1
2
3
4
5
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
38int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
39 struct file *filp)
40{
41 int ret;
42 struct iattr newattrs;
43
44
45 if (length < 0)
46 return -EINVAL;
47
48 newattrs.ia_size = length;
49 newattrs.ia_valid = ATTR_SIZE | time_attrs;
50 if (filp) {
51 newattrs.ia_file = filp;
52 newattrs.ia_valid |= ATTR_FILE;
53 }
54
55
56 ret = dentry_needs_remove_privs(dentry);
57 if (ret < 0)
58 return ret;
59 if (ret)
60 newattrs.ia_valid |= ret | ATTR_FORCE;
61
62 inode_lock(dentry->d_inode);
63
64 ret = notify_change(dentry, &newattrs, NULL);
65 inode_unlock(dentry->d_inode);
66 return ret;
67}
68
69long vfs_truncate(const struct path *path, loff_t length)
70{
71 struct inode *inode;
72 long error;
73
74 inode = path->dentry->d_inode;
75
76
77 if (S_ISDIR(inode->i_mode))
78 return -EISDIR;
79 if (!S_ISREG(inode->i_mode))
80 return -EINVAL;
81
82 error = mnt_want_write(path->mnt);
83 if (error)
84 goto out;
85
86 error = inode_permission(inode, MAY_WRITE);
87 if (error)
88 goto mnt_drop_write_and_out;
89
90 error = -EPERM;
91 if (IS_APPEND(inode))
92 goto mnt_drop_write_and_out;
93
94 error = get_write_access(inode);
95 if (error)
96 goto mnt_drop_write_and_out;
97
98
99
100
101
102 error = break_lease(inode, O_WRONLY);
103 if (error)
104 goto put_write_and_out;
105
106 error = locks_verify_truncate(inode, NULL, length);
107 if (!error)
108 error = security_path_truncate(path);
109 if (!error)
110 error = do_truncate(path->dentry, length, 0, NULL);
111
112put_write_and_out:
113 put_write_access(inode);
114mnt_drop_write_and_out:
115 mnt_drop_write(path->mnt);
116out:
117 return error;
118}
119EXPORT_SYMBOL_GPL(vfs_truncate);
120
121long do_sys_truncate(const char __user *pathname, loff_t length)
122{
123 unsigned int lookup_flags = LOOKUP_FOLLOW;
124 struct path path;
125 int error;
126
127 if (length < 0)
128 return -EINVAL;
129
130retry:
131 error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
132 if (!error) {
133 error = vfs_truncate(&path, length);
134 path_put(&path);
135 }
136 if (retry_estale(error, lookup_flags)) {
137 lookup_flags |= LOOKUP_REVAL;
138 goto retry;
139 }
140 return error;
141}
142
143SYSCALL_DEFINE2(truncate, const char __user *, path, long, length)
144{
145 return do_sys_truncate(path, length);
146}
147
148#ifdef CONFIG_COMPAT
149COMPAT_SYSCALL_DEFINE2(truncate, const char __user *, path, compat_off_t, length)
150{
151 return do_sys_truncate(path, length);
152}
153#endif
154
155long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
156{
157 struct inode *inode;
158 struct dentry *dentry;
159 struct fd f;
160 int error;
161
162 error = -EINVAL;
163 if (length < 0)
164 goto out;
165 error = -EBADF;
166 f = fdget(fd);
167 if (!f.file)
168 goto out;
169
170
171 if (f.file->f_flags & O_LARGEFILE)
172 small = 0;
173
174 dentry = f.file->f_path.dentry;
175 inode = dentry->d_inode;
176 error = -EINVAL;
177 if (!S_ISREG(inode->i_mode) || !(f.file->f_mode & FMODE_WRITE))
178 goto out_putf;
179
180 error = -EINVAL;
181
182 if (small && length > MAX_NON_LFS)
183 goto out_putf;
184
185 error = -EPERM;
186
187 if (IS_APPEND(file_inode(f.file)))
188 goto out_putf;
189
190 sb_start_write(inode->i_sb);
191 error = locks_verify_truncate(inode, f.file, length);
192 if (!error)
193 error = security_path_truncate(&f.file->f_path);
194 if (!error)
195 error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, f.file);
196 sb_end_write(inode->i_sb);
197out_putf:
198 fdput(f);
199out:
200 return error;
201}
