
669 : }
670 194 : if (group != (gid_t) -1) {
671 193 : if (!gid_valid(gid))
672 : return -EINVAL;
673 193 : newattrs.ia_valid |= ATTR_GID;
674 193 : newattrs.ia_gid = gid;
675 : }
676 194 : if (!S_ISDIR(inode->i_mode))
677 179 : newattrs.ia_valid |=
678 : ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
679 194 : inode_lock(inode);
680 194 : error = security_path_chown(path, uid, gid);
681 194 : if (!error)
682 194 : error = notify_change(mnt_userns, path->dentry, &newattrs,
683 : &delegated_inode);
684 194 : inode_unlock(inode);
685 194 : if (delegated_inode) {
686 0 : error = break_deleg_wait(&delegated_inode);
687 0 : if (!error)
688 0 : goto retry_deleg;
689 : }
690 194 : return error;
691 : }
692 :
693 125 : int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group,
694 : int flag)
695 : {
696 125 : struct path path;
697 125 : int error = -EINVAL;
698 125 : int lookup_flags;
699 :
700 125 : if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0)
701 0 : goto out;
702 :
703 125 : lookup_flags = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
704 125 : if (flag & AT_EMPTY_PATH)
705 8 : lookup_flags |= LOOKUP_EMPTY;
706 117 : retry:
707 125 : error = user_path_at(dfd, filename, lookup_flags, &path);
708 125 : if (error)
709 0 : goto out;
710 125 : error = mnt_want_write(path.mnt);
711 125 : if (error)
712 0 : goto out_release;
713 125 : error = chown_common(&path, user, group);
714 125 : mnt_drop_write(path.mnt);
715 125 : out_release:
716 125 : path_put(&path);
717 250 : if (retry_estale(error, lookup_flags)) {
718 0 : lookup_flags |= LOOKUP_REVAL;
719 0 : goto retry;
720 : }
721 125 : out:
722 125 : return error;
723 : }
724 :
725 28 : SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user,
726 : gid_t, group, int, flag)
727 : {
728 14 : return do_fchownat(dfd, filename, user, group, flag);
729 : }
730 :
731 222 : SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group)
732 : {
733 111 : return do_fchownat(AT_FDCWD, filename, user, group, 0);
734 : }
735 :
736 0 : SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group)
737 : {
738 0 : return do_fchownat(AT_FDCWD, filename, user, group,
739 : AT_SYMLINK_NOFOLLOW);
740 : }
741 :
742 66 : int vfs_fchown(struct file *file, uid_t user, gid_t group)
743 : {
744 66 : int error;
745 :
746 66 : error = mnt_want_write_file(file);
747 66 : if (error)
748 : return error;
749 66 : audit_file(file);
750 66 : error = chown_common(&file->f_path, user, group);
751 66 : mnt_drop_write_file(file);
752 66 : return error;
753 : }
754 :
755 66 : int ksys_fchown(unsigned int fd, uid_t user, gid_t group)
756 : {
757 66 : struct fd f = fdget(fd);
758 66 : int error = -EBADF;
759 :
760 66 : if (f.file) {
761 66 : error = vfs_fchown(f.file, user, group);
762 66 : fdput(f);
763 : }
764 66 : return error;
765 : }
766 :
767 132 : SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group)
768 : {
769 66 : return ksys_fchown(fd, user, group);
770 : }
771 :
772 45775 : static int do_dentry_open(struct file *f,
773 : struct inode *inode,
774 : int (*open)(struct inode *, struct file *))
775 : {
776 45775 : static const struct file_operations empty_fops = {};
777 45775 : int error;
778 :
779 45775 : path_get(&f->f_path);
780 45803 : f->f_inode = inode;
781 45803 : f->f_mapping = inode->i_mapping;
782 45803 : f->f_wb_err = filemap_sample_wb_err(f->f_mapping);
783 45803 : f->f_sb_err = file_sample_sb_err(f);
784 :
785 45803 : if (unlikely(f->f_flags & O_PATH)) {
786 30265 : f->f_mode = FMODE_PATH | FMODE_OPENED;
787 30265 : f->f_op = &empty_fops;
