1 #include <linux/compiler.h>
2 #include <linux/file.h>
4 #include <linux/linkage.h>
5 #include <linux/mount.h>
6 #include <linux/namei.h>
7 #include <linux/sched.h>
8 #include <linux/stat.h>
9 #include <linux/utime.h>
10 #include <linux/syscalls.h>
11 #include <asm/uaccess.h>
12 #include <asm/unistd.h>
14 #ifdef __ARCH_WANT_SYS_UTIME
17 * sys_utime() can be implemented in user-level using sys_utimes().
18 * Is this for backwards compatibility? If so, why not move it
19 * into the appropriate arch directory (for those architectures that
23 /* If times==NULL, set access and modification to current time,
24 * must be owner or have write permission.
25 * Else, update from *times, must be owner or super user.
27 asmlinkage
long sys_utime(char __user
*filename
, struct utimbuf __user
*times
)
29 struct timespec tv
[2];
32 if (get_user(tv
[0].tv_sec
, ×
->actime
) ||
33 get_user(tv
[1].tv_sec
, ×
->modtime
))
38 return do_utimes(AT_FDCWD
, filename
, times
? tv
: NULL
, 0);
43 static bool nsec_valid(long nsec
)
45 if (nsec
== UTIME_OMIT
|| nsec
== UTIME_NOW
)
48 return nsec
>= 0 && nsec
<= 999999999;
51 /* If times==NULL, set access and modification to current time,
52 * must be owner or have write permission.
53 * Else, update from *times, must be owner or super user.
55 long do_utimes(int dfd
, char __user
*filename
, struct timespec
*times
, int flags
)
59 struct dentry
*dentry
;
61 struct iattr newattrs
;
62 struct file
*f
= NULL
;
66 if (times
&& (!nsec_valid(times
[0].tv_nsec
) ||
67 !nsec_valid(times
[1].tv_nsec
))) {
71 if (flags
& ~AT_SYMLINK_NOFOLLOW
)
74 if (filename
== NULL
&& dfd
!= AT_FDCWD
) {
76 if (flags
& AT_SYMLINK_NOFOLLOW
)
83 dentry
= f
->f_path
.dentry
;
86 error
= __user_walk_fd(dfd
, filename
, (flags
& AT_SYMLINK_NOFOLLOW
) ? 0 : LOOKUP_FOLLOW
, &nd
);
90 dentry
= nd
.path
.dentry
;
94 inode
= dentry
->d_inode
;
96 error
= mnt_want_write(mnt
);
100 if (times
&& times
[0].tv_nsec
== UTIME_NOW
&&
101 times
[1].tv_nsec
== UTIME_NOW
)
104 newattrs
.ia_valid
= ATTR_CTIME
| ATTR_MTIME
| ATTR_ATIME
;
107 if (IS_APPEND(inode
) || IS_IMMUTABLE(inode
))
108 goto mnt_drop_write_and_out
;
110 if (times
[0].tv_nsec
== UTIME_OMIT
)
111 newattrs
.ia_valid
&= ~ATTR_ATIME
;
112 else if (times
[0].tv_nsec
!= UTIME_NOW
) {
113 newattrs
.ia_atime
.tv_sec
= times
[0].tv_sec
;
114 newattrs
.ia_atime
.tv_nsec
= times
[0].tv_nsec
;
115 newattrs
.ia_valid
|= ATTR_ATIME_SET
;
118 if (times
[1].tv_nsec
== UTIME_OMIT
)
119 newattrs
.ia_valid
&= ~ATTR_MTIME
;
120 else if (times
[1].tv_nsec
!= UTIME_NOW
) {
121 newattrs
.ia_mtime
.tv_sec
= times
[1].tv_sec
;
122 newattrs
.ia_mtime
.tv_nsec
= times
[1].tv_nsec
;
123 newattrs
.ia_valid
|= ATTR_MTIME_SET
;
126 * Tell inode_change_ok(), that this is an explicit time
127 * update, even if neither ATTR_ATIME_SET nor ATTR_MTIME_SET
130 newattrs
.ia_valid
|= ATTR_TIMES_SET
;
133 * If times is NULL (or both times are UTIME_NOW),
134 * then we need to check permissions, because
135 * inode_change_ok() won't do it.
138 if (IS_IMMUTABLE(inode
))
139 goto mnt_drop_write_and_out
;
141 if (!is_owner_or_cap(inode
)) {
142 error
= permission(inode
, MAY_WRITE
, NULL
);
144 goto mnt_drop_write_and_out
;
147 mutex_lock(&inode
->i_mutex
);
148 error
= notify_change(dentry
, &newattrs
);
149 mutex_unlock(&inode
->i_mutex
);
150 mnt_drop_write_and_out
:
161 asmlinkage
long sys_utimensat(int dfd
, char __user
*filename
, struct timespec __user
*utimes
, int flags
)
163 struct timespec tstimes
[2];
166 if (copy_from_user(&tstimes
, utimes
, sizeof(tstimes
)))
169 /* Nothing to do, we must not even check the path. */
170 if (tstimes
[0].tv_nsec
== UTIME_OMIT
&&
171 tstimes
[1].tv_nsec
== UTIME_OMIT
)
175 return do_utimes(dfd
, filename
, utimes
? tstimes
: NULL
, flags
);
178 asmlinkage
long sys_futimesat(int dfd
, char __user
*filename
, struct timeval __user
*utimes
)
180 struct timeval times
[2];
181 struct timespec tstimes
[2];
184 if (copy_from_user(×
, utimes
, sizeof(times
)))
187 /* This test is needed to catch all invalid values. If we
188 would test only in do_utimes we would miss those invalid
189 values truncated by the multiplication with 1000. Note
190 that we also catch UTIME_{NOW,OMIT} here which are only
191 valid for utimensat. */
192 if (times
[0].tv_usec
>= 1000000 || times
[0].tv_usec
< 0 ||
193 times
[1].tv_usec
>= 1000000 || times
[1].tv_usec
< 0)
196 tstimes
[0].tv_sec
= times
[0].tv_sec
;
197 tstimes
[0].tv_nsec
= 1000 * times
[0].tv_usec
;
198 tstimes
[1].tv_sec
= times
[1].tv_sec
;
199 tstimes
[1].tv_nsec
= 1000 * times
[1].tv_usec
;
202 return do_utimes(dfd
, filename
, utimes
? tstimes
: NULL
, 0);
205 asmlinkage
long sys_utimes(char __user
*filename
, struct timeval __user
*utimes
)
207 return sys_futimesat(AT_FDCWD
, filename
, utimes
);
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