4 * Copyright (C) 1991, 1992 Linus Torvalds
7 #include <linux/string.h>
9 #include <linux/file.h>
10 #include <linux/fdtable.h>
11 #include <linux/fsnotify.h>
12 #include <linux/module.h>
13 #include <linux/tty.h>
14 #include <linux/namei.h>
15 #include <linux/backing-dev.h>
16 #include <linux/capability.h>
17 #include <linux/securebits.h>
18 #include <linux/security.h>
19 #include <linux/mount.h>
20 #include <linux/fcntl.h>
21 #include <linux/slab.h>
22 #include <asm/uaccess.h>
24 #include <linux/personality.h>
25 #include <linux/pagemap.h>
26 #include <linux/syscalls.h>
27 #include <linux/rcupdate.h>
28 #include <linux/audit.h>
29 #include <linux/falloc.h>
30 #include <linux/fs_struct.h>
31 #include <linux/ima.h>
32 #include <linux/dnotify.h>
36 int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
40 struct iattr newattrs;
42 /* Not pretty: "inode->i_size" shouldn't really be signed. But it is. */
46 newattrs.ia_size = length;
47 newattrs.ia_valid = ATTR_SIZE | time_attrs;
49 newattrs.ia_file = filp;
50 newattrs.ia_valid |= ATTR_FILE;
53 /* Remove suid/sgid on truncate too */
54 ret = should_remove_suid(dentry);
56 newattrs.ia_valid |= ret | ATTR_FORCE;
58 mutex_lock(&dentry->d_inode->i_mutex);
59 ret = notify_change(dentry, &newattrs);
60 mutex_unlock(&dentry->d_inode->i_mutex);
64 static long do_sys_truncate(const char __user *pathname, loff_t length)
71 if (length < 0) /* sorry, but loff_t says... */
74 error = user_path(pathname, &path);
77 inode = path.dentry->d_inode;
79 /* For directories it's -EISDIR, for other non-regulars - -EINVAL */
81 if (S_ISDIR(inode->i_mode))
85 if (!S_ISREG(inode->i_mode))
88 error = mnt_want_write(path.mnt);
92 error = inode_permission(inode, MAY_WRITE);
94 goto mnt_drop_write_and_out;
98 goto mnt_drop_write_and_out;
100 error = get_write_access(inode);
102 goto mnt_drop_write_and_out;
105 * Make sure that there are no leases. get_write_access() protects
106 * against the truncate racing with a lease-granting setlease().
108 error = break_lease(inode, O_WRONLY);
110 goto put_write_and_out;
112 error = locks_verify_truncate(inode, NULL, length);
114 error = security_path_truncate(&path);
116 error = do_truncate(path.dentry, length, 0, NULL);
119 put_write_access(inode);
120 mnt_drop_write_and_out:
121 mnt_drop_write(path.mnt);
128 SYSCALL_DEFINE2(truncate, const char __user *, path, long, length)
130 return do_sys_truncate(path, length);
133 static long do_sys_ftruncate(unsigned int fd, loff_t length, int small)
135 struct inode * inode;
136 struct dentry *dentry;
148 /* explicitly opened as large or we are on 64-bit box */
149 if (file->f_flags & O_LARGEFILE)
152 dentry = file->f_path.dentry;
153 inode = dentry->d_inode;
155 if (!S_ISREG(inode->i_mode) || !(file->f_mode & FMODE_WRITE))
159 /* Cannot ftruncate over 2^31 bytes without large file support */
160 if (small && length > MAX_NON_LFS)
164 if (IS_APPEND(inode))
167 error = locks_verify_truncate(inode, file, length);
169 error = security_path_truncate(&file->f_path);
171 error = do_truncate(dentry, length, ATTR_MTIME|ATTR_CTIME, file);
178 SYSCALL_DEFINE2(ftruncate, unsigned int, fd, unsigned long, length)
180 long ret = do_sys_ftruncate(fd, length, 1);
181 /* avoid REGPARM breakage on x86: */
182 asmlinkage_protect(2, ret, fd, length);
186 /* LFS versions of truncate are only needed on 32 bit machines */
187 #if BITS_PER_LONG == 32
188 SYSCALL_DEFINE(truncate64)(const char __user * path, loff_t length)
190 return do_sys_truncate(path, length);
192 #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
193 asmlinkage long SyS_truncate64(long path, loff_t length)
195 return SYSC_truncate64((const char __user *) path, length);
