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1#include <linux/compiler.h>
2#include <linux/file.h>
3#include <linux/fs.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 <linux/uaccess.h>
12#include <asm/unistd.h>
13
14#ifdef __ARCH_WANT_SYS_UTIME
15
16/*
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
20 * need it).
21 */
22
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.
26 */
27SYSCALL_DEFINE2(utime, char __user *, filename, struct utimbuf __user *, times)
28{
29 struct timespec tv[2];
30
31 if (times) {
32 if (get_user(tv[0].tv_sec, ×->actime) ||
33 get_user(tv[1].tv_sec, ×->modtime))
34 return -EFAULT;
35 tv[0].tv_nsec = 0;
36 tv[1].tv_nsec = 0;
37 }
38 return do_utimes(AT_FDCWD, filename, times ? tv : NULL, 0);
39}
40
41#endif
42
43static bool nsec_valid(long nsec)
44{
45 if (nsec == UTIME_OMIT || nsec == UTIME_NOW)
46 return true;
47
48 return nsec >= 0 && nsec <= 999999999;
49}
50
51static int utimes_common(const struct path *path, struct timespec *times)
52{
53 int error;
54 struct iattr newattrs;
55 struct inode *inode = path->dentry->d_inode;
56 struct inode *delegated_inode = NULL;
57
58 error = mnt_want_write(path->mnt);
59 if (error)
60 goto out;
61
62 if (times && times[0].tv_nsec == UTIME_NOW &&
63 times[1].tv_nsec == UTIME_NOW)
64 times = NULL;
65
66 newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
67 if (times) {
68 if (times[0].tv_nsec == UTIME_OMIT)
69 newattrs.ia_valid &= ~ATTR_ATIME;
70 else if (times[0].tv_nsec != UTIME_NOW) {
71 newattrs.ia_atime.tv_sec = times[0].tv_sec;
72 newattrs.ia_atime.tv_nsec = times[0].tv_nsec;
73 newattrs.ia_valid |= ATTR_ATIME_SET;
74 }
75
76 if (times[1].tv_nsec == UTIME_OMIT)
77 newattrs.ia_valid &= ~ATTR_MTIME;
78 else if (times[1].tv_nsec != UTIME_NOW) {
79 newattrs.ia_mtime.tv_sec = times[1].tv_sec;
80 newattrs.ia_mtime.tv_nsec = times[1].tv_nsec;
81 newattrs.ia_valid |= ATTR_MTIME_SET;
82 }
83 /*
84 * Tell setattr_prepare(), that this is an explicit time
85 * update, even if neither ATTR_ATIME_SET nor ATTR_MTIME_SET
86 * were used.
87 */
88 newattrs.ia_valid |= ATTR_TIMES_SET;
89 } else {
90 newattrs.ia_valid |= ATTR_TOUCH;
91 }
92retry_deleg:
93 inode_lock(inode);
94 error = notify_change(path->dentry, &newattrs, &delegated_inode);
95 inode_unlock(inode);
96 if (delegated_inode) {
97 error = break_deleg_wait(&delegated_inode);
98 if (!error)
99 goto retry_deleg;
100 }
101
102 mnt_drop_write(path->mnt);
103out:
104 return error;
105}
106
107/*
108 * do_utimes - change times on filename or file descriptor
109 * @dfd: open file descriptor, -1 or AT_FDCWD
110 * @filename: path name or NULL
111 * @times: new times or NULL
112 * @flags: zero or more flags (only AT_SYMLINK_NOFOLLOW for the moment)
113 *
114 * If filename is NULL and dfd refers to an open file, then operate on
115 * the file. Otherwise look up filename, possibly using dfd as a
116 * starting point.
117 *
118 * If times==NULL, set access and modification to current time,
119 * must be owner or have write permission.
120 * Else, update from *times, must be owner or super user.