202
203SYSCALL_DEFINE2(ftruncate, unsigned int, fd, unsigned long, length)
204{
205 return do_sys_ftruncate(fd, length, 1);
206}
207
208#ifdef CONFIG_COMPAT
209COMPAT_SYSCALL_DEFINE2(ftruncate, unsigned int, fd, compat_ulong_t, length)
210{
211 return do_sys_ftruncate(fd, length, 1);
212}
213#endif
214
215
216#if BITS_PER_LONG == 32
217SYSCALL_DEFINE2(truncate64, const char __user *, path, loff_t, length)
218{
219 return do_sys_truncate(path, length);
220}
221
222SYSCALL_DEFINE2(ftruncate64, unsigned int, fd, loff_t, length)
223{
224 return do_sys_ftruncate(fd, length, 0);
225}
226#endif
227
228
229int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
230{
231 struct inode *inode = file_inode(file);
232 long ret;
233
234 if (offset < 0 || len <= 0)
235 return -EINVAL;
236
237
238 if (mode & ~FALLOC_FL_SUPPORTED_MASK)
239 return -EOPNOTSUPP;
240
241
242 if ((mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) ==
243 (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE))
244 return -EOPNOTSUPP;
245
246
247 if ((mode & FALLOC_FL_PUNCH_HOLE) &&
248 !(mode & FALLOC_FL_KEEP_SIZE))
249 return -EOPNOTSUPP;
250
251
252 if ((mode & FALLOC_FL_COLLAPSE_RANGE) &&
253 (mode & ~FALLOC_FL_COLLAPSE_RANGE))
254 return -EINVAL;
255
256
257 if ((mode & FALLOC_FL_INSERT_RANGE) &&
258 (mode & ~FALLOC_FL_INSERT_RANGE))
259 return -EINVAL;
260
261
262 if ((mode & FALLOC_FL_UNSHARE_RANGE) &&
263 (mode & ~(FALLOC_FL_UNSHARE_RANGE | FALLOC_FL_KEEP_SIZE)))
264 return -EINVAL;
265
266 if (!(file->f_mode & FMODE_WRITE))
267 return -EBADF;
268
269
270
271
272 if ((mode & ~FALLOC_FL_KEEP_SIZE) && IS_APPEND(inode))
273 return -EPERM;
274
275 if (IS_IMMUTABLE(inode))
276 return -EPERM;
277
278
279
280
281 if (IS_SWAPFILE(inode))
282 return -ETXTBSY;
283
284
285
286
287
288 ret = security_file_permission(file, MAY_WRITE);
289 if (ret)
290 return ret;
291
292 if (S_ISFIFO(inode->i_mode))
293 return -ESPIPE;
294
295 if (S_ISDIR(inode->i_mode))
296 return -EISDIR;
297
298 if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))
299 return -ENODEV;
300
301
302 if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0))
303 return -EFBIG;
304
305 if (!file->f_op->fallocate)
306 return -EOPNOTSUPP;
307
308 file_start_write(file);
309 ret = file->f_op->fallocate(file, mode, offset, len);
310
311
312
313
314
315
316
317
318 if (ret == 0)
319 fsnotify_modify(file);
320
321 file_end_write(file);
322 return ret;
323}
324EXPORT_SYMBOL_GPL(vfs_fallocate);
325
326int ksys_fallocate(int fd, int mode, loff_t offset, loff_t len)
327{
328 struct fd f = fdget(fd);
329 int error = -EBADF;
330
331 if (f.file) {
332 error = vfs_fallocate(f.file, mode, offset, len);
333 fdput(f);
334 }
335 return error;
336}
337
338SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len)
339{
340 return ksys_fallocate(fd, mode, offset, len);
341}
342
343
344
345
346
347
348static const struct cred *access_override_creds(void)
349{
350 const struct cred *old_cred;
351 struct cred *override_cred;
352
353 override_cred = prepare_creds();
354 if (!override_cred)
355 return NULL;
356
357 override_cred->fsuid = override_cred->uid;
358 override_cred->fsgid = override_cred->gid;
359
360 if (!issecure(SECURE_NO_SETUID_FIXUP)) {
361
362 kuid_t root_uid = make_kuid(override_cred->user_ns, 0);
363 if (!uid_eq(override_cred->uid, root_uid))
364 cap_clear(override_cred->cap_effective);
365 else
366 override_cred->cap_effective =
367 override_cred->cap_permitted;
368 }
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387 override_cred->non_rcu = 1;
388
