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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 user_namespace *mnt_userns, struct dentry *dentry,
39 loff_t length, unsigned int time_attrs, 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(mnt_userns, 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 user_namespace *mnt_userns;
72 struct inode *inode;
73 long error;
74
75 inode = path->dentry->d_inode;
76
77
78 if (S_ISDIR(inode->i_mode))
79 return -EISDIR;
80 if (!S_ISREG(inode->i_mode))
81 return -EINVAL;
82
83 error = mnt_want_write(path->mnt);
84 if (error)
85 goto out;
86
87 mnt_userns = mnt_user_ns(path->mnt);
88 error = inode_permission(mnt_userns, inode, MAY_WRITE);
89 if (error)
90 goto mnt_drop_write_and_out;
91
92 error = -EPERM;
93 if (IS_APPEND(inode))
94 goto mnt_drop_write_and_out;
95
96 error = get_write_access(inode);
97 if (error)
98 goto mnt_drop_write_and_out;
99
100
101
102
103
104 error = break_lease(inode, O_WRONLY);
105 if (error)
106 goto put_write_and_out;
107
108 error = locks_verify_truncate(inode, NULL, length);
109 if (!error)
110 error = security_path_truncate(path);
111 if (!error)
112 error = do_truncate(mnt_userns, path->dentry, length, 0, NULL);
113
114put_write_and_out:
115 put_write_access(inode);
116mnt_drop_write_and_out:
117 mnt_drop_write(path->mnt);
118out:
119 return error;
120}
121EXPORT_SYMBOL_GPL(vfs_truncate);
122
123long do_sys_truncate(const char __user *pathname, loff_t length)
124{
125 unsigned int lookup_flags = LOOKUP_FOLLOW;
126 struct path path;
127 int error;
128
129 if (length < 0)
130 return -EINVAL;
131
132retry:
133 error = user_path_at(AT_FDCWD, pathname, lookup_flags, &path);
134 if (!error) {
135 error = vfs_truncate(&path, length);
136 path_put(&path);
137 }
138 if (retry_estale(error, lookup_flags)) {
139 lookup_flags |= LOOKUP_REVAL;
140 goto retry;
141 }
142 return error;
143}
144
145SYSCALL_DEFINE2(truncate, const char __user *, path, long, length)
146{
147 return do_sys_truncate(path, length);
148}
149
150#ifdef CONFIG_COMPAT
151COMPAT_SYSCALL_DEFINE2(truncate, const char __user *, path, compat_off_t, length)
152{
153 return do_sys_truncate(path, length);
154}
155#endif
156
157long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
158{
159 struct inode *inode;
160 struct dentry *dentry;
161 struct fd f;
162 int error;
163
164 error = -EINVAL;
165 if (length < 0)
166 goto out;
167 error = -EBADF;
168 f = fdget(fd);
169 if (!f.file)
170 goto out;
171
172
173 if (f.file->f_flags & O_LARGEFILE)
174 small = 0;
175
176 dentry = f.file->f_path.dentry;
177 inode = dentry->d_inode;
178 error = -EINVAL;
179 if (!S_ISREG(inode->i_mode) || !(f.file->f_mode & FMODE_WRITE))
180 goto out_putf;
181
182 error = -EINVAL;
183
184 if (small && length > MAX_NON_LFS)
185 goto out_putf;
186
187 error = -EPERM;
188
189 if (IS_APPEND(file_inode(f.file)))
190 goto out_putf;
191 sb_start_write(inode->i_sb);
192 error = locks_verify_truncate(inode, f.file, length);
193 if (!error)
194 error = security_path_truncate(&f.file->f_path);
195 if (!error)
196 error = do_truncate(file_mnt_user_ns(f.file), dentry, length,
197 ATTR_MTIME | ATTR_CTIME, f.file);
198 sb_end_write(inode->i_sb);
199out_putf:
200 fdput(f);
201out:
202 return error;
203}
204
205SYSCALL_DEFINE2(ftruncate, unsigned int, fd, unsigned long, length)
206{
207 return do_sys_ftruncate(fd, length, 1);
208}
209
210#ifdef CONFIG_COMPAT
211COMPAT_SYSCALL_DEFINE2(ftruncate, unsigned int, fd, compat_ulong_t, length)
212{
213 return do_sys_ftruncate(fd, length, 1);
214}
215#endif
216
217
218#if BITS_PER_LONG == 32