121 */
122long do_utimes(int dfd, const char __user *filename, struct timespec *times,
123 int flags)
124{
125 int error = -EINVAL;
126
127 if (times && (!nsec_valid(times[0].tv_nsec) ||
128 !nsec_valid(times[1].tv_nsec))) {
129 goto out;
130 }
131
132 if (flags & ~AT_SYMLINK_NOFOLLOW)
133 goto out;
134
135 if (filename == NULL && dfd != AT_FDCWD) {
136 struct fd f;
137
138 if (flags & AT_SYMLINK_NOFOLLOW)
139 goto out;
140
141 f = fdget(dfd);
142 error = -EBADF;
143 if (!f.file)
144 goto out;
145
146 error = utimes_common(&f.file->f_path, times);
147 fdput(f);
148 } else {
149 struct path path;
150 int lookup_flags = 0;
151
152 if (!(flags & AT_SYMLINK_NOFOLLOW))
153 lookup_flags |= LOOKUP_FOLLOW;
154retry:
155 error = user_path_at(dfd, filename, lookup_flags, &path);
156 if (error)
157 goto out;
158
159 error = utimes_common(&path, times);
160 path_put(&path);
161 if (retry_estale(error, lookup_flags)) {
162 lookup_flags |= LOOKUP_REVAL;
163 goto retry;
164 }
165 }
166
167out:
168 return error;
169}
170
171SYSCALL_DEFINE4(utimensat, int, dfd, const char __user *, filename,
172 struct timespec __user *, utimes, int, flags)
173{
174 struct timespec tstimes[2];
175
176 if (utimes) {
177 if (copy_from_user(&tstimes, utimes, sizeof(tstimes)))
178 return -EFAULT;
179
180 /* Nothing to do, we must not even check the path. */
181 if (tstimes[0].tv_nsec == UTIME_OMIT &&
182 tstimes[1].tv_nsec == UTIME_OMIT)
183 return 0;
184 }
185
186 return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags);
187}
188
189SYSCALL_DEFINE3(futimesat, int, dfd, const char __user *, filename,
190 struct timeval __user *, utimes)
191{
192 struct timeval times[2];
193 struct timespec tstimes[2];
194
195 if (utimes) {
196 if (copy_from_user(×, utimes, sizeof(times)))
197 return -EFAULT;
198
199 /* This test is needed to catch all invalid values. If we
200 would test only in do_utimes we would miss those invalid
201 values truncated by the multiplication with 1000. Note
202 that we also catch UTIME_{NOW,OMIT} here which are only
203 valid for utimensat. */
204 if (times[0].tv_usec >= 1000000 || times[0].tv_usec < 0 ||
205 times[1].tv_usec >= 1000000 || times[1].tv_usec < 0)
206 return -EINVAL;
207
208 tstimes[0].tv_sec = times[0].tv_sec;
209 tstimes[0].tv_nsec = 1000 * times[0].tv_usec;
210 tstimes[1].tv_sec = times[1].tv_sec;
211 tstimes[1].tv_nsec = 1000 * times[1].tv_usec;
212 }
213
214 return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0);
215}
216
217SYSCALL_DEFINE2(utimes, char __user *, filename,
218 struct timeval __user *, utimes)
219{
220 return sys_futimesat(AT_FDCWD, filename, utimes);
221}
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
11static bool nsec_valid(long nsec)
12{
13 if (nsec == UTIME_OMIT || nsec == UTIME_NOW)
14 return true;
15
16 return nsec >= 0 && nsec <= 999999999;
17}
18
19int vfs_utimes(const struct path *path, struct timespec64 *times)
20{
21 int error;
22 struct iattr newattrs;
23 struct inode *inode = path->dentry->d_inode;
24 struct inode *delegated_inode = NULL;
25
26 if (times) {
27 if (!nsec_valid(times[0].tv_nsec) ||
28 !nsec_valid(times[1].tv_nsec))
29 return -EINVAL;
30 if (times[0].tv_nsec == UTIME_NOW &&
31 times[1].tv_nsec == UTIME_NOW)
32 times = NULL;
33 }
34
35 error = mnt_want_write(path->mnt);
36 if (error)
37 goto out;
38
39 newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
40 if (times) {
41 if (times[0].tv_nsec == UTIME_OMIT)
42 newattrs.ia_valid &= ~ATTR_ATIME;
43 else if (times[0].tv_nsec != UTIME_NOW) {
44 newattrs.ia_atime = times[0];
45 newattrs.ia_valid |= ATTR_ATIME_SET;
46 }
47
48 if (times[1].tv_nsec == UTIME_OMIT)
49 newattrs.ia_valid &= ~ATTR_MTIME;
50 else if (times[1].tv_nsec != UTIME_NOW) {
51 newattrs.ia_mtime = times[1];
52 newattrs.ia_valid |= ATTR_MTIME_SET;
53 }
54 /*
55 * Tell setattr_prepare(), that this is an explicit time
56 * update, even if neither ATTR_ATIME_SET nor ATTR_MTIME_SET
57 * were used.