389 old_cred = override_creds(override_cred);
390
391
392 put_cred(override_cred);
393
394 return old_cred;
395}
396
397static long do_faccessat(int dfd, const char __user *filename, int mode, int flags)
398{
399 struct path path;
400 struct inode *inode;
401 int res;
402 unsigned int lookup_flags = LOOKUP_FOLLOW;
403 const struct cred *old_cred = NULL;
404
405 if (mode & ~S_IRWXO)
406 return -EINVAL;
407
408 if (flags & ~(AT_EACCESS | AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH))
409 return -EINVAL;
410
411 if (flags & AT_SYMLINK_NOFOLLOW)
412 lookup_flags &= ~LOOKUP_FOLLOW;
413 if (flags & AT_EMPTY_PATH)
414 lookup_flags |= LOOKUP_EMPTY;
415
416 if (!(flags & AT_EACCESS)) {
417 old_cred = access_override_creds();
418 if (!old_cred)
419 return -ENOMEM;
420 }
421
422retry:
423 res = user_path_at(dfd, filename, lookup_flags, &path);
424 if (res)
425 goto out;
426
427 inode = d_backing_inode(path.dentry);
428
429 if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) {
430
431
432
433
434 res = -EACCES;
435 if (path_noexec(&path))
436 goto out_path_release;
437 }
438
439 res = inode_permission(inode, mode | MAY_ACCESS);
440
441 if (res || !(mode & S_IWOTH) || special_file(inode->i_mode))
442 goto out_path_release;
443
444
445
446
447
448
449
450
451
452
453 if (__mnt_is_readonly(path.mnt))
454 res = -EROFS;
455
456out_path_release:
457 path_put(&path);
458 if (retry_estale(res, lookup_flags)) {
459 lookup_flags |= LOOKUP_REVAL;
460 goto retry;
461 }
462out:
463 if (old_cred)
464 revert_creds(old_cred);
465
466 return res;
467}
468
469SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode)
470{
471 return do_faccessat(dfd, filename, mode, 0);
472}
473
474SYSCALL_DEFINE4(faccessat2, int, dfd, const char __user *, filename, int, mode,
475 int, flags)
476{
477 return do_faccessat(dfd, filename, mode, flags);
478}
479
480SYSCALL_DEFINE2(access, const char __user *, filename, int, mode)
481{
482 return do_faccessat(AT_FDCWD, filename, mode, 0);
483}
484
485SYSCALL_DEFINE1(chdir, const char __user *, filename)
486{
487 struct path path;
488 int error;
489 unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
490retry:
491 error = user_path_at(AT_FDCWD, filename, lookup_flags, &path);
492 if (error)
493 goto out;
494
495 error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
496 if (error)
497 goto dput_and_out;
498
499 set_fs_pwd(current->fs, &path);
500
501dput_and_out:
502 path_put(&path);
503 if (retry_estale(error, lookup_flags)) {
504 lookup_flags |= LOOKUP_REVAL;
505 goto retry;
506 }
507out:
508 return error;
509}
510
511SYSCALL_DEFINE1(fchdir, unsigned int, fd)
512{
513 struct fd f = fdget_raw(fd);
514 int error;
515
516 error = -EBADF;
517 if (!f.file)
518 goto out;
519
520 error = -ENOTDIR;
521 if (!d_can_lookup(f.file->f_path.dentry))
522 goto out_putf;
523
524 error = inode_permission(file_inode(f.file), MAY_EXEC | MAY_CHDIR);
525 if (!error)
526 set_fs_pwd(current->fs, &f.file->f_path);
527out_putf:
528 fdput(f);
529out:
530 return error;
531}
532
533SYSCALL_DEFINE1(chroot, const char __user *, filename)
534{
535 struct path path;
536 int error;
537 unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
538retry:
539 error = user_path_at(AT_FDCWD, filename, lookup_flags, &path);
540 if (error)
541 goto out;
542
543 error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
544 if (error)
545 goto dput_and_out;
546
547 error = -EPERM;
548 if (!ns_capable(current_user_ns(), CAP_SYS_CHROOT))
549 goto dput_and_out;
550 error = security_path_chroot(&path);