219SYSCALL_DEFINE2(truncate64, const char __user *, path, loff_t, length)
220{
221 return do_sys_truncate(path, length);
222}
223
224SYSCALL_DEFINE2(ftruncate64, unsigned int, fd, loff_t, length)
225{
226 return do_sys_ftruncate(fd, length, 0);
227}
228#endif
229
230
231int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
232{
233 struct inode *inode = file_inode(file);
234 long ret;
235
236 if (offset < 0 || len <= 0)
237 return -EINVAL;
238
239
240 if (mode & ~FALLOC_FL_SUPPORTED_MASK)
241 return -EOPNOTSUPP;
242
243
244 if ((mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE)) ==
245 (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE))
246 return -EOPNOTSUPP;
247
248
249 if ((mode & FALLOC_FL_PUNCH_HOLE) &&
250 !(mode & FALLOC_FL_KEEP_SIZE))
251 return -EOPNOTSUPP;
252
253
254 if ((mode & FALLOC_FL_COLLAPSE_RANGE) &&
255 (mode & ~FALLOC_FL_COLLAPSE_RANGE))
256 return -EINVAL;
257
258
259 if ((mode & FALLOC_FL_INSERT_RANGE) &&
260 (mode & ~FALLOC_FL_INSERT_RANGE))
261 return -EINVAL;
262
263
264 if ((mode & FALLOC_FL_UNSHARE_RANGE) &&
265 (mode & ~(FALLOC_FL_UNSHARE_RANGE | FALLOC_FL_KEEP_SIZE)))
266 return -EINVAL;
267
268 if (!(file->f_mode & FMODE_WRITE))
269 return -EBADF;
270
271
272
273
274 if ((mode & ~FALLOC_FL_KEEP_SIZE) && IS_APPEND(inode))
275 return -EPERM;
276
277 if (IS_IMMUTABLE(inode))
278 return -EPERM;
279
280
281
282
283 if (IS_SWAPFILE(inode))
284 return -ETXTBSY;
285
286
287
288
289
290 ret = security_file_permission(file, MAY_WRITE);
291 if (ret)
292 return ret;
293
294 if (S_ISFIFO(inode->i_mode))
295 return -ESPIPE;
296
297 if (S_ISDIR(inode->i_mode))
298 return -EISDIR;
299
300 if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))
301 return -ENODEV;
302
303
304 if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0))
305 return -EFBIG;
306
307 if (!file->f_op->fallocate)
308 return -EOPNOTSUPP;
309
310 file_start_write(file);
311 ret = file->f_op->fallocate(file, mode, offset, len);
312
313
314
315
316
317
318
319
320 if (ret == 0)
321 fsnotify_modify(file);
322
323 file_end_write(file);
324 return ret;
325}
326EXPORT_SYMBOL_GPL(vfs_fallocate);
327
328int ksys_fallocate(int fd, int mode, loff_t offset, loff_t len)
329{
330 struct fd f = fdget(fd);
331 int error = -EBADF;
332
333 if (f.file) {
334 error = vfs_fallocate(f.file, mode, offset, len);
335 fdput(f);
336 }
337 return error;
338}
339
340SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len)
341{
342 return ksys_fallocate(fd, mode, offset, len);
343}
344
345
346
347
348
349
350static const struct cred *access_override_creds(void)
351{
352 const struct cred *old_cred;
353 struct cred *override_cred;
354
355 override_cred = prepare_creds();
356 if (!override_cred)
357 return NULL;
358
359 override_cred->fsuid = override_cred->uid;
360 override_cred->fsgid = override_cred->gid;
361
362 if (!issecure(SECURE_NO_SETUID_FIXUP)) {
363
364 kuid_t root_uid = make_kuid(override_cred->user_ns, 0);
365 if (!uid_eq(override_cred->uid, root_uid))
366 cap_clear(override_cred->cap_effective);
367 else
368 override_cred->cap_effective =
369 override_cred->cap_permitted;
370 }
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389 override_cred->non_rcu = 1;
390
391 old_cred = override_creds(override_cred);
392
393
394 put_cred(override_cred);
395
396 return old_cred;
397}
398
399static long do_faccessat(int dfd, const char __user *filename, int mode, int flags)
400{
401 struct path path;
402 struct inode *inode;
403 int res;
404 unsigned int lookup_flags = LOOKUP_FOLLOW;
405 const struct cred *old_cred = NULL;
406
407 if (mode & ~S_IRWXO)