58 */
59 newattrs.ia_valid |= ATTR_TIMES_SET;
60 } else {
61 newattrs.ia_valid |= ATTR_TOUCH;
62 }
63retry_deleg:
64 inode_lock(inode);
65 error = notify_change(path->dentry, &newattrs, &delegated_inode);
66 inode_unlock(inode);
67 if (delegated_inode) {
68 error = break_deleg_wait(&delegated_inode);
69 if (!error)
70 goto retry_deleg;
71 }
72
73 mnt_drop_write(path->mnt);
74out:
75 return error;
76}
77
78static int do_utimes_path(int dfd, const char __user *filename,
79 struct timespec64 *times, int flags)
80{
81 struct path path;
82 int lookup_flags = 0, error;
83
84 if (flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH))
85 return -EINVAL;
86
87 if (!(flags & AT_SYMLINK_NOFOLLOW))
88 lookup_flags |= LOOKUP_FOLLOW;
89 if (flags & AT_EMPTY_PATH)
90 lookup_flags |= LOOKUP_EMPTY;
91
92retry:
93 error = user_path_at(dfd, filename, lookup_flags, &path);
94 if (error)
95 return error;
96
97 error = vfs_utimes(&path, times);
98 path_put(&path);
99 if (retry_estale(error, lookup_flags)) {
100 lookup_flags |= LOOKUP_REVAL;
101 goto retry;
102 }
103
104 return error;
105}
106
107static int do_utimes_fd(int fd, struct timespec64 *times, int flags)
108{
109 struct fd f;
110 int error;
111
112 if (flags)
113 return -EINVAL;
114
115 f = fdget(fd);
116 if (!f.file)
117 return -EBADF;
118 error = vfs_utimes(&f.file->f_path, times);
119 fdput(f);
120 return error;
121}
122
123/*
124 * do_utimes - change times on filename or file descriptor
125 * @dfd: open file descriptor, -1 or AT_FDCWD
126 * @filename: path name or NULL
127 * @times: new times or NULL
128 * @flags: zero or more flags (only AT_SYMLINK_NOFOLLOW for the moment)
129 *
130 * If filename is NULL and dfd refers to an open file, then operate on
131 * the file. Otherwise look up filename, possibly using dfd as a
132 * starting point.
133 *
134 * If times==NULL, set access and modification to current time,
135 * must be owner or have write permission.
136 * Else, update from *times, must be owner or super user.
137 */
138long do_utimes(int dfd, const char __user *filename, struct timespec64 *times,
139 int flags)
140{
141 if (filename == NULL && dfd != AT_FDCWD)
142 return do_utimes_fd(dfd, times, flags);
143 return do_utimes_path(dfd, filename, times, flags);
144}
145
146SYSCALL_DEFINE4(utimensat, int, dfd, const char __user *, filename,
147 struct __kernel_timespec __user *, utimes, int, flags)
148{
149 struct timespec64 tstimes[2];
150
151 if (utimes) {
152 if ((get_timespec64(&tstimes[0], &utimes[0]) ||
153 get_timespec64(&tstimes[1], &utimes[1])))
154 return -EFAULT;
155
156 /* Nothing to do, we must not even check the path. */
157 if (tstimes[0].tv_nsec == UTIME_OMIT &&
158 tstimes[1].tv_nsec == UTIME_OMIT)
159 return 0;
160 }
161
162 return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags);
163}
164
165#ifdef __ARCH_WANT_SYS_UTIME
166/*
167 * futimesat(), utimes() and utime() are older versions of utimensat()
168 * that are provided for compatibility with traditional C libraries.
169 * On modern architectures, we always use libc wrappers around
170 * utimensat() instead.