788 30265 : return 0;
789 : }
790 :
791 15538 : if (f->f_mode & FMODE_WRITE && !special_file(inode->i_mode)) {
792 1234 : error = get_write_access(inode);
793 1234 : if (unlikely(error))
794 0 : goto cleanup_file;
795 1234 : error = __mnt_want_write(f->f_path.mnt);
796 1234 : if (unlikely(error)) {
797 0 : put_write_access(inode);
798 0 : goto cleanup_file;
799 : }
800 1234 : f->f_mode |= FMODE_WRITER;
801 : }
802 :
803 : /* POSIX.1-2008/SUSv4 Section XSI 2.9.7 */
804 15538 : if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))
805 15082 : f->f_mode |= FMODE_ATOMIC_POS;
806 :
807 15538 : f->f_op = fops_get(inode->i_fop);
808 15538 : if (WARN_ON(!f->f_op)) {
809 0 : error = -ENODEV;
810 0 : goto cleanup_all;
811 : }
812 :
813 15538 : error = security_file_open(f);
814 15538 : if (error)
815 143 : goto cleanup_all;
816 :
817 15395 : error = break_lease(locks_inode(f), f->f_flags);
818 15394 : if (error)
819 0 : goto cleanup_all;
820 :
821 : /* normally all 3 are set; ->open() can clear them if needed */
822 15394 : f->f_mode |= FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE;
823 15394 : if (!open)
824 15394 : open = f->f_op->open;
825 15394 : if (open) {
826 13604 : error = open(inode, f);
827 13604 : if (error)
828 76 : goto cleanup_all;
829 : }
830 15318 : f->f_mode |= FMODE_OPENED;
831 15318 : if ((f->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
832 13859 : i_readcount_inc(inode);
833 15319 : if ((f->f_mode & FMODE_READ) &&
834 14331 : likely(f->f_op->read || f->f_op->read_iter))
835 14329 : f->f_mode |= FMODE_CAN_READ;
836 15319 : if ((f->f_mode & FMODE_WRITE) &&
837 1458 : likely(f->f_op->write || f->f_op->write_iter))
838 1458 : f->f_mode |= FMODE_CAN_WRITE;
839 :
840 15319 : f->f_write_hint = WRITE_LIFE_NOT_SET;
841 15319 : f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
842 :
843 15319 : file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);
844 :
845 : /* NB: we're sure to have correct a_ops only after f_op->open */
846 15316 : if (f->f_flags & O_DIRECT) {
847 0 : if (!f->f_mapping->a_ops || !f->f_mapping->a_ops->direct_IO)
848 : return -EINVAL;
849 : }
850 :
851 : /*
852 : * XXX: Huge page cache doesn't support writing yet. Drop all page
853 : * cache for this file before processing writes.
854 : */
855 15316 : if ((f->f_mode & FMODE_WRITE) && filemap_nr_thps(inode->i_mapping))
856 : truncate_pagecache(inode, 0);
857 :
858 : return 0;
859 :
860 219 : cleanup_all:
861 219 : if (WARN_ON_ONCE(error > 0))
862 0 : error = -EINVAL;
863 219 : fops_put(f->f_op);
864 219 : if (f->f_mode & FMODE_WRITER) {
865 62 : put_write_access(inode);
866 62 : __mnt_drop_write(f->f_path.mnt);
867 : }
868 157 : cleanup_file:
869 219 : path_put(&f->f_path);
870 219 : f->f_path.mnt = NULL;
871 219 : f->f_path.dentry = NULL;
872 219 : f->f_inode = NULL;
873 219 : return error;
874 : }
875 :
876 : /**
877 : * finish_open - finish opening a file
878 : * @file: file pointer
879 : * @dentry: pointer to dentry
880 : * @open: open callback
881 : * @opened: state of open
882 : *
883 : * This can be used to finish opening a file passed to i_op->atomic_open().
884 : *
885 : * If the open callback is set to NULL, then the standard f_op->open()
886 : * filesystem callback is substituted.
887 : *
888 : * NB: the dentry reference is _not_ consumed. If, for example, the dentry is
889 : * the return value of d_splice_alias(), then the caller needs to perform dput()
890 : * on it after finish_open().
891 : *
892 : * Returns zero on success or -errno if the open failed.