408 return -EINVAL;
409
410 if (flags & ~(AT_EACCESS | AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH))
411 return -EINVAL;
412
413 if (flags & AT_SYMLINK_NOFOLLOW)
414 lookup_flags &= ~LOOKUP_FOLLOW;
415 if (flags & AT_EMPTY_PATH)
416 lookup_flags |= LOOKUP_EMPTY;
417
418 if (!(flags & AT_EACCESS)) {
419 old_cred = access_override_creds();
420 if (!old_cred)
421 return -ENOMEM;
422 }
423
424retry:
425 res = user_path_at(dfd, filename, lookup_flags, &path);
426 if (res)
427 goto out;
428
429 inode = d_backing_inode(path.dentry);
430
431 if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) {
432
433
434
435
436 res = -EACCES;
437 if (path_noexec(&path))
438 goto out_path_release;
439 }
440
441 res = inode_permission(mnt_user_ns(path.mnt), inode, mode | MAY_ACCESS);
442
443 if (res || !(mode & S_IWOTH) || special_file(inode->i_mode))
444 goto out_path_release;
445
446
447
448
449
450
451
452
453
454
455 if (__mnt_is_readonly(path.mnt))
456 res = -EROFS;
457
458out_path_release:
459 path_put(&path);
460 if (retry_estale(res, lookup_flags)) {
461 lookup_flags |= LOOKUP_REVAL;
462 goto retry;
463 }
464out:
465 if (old_cred)
466 revert_creds(old_cred);
467
468 return res;
469}
470
471SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode)
472{
473 return do_faccessat(dfd, filename, mode, 0);
474}
475
476SYSCALL_DEFINE4(faccessat2, int, dfd, const char __user *, filename, int, mode,
477 int, flags)
478{
479 return do_faccessat(dfd, filename, mode, flags);
480}
481
482SYSCALL_DEFINE2(access, const char __user *, filename, int, mode)
483{
484 return do_faccessat(AT_FDCWD, filename, mode, 0);
485}
486
487SYSCALL_DEFINE1(chdir, const char __user *, filename)
488{
489 struct path path;
490 int error;
491 unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
492retry:
493 error = user_path_at(AT_FDCWD, filename, lookup_flags, &path);
494 if (error)
495 goto out;
496
497 error = path_permission(&path, MAY_EXEC | MAY_CHDIR);
498 if (error)
499 goto dput_and_out;
500
501 set_fs_pwd(current->fs, &path);
502
503dput_and_out:
504 path_put(&path);
505 if (retry_estale(error, lookup_flags)) {
506 lookup_flags |= LOOKUP_REVAL;
507 goto retry;
508 }
509out:
510 return error;
511}
512
513SYSCALL_DEFINE1(fchdir, unsigned int, fd)
514{
515 struct fd f = fdget_raw(fd);
516 int error;
517
518 error = -EBADF;
519 if (!f.file)
520 goto out;
521
522 error = -ENOTDIR;
523 if (!d_can_lookup(f.file->f_path.dentry))
524 goto out_putf;
525
526 error = file_permission(f.file, MAY_EXEC | MAY_CHDIR);
527 if (!error)
528 set_fs_pwd(current->fs, &f.file->f_path);
529out_putf:
530 fdput(f);
531out:
532 return error;
533}
534
535SYSCALL_DEFINE1(chroot, const char __user *, filename)
536{
537 struct path path;
538 int error;
539 unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
540retry:
541 error = user_path_at(AT_FDCWD, filename, lookup_flags, &path);
542 if (error)
543 goto out;
544
545 error = path_permission(&path, MAY_EXEC | MAY_CHDIR);
546 if (error)
547 goto dput_and_out;
548
549 error = -EPERM;
550 if (!ns_capable(current_user_ns(), CAP_SYS_CHROOT))
551 goto dput_and_out;
552 error = security_path_chroot(&path);
553 if (error)
554 goto dput_and_out;
555
556 set_fs_root(current->fs, &path);
557 error = 0;
558dput_and_out:
559 path_put(&path);
560 if (retry_estale(error, lookup_flags)) {
561 lookup_flags |= LOOKUP_REVAL;
562 goto retry;
563 }
564out:
565 return error;
566}
567
568int chmod_common(const struct path *path, umode_t mode)
569{
570 struct inode *inode = path->dentry->d_inode;
571 struct inode *delegated_inode = NULL;
572 struct iattr newattrs;