551 if (error)
552 goto dput_and_out;
553
554 set_fs_root(current->fs, &path);
555 error = 0;
556dput_and_out:
557 path_put(&path);
558 if (retry_estale(error, lookup_flags)) {
559 lookup_flags |= LOOKUP_REVAL;
560 goto retry;
561 }
562out:
563 return error;
564}
565
566int chmod_common(const struct path *path, umode_t mode)
567{
568 struct inode *inode = path->dentry->d_inode;
569 struct inode *delegated_inode = NULL;
570 struct iattr newattrs;
571 int error;
572
573 error = mnt_want_write(path->mnt);
574 if (error)
575 return error;
576retry_deleg:
577 inode_lock(inode);
578 error = security_path_chmod(path, mode);
579 if (error)
580 goto out_unlock;
581 newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
582 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
583 error = notify_change(path->dentry, &newattrs, &delegated_inode);
584out_unlock:
585 inode_unlock(inode);
586 if (delegated_inode) {
587 error = break_deleg_wait(&delegated_inode);
588 if (!error)
589 goto retry_deleg;
590 }
591 mnt_drop_write(path->mnt);
592 return error;
593}
594
595int vfs_fchmod(struct file *file, umode_t mode)
596{
597 audit_file(file);
598 return chmod_common(&file->f_path, mode);
599}
600
601SYSCALL_DEFINE2(fchmod, unsigned int, fd, umode_t, mode)
602{
603 struct fd f = fdget(fd);
604 int err = -EBADF;
605
606 if (f.file) {
607 err = vfs_fchmod(f.file, mode);
608 fdput(f);
609 }
610 return err;
611}
612
613static int do_fchmodat(int dfd, const char __user *filename, umode_t mode)
614{
615 struct path path;
616 int error;
617 unsigned int lookup_flags = LOOKUP_FOLLOW;
618retry:
619 error = user_path_at(dfd, filename, lookup_flags, &path);
620 if (!error) {
621 error = chmod_common(&path, mode);
622 path_put(&path);
623 if (retry_estale(error, lookup_flags)) {
624 lookup_flags |= LOOKUP_REVAL;
625 goto retry;
626 }
627 }
628 return error;
629}
630
631SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename,
632 umode_t, mode)
633{
634 return do_fchmodat(dfd, filename, mode);
635}
636
637SYSCALL_DEFINE2(chmod, const char __user *, filename, umode_t, mode)
638{
639 return do_fchmodat(AT_FDCWD, filename, mode);
640}
641
642int chown_common(const struct path *path, uid_t user, gid_t group)
643{
644 struct inode *inode = path->dentry->d_inode;
645 struct inode *delegated_inode = NULL;
646 int error;
647 struct iattr newattrs;
648 kuid_t uid;
649 kgid_t gid;
650
651 uid = make_kuid(current_user_ns(), user);
652 gid = make_kgid(current_user_ns(), group);
653
654retry_deleg:
655 newattrs.ia_valid = ATTR_CTIME;
656 if (user != (uid_t) -1) {
657 if (!uid_valid(uid))
658 return -EINVAL;
659 newattrs.ia_valid |= ATTR_UID;
660 newattrs.ia_uid = uid;
661 }
662 if (group != (gid_t) -1) {
663 if (!gid_valid(gid))
664 return -EINVAL;
665 newattrs.ia_valid |= ATTR_GID;
666 newattrs.ia_gid = gid;
667 }
668 if (!S_ISDIR(inode->i_mode))
669 newattrs.ia_valid |=
670 ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
671 inode_lock(inode);
672 error = security_path_chown(path, uid, gid);
673 if (!error)
674 error = notify_change(path->dentry, &newattrs, &delegated_inode);
675 inode_unlock(inode);
676 if (delegated_inode) {
677 error = break_deleg_wait(&delegated_inode);
678 if (!error)
679 goto retry_deleg;
680 }
681 return error;
682}
683
684int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group,
685 int flag)
686{
687 struct path path;
688 int error = -EINVAL;
689 int lookup_flags;
690
691 if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0)
692 goto out;
693
694 lookup_flags = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