893 : */
894 0 : int finish_open(struct file *file, struct dentry *dentry,
895 : int (*open)(struct inode *, struct file *))
896 : {
897 0 : BUG_ON(file->f_mode & FMODE_OPENED); /* once it's opened, it's opened */
898 :
899 0 : file->f_path.dentry = dentry;
900 0 : return do_dentry_open(file, d_backing_inode(dentry), open);
901 : }
902 : EXPORT_SYMBOL(finish_open);
903 :
904 : /**
905 : * finish_no_open - finish ->atomic_open() without opening the file
906 : *
907 : * @file: file pointer
908 : * @dentry: dentry or NULL (as returned from ->lookup())
909 : *
910 : * This can be used to set the result of a successful lookup in ->atomic_open().
911 : *
912 : * NB: unlike finish_open() this function does consume the dentry reference and
913 : * the caller need not dput() it.
914 : *
915 : * Returns "0" which must be the return value of ->atomic_open() after having
916 : * called this function.
917 : */
918 0 : int finish_no_open(struct file *file, struct dentry *dentry)
919 : {
920 0 : file->f_path.dentry = dentry;
921 0 : return 0;
922 : }
923 : EXPORT_SYMBOL(finish_no_open);
924 :
925 0 : char *file_path(struct file *filp, char *buf, int buflen)
926 : {
927 0 : return d_path(&filp->f_path, buf, buflen);
928 : }
929 : EXPORT_SYMBOL(file_path);
930 :
931 : /**
932 : * vfs_open - open the file at the given path
933 : * @path: path to open
934 : * @file: newly allocated file with f_flag initialized
935 : * @cred: credentials to use
936 : */
937 45745 : int vfs_open(const struct path *path, struct file *file)
938 : {
939 45745 : file->f_path = *path;
940 45745 : return do_dentry_open(file, d_backing_inode(path->dentry), NULL);
941 : }
942 :
943 14 : struct file *dentry_open(const struct path *path, int flags,
944 : const struct cred *cred)
945 : {
946 14 : int error;
947 14 : struct file *f;
948 :
949 14 : validate_creds(cred);
950 :
951 : /* We must always pass in a valid mount pointer. */
952 14 : BUG_ON(!path->mnt);
953 :
954 14 : f = alloc_empty_file(flags, cred);
955 14 : if (!IS_ERR(f)) {
956 14 : error = vfs_open(path, f);
957 14 : if (error) {
958 0 : fput(f);
959 0 : f = ERR_PTR(error);
960 : }
961 : }
962 14 : return f;
963 : }
964 : EXPORT_SYMBOL(dentry_open);
965 :
966 39 : struct file *open_with_fake_path(const struct path *path, int flags,
967 : struct inode *inode, const struct cred *cred)
968 : {
969 39 : struct file *f = alloc_empty_file_noaccount(flags, cred);
970 39 : if (!IS_ERR(f)) {
971 39 : int error;
972 :
973 39 : f->f_path = *path;
974 39 : error = do_dentry_open(f, inode, NULL);
975 39 : if (error) {
976 0 : fput(f);
977 0 : f = ERR_PTR(error);
978 : }
979 : }
980 39 : return f;
981 : }
982 : EXPORT_SYMBOL(open_with_fake_path);
983 :
984 : #define WILL_CREATE(flags) (flags & (O_CREAT | __O_TMPFILE))
985 : #define O_PATH_FLAGS (O_DIRECTORY | O_NOFOLLOW | O_PATH | O_CLOEXEC)
986 :
987 56199 : inline struct open_how build_open_how(int flags, umode_t mode)
988 : {
989 56199 : struct open_how how = {
990 0 : .flags = flags & VALID_OPEN_FLAGS,
991 : .mode = mode & S_IALLUGO,
992 : };
993 :
994 : /* O_PATH beats everything else. */
995 0 : if (how.flags & O_PATH)
996 36249 : how.flags &= O_PATH_FLAGS;
997 : /* Modes should only be set for create-like flags. */
998 56199 : if (!WILL_CREATE(how.flags))
999 54832 : how.mode = 0;
1000 56199 : return how;
1001 : }
1002 :
1003 56200 : inline int build_open_flags(const struct open_how *how, struct open_flags *op)
1004 : {
1005 56200 : int flags = how->flags;
1006 56200 : int lookup_flags = 0;
1007 56200 : int acc_mode = ACC_MODE(flags);
1008 :
1009 : /* Must never be set by userspace */
1010 56200 : flags &= ~(FMODE_NONOTIFY | O_CLOEXEC);
1011 :
1012 : /*
1013 : * Older syscalls implicitly clear all of the invalid flags or argument
1014 : * values before calling build_open_flags(), but openat2(2) checks all
1015 : * of its arguments.