573 int error;
574
575 error = mnt_want_write(path->mnt);
576 if (error)
577 return error;
578retry_deleg:
579 inode_lock(inode);
580 error = security_path_chmod(path, mode);
581 if (error)
582 goto out_unlock;
583 newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
584 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
585 error = notify_change(mnt_user_ns(path->mnt), path->dentry,
586 &newattrs, &delegated_inode);
587out_unlock:
588 inode_unlock(inode);
589 if (delegated_inode) {
590 error = break_deleg_wait(&delegated_inode);
591 if (!error)
592 goto retry_deleg;
593 }
594 mnt_drop_write(path->mnt);
595 return error;
596}
597
598int vfs_fchmod(struct file *file, umode_t mode)
599{
600 audit_file(file);
601 return chmod_common(&file->f_path, mode);
602}
603
604SYSCALL_DEFINE2(fchmod, unsigned int, fd, umode_t, mode)
605{
606 struct fd f = fdget(fd);
607 int err = -EBADF;
608
609 if (f.file) {
610 err = vfs_fchmod(f.file, mode);
611 fdput(f);
612 }
613 return err;
614}
615
616static int do_fchmodat(int dfd, const char __user *filename, umode_t mode)
617{
618 struct path path;
619 int error;
620 unsigned int lookup_flags = LOOKUP_FOLLOW;
621retry:
622 error = user_path_at(dfd, filename, lookup_flags, &path);
623 if (!error) {
624 error = chmod_common(&path, mode);
625 path_put(&path);
626 if (retry_estale(error, lookup_flags)) {
627 lookup_flags |= LOOKUP_REVAL;
628 goto retry;
629 }
630 }
631 return error;
632}
633
634SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename,
635 umode_t, mode)
636{
637 return do_fchmodat(dfd, filename, mode);
638}
639
640SYSCALL_DEFINE2(chmod, const char __user *, filename, umode_t, mode)
641{
642 return do_fchmodat(AT_FDCWD, filename, mode);
643}
644
645int chown_common(const struct path *path, uid_t user, gid_t group)
646{
647 struct user_namespace *mnt_userns;
648 struct inode *inode = path->dentry->d_inode;
649 struct inode *delegated_inode = NULL;
650 int error;
651 struct iattr newattrs;
652 kuid_t uid;
653 kgid_t gid;
654
655 uid = make_kuid(current_user_ns(), user);
656 gid = make_kgid(current_user_ns(), group);
657
658 mnt_userns = mnt_user_ns(path->mnt);
659 uid = kuid_from_mnt(mnt_userns, uid);
660 gid = kgid_from_mnt(mnt_userns, gid);
661
662retry_deleg:
663 newattrs.ia_valid = ATTR_CTIME;
664 if (user != (uid_t) -1) {
665 if (!uid_valid(uid))
666 return -EINVAL;
667 newattrs.ia_valid |= ATTR_UID;
668 newattrs.ia_uid = uid;
669 }
670 if (group != (gid_t) -1) {
671 if (!gid_valid(gid))
672 return -EINVAL;
673 newattrs.ia_valid |= ATTR_GID;
674 newattrs.ia_gid = gid;
675 }
676 if (!S_ISDIR(inode->i_mode))
677 newattrs.ia_valid |=
678 ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
679 inode_lock(inode);
680 error = security_path_chown(path, uid, gid);
681 if (!error)
682 error = notify_change(mnt_userns, path->dentry, &newattrs,
683 &delegated_inode);
684 inode_unlock(inode);
685 if (delegated_inode) {
686 error = break_deleg_wait(&delegated_inode);
687 if (!error)
688 goto retry_deleg;
689 }
690 return error;
691}
692
693int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group,
694 int flag)
695{
696 struct path path;
697 int error = -EINVAL;
698 int lookup_flags;
699
700 if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0)
701 goto out;
702
703 lookup_flags = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
704 if (flag & AT_EMPTY_PATH)
705 lookup_flags |= LOOKUP_EMPTY;
706retry:
707 error = user_path_at(dfd, filename, lookup_flags, &path);
708 if (error)
709 goto out;
710 error = mnt_want_write(path.mnt);
711 if (error)
712 goto out_release;