171 */
172static long do_futimesat(int dfd, const char __user *filename,
173 struct __kernel_old_timeval __user *utimes)
174{
175 struct __kernel_old_timeval times[2];
176 struct timespec64 tstimes[2];
177
178 if (utimes) {
179 if (copy_from_user(×, utimes, sizeof(times)))
180 return -EFAULT;
181
182 /* This test is needed to catch all invalid values. If we
183 would test only in do_utimes we would miss those invalid
184 values truncated by the multiplication with 1000. Note
185 that we also catch UTIME_{NOW,OMIT} here which are only
186 valid for utimensat. */
187 if (times[0].tv_usec >= 1000000 || times[0].tv_usec < 0 ||
188 times[1].tv_usec >= 1000000 || times[1].tv_usec < 0)
189 return -EINVAL;
190
191 tstimes[0].tv_sec = times[0].tv_sec;
192 tstimes[0].tv_nsec = 1000 * times[0].tv_usec;
193 tstimes[1].tv_sec = times[1].tv_sec;
194 tstimes[1].tv_nsec = 1000 * times[1].tv_usec;
195 }
196
197 return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0);
198}
199
200
201SYSCALL_DEFINE3(futimesat, int, dfd, const char __user *, filename,
202 struct __kernel_old_timeval __user *, utimes)
203{
204 return do_futimesat(dfd, filename, utimes);
205}
206
207SYSCALL_DEFINE2(utimes, char __user *, filename,
208 struct __kernel_old_timeval __user *, utimes)
209{
210 return do_futimesat(AT_FDCWD, filename, utimes);
211}
212
213SYSCALL_DEFINE2(utime, char __user *, filename, struct utimbuf __user *, times)
214{
215 struct timespec64 tv[2];
216
217 if (times) {
218 if (get_user(tv[0].tv_sec, ×->actime) ||
219 get_user(tv[1].tv_sec, ×->modtime))
220 return -EFAULT;
221 tv[0].tv_nsec = 0;
222 tv[1].tv_nsec = 0;
223 }
224 return do_utimes(AT_FDCWD, filename, times ? tv : NULL, 0);
225}
226#endif
227
228#ifdef CONFIG_COMPAT_32BIT_TIME
229/*
230 * Not all architectures have sys_utime, so implement this in terms
231 * of sys_utimes.
232 */
233#ifdef __ARCH_WANT_SYS_UTIME32
234SYSCALL_DEFINE2(utime32, const char __user *, filename,
235 struct old_utimbuf32 __user *, t)
236{
237 struct timespec64 tv[2];
238
239 if (t) {
240 if (get_user(tv[0].tv_sec, &t->actime) ||
241 get_user(tv[1].tv_sec, &t->modtime))
242 return -EFAULT;
243 tv[0].tv_nsec = 0;
244 tv[1].tv_nsec = 0;
245 }
246 return do_utimes(AT_FDCWD, filename, t ? tv : NULL, 0);
247}
248#endif
249
250SYSCALL_DEFINE4(utimensat_time32, unsigned int, dfd, const char __user *, filename, struct old_timespec32 __user *, t, int, flags)
251{
252 struct timespec64 tv[2];
253
254 if (t) {
255 if (get_old_timespec32(&tv[0], &t[0]) ||
256 get_old_timespec32(&tv[1], &t[1]))
257 return -EFAULT;
258
259 if (tv[0].tv_nsec == UTIME_OMIT && tv[1].tv_nsec == UTIME_OMIT)
260 return 0;
261 }
262 return do_utimes(dfd, filename, t ? tv : NULL, flags);
263}
264
265#ifdef __ARCH_WANT_SYS_UTIME32
266static long do_compat_futimesat(unsigned int dfd, const char __user *filename,
267 struct old_timeval32 __user *t)
268{
269 struct timespec64 tv[2];
270
271 if (t) {
272 if (get_user(tv[0].tv_sec, &t[0].tv_sec) ||
273 get_user(tv[0].tv_nsec, &t[0].tv_usec) ||
274 get_user(tv[1].tv_sec, &t[1].tv_sec) ||
275 get_user(tv[1].tv_nsec, &t[1].tv_usec))
276 return -EFAULT;
277 if (tv[0].tv_nsec >= 1000000 || tv[0].tv_nsec < 0 ||
278 tv[1].tv_nsec >= 1000000 || tv[1].tv_nsec < 0)
279 return -EINVAL;
280 tv[0].tv_nsec *= 1000;
281 tv[1].tv_nsec *= 1000;
282 }
283 return do_utimes(dfd, filename, t ? tv : NULL, 0);
284}
285
286SYSCALL_DEFINE3(futimesat_time32, unsigned int, dfd,
287 const char __user *, filename,
288 struct old_timeval32 __user *, t)
289{
290 return do_compat_futimesat(dfd, filename, t);
291}
292
293SYSCALL_DEFINE2(utimes_time32, const char __user *, filename, struct old_timeval32 __user *, t)
294{
295 return do_compat_futimesat(AT_FDCWD, filename, t);
296}
297#endif
298#endif