695 if (flag & AT_EMPTY_PATH)
696 lookup_flags |= LOOKUP_EMPTY;
697retry:
698 error = user_path_at(dfd, filename, lookup_flags, &path);
699 if (error)
700 goto out;
701 error = mnt_want_write(path.mnt);
702 if (error)
703 goto out_release;
704 error = chown_common(&path, user, group);
705 mnt_drop_write(path.mnt);
706out_release:
707 path_put(&path);
708 if (retry_estale(error, lookup_flags)) {
709 lookup_flags |= LOOKUP_REVAL;
710 goto retry;
711 }
712out:
713 return error;
714}
715
716SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user,
717 gid_t, group, int, flag)
718{
719 return do_fchownat(dfd, filename, user, group, flag);
720}
721
722SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group)
723{
724 return do_fchownat(AT_FDCWD, filename, user, group, 0);
725}
726
727SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group)
728{
729 return do_fchownat(AT_FDCWD, filename, user, group,
730 AT_SYMLINK_NOFOLLOW);
731}
732
733int vfs_fchown(struct file *file, uid_t user, gid_t group)
734{
735 int error;
736
737 error = mnt_want_write_file(file);
738 if (error)
739 return error;
740 audit_file(file);
741 error = chown_common(&file->f_path, user, group);
742 mnt_drop_write_file(file);
743 return error;
744}
745
746int ksys_fchown(unsigned int fd, uid_t user, gid_t group)
747{
748 struct fd f = fdget(fd);
749 int error = -EBADF;
750
751 if (f.file) {
752 error = vfs_fchown(f.file, user, group);
753 fdput(f);
754 }
755 return error;
756}
757
758SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group)
759{
760 return ksys_fchown(fd, user, group);
761}
762
763static int do_dentry_open(struct file *f,
764 struct inode *inode,
765 int (*open)(struct inode *, struct file *))
766{
767 static const struct file_operations empty_fops = {};
768 int error;
769
770 path_get(&f->f_path);
771 f->f_inode = inode;
772 f->f_mapping = inode->i_mapping;
773 f->f_wb_err = filemap_sample_wb_err(f->f_mapping);
774 f->f_sb_err = file_sample_sb_err(f);
775
776 if (unlikely(f->f_flags & O_PATH)) {
777 f->f_mode = FMODE_PATH | FMODE_OPENED;
778 f->f_op = &empty_fops;
779 return 0;
780 }
781
782 if (f->f_mode & FMODE_WRITE && !special_file(inode->i_mode)) {
783 error = get_write_access(inode);
784 if (unlikely(error))
785 goto cleanup_file;
786 error = __mnt_want_write(f->f_path.mnt);
787 if (unlikely(error)) {
788 put_write_access(inode);
789 goto cleanup_file;
790 }
791 f->f_mode |= FMODE_WRITER;
792 }
793
794
795 if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))
796 f->f_mode |= FMODE_ATOMIC_POS;
797
798 f->f_op = fops_get(inode->i_fop);
799 if (WARN_ON(!f->f_op)) {
800 error = -ENODEV;
801 goto cleanup_all;
802 }
803
804 error = security_file_open(f);
805 if (error)
806 goto cleanup_all;
807
808 error = break_lease(locks_inode(f), f->f_flags);
809 if (error)
810 goto cleanup_all;
811
812
813 f->f_mode |= FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE;
814 if (!open)
815 open = f->f_op->open;
816 if (open) {
817 error = open(inode, f);
818 if (error)
819 goto cleanup_all;
820 }
821 f->f_mode |= FMODE_OPENED;
822 if ((f->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
823 i_readcount_inc(inode);
824 if ((f->f_mode & FMODE_READ) &&
825 likely(f->f_op->read || f->f_op->read_iter))
826 f->f_mode |= FMODE_CAN_READ;
827 if ((f->f_mode & FMODE_WRITE) &&
828 likely(f->f_op->write || f->f_op->write_iter))
829 f->f_mode |= FMODE_CAN_WRITE;
830
831 f->f_write_hint = WRITE_LIFE_NOT_SET;
832 f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
833