713 error = chown_common(&path, user, group);
714 mnt_drop_write(path.mnt);
715out_release:
716 path_put(&path);
717 if (retry_estale(error, lookup_flags)) {
718 lookup_flags |= LOOKUP_REVAL;
719 goto retry;
720 }
721out:
722 return error;
723}
724
725SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user,
726 gid_t, group, int, flag)
727{
728 return do_fchownat(dfd, filename, user, group, flag);
729}
730
731SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group)
732{
733 return do_fchownat(AT_FDCWD, filename, user, group, 0);
734}
735
736SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group)
737{
738 return do_fchownat(AT_FDCWD, filename, user, group,
739 AT_SYMLINK_NOFOLLOW);
740}
741
742int vfs_fchown(struct file *file, uid_t user, gid_t group)
743{
744 int error;
745
746 error = mnt_want_write_file(file);
747 if (error)
748 return error;
749 audit_file(file);
750 error = chown_common(&file->f_path, user, group);
751 mnt_drop_write_file(file);
752 return error;
753}
754
755int ksys_fchown(unsigned int fd, uid_t user, gid_t group)
756{
757 struct fd f = fdget(fd);
758 int error = -EBADF;
759
760 if (f.file) {
761 error = vfs_fchown(f.file, user, group);
762 fdput(f);
763 }
764 return error;
765}
766
767SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group)
768{
769 return ksys_fchown(fd, user, group);
770}
771
772static int do_dentry_open(struct file *f,
773 struct inode *inode,
774 int (*open)(struct inode *, struct file *))
775{
776 static const struct file_operations empty_fops = {};
777 int error;
778
779 path_get(&f->f_path);
780 f->f_inode = inode;
781 f->f_mapping = inode->i_mapping;
782 f->f_wb_err = filemap_sample_wb_err(f->f_mapping);
783 f->f_sb_err = file_sample_sb_err(f);
784
785 if (unlikely(f->f_flags & O_PATH)) {
786 f->f_mode = FMODE_PATH | FMODE_OPENED;
787 f->f_op = &empty_fops;
788 return 0;
789 }
790
791 if (f->f_mode & FMODE_WRITE && !special_file(inode->i_mode)) {
792 error = get_write_access(inode);
793 if (unlikely(error))
794 goto cleanup_file;
795 error = __mnt_want_write(f->f_path.mnt);
796 if (unlikely(error)) {
797 put_write_access(inode);
798 goto cleanup_file;
799 }
800 f->f_mode |= FMODE_WRITER;
801 }
802
803
804 if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))
805 f->f_mode |= FMODE_ATOMIC_POS;
806
807 f->f_op = fops_get(inode->i_fop);
808 if (WARN_ON(!f->f_op)) {
809 error = -ENODEV;
810 goto cleanup_all;
811 }
812
813 error = security_file_open(f);
814 if (error)
815 goto cleanup_all;
816
817 error = break_lease(locks_inode(f), f->f_flags);
818 if (error)
819 goto cleanup_all;
820
821
822 f->f_mode |= FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE;
823 if (!open)
824 open = f->f_op->open;
825 if (open) {
826 error = open(inode, f);
827 if (error)
828 goto cleanup_all;
829 }
830 f->f_mode |= FMODE_OPENED;
831 if ((f->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
832 i_readcount_inc(inode);
833 if ((f->f_mode & FMODE_READ) &&
834 likely(f->f_op->read || f->f_op->read_iter))
835 f->f_mode |= FMODE_CAN_READ;
836 if ((f->f_mode & FMODE_WRITE) &&
837 likely(f->f_op->write || f->f_op->write_iter))
838 f->f_mode |= FMODE_CAN_WRITE;
839
840 f->f_write_hint = WRITE_LIFE_NOT_SET;
841 f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
842
843 file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);
844
845
846 if (f->f_flags & O_DIRECT) {
847 if (!f->f_mapping->a_ops || !f->f_mapping->a_ops->direct_IO)
848 return -EINVAL;
849 }
850
851
852
853
854
855 if (f->f_mode & FMODE_WRITE) {
856
857
858
859
860
861
862 smp_mb();
863 if (filemap_nr_thps(inode->i_mapping))