1016 : */
1017 56200 : if (flags & ~VALID_OPEN_FLAGS)
1018 : return -EINVAL;
1019 56200 : if (how->resolve & ~VALID_RESOLVE_FLAGS)
1020 : return -EINVAL;
1021 :
1022 : /* Scoping flags are mutually exclusive. */
1023 56200 : if ((how->resolve & RESOLVE_BENEATH) && (how->resolve & RESOLVE_IN_ROOT))
1024 : return -EINVAL;
1025 :
1026 : /* Deal with the mode. */
1027 56200 : if (WILL_CREATE(flags)) {
1028 1388 : if (how->mode & ~S_IALLUGO)
1029 : return -EINVAL;
1030 1388 : op->mode = how->mode | S_IFREG;
1031 : } else {
1032 54812 : if (how->mode != 0)
1033 : return -EINVAL;
1034 54812 : op->mode = 0;
1035 : }
1036 :
1037 : /*
1038 : * In order to ensure programs get explicit errors when trying to use
1039 : * O_TMPFILE on old kernels, O_TMPFILE is implemented such that it
1040 : * looks like (O_DIRECTORY|O_RDWR & ~O_CREAT) to old kernels. But we
1041 : * have to require userspace to explicitly set it.
1042 : */
1043 56200 : if (flags & __O_TMPFILE) {
1044 0 : if ((flags & O_TMPFILE_MASK) != O_TMPFILE)
1045 : return -EINVAL;
1046 0 : if (!(acc_mode & MAY_WRITE))
1047 : return -EINVAL;
1048 : }
1049 56200 : if (flags & O_PATH) {
1050 : /* O_PATH only permits certain other flags to be set. */
1051 36271 : if (flags & ~O_PATH_FLAGS)
1052 : return -EINVAL;
1053 : acc_mode = 0;
1054 : }
1055 :
1056 : /*
1057 : * O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only
1058 : * check for O_DSYNC if the need any syncing at all we enforce it's
1059 : * always set instead of having to deal with possibly weird behaviour
1060 : * for malicious applications setting only __O_SYNC.
1061 : */
1062 56200 : if (flags & __O_SYNC)
1063 0 : flags |= O_DSYNC;
1064 :
1065 56200 : op->open_flag = flags;
1066 :
1067 : /* O_TRUNC implies we need access checks for write permissions */
1068 56200 : if (flags & O_TRUNC)
1069 370 : acc_mode |= MAY_WRITE;
1070 :
1071 : /* Allow the LSM permission hook to distinguish append
1072 : access from general write access. */
1073 56200 : if (flags & O_APPEND)
1074 36 : acc_mode |= MAY_APPEND;
1075 :
1076 56200 : op->acc_mode = acc_mode;
1077 :
1078 56200 : op->intent = flags & O_PATH ? 0 : LOOKUP_OPEN;
1079 :
1080 56200 : if (flags & O_CREAT) {
1081 1388 : op->intent |= LOOKUP_CREATE;
1082 1388 : if (flags & O_EXCL) {
1083 316 : op->intent |= LOOKUP_EXCL;
1084 316 : flags |= O_NOFOLLOW;
1085 : }
1086 : }
1087 :
1088 56200 : if (flags & O_DIRECTORY)
1089 1606 : lookup_flags |= LOOKUP_DIRECTORY;
1090 56200 : if (!(flags & O_NOFOLLOW))
1091 18059 : lookup_flags |= LOOKUP_FOLLOW;
1092 :
1093 56200 : if (how->resolve & RESOLVE_NO_XDEV)
1094 0 : lookup_flags |= LOOKUP_NO_XDEV;
1095 56200 : if (how->resolve & RESOLVE_NO_MAGICLINKS)
1096 0 : lookup_flags |= LOOKUP_NO_MAGICLINKS;
1097 56200 : if (how->resolve & RESOLVE_NO_SYMLINKS)
1098 0 : lookup_flags |= LOOKUP_NO_SYMLINKS;
1099 56200 : if (how->resolve & RESOLVE_BENEATH)
1100 0 : lookup_flags |= LOOKUP_BENEATH;
1101 56200 : if (how->resolve & RESOLVE_IN_ROOT)