834 file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);
835
836
837 if (f->f_flags & O_DIRECT) {
838 if (!f->f_mapping->a_ops || !f->f_mapping->a_ops->direct_IO)
839 return -EINVAL;
840 }
841
842
843
844
845
846 if ((f->f_mode & FMODE_WRITE) && filemap_nr_thps(inode->i_mapping))
847 truncate_pagecache(inode, 0);
848
849 return 0;
850
851cleanup_all:
852 if (WARN_ON_ONCE(error > 0))
853 error = -EINVAL;
854 fops_put(f->f_op);
855 if (f->f_mode & FMODE_WRITER) {
856 put_write_access(inode);
857 __mnt_drop_write(f->f_path.mnt);
858 }
859cleanup_file:
860 path_put(&f->f_path);
861 f->f_path.mnt = NULL;
862 f->f_path.dentry = NULL;
863 f->f_inode = NULL;
864 return error;
865}
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885int finish_open(struct file *file, struct dentry *dentry,
886 int (*open)(struct inode *, struct file *))
887{
888 BUG_ON(file->f_mode & FMODE_OPENED);
889
890 file->f_path.dentry = dentry;
891 return do_dentry_open(file, d_backing_inode(dentry), open);
892}
893EXPORT_SYMBOL(finish_open);
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909int finish_no_open(struct file *file, struct dentry *dentry)
910{
911 file->f_path.dentry = dentry;
912 return 0;
913}
914EXPORT_SYMBOL(finish_no_open);
915
916char *file_path(struct file *filp, char *buf, int buflen)
917{
918 return d_path(&filp->f_path, buf, buflen);
919}
920EXPORT_SYMBOL(file_path);
921
922
923
924
925
926
927
928int vfs_open(const struct path *path, struct file *file)
929{
930 file->f_path = *path;
931 return do_dentry_open(file, d_backing_inode(path->dentry), NULL);
932}
933
934struct file *dentry_open(const struct path *path, int flags,
935 const struct cred *cred)
936{
937 int error;
938 struct file *f;
939
940 validate_creds(cred);
941
942
943 BUG_ON(!path->mnt);
944
945 f = alloc_empty_file(flags, cred);
946 if (!IS_ERR(f)) {
947 error = vfs_open(path, f);
948 if (error) {
949 fput(f);
950 f = ERR_PTR(error);
951 }
952 }
953 return f;
954}
955EXPORT_SYMBOL(dentry_open);
956
957struct file *open_with_fake_path(const struct path *path, int flags,
958 struct inode *inode, const struct cred *cred)
959{
960 struct file *f = alloc_empty_file_noaccount(flags, cred);
961 if (!IS_ERR(f)) {
962 int error;
963
964 f->f_path = *path;
965 error = do_dentry_open(f, inode, NULL);
966 if (error) {
967 fput(f);
968 f = ERR_PTR(error);
969 }
970 }
971 return f;
972}
973EXPORT_SYMBOL(open_with_fake_path);
974
975#define WILL_CREATE(flags) (flags & (O_CREAT | __O_TMPFILE))
976#define O_PATH_FLAGS (O_DIRECTORY | O_NOFOLLOW | O_PATH | O_CLOEXEC)
977
978inline struct open_how build_open_how(int flags, umode_t mode)
979{
980 struct open_how how = {
981 .flags = flags & VALID_OPEN_FLAGS,
982 .mode = mode & S_IALLUGO,
983 };
984
985
986 if (how.flags & O_PATH)
987 how.flags &= O_PATH_FLAGS;
988
989 if (!WILL_CREATE(how.flags))
990 how.mode = 0;
991 return how;
992}
993
994inline int build_open_flags(const struct open_how *how, struct open_flags *op)
995{
996 int flags = how->flags;
997 int lookup_flags = 0;
998 int acc_mode = ACC_MODE(flags);
999
1000
1001 flags &= ~(FMODE_NONOTIFY | O_CLOEXEC);
1002
1003
1004
1005
1006
1007
1008 if (flags & ~VALID_OPEN_FLAGS)
1009 return -EINVAL;
1010 if (how->resolve & ~VALID_RESOLVE_FLAGS)
1011 return -EINVAL;
1012
1013
1014 if (WILL_CREATE(flags)) {
1015 if (how->mode & ~S_IALLUGO)
1016 return -EINVAL;
1017 op->mode = how->mode | S_IFREG;
1018 } else {
1019 if (how->mode != 0)
1020 return -EINVAL;
1021 op->mode = 0;
1022 }
1023
1024
1025
1026
1027
1028
1029
1030 if (flags & __O_TMPFILE) {