864 truncate_pagecache(inode, 0);
865 }
866
867 return 0;
868
869cleanup_all:
870 if (WARN_ON_ONCE(error > 0))
871 error = -EINVAL;
872 fops_put(f->f_op);
873 if (f->f_mode & FMODE_WRITER) {
874 put_write_access(inode);
875 __mnt_drop_write(f->f_path.mnt);
876 }
877cleanup_file:
878 path_put(&f->f_path);
879 f->f_path.mnt = NULL;
880 f->f_path.dentry = NULL;
881 f->f_inode = NULL;
882 return error;
883}
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903int finish_open(struct file *file, struct dentry *dentry,
904 int (*open)(struct inode *, struct file *))
905{
906 BUG_ON(file->f_mode & FMODE_OPENED);
907
908 file->f_path.dentry = dentry;
909 return do_dentry_open(file, d_backing_inode(dentry), open);
910}
911EXPORT_SYMBOL(finish_open);
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927int finish_no_open(struct file *file, struct dentry *dentry)
928{
929 file->f_path.dentry = dentry;
930 return 0;
931}
932EXPORT_SYMBOL(finish_no_open);
933
934char *file_path(struct file *filp, char *buf, int buflen)
935{
936 return d_path(&filp->f_path, buf, buflen);
937}
938EXPORT_SYMBOL(file_path);
939
940
941
942
943
944
945
946int vfs_open(const struct path *path, struct file *file)
947{
948 file->f_path = *path;
949 return do_dentry_open(file, d_backing_inode(path->dentry), NULL);
950}
951
952struct file *dentry_open(const struct path *path, int flags,
953 const struct cred *cred)
954{
955 int error;
956 struct file *f;
957
958 validate_creds(cred);
959
960
961 BUG_ON(!path->mnt);
962
963 f = alloc_empty_file(flags, cred);
964 if (!IS_ERR(f)) {
965 error = vfs_open(path, f);
966 if (error) {
967 fput(f);
968 f = ERR_PTR(error);
969 }
970 }
971 return f;
972}
973EXPORT_SYMBOL(dentry_open);
974
975struct file *open_with_fake_path(const struct path *path, int flags,
976 struct inode *inode, const struct cred *cred)
977{
978 struct file *f = alloc_empty_file_noaccount(flags, cred);
979 if (!IS_ERR(f)) {
980 int error;
981
982 f->f_path = *path;
983 error = do_dentry_open(f, inode, NULL);
984 if (error) {
985 fput(f);
986 f = ERR_PTR(error);
987 }
988 }
989 return f;
990}
991EXPORT_SYMBOL(open_with_fake_path);
992
993#define WILL_CREATE(flags) (flags & (O_CREAT | __O_TMPFILE))
994#define O_PATH_FLAGS (O_DIRECTORY | O_NOFOLLOW | O_PATH | O_CLOEXEC)
995
996inline struct open_how build_open_how(int flags, umode_t mode)
997{
998 struct open_how how = {
999 .flags = flags & VALID_OPEN_FLAGS,
1000 .mode = mode & S_IALLUGO,
1001 };
1002
1003
1004 if (how.flags & O_PATH)
1005 how.flags &= O_PATH_FLAGS;
1006
1007 if (!WILL_CREATE(how.flags))
1008 how.mode = 0;
1009 return how;
1010}
1011
1012inline int build_open_flags(const struct open_how *how, struct open_flags *op)
1013{
1014 u64 flags = how->flags;
1015 u64 strip = FMODE_NONOTIFY | O_CLOEXEC;
1016 int lookup_flags = 0;
1017 int acc_mode = ACC_MODE(flags);
1018
1019 BUILD_BUG_ON_MSG(upper_32_bits(VALID_OPEN_FLAGS),
1020 "struct open_flags doesn't yet handle flags > 32 bits");
1021
1022
1023
1024
1025
1026
1027 flags &= ~strip;
1028
1029
1030
1031
1032
1033
1034 if (flags & ~VALID_OPEN_FLAGS)
1035 return -EINVAL;
1036 if (how->resolve & ~VALID_RESOLVE_FLAGS)
1037 return -EINVAL;
1038
1039
1040 if ((how->resolve & RESOLVE_BENEATH) && (how->resolve & RESOLVE_IN_ROOT))
1041 return -EINVAL;
1042
1043
1044 if (WILL_CREATE(flags)) {
1045 if (how->mode & ~S_IALLUGO)
1046 return -EINVAL;
1047 op->mode = how->mode | S_IFREG;
1048 } else {
1049 if (how->mode != 0)
1050 return -EINVAL;
1051 op->mode = 0;
1052 }
1053
1054
1055
1056
1057
1058
1059
1060 if (flags & __O_TMPFILE) {
