1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/file.h>
3 #include <linux/mount.h>
4 #include <linux/namei.h>
5 #include <linux/utime.h>
6 #include <linux/syscalls.h>
7 #include <linux/uaccess.h>
8 #include <linux/compat.h>
9 #include <asm/unistd.h>
10 #include <linux/filelock.h>
12 static bool nsec_valid(long nsec)
14 if (nsec == UTIME_OMIT || nsec == UTIME_NOW)
17 return nsec >= 0 && nsec <= 999999999;
20 int vfs_utimes(const struct path *path, struct timespec64 *times)
23 struct iattr newattrs;
24 struct inode *inode = path->dentry->d_inode;
25 struct inode *delegated_inode = NULL;
28 if (!nsec_valid(times[0].tv_nsec) ||
29 !nsec_valid(times[1].tv_nsec))
31 if (times[0].tv_nsec == UTIME_NOW &&
32 times[1].tv_nsec == UTIME_NOW)
36 error = mnt_want_write(path->mnt);
40 newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
42 if (times[0].tv_nsec == UTIME_OMIT)
43 newattrs.ia_valid &= ~ATTR_ATIME;
44 else if (times[0].tv_nsec != UTIME_NOW) {
45 newattrs.ia_atime = times[0];
46 newattrs.ia_valid |= ATTR_ATIME_SET;
49 if (times[1].tv_nsec == UTIME_OMIT)
50 newattrs.ia_valid &= ~ATTR_MTIME;
51 else if (times[1].tv_nsec != UTIME_NOW) {
52 newattrs.ia_mtime = times[1];
53 newattrs.ia_valid |= ATTR_MTIME_SET;
56 * Tell setattr_prepare(), that this is an explicit time
57 * update, even if neither ATTR_ATIME_SET nor ATTR_MTIME_SET
60 newattrs.ia_valid |= ATTR_TIMES_SET;
62 newattrs.ia_valid |= ATTR_TOUCH;
66 error = notify_change(mnt_idmap(path->mnt), path->dentry, &newattrs,
69 if (delegated_inode) {
70 error = break_deleg_wait(&delegated_inode);
75 mnt_drop_write(path->mnt);
80 static int do_utimes_path(int dfd, const char __user *filename,
81 struct timespec64 *times, int flags)
84 int lookup_flags = 0, error;
86 if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH))
89 if (!(flags & AT_SYMLINK_NOFOLLOW))
90 lookup_flags |= LOOKUP_FOLLOW;
91 if (flags & AT_EMPTY_PATH)
92 lookup_flags |= LOOKUP_EMPTY;
95 error = user_path_at(dfd, filename, lookup_flags, &path);
99 error = vfs_utimes(&path, times);
101 if (retry_estale(error, lookup_flags)) {
102 lookup_flags |= LOOKUP_REVAL;
109 static int do_utimes_fd(int fd, struct timespec64 *times, int flags)
120 error = vfs_utimes(&f.file->f_path, times);
126 * do_utimes - change times on filename or file descriptor
127 * @dfd: open file descriptor, -1 or AT_FDCWD
128 * @filename: path name or NULL
129 * @times: new times or NULL
130 * @flags: zero or more flags (only AT_SYMLINK_NOFOLLOW for the moment)
132 * If filename is NULL and dfd refers to an open file, then operate on
133 * the file. Otherwise look up filename, possibly using dfd as a
136 * If times==NULL, set access and modification to current time,
137 * must be owner or have write permission.
138 * Else, update from *times, must be owner or super user.
140 long do_utimes(int dfd, const char __user *filename, struct timespec64 *times,
143 if (filename == NULL && dfd != AT_FDCWD)
144 return do_utimes_fd(dfd, times, flags);
145 return do_utimes_path(dfd, filename, times, flags);
148 SYSCALL_DEFINE4(utimensat, int, dfd, const char __user *, filename,
149 struct __kernel_timespec __user *, utimes, int, flags)
151 struct timespec64 tstimes[2];
154 if ((get_timespec64(&tstimes[0], &utimes[0]) ||
155 get_timespec64(&tstimes[1], &utimes[1])))
158 /* Nothing to do, we must not even check the path. */
159 if (tstimes[0].tv_nsec == UTIME_OMIT &&
160 tstimes[1].tv_nsec == UTIME_OMIT)
164 return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags);
167 #ifdef __ARCH_WANT_SYS_UTIME
169 * futimesat(), utimes() and utime() are older versions of utimensat()
170 * that are provided for compatibility with traditional C libraries.