197 SYSCALL_ALIAS(sys_truncate64, SyS_truncate64);
200 SYSCALL_DEFINE(ftruncate64)(unsigned int fd, loff_t length)
202 long ret = do_sys_ftruncate(fd, length, 0);
203 /* avoid REGPARM breakage on x86: */
204 asmlinkage_protect(2, ret, fd, length);
207 #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
208 asmlinkage long SyS_ftruncate64(long fd, loff_t length)
210 return SYSC_ftruncate64((unsigned int) fd, length);
212 SYSCALL_ALIAS(sys_ftruncate64, SyS_ftruncate64);
214 #endif /* BITS_PER_LONG == 32 */
217 int do_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
219 struct inode *inode = file->f_path.dentry->d_inode;
222 if (offset < 0 || len <= 0)
225 /* Return error if mode is not supported */
226 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
229 /* Punch hole must have keep size set */
230 if ((mode & FALLOC_FL_PUNCH_HOLE) &&
231 !(mode & FALLOC_FL_KEEP_SIZE))
234 if (!(file->f_mode & FMODE_WRITE))
237 /* It's not possible punch hole on append only file */
238 if (mode & FALLOC_FL_PUNCH_HOLE && IS_APPEND(inode))
241 if (IS_IMMUTABLE(inode))
245 * Revalidate the write permissions, in case security policy has
246 * changed since the files were opened.
248 ret = security_file_permission(file, MAY_WRITE);
252 if (S_ISFIFO(inode->i_mode))
256 * Let individual file system decide if it supports preallocation
257 * for directories or not.
259 if (!S_ISREG(inode->i_mode) && !S_ISDIR(inode->i_mode))
262 /* Check for wrap through zero too */
263 if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0))
266 if (!file->f_op->fallocate)
269 return file->f_op->fallocate(file, mode, offset, len);
272 SYSCALL_DEFINE(fallocate)(int fd, int mode, loff_t offset, loff_t len)
279 error = do_fallocate(file, mode, offset, len);
286 #ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
287 asmlinkage long SyS_fallocate(long fd, long mode, loff_t offset, loff_t len)
289 return SYSC_fallocate((int)fd, (int)mode, offset, len);
291 SYSCALL_ALIAS(sys_fallocate, SyS_fallocate);
295 * access() needs to use the real uid/gid, not the effective uid/gid.
296 * We do this by temporarily clearing all FS-related capabilities and
297 * switching the fsuid/fsgid around to the real ones.
299 SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode)
301 const struct cred *old_cred;
302 struct cred *override_cred;
307 if (mode & ~S_IRWXO) /* where's F_OK, X_OK, W_OK, R_OK? */
310 override_cred = prepare_creds();
314 override_cred->fsuid = override_cred->uid;
315 override_cred->fsgid = override_cred->gid;
317 if (!issecure(SECURE_NO_SETUID_FIXUP)) {
318 /* Clear the capabilities if we switch to a non-root user */
319 kuid_t root_uid = make_kuid(override_cred->user_ns, 0);
320 if (!uid_eq(override_cred->uid, root_uid))
321 cap_clear(override_cred->cap_effective);
323 override_cred->cap_effective =
324 override_cred->cap_permitted;
327 old_cred = override_creds(override_cred);
329 res = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path);
333 inode = path.dentry->d_inode;
335 if ((mode & MAY_EXEC) && S_ISREG(inode->i_mode)) {
337 * MAY_EXEC on regular files is denied if the fs is mounted
338 * with the "noexec" flag.
341 if (path.mnt->mnt_flags & MNT_NOEXEC)
342 goto out_path_release;
345 res = inode_permission(inode, mode | MAY_ACCESS);
346 /* SuS v2 requires we report a read only fs too */
347 if (res || !(mode & S_IWOTH) || special_file(inode->i_mode))
348 goto out_path_release;
350 * This is a rare case where using __mnt_is_readonly()
351 * is OK without a mnt_want/drop_write() pair. Since
352 * no actual write to the fs is performed here, we do
353 * not need to telegraph to that to anyone.