1061 if ((flags & O_TMPFILE_MASK) != O_TMPFILE)
1062 return -EINVAL;
1063 if (!(acc_mode & MAY_WRITE))
1064 return -EINVAL;
1065 }
1066 if (flags & O_PATH) {
1067
1068 if (flags & ~O_PATH_FLAGS)
1069 return -EINVAL;
1070 acc_mode = 0;
1071 }
1072
1073
1074
1075
1076
1077
1078
1079 if (flags & __O_SYNC)
1080 flags |= O_DSYNC;
1081
1082 op->open_flag = flags;
1083
1084
1085 if (flags & O_TRUNC)
1086 acc_mode |= MAY_WRITE;
1087
1088
1089
1090 if (flags & O_APPEND)
1091 acc_mode |= MAY_APPEND;
1092
1093 op->acc_mode = acc_mode;
1094
1095 op->intent = flags & O_PATH ? 0 : LOOKUP_OPEN;
1096
1097 if (flags & O_CREAT) {
1098 op->intent |= LOOKUP_CREATE;
1099 if (flags & O_EXCL) {
1100 op->intent |= LOOKUP_EXCL;
1101 flags |= O_NOFOLLOW;
1102 }
1103 }
1104
1105 if (flags & O_DIRECTORY)
1106 lookup_flags |= LOOKUP_DIRECTORY;
1107 if (!(flags & O_NOFOLLOW))
1108 lookup_flags |= LOOKUP_FOLLOW;
1109
1110 if (how->resolve & RESOLVE_NO_XDEV)
1111 lookup_flags |= LOOKUP_NO_XDEV;
1112 if (how->resolve & RESOLVE_NO_MAGICLINKS)
1113 lookup_flags |= LOOKUP_NO_MAGICLINKS;
1114 if (how->resolve & RESOLVE_NO_SYMLINKS)
1115 lookup_flags |= LOOKUP_NO_SYMLINKS;
1116 if (how->resolve & RESOLVE_BENEATH)
1117 lookup_flags |= LOOKUP_BENEATH;
1118 if (how->resolve & RESOLVE_IN_ROOT)
1119 lookup_flags |= LOOKUP_IN_ROOT;
1120 if (how->resolve & RESOLVE_CACHED) {
1121
1122 if (flags & (O_TRUNC | O_CREAT | O_TMPFILE))
1123 return -EAGAIN;
1124 lookup_flags |= LOOKUP_CACHED;
1125 }
1126
1127 op->lookup_flags = lookup_flags;
1128 return 0;
1129}
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142struct file *file_open_name(struct filename *name, int flags, umode_t mode)
1143{
1144 struct open_flags op;
1145 struct open_how how = build_open_how(flags, mode);
1146 int err = build_open_flags(&how, &op);
1147 if (err)
1148 return ERR_PTR(err);
1149 return do_filp_open(AT_FDCWD, name, &op);
1150}
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163struct file *filp_open(const char *filename, int flags, umode_t mode)
1164{
1165 struct filename *name = getname_kernel(filename);
1166 struct file *file = ERR_CAST(name);
1167
1168 if (!IS_ERR(name)) {
1169 file = file_open_name(name, flags, mode);
1170 putname(name);
1171 }
1172 return file;
1173}
1174EXPORT_SYMBOL(filp_open);
1175
1176struct file *file_open_root(const struct path *root,
1177 const char *filename, int flags, umode_t mode)
1178{
1179 struct open_flags op;
1180 struct open_how how = build_open_how(flags, mode);
1181 int err = build_open_flags(&how, &op);
1182 if (err)
1183 return ERR_PTR(err);
1184 return do_file_open_root(root, filename, &op);
1185}
1186EXPORT_SYMBOL(file_open_root);
1187
1188static long do_sys_openat2(int dfd, const char __user *filename,
1189 struct open_how *how)
1190{
1191 struct open_flags op;
1192 int fd = build_open_flags(how, &op);
1193 struct filename *tmp;
1194
1195 if (fd)
1196 return fd;
1197
1198 tmp = getname(filename);
1199 if (IS_ERR(tmp))
1200 return PTR_ERR(tmp);
1201
1202 fd = get_unused_fd_flags(how->flags);
1203 if (fd >= 0) {
1204 struct file *f = do_filp_open(dfd, tmp, &op);
1205 if (IS_ERR(f)) {
1206 put_unused_fd(fd);
1207 fd = PTR_ERR(f);
1208 } else {
1209 fsnotify_open(f);
1210 fd_install(fd, f);
1211 }
1212 }
1213 putname(tmp);
1214 return fd;
1215}
1216
1217long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode)
1218{
1219 struct open_how how = build_open_how(flags, mode);
1220 return do_sys_openat2(dfd, filename, &how);
1221}
1222
1223
1224SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode)
1225{
1226 if (force_o_largefile())
1227 flags |= O_LARGEFILE;