1031 if ((flags & O_TMPFILE_MASK) != O_TMPFILE)
1032 return -EINVAL;
1033 if (!(acc_mode & MAY_WRITE))
1034 return -EINVAL;
1035 }
1036 if (flags & O_PATH) {
1037
1038 if (flags & ~O_PATH_FLAGS)
1039 return -EINVAL;
1040 acc_mode = 0;
1041 }
1042
1043
1044
1045
1046
1047
1048
1049 if (flags & __O_SYNC)
1050 flags |= O_DSYNC;
1051
1052 op->open_flag = flags;
1053
1054
1055 if (flags & O_TRUNC)
1056 acc_mode |= MAY_WRITE;
1057
1058
1059
1060 if (flags & O_APPEND)
1061 acc_mode |= MAY_APPEND;
1062
1063 op->acc_mode = acc_mode;
1064
1065 op->intent = flags & O_PATH ? 0 : LOOKUP_OPEN;
1066
1067 if (flags & O_CREAT) {
1068 op->intent |= LOOKUP_CREATE;
1069 if (flags & O_EXCL) {
1070 op->intent |= LOOKUP_EXCL;
1071 flags |= O_NOFOLLOW;
1072 }
1073 }
1074
1075 if (flags & O_DIRECTORY)
1076 lookup_flags |= LOOKUP_DIRECTORY;
1077 if (!(flags & O_NOFOLLOW))
1078 lookup_flags |= LOOKUP_FOLLOW;
1079
1080 if (how->resolve & RESOLVE_NO_XDEV)
1081 lookup_flags |= LOOKUP_NO_XDEV;
1082 if (how->resolve & RESOLVE_NO_MAGICLINKS)
1083 lookup_flags |= LOOKUP_NO_MAGICLINKS;
1084 if (how->resolve & RESOLVE_NO_SYMLINKS)
1085 lookup_flags |= LOOKUP_NO_SYMLINKS;
1086 if (how->resolve & RESOLVE_BENEATH)
1087 lookup_flags |= LOOKUP_BENEATH;
1088 if (how->resolve & RESOLVE_IN_ROOT)
1089 lookup_flags |= LOOKUP_IN_ROOT;
1090
1091 op->lookup_flags = lookup_flags;
1092 return 0;
1093}
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106struct file *file_open_name(struct filename *name, int flags, umode_t mode)
1107{
1108 struct open_flags op;
1109 struct open_how how = build_open_how(flags, mode);
1110 int err = build_open_flags(&how, &op);
1111 if (err)
1112 return ERR_PTR(err);
1113 return do_filp_open(AT_FDCWD, name, &op);
1114}
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127struct file *filp_open(const char *filename, int flags, umode_t mode)
1128{
1129 struct filename *name = getname_kernel(filename);
1130 struct file *file = ERR_CAST(name);
1131
1132 if (!IS_ERR(name)) {
1133 file = file_open_name(name, flags, mode);
1134 putname(name);
1135 }
1136 return file;
1137}
1138EXPORT_SYMBOL(filp_open);
1139
1140struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt,
1141 const char *filename, int flags, umode_t mode)
1142{
1143 struct open_flags op;
1144 struct open_how how = build_open_how(flags, mode);
1145 int err = build_open_flags(&how, &op);
1146 if (err)
1147 return ERR_PTR(err);
1148 return do_file_open_root(dentry, mnt, filename, &op);
1149}
1150EXPORT_SYMBOL(file_open_root);
1151
1152static long do_sys_openat2(int dfd, const char __user *filename,
1153 struct open_how *how)
1154{
1155 struct open_flags op;
1156 int fd = build_open_flags(how, &op);
1157 struct filename *tmp;
1158
1159 if (fd)
1160 return fd;
1161
1162 tmp = getname(filename);
1163 if (IS_ERR(tmp))
1164 return PTR_ERR(tmp);
1165
1166 fd = get_unused_fd_flags(how->flags);
1167 if (fd >= 0) {
1168 struct file *f = do_filp_open(dfd, tmp, &op);
1169 if (IS_ERR(f)) {
1170 put_unused_fd(fd);
1171 fd = PTR_ERR(f);
1172 } else {
1173 fsnotify_open(f);
1174 fd_install(fd, f);
1175 }
1176 }
1177 putname(tmp);
1178 return fd;
1179}
1180
1181long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode)
1182{
1183 struct open_how how = build_open_how(flags, mode);
1184 return do_sys_openat2(dfd, filename, &how);
1185}
1186
1187
1188SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode)
1189{
1190 if (force_o_largefile())
1191 flags |= O_LARGEFILE;
1192 return do_sys_open(AT_FDCWD, filename, flags, mode);
1193}
1194