355 * By doing this, we accept that this access is
356 * inherently racy and know that the fs may change
357 * state before we even see this result.
359 if (__mnt_is_readonly(path.mnt))
365 revert_creds(old_cred);
366 put_cred(override_cred);
370 SYSCALL_DEFINE2(access, const char __user *, filename, int, mode)
372 return sys_faccessat(AT_FDCWD, filename, mode);
375 SYSCALL_DEFINE1(chdir, const char __user *, filename)
380 error = user_path_dir(filename, &path);
384 error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
388 set_fs_pwd(current->fs, &path);
396 SYSCALL_DEFINE1(fchdir, unsigned int, fd)
400 int error, fput_needed;
403 file = fget_raw_light(fd, &fput_needed);
407 inode = file->f_path.dentry->d_inode;
410 if (!S_ISDIR(inode->i_mode))
413 error = inode_permission(inode, MAY_EXEC | MAY_CHDIR);
415 set_fs_pwd(current->fs, &file->f_path);
417 fput_light(file, fput_needed);
422 SYSCALL_DEFINE1(chroot, const char __user *, filename)
427 error = user_path_dir(filename, &path);
431 error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
436 if (!capable(CAP_SYS_CHROOT))
438 error = security_path_chroot(&path);
442 set_fs_root(current->fs, &path);
450 static int chmod_common(struct path *path, umode_t mode)
452 struct inode *inode = path->dentry->d_inode;
453 struct iattr newattrs;
456 error = mnt_want_write(path->mnt);
459 mutex_lock(&inode->i_mutex);
460 error = security_path_chmod(path, mode);
463 newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
464 newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
465 error = notify_change(path->dentry, &newattrs);
467 mutex_unlock(&inode->i_mutex);
468 mnt_drop_write(path->mnt);
472 SYSCALL_DEFINE2(fchmod, unsigned int, fd, umode_t, mode)
479 audit_inode(NULL, file->f_path.dentry);
480 err = chmod_common(&file->f_path, mode);
486 SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, umode_t, mode)
491 error = user_path_at(dfd, filename, LOOKUP_FOLLOW, &path);
493 error = chmod_common(&path, mode);
499 SYSCALL_DEFINE2(chmod, const char __user *, filename, umode_t, mode)
501 return sys_fchmodat(AT_FDCWD, filename, mode);
504 static int chown_common(struct path *path, uid_t user, gid_t group)
506 struct inode *inode = path->dentry->d_inode;
508 struct iattr newattrs;
512 uid = make_kuid(current_user_ns(), user);
513 gid = make_kgid(current_user_ns(), group);
515 newattrs.ia_valid = ATTR_CTIME;
516 if (user != (uid_t) -1) {
519 newattrs.ia_valid |= ATTR_UID;
520 newattrs.ia_uid = uid;
522 if (group != (gid_t) -1) {
525 newattrs.ia_valid |= ATTR_GID;
526 newattrs.ia_gid = gid;
528 if (!S_ISDIR(inode->i_mode))
530 ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV;
531 mutex_lock(&inode->i_mutex);
532 error = security_path_chown(path, user, group);
534 error = notify_change(path->dentry, &newattrs);
535 mutex_unlock(&inode->i_mutex);
540 SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group)
545 error = user_path(filename, &path);
548 error = mnt_want_write(path.mnt);
551 error = chown_common(&path, user, group);
552 mnt_drop_write(path.mnt);
559 SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user,
560 gid_t, group, int, flag)
566 if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0)
569 lookup_flags = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
570 if (flag & AT_EMPTY_PATH)
571 lookup_flags |= LOOKUP_EMPTY;
572 error = user_path_at(dfd, filename, lookup_flags, &path);
575 error = mnt_want_write(path.mnt);
578 error = chown_common(&path, user, group);
579 mnt_drop_write(path.mnt);
586 SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group)
591 error = user_lpath(filename, &path);
594 error = mnt_want_write(path.mnt);
597 error = chown_common(&path, user, group);
598 mnt_drop_write(path.mnt);
605 SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group)
609 struct dentry * dentry;
615 error = mnt_want_write_file(file);
618 dentry = file->f_path.dentry;
619 audit_inode(NULL, dentry);
620 error = chown_common(&file->f_path, user, group);
621 mnt_drop_write_file(file);
629 * You have to be very careful that these write
630 * counts get cleaned up in error cases and
631 * upon __fput(). This should probably never
632 * be called outside of __dentry_open().