1102 0 : lookup_flags |= LOOKUP_IN_ROOT;
1103 56200 : if (how->resolve & RESOLVE_CACHED) {
1104 : /* Don't bother even trying for create/truncate/tmpfile open */
1105 0 : if (flags & (O_TRUNC | O_CREAT | O_TMPFILE))
1106 : return -EAGAIN;
1107 0 : lookup_flags |= LOOKUP_CACHED;
1108 : }
1109 :
1110 56200 : op->lookup_flags = lookup_flags;
1111 56200 : return 0;
1112 : }
1113 :
1114 : /**
1115 : * file_open_name - open file and return file pointer
1116 : *
1117 : * @name: struct filename containing path to open
1118 : * @flags: open flags as per the open(2) second argument
1119 : * @mode: mode for the new file if O_CREAT is set, else ignored
1120 : *
1121 : * This is the helper to open a file from kernelspace if you really
1122 : * have to. But in generally you should not do this, so please move
1123 : * along, nothing to see here..
1124 : */
1125 1 : struct file *file_open_name(struct filename *name, int flags, umode_t mode)
1126 : {
1127 1 : struct open_flags op;
1128 1 : struct open_how how = build_open_how(flags, mode);
1129 1 : int err = build_open_flags(&how, &op);
1130 1 : if (err)
1131 0 : return ERR_PTR(err);
1132 1 : return do_filp_open(AT_FDCWD, name, &op);
1133 : }
1134 :
1135 : /**
1136 : * filp_open - open file and return file pointer
1137 : *
1138 : * @filename: path to open
1139 : * @flags: open flags as per the open(2) second argument
1140 : * @mode: mode for the new file if O_CREAT is set, else ignored
1141 : *
1142 : * This is the helper to open a file from kernelspace if you really
1143 : * have to. But in generally you should not do this, so please move
1144 : * along, nothing to see here..
1145 : */
1146 1 : struct file *filp_open(const char *filename, int flags, umode_t mode)
1147 : {
1148 1 : struct filename *name = getname_kernel(filename);
1149 1 : struct file *file = ERR_CAST(name);
1150 :
1151 1 : if (!IS_ERR(name)) {
1152 1 : file = file_open_name(name, flags, mode);
1153 1 : putname(name);
1154 : }
1155 1 : return file;
1156 : }
1157 : EXPORT_SYMBOL(filp_open);
1158 :
1159 0 : struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt,
1160 : const char *filename, int flags, umode_t mode)
1161 : {
1162 0 : struct open_flags op;
1163 0 : struct open_how how = build_open_how(flags, mode);
1164 0 : int err = build_open_flags(&how, &op);
1165 0 : if (err)
1166 0 : return ERR_PTR(err);
1167 0 : return do_file_open_root(dentry, mnt, filename, &op);
1168 : }
1169 : EXPORT_SYMBOL(file_open_root);
1170 :
1171 56207 : static long do_sys_openat2(int dfd, const char __user *filename,
1172 : struct open_how *how)
1173 : {
1174 56207 : struct open_flags op;
1175 56207 : int fd = build_open_flags(how, &op);
1176 56227 : struct filename *tmp;
1177 :
1178 56227 : if (fd)
1179 0 : return fd;
1180 :
1181 56227 : tmp = getname(filename);
1182 56239 : if (IS_ERR(tmp))
1183 0 : return PTR_ERR(tmp);
1184 :
1185 56239 : fd = get_unused_fd_flags(how->flags);