171 * On modern architectures, we always use libc wrappers around
172 * utimensat() instead.
174 static long do_futimesat(int dfd, const char __user *filename,
175 struct __kernel_old_timeval __user *utimes)
177 struct __kernel_old_timeval times[2];
178 struct timespec64 tstimes[2];
181 if (copy_from_user(×, utimes, sizeof(times)))
184 /* This test is needed to catch all invalid values. If we
185 would test only in do_utimes we would miss those invalid
186 values truncated by the multiplication with 1000. Note
187 that we also catch UTIME_{NOW,OMIT} here which are only
188 valid for utimensat. */
189 if (times[0].tv_usec >= 1000000 || times[0].tv_usec < 0 ||
190 times[1].tv_usec >= 1000000 || times[1].tv_usec < 0)
193 tstimes[0].tv_sec = times[0].tv_sec;
194 tstimes[0].tv_nsec = 1000 * times[0].tv_usec;
195 tstimes[1].tv_sec = times[1].tv_sec;
196 tstimes[1].tv_nsec = 1000 * times[1].tv_usec;
199 return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0);
203 SYSCALL_DEFINE3(futimesat, int, dfd, const char __user *, filename,
204 struct __kernel_old_timeval __user *, utimes)
206 return do_futimesat(dfd, filename, utimes);
209 SYSCALL_DEFINE2(utimes, char __user *, filename,
210 struct __kernel_old_timeval __user *, utimes)
212 return do_futimesat(AT_FDCWD, filename, utimes);
215 SYSCALL_DEFINE2(utime, char __user *, filename, struct utimbuf __user *, times)
217 struct timespec64 tv[2];
220 if (get_user(tv[0].tv_sec, ×->actime) ||
221 get_user(tv[1].tv_sec, ×->modtime))
226 return do_utimes(AT_FDCWD, filename, times ? tv : NULL, 0);
230 #ifdef CONFIG_COMPAT_32BIT_TIME
232 * Not all architectures have sys_utime, so implement this in terms
235 #ifdef __ARCH_WANT_SYS_UTIME32
236 SYSCALL_DEFINE2(utime32, const char __user *, filename,
237 struct old_utimbuf32 __user *, t)
239 struct timespec64 tv[2];
242 if (get_user(tv[0].tv_sec, &t->actime) ||
243 get_user(tv[1].tv_sec, &t->modtime))
248 return do_utimes(AT_FDCWD, filename, t ? tv : NULL, 0);
252 SYSCALL_DEFINE4(utimensat_time32, unsigned int, dfd, const char __user *, filename, struct old_timespec32 __user *, t, int, flags)
254 struct timespec64 tv[2];
257 if (get_old_timespec32(&tv[0], &t[0]) ||
258 get_old_timespec32(&tv[1], &t[1]))
261 if (tv[0].tv_nsec == UTIME_OMIT && tv[1].tv_nsec == UTIME_OMIT)
264 return do_utimes(dfd, filename, t ? tv : NULL, flags);
267 #ifdef __ARCH_WANT_SYS_UTIME32
268 static long do_compat_futimesat(unsigned int dfd, const char __user *filename,
269 struct old_timeval32 __user *t)
271 struct timespec64 tv[2];
274 if (get_user(tv[0].tv_sec, &t[0].tv_sec) ||
275 get_user(tv[0].tv_nsec, &t[0].tv_usec) ||
276 get_user(tv[1].tv_sec, &t[1].tv_sec) ||
277 get_user(tv[1].tv_nsec, &t[1].tv_usec))
279 if (tv[0].tv_nsec >= 1000000 || tv[0].tv_nsec < 0 ||
280 tv[1].tv_nsec >= 1000000 || tv[1].tv_nsec < 0)
282 tv[0].tv_nsec *= 1000;
283 tv[1].tv_nsec *= 1000;
285 return do_utimes(dfd, filename, t ? tv : NULL, 0);
288 SYSCALL_DEFINE3(futimesat_time32, unsigned int, dfd,
289 const char __user *, filename,
290 struct old_timeval32 __user *, t)
292 return do_compat_futimesat(dfd, filename, t);
295 SYSCALL_DEFINE2(utimes_time32, const char __user *, filename, struct old_timeval32 __user *, t)
297 return do_compat_futimesat(AT_FDCWD, filename, t);