634 static inline int __get_file_write_access(struct inode *inode,
635 struct vfsmount *mnt)
638 error = get_write_access(inode);
642 * Do not take mount writer counts on
643 * special files since no writes to
644 * the mount itself will occur.
646 if (!special_file(inode->i_mode)) {
648 * Balanced in __fput()
650 error = mnt_want_write(mnt);
652 put_write_access(inode);
657 int open_check_o_direct(struct file *f)
659 /* NB: we're sure to have correct a_ops only after f_op->open */
660 if (f->f_flags & O_DIRECT) {
661 if (!f->f_mapping->a_ops ||
662 ((!f->f_mapping->a_ops->direct_IO) &&
663 (!f->f_mapping->a_ops->get_xip_mem))) {
670 static int do_dentry_open(struct dentry *dentry, struct vfsmount *mnt,
672 int (*open)(struct inode *, struct file *),
673 const struct cred *cred)
675 static const struct file_operations empty_fops = {};
679 f->f_mode = OPEN_FMODE(f->f_flags) | FMODE_LSEEK |
680 FMODE_PREAD | FMODE_PWRITE;
682 if (unlikely(f->f_flags & O_PATH))
683 f->f_mode = FMODE_PATH;
685 inode = dentry->d_inode;
686 if (f->f_mode & FMODE_WRITE) {
687 error = __get_file_write_access(inode, mnt);
690 if (!special_file(inode->i_mode))
694 f->f_mapping = inode->i_mapping;
695 f->f_path.dentry = dentry;
698 file_sb_list_add(f, inode->i_sb);
700 if (unlikely(f->f_mode & FMODE_PATH)) {
701 f->f_op = &empty_fops;
705 f->f_op = fops_get(inode->i_fop);
707 error = security_file_open(f, cred);
711 error = break_lease(inode, f->f_flags);
715 if (!open && f->f_op)
716 open = f->f_op->open;
718 error = open(inode, f);
722 if ((f->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
723 i_readcount_inc(inode);
725 f->f_flags &= ~(O_CREAT | O_EXCL | O_NOCTTY | O_TRUNC);
727 file_ra_state_init(&f->f_ra, f->f_mapping->host->i_mapping);
733 if (f->f_mode & FMODE_WRITE) {
734 put_write_access(inode);
735 if (!special_file(inode->i_mode)) {
737 * We don't consider this a real
738 * mnt_want/drop_write() pair
739 * because it all happenend right
740 * here, so just reset the state.
747 f->f_path.dentry = NULL;
748 f->f_path.mnt = NULL;
756 * finish_open - finish opening a file
757 * @od: opaque open data
758 * @dentry: pointer to dentry
759 * @open: open callback
761 * This can be used to finish opening a file passed to i_op->atomic_open().
763 * If the open callback is set to NULL, then the standard f_op->open()
764 * filesystem callback is substituted.
766 int finish_open(struct file *file, struct dentry *dentry,
767 int (*open)(struct inode *, struct file *),
771 BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */
773 mntget(file->f_path.mnt);
776 error = do_dentry_open(dentry, file->f_path.mnt, file, open, current_cred());
778 *opened |= FILE_OPENED;
782 EXPORT_SYMBOL(finish_open);
785 * finish_no_open - finish ->atomic_open() without opening the file
787 * @od: opaque open data
788 * @dentry: dentry or NULL (as returned from ->lookup())
790 * This can be used to set the result of a successful lookup in ->atomic_open().
791 * The filesystem's atomic_open() method shall return NULL after calling this.