1186 56237 : if (fd >= 0) {
1187 56237 : struct file *f = do_filp_open(dfd, tmp, &op);
1188 56230 : if (IS_ERR(f)) {
1189 12770 : put_unused_fd(fd);
1190 12770 : fd = PTR_ERR(f);
1191 : } else {
1192 43460 : fsnotify_open(f);
1193 43466 : fd_install(fd, f);
1194 : }
1195 : }
1196 56230 : putname(tmp);
1197 56210 : return fd;
1198 : }
1199 :
1200 56198 : long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode)
1201 : {
1202 56198 : struct open_how how = build_open_how(flags, mode);
1203 56198 : return do_sys_openat2(dfd, filename, &how);
1204 : }
1205 :
1206 :
1207 0 : SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode)
1208 : {
1209 0 : if (force_o_largefile())
1210 0 : flags |= O_LARGEFILE;
1211 0 : return do_sys_open(AT_FDCWD, filename, flags, mode);
1212 : }
1213 :
1214 112418 : SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags,
1215 : umode_t, mode)
1216 : {
1217 56214 : if (force_o_largefile())
1218 56214 : flags |= O_LARGEFILE;
1219 56214 : return do_sys_open(dfd, filename, flags, mode);
1220 : }
1221 :
1222 0 : SYSCALL_DEFINE4(openat2, int, dfd, const char __user *, filename,
1223 : struct open_how __user *, how, size_t, usize)
1224 : {
1225 0 : int err;
1226 0 : struct open_how tmp;
1227 :
1228 0 : BUILD_BUG_ON(sizeof(struct open_how) < OPEN_HOW_SIZE_VER0);
1229 0 : BUILD_BUG_ON(sizeof(struct open_how) != OPEN_HOW_SIZE_LATEST);
1230 :
1231 0 : if (unlikely(usize < OPEN_HOW_SIZE_VER0))
1232 : return -EINVAL;
1233 :
1234 0 : err = copy_struct_from_user(&tmp, sizeof(tmp), how, usize);
1235 0 : if (err)
1236 0 : return err;
1237 :
1238 : /* O_LARGEFILE is only allowed for non-O_PATH. */
1239 0 : if (!(tmp.flags & O_PATH) && force_o_largefile())
1240 0 : tmp.flags |= O_LARGEFILE;
1241 :
1242 0 : return do_sys_openat2(dfd, filename, &tmp);
1243 : }
1244 :
1245 : #ifdef CONFIG_COMPAT
1246 : /*
1247 : * Exactly like sys_open(), except that it doesn't set the
1248 : * O_LARGEFILE flag.
1249 : */
1250 0 : COMPAT_SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode)
1251 : {
1252 0 : return do_sys_open(AT_FDCWD, filename, flags, mode);
1253 : }
1254 :
1255 : /*
1256 : * Exactly like sys_openat(), except that it doesn't set the
1257 : * O_LARGEFILE flag.
1258 : */
1259 0 : COMPAT_SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags, umode_t, mode)
1260 : {
1261 0 : return do_sys_open(dfd, filename, flags, mode);
1262 : }
1263 : #endif
1264 :
1265 : #ifndef __alpha__
1266 :
1267 : /*
1268 : * For backward compatibility? Maybe this should be moved
1269 : * into arch/i386 instead?
1270 : */
1271 2 : SYSCALL_DEFINE2(creat, const char __user *, pathname, umode_t, mode)
1272 : {
1273 1 : int flags = O_CREAT | O_WRONLY | O_TRUNC;
1274 :
1275 1 : if (force_o_largefile())
1276 1 : flags |= O_LARGEFILE;
1277 1 : return do_sys_open(AT_FDCWD, pathname, flags, mode);
1278 : }
1279 : #endif
1280 :
1281 : /*
1282 : * "id" is the POSIX thread ID. We use the
1283 : * files pointer for this..
