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