793 int finish_no_open(struct file *file, struct dentry *dentry)
795 file->f_path.dentry = dentry;
798 EXPORT_SYMBOL(finish_no_open);
801 * dentry_open() will have done dput(dentry) and mntput(mnt) if it returns an
804 struct file *dentry_open(struct dentry *dentry, struct vfsmount *mnt, int flags,
805 const struct cred *cred)
810 validate_creds(cred);
812 /* We must always pass in a valid mount pointer. */
816 f = get_empty_filp();
820 return ERR_PTR(error);
824 error = do_dentry_open(dentry, mnt, f, NULL, cred);
826 error = open_check_o_direct(f);
837 EXPORT_SYMBOL(dentry_open);
839 static void __put_unused_fd(struct files_struct *files, unsigned int fd)
841 struct fdtable *fdt = files_fdtable(files);
842 __clear_open_fd(fd, fdt);
843 if (fd < files->next_fd)
847 void put_unused_fd(unsigned int fd)
849 struct files_struct *files = current->files;
850 spin_lock(&files->file_lock);
851 __put_unused_fd(files, fd);
852 spin_unlock(&files->file_lock);
855 EXPORT_SYMBOL(put_unused_fd);
858 * Install a file pointer in the fd array.
860 * The VFS is full of places where we drop the files lock between
861 * setting the open_fds bitmap and installing the file in the file
862 * array. At any such point, we are vulnerable to a dup2() race
863 * installing a file in the array before us. We need to detect this and
864 * fput() the struct file we are about to overwrite in this case.
866 * It should never happen - if we allow dup2() do it, _really_ bad things
870 void fd_install(unsigned int fd, struct file *file)
872 struct files_struct *files = current->files;
874 spin_lock(&files->file_lock);
875 fdt = files_fdtable(files);
876 BUG_ON(fdt->fd[fd] != NULL);
877 rcu_assign_pointer(fdt->fd[fd], file);
878 spin_unlock(&files->file_lock);
881 EXPORT_SYMBOL(fd_install);
883 static inline int build_open_flags(int flags, umode_t mode, struct open_flags *op)
885 int lookup_flags = 0;
888 if (!(flags & O_CREAT))
892 /* Must never be set by userspace */
893 flags &= ~FMODE_NONOTIFY;
896 * O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only
897 * check for O_DSYNC if the need any syncing at all we enforce it's
898 * always set instead of having to deal with possibly weird behaviour
899 * for malicious applications setting only __O_SYNC.
901 if (flags & __O_SYNC)
905 * If we have O_PATH in the open flag. Then we
906 * cannot have anything other than the below set of flags
908 if (flags & O_PATH) {
909 flags &= O_DIRECTORY | O_NOFOLLOW | O_PATH;
912 acc_mode = MAY_OPEN | ACC_MODE(flags);
915 op->open_flag = flags;
917 /* O_TRUNC implies we need access checks for write permissions */
919 acc_mode |= MAY_WRITE;
921 /* Allow the LSM permission hook to distinguish append
922 access from general write access. */
923 if (flags & O_APPEND)
924 acc_mode |= MAY_APPEND;
926 op->acc_mode = acc_mode;
928 op->intent = flags & O_PATH ? 0 : LOOKUP_OPEN;
930 if (flags & O_CREAT) {
931 op->intent |= LOOKUP_CREATE;
933 op->intent |= LOOKUP_EXCL;
936 if (flags & O_DIRECTORY)
937 lookup_flags |= LOOKUP_DIRECTORY;
938 if (!(flags & O_NOFOLLOW))
939 lookup_flags |= LOOKUP_FOLLOW;
944 * filp_open - open file and return file pointer
946 * @filename: path to open
947 * @flags: open flags as per the open(2) second argument
948 * @mode: mode for the new file if O_CREAT is set, else ignored
950 * This is the helper to open a file from kernelspace if you really
951 * have to. But in generally you should not do this, so please move
952 * along, nothing to see here..