1284 : */
1285 57997 : int filp_close(struct file *filp, fl_owner_t id)
1286 : {
1287 57997 : int retval = 0;
1288 :
1289 57997 : if (!file_count(filp)) {
1290 0 : printk(KERN_ERR "VFS: Close: file count is 0\n");
1291 0 : return 0;
1292 : }
1293 :
1294 57997 : if (filp->f_op->flush)
1295 0 : retval = filp->f_op->flush(filp, id);
1296 :
1297 58000 : if (likely(!(filp->f_mode & FMODE_PATH))) {
1298 27717 : dnotify_flush(filp, id);
1299 27717 : locks_remove_posix(filp, id);
1300 : }
1301 58000 : fput(filp);
1302 58000 : return retval;
1303 : }
1304 :
1305 : EXPORT_SYMBOL(filp_close);
1306 :
1307 : /*
1308 : * Careful here! We test whether the file pointer is NULL before
1309 : * releasing the fd. This ensures that one clone task can't release
1310 : * an fd while another clone is opening it.
1311 : */
1312 101619 : SYSCALL_DEFINE1(close, unsigned int, fd)
1313 : {
1314 50809 : int retval = close_fd(fd);
1315 :
1316 : /* can't restart close syscall because file table entry was cleared */
1317 50840 : if (unlikely(retval == -ERESTARTSYS ||
1318 : retval == -ERESTARTNOINTR ||
1319 : retval == -ERESTARTNOHAND ||
1320 : retval == -ERESTART_RESTARTBLOCK))
1321 0 : retval = -EINTR;
1322 :
1323 50840 : return retval;
1324 : }
1325 :
1326 : /**
1327 : * close_range() - Close all file descriptors in a given range.
1328 : *
1329 : * @fd: starting file descriptor to close
1330 : * @max_fd: last file descriptor to close
1331 : * @flags: reserved for future extensions
1332 : *
1333 : * This closes a range of file descriptors. All file descriptors
1334 : * from @fd up to and including @max_fd are closed.
1335 : * Currently, errors to close a given file descriptor are ignored.
1336 : */
1337 0 : SYSCALL_DEFINE3(close_range, unsigned int, fd, unsigned int, max_fd,
1338 : unsigned int, flags)
1339 : {
1340 0 : return __close_range(fd, max_fd, flags);
1341 : }
1342 :
1343 : /*
1344 : * This routine simulates a hangup on the tty, to arrange that users
1345 : * are given clean terminals at login time.
1346 : */
1347 0 : SYSCALL_DEFINE0(vhangup)
1348 : {
1349 0 : if (capable(CAP_SYS_TTY_CONFIG)) {
1350 0 : tty_vhangup_self();
1351 0 : return 0;
1352 : }
1353 : return -EPERM;
1354 : }
1355 :
1356 : /*
1357 : * Called when an inode is about to be open.
1358 : * We use this to disallow opening large files on 32bit systems if
1359 : * the caller didn't specify O_LARGEFILE. On 64bit systems we force
1360 : * on this flag in sys_open.
1361 : */
1362 10147 : int generic_file_open(struct inode * inode, struct file * filp)
1363 : {
1364 10147 : if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
1365 0 : return -EOVERFLOW;
1366 : return 0;
1367 : }
1368 :
1369 : EXPORT_SYMBOL(generic_file_open);
1370 :
1371 : /*
1372 : * This is used by subsystems that don't want seekable
1373 : * file descriptors. The function is not supposed to ever fail, the only
1374 : * reason it returns an 'int' and not 'void' is so that it can be plugged
1375 : * directly into file_operations structure.
1376 : */
1377 194 : int nonseekable_open(struct inode *inode, struct file *filp)
1378 : {
1379 194 : filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
1380 194 : return 0;
1381 : }
1382 :
1383 : EXPORT_SYMBOL(nonseekable_open);
1384 :
1385 : /*
1386 : * stream_open is used by subsystems that want stream-like file descriptors.
1387 : * Such file descriptors are not seekable and don't have notion of position
1388 : * (file.f_pos is always 0 and ppos passed to .read()/.write() is always NULL).
1389 : * Contrary to file descriptors of other regular files, .read() and .write()
1390 : * can run simultaneously.
1391 : *
1392 : * stream_open never fails and is marked to return int so that it could be
1393 : * directly used as file_operations.open .
1394 : */
1395 1315 : int stream_open(struct inode *inode, struct file *filp)
1396 : {
1397 1315 : filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE | FMODE_ATOMIC_POS);
1398 1315 : filp->f_mode |= FMODE_STREAM;
1399 1315 : return 0;
1400 : }
1401 :
1402 : EXPORT_SYMBOL(stream_open);
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