1195SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags,
1196 umode_t, mode)
1197{
1198 if (force_o_largefile())
1199 flags |= O_LARGEFILE;
1200 return do_sys_open(dfd, filename, flags, mode);
1201}
1202
1203SYSCALL_DEFINE4(openat2, int, dfd, const char __user *, filename,
1204 struct open_how __user *, how, size_t, usize)
1205{
1206 int err;
1207 struct open_how tmp;
1208
1209 BUILD_BUG_ON(sizeof(struct open_how) < OPEN_HOW_SIZE_VER0);
1210 BUILD_BUG_ON(sizeof(struct open_how) != OPEN_HOW_SIZE_LATEST);
1211
1212 if (unlikely(usize < OPEN_HOW_SIZE_VER0))
1213 return -EINVAL;
1214
1215 err = copy_struct_from_user(&tmp, sizeof(tmp), how, usize);
1216 if (err)
1217 return err;
1218
1219
1220 if (!(tmp.flags & O_PATH) && force_o_largefile())
1221 tmp.flags |= O_LARGEFILE;
1222
1223 return do_sys_openat2(dfd, filename, &tmp);
1224}
1225
1226#ifdef CONFIG_COMPAT
1227
1228
1229
1230
1231COMPAT_SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode)
1232{
1233 return do_sys_open(AT_FDCWD, filename, flags, mode);
1234}
1235
1236
1237
1238
1239
1240COMPAT_SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags, umode_t, mode)
1241{
1242 return do_sys_open(dfd, filename, flags, mode);
1243}
1244#endif
1245
1246#ifndef __alpha__
1247
1248
1249
1250
1251
1252SYSCALL_DEFINE2(creat, const char __user *, pathname, umode_t, mode)
1253{
1254 int flags = O_CREAT | O_WRONLY | O_TRUNC;
1255
1256 if (force_o_largefile())
1257 flags |= O_LARGEFILE;
1258 return do_sys_open(AT_FDCWD, pathname, flags, mode);
1259}
1260#endif
1261
1262
1263
1264
1265
1266int filp_close(struct file *filp, fl_owner_t id)
1267{
1268 int retval = 0;
1269
1270 if (!file_count(filp)) {
1271 printk(KERN_ERR "VFS: Close: file count is 0\n");
1272 return 0;
1273 }
1274
1275 if (filp->f_op->flush)
1276 retval = filp->f_op->flush(filp, id);
1277
1278 if (likely(!(filp->f_mode & FMODE_PATH))) {
1279 dnotify_flush(filp, id);
1280 locks_remove_posix(filp, id);
1281 }
1282 fput(filp);
1283 return retval;
1284}
1285
1286EXPORT_SYMBOL(filp_close);
1287
1288
1289
1290
1291
1292
1293SYSCALL_DEFINE1(close, unsigned int, fd)
1294{
1295 int retval = __close_fd(current->files, fd);
1296
1297
1298 if (unlikely(retval == -ERESTARTSYS ||
1299 retval == -ERESTARTNOINTR ||
1300 retval == -ERESTARTNOHAND ||
1301 retval == -ERESTART_RESTARTBLOCK))
1302 retval = -EINTR;
1303
1304 return retval;
1305}
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318SYSCALL_DEFINE3(close_range, unsigned int, fd, unsigned int, max_fd,
1319 unsigned int, flags)
1320{
1321 return __close_range(fd, max_fd, flags);
1322}
1323
1324
1325
1326
1327
1328SYSCALL_DEFINE0(vhangup)
1329{
1330 if (capable(CAP_SYS_TTY_CONFIG)) {
1331 tty_vhangup_self();
1332 return 0;
1333 }
1334 return -EPERM;
1335}
1336
1337
1338
1339
1340
1341
1342
1343int generic_file_open(struct inode * inode, struct file * filp)
1344{
1345 if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
1346 return -EOVERFLOW;
1347 return 0;
1348}
1349
1350EXPORT_SYMBOL(generic_file_open);
1351
1352
1353
1354
1355
1356
1357
1358int nonseekable_open(struct inode *inode, struct file *filp)
1359{
1360 filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
1361 return 0;
1362}
1363
1364EXPORT_SYMBOL(nonseekable_open);
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376int stream_open(struct inode *inode, struct file *filp)
1377{
1378 filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE | FMODE_ATOMIC_POS);
1379 filp->f_mode |= FMODE_STREAM;
1380 return 0;
1381}
1382
1383EXPORT_SYMBOL(stream_open);
1384