954 struct file *filp_open(const char *filename, int flags, umode_t mode)
956 struct open_flags op;
957 int lookup = build_open_flags(flags, mode, &op);
958 return do_filp_open(AT_FDCWD, filename, &op, lookup);
960 EXPORT_SYMBOL(filp_open);
962 struct file *file_open_root(struct dentry *dentry, struct vfsmount *mnt,
963 const char *filename, int flags)
965 struct open_flags op;
966 int lookup = build_open_flags(flags, 0, &op);
968 return ERR_PTR(-EINVAL);
969 if (!filename && (flags & O_DIRECTORY))
970 if (!dentry->d_inode->i_op->lookup)
971 return ERR_PTR(-ENOTDIR);
972 return do_file_open_root(dentry, mnt, filename, &op, lookup);
974 EXPORT_SYMBOL(file_open_root);
976 long do_sys_open(int dfd, const char __user *filename, int flags, umode_t mode)
978 struct open_flags op;
979 int lookup = build_open_flags(flags, mode, &op);
980 char *tmp = getname(filename);
981 int fd = PTR_ERR(tmp);
984 fd = get_unused_fd_flags(flags);
986 struct file *f = do_filp_open(dfd, tmp, &op, lookup);
1000 SYSCALL_DEFINE3(open, const char __user *, filename, int, flags, umode_t, mode)
1004 if (force_o_largefile())
1005 flags |= O_LARGEFILE;
1007 ret = do_sys_open(AT_FDCWD, filename, flags, mode);
1008 /* avoid REGPARM breakage on x86: */
1009 asmlinkage_protect(3, ret, filename, flags, mode);
1013 SYSCALL_DEFINE4(openat, int, dfd, const char __user *, filename, int, flags,
1018 if (force_o_largefile())
1019 flags |= O_LARGEFILE;
1021 ret = do_sys_open(dfd, filename, flags, mode);
1022 /* avoid REGPARM breakage on x86: */
1023 asmlinkage_protect(4, ret, dfd, filename, flags, mode);
1030 * For backward compatibility? Maybe this should be moved
1031 * into arch/i386 instead?
1033 SYSCALL_DEFINE2(creat, const char __user *, pathname, umode_t, mode)
1035 return sys_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode);
1041 * "id" is the POSIX thread ID. We use the
1042 * files pointer for this..
1044 int filp_close(struct file *filp, fl_owner_t id)
1048 if (!file_count(filp)) {
1049 printk(KERN_ERR "VFS: Close: file count is 0\n");
1053 if (filp->f_op && filp->f_op->flush)
1054 retval = filp->f_op->flush(filp, id);
1056 if (likely(!(filp->f_mode & FMODE_PATH))) {
1057 dnotify_flush(filp, id);
1058 locks_remove_posix(filp, id);
1064 EXPORT_SYMBOL(filp_close);
1067 * Careful here! We test whether the file pointer is NULL before
1068 * releasing the fd. This ensures that one clone task can't release
1069 * an fd while another clone is opening it.
1071 SYSCALL_DEFINE1(close, unsigned int, fd)
1074 struct files_struct *files = current->files;
1075 struct fdtable *fdt;
1078 spin_lock(&files->file_lock);
1079 fdt = files_fdtable(files);
1080 if (fd >= fdt->max_fds)
1085 rcu_assign_pointer(fdt->fd[fd], NULL);
1086 __clear_close_on_exec(fd, fdt);
1087 __put_unused_fd(files, fd);
1088 spin_unlock(&files->file_lock);
1089 retval = filp_close(filp, files);
1091 /* can't restart close syscall because file table entry was cleared */
1092 if (unlikely(retval == -ERESTARTSYS ||
1093 retval == -ERESTARTNOINTR ||
1094 retval == -ERESTARTNOHAND ||
1095 retval == -ERESTART_RESTARTBLOCK))
1101 spin_unlock(&files->file_lock);
1104 EXPORT_SYMBOL(sys_close);
1107 * This routine simulates a hangup on the tty, to arrange that users
1108 * are given clean terminals at login time.
1110 SYSCALL_DEFINE0(vhangup)
1112 if (capable(CAP_SYS_TTY_CONFIG)) {
1120 * Called when an inode is about to be open.
1121 * We use this to disallow opening large files on 32bit systems if
1122 * the caller didn't specify O_LARGEFILE. On 64bit systems we force
1123 * on this flag in sys_open.
1125 int generic_file_open(struct inode * inode, struct file * filp)
1127 if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
1132 EXPORT_SYMBOL(generic_file_open);
1135 * This is used by subsystems that don't want seekable
1136 * file descriptors. The function is not supposed to ever fail, the only
1137 * reason it returns an 'int' and not 'void' is so that it can be plugged
1138 * directly into file_operations structure.
1140 int nonseekable_open(struct inode *inode, struct file *filp)
1142 filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
1146 EXPORT_SYMBOL(nonseekable_open);