1228 return do_sys_open(AT_FDCWD, filename, flags, mode);
1229}
1230
1231SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags,
1232 umode_t, mode)
1233{
1234 if (force_o_largefile())
1235 flags |= O_LARGEFILE;
1236 return do_sys_open(dfd, filename, flags, mode);
1237}
1238
1239SYSCALL_DEFINE4(openat2, int, dfd, const char __user *, filename,
1240 struct open_how __user *, how, size_t, usize)
1241{
1242 int err;
1243 struct open_how tmp;
1244
1245 BUILD_BUG_ON(sizeof(struct open_how) < OPEN_HOW_SIZE_VER0);
1246 BUILD_BUG_ON(sizeof(struct open_how) != OPEN_HOW_SIZE_LATEST);
1247
1248 if (unlikely(usize < OPEN_HOW_SIZE_VER0))
1249 return -EINVAL;
1250
1251 err = copy_struct_from_user(&tmp, sizeof(tmp), how, usize);
1252 if (err)
1253 return err;
1254
1255
1256 if (!(tmp.flags & O_PATH) && force_o_largefile())
1257 tmp.flags |= O_LARGEFILE;
1258
1259 return do_sys_openat2(dfd, filename, &tmp);
1260}
1261
1262#ifdef CONFIG_COMPAT
1263
1264
1265
1266
1267COMPAT_SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode)
1268{
1269 return do_sys_open(AT_FDCWD, filename, flags, mode);
1270}
1271
1272
1273
1274
1275
1276COMPAT_SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags, umode_t, mode)
1277{
1278 return do_sys_open(dfd, filename, flags, mode);
1279}
1280#endif
1281
1282#ifndef __alpha__
1283
1284
1285
1286
1287
1288SYSCALL_DEFINE2(creat, const char __user *, pathname, umode_t, mode)
1289{
1290 int flags = O_CREAT | O_WRONLY | O_TRUNC;
1291
1292 if (force_o_largefile())
1293 flags |= O_LARGEFILE;
1294 return do_sys_open(AT_FDCWD, pathname, flags, mode);
1295}
1296#endif
1297
1298
1299
1300
1301
1302int filp_close(struct file *filp, fl_owner_t id)
1303{
1304 int retval = 0;
1305
1306 if (!file_count(filp)) {
1307 printk(KERN_ERR "VFS: Close: file count is 0\n");
1308 return 0;
1309 }
1310
1311 if (filp->f_op->flush)
1312 retval = filp->f_op->flush(filp, id);
1313
1314 if (likely(!(filp->f_mode & FMODE_PATH))) {
1315 dnotify_flush(filp, id);
1316 locks_remove_posix(filp, id);
1317 }
1318 fput(filp);
1319 return retval;
1320}
1321
1322EXPORT_SYMBOL(filp_close);
1323
1324
1325
1326
1327
1328
1329SYSCALL_DEFINE1(close, unsigned int, fd)
1330{
1331 int retval = close_fd(fd);
1332
1333
1334 if (unlikely(retval == -ERESTARTSYS ||
1335 retval == -ERESTARTNOINTR ||
1336 retval == -ERESTARTNOHAND ||
1337 retval == -ERESTART_RESTARTBLOCK))
1338 retval = -EINTR;
1339
1340 return retval;
1341}
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354SYSCALL_DEFINE3(close_range, unsigned int, fd, unsigned int, max_fd,
1355 unsigned int, flags)
1356{
1357 return __close_range(fd, max_fd, flags);
1358}
1359
1360
1361
1362
1363
1364SYSCALL_DEFINE0(vhangup)
1365{
1366 if (capable(CAP_SYS_TTY_CONFIG)) {
1367 tty_vhangup_self();
1368 return 0;
1369 }
1370 return -EPERM;
1371}
1372
1373
1374
1375
1376
1377
1378
1379int generic_file_open(struct inode * inode, struct file * filp)
1380{
1381 if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
1382 return -EOVERFLOW;
1383 return 0;
1384}
1385
1386EXPORT_SYMBOL(generic_file_open);
1387
1388
1389
1390
1391
1392
1393
1394int nonseekable_open(struct inode *inode, struct file *filp)
1395{
1396 filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
1397 return 0;
1398}
1399
1400EXPORT_SYMBOL(nonseekable_open);
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412int stream_open(struct inode *inode, struct file *filp)
1413{
1414 filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE | FMODE_ATOMIC_POS);
1415 filp->f_mode |= FMODE_STREAM;
1416 return 0;
1417}
1418
1419EXPORT_SYMBOL(stream_open);
1420