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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
11#ifdef __ARCH_WANT_SYS_UTIME
12
13/*
14 * sys_utime() can be implemented in user-level using sys_utimes().
15 * Is this for backwards compatibility? If so, why not move it
16 * into the appropriate arch directory (for those architectures that
17 * need it).
18 */
19
20/* If times==NULL, set access and modification to current time,
21 * must be owner or have write permission.
22 * Else, update from *times, must be owner or super user.
23 */
24SYSCALL_DEFINE2(utime, char __user *, filename, struct utimbuf __user *, times)
25{
26 struct timespec64 tv[2];
27
28 if (times) {
29 if (get_user(tv[0].tv_sec, ×->actime) ||
30 get_user(tv[1].tv_sec, ×->modtime))
31 return -EFAULT;
32 tv[0].tv_nsec = 0;
33 tv[1].tv_nsec = 0;
34 }
35 return do_utimes(AT_FDCWD, filename, times ? tv : NULL, 0);
36}
37
38#endif
39
40static bool nsec_valid(long nsec)
41{
42 if (nsec == UTIME_OMIT || nsec == UTIME_NOW)
43 return true;
44
45 return nsec >= 0 && nsec <= 999999999;
46}
47
48static int utimes_common(const struct path *path, struct timespec64 *times)
49{
50 int error;
51 struct iattr newattrs;
52 struct inode *inode = path->dentry->d_inode;
53 struct inode *delegated_inode = NULL;
54
55 error = mnt_want_write(path->mnt);
56 if (error)
57 goto out;
58
59 if (times && times[0].tv_nsec == UTIME_NOW &&
60 times[1].tv_nsec == UTIME_NOW)
61 times = NULL;
62
63 newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
64 if (times) {
65 if (times[0].tv_nsec == UTIME_OMIT)
66 newattrs.ia_valid &= ~ATTR_ATIME;
67 else if (times[0].tv_nsec != UTIME_NOW) {
68 newattrs.ia_atime.tv_sec = times[0].tv_sec;
69 newattrs.ia_atime.tv_nsec = times[0].tv_nsec;
70 newattrs.ia_valid |= ATTR_ATIME_SET;
71 }
72
73 if (times[1].tv_nsec == UTIME_OMIT)
74 newattrs.ia_valid &= ~ATTR_MTIME;
75 else if (times[1].tv_nsec != UTIME_NOW) {
76 newattrs.ia_mtime.tv_sec = times[1].tv_sec;
77 newattrs.ia_mtime.tv_nsec = times[1].tv_nsec;
78 newattrs.ia_valid |= ATTR_MTIME_SET;
79 }
80 /*
81 * Tell setattr_prepare(), that this is an explicit time
82 * update, even if neither ATTR_ATIME_SET nor ATTR_MTIME_SET
83 * were used.
84 */
85 newattrs.ia_valid |= ATTR_TIMES_SET;
86 } else {
87 newattrs.ia_valid |= ATTR_TOUCH;
88 }
89retry_deleg:
90 inode_lock(inode);
91 error = notify_change(path->dentry, &newattrs, &delegated_inode);
92 inode_unlock(inode);
93 if (delegated_inode) {
94 error = break_deleg_wait(&delegated_inode);
95 if (!error)
96 goto retry_deleg;
97 }
98
99 mnt_drop_write(path->mnt);
100out:
101 return error;
102}
103
104/*
105 * do_utimes - change times on filename or file descriptor
106 * @dfd: open file descriptor, -1 or AT_FDCWD
107 * @filename: path name or NULL
108 * @times: new times or NULL
109 * @flags: zero or more flags (only AT_SYMLINK_NOFOLLOW for the moment)
110 *
111 * If filename is NULL and dfd refers to an open file, then operate on
112 * the file. Otherwise look up filename, possibly using dfd as a
113 * starting point.
114 *
115 * If times==NULL, set access and modification to current time,
116 * must be owner or have write permission.
117 * Else, update from *times, must be owner or super user.
118 */
119long do_utimes(int dfd, const char __user *filename, struct timespec64 *times,
120 int flags)
121{
122 int error = -EINVAL;
123
124 if (times && (!nsec_valid(times[0].tv_nsec) ||
125 !nsec_valid(times[1].tv_nsec))) {
126 goto out;
127 }
128
129 if (flags & ~AT_SYMLINK_NOFOLLOW)
130 goto out;
131
132 if (filename == NULL && dfd != AT_FDCWD) {
133 struct fd f;
134
135 if (flags & AT_SYMLINK_NOFOLLOW)
136 goto out;
137
138 f = fdget(dfd);
139 error = -EBADF;
140 if (!f.file)
141 goto out;
142
143 error = utimes_common(&f.file->f_path, times);
144 fdput(f);
145 } else {
146 struct path path;
147 int lookup_flags = 0;
148
149 if (!(flags & AT_SYMLINK_NOFOLLOW))
150 lookup_flags |= LOOKUP_FOLLOW;
151retry:
152 error = user_path_at(dfd, filename, lookup_flags, &path);
153 if (error)
154 goto out;
155
156 error = utimes_common(&path, times);
157 path_put(&path);
158 if (retry_estale(error, lookup_flags)) {
159 lookup_flags |= LOOKUP_REVAL;
160 goto retry;
161 }
162 }
163
164out:
165 return error;
166}
167
168SYSCALL_DEFINE4(utimensat, int, dfd, const char __user *, filename,
169 struct timespec __user *, utimes, int, flags)
170{
171 struct timespec64 tstimes[2];
172
173 if (utimes) {
174 if ((get_timespec64(&tstimes[0], &utimes[0]) ||
175 get_timespec64(&tstimes[1], &utimes[1])))
176 return -EFAULT;
177
178 /* Nothing to do, we must not even check the path. */
179 if (tstimes[0].tv_nsec == UTIME_OMIT &&
180 tstimes[1].tv_nsec == UTIME_OMIT)
181 return 0;
182 }
183
184 return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags);
185}
186
187static long do_futimesat(int dfd, const char __user *filename,
188 struct timeval __user *utimes)
189{
190 struct timeval times[2];
191 struct timespec64 tstimes[2];
192
193 if (utimes) {
194 if (copy_from_user(×, utimes, sizeof(times)))
195 return -EFAULT;
196
197 /* This test is needed to catch all invalid values. If we
198 would test only in do_utimes we would miss those invalid
199 values truncated by the multiplication with 1000. Note
200 that we also catch UTIME_{NOW,OMIT} here which are only
201 valid for utimensat. */
202 if (times[0].tv_usec >= 1000000 || times[0].tv_usec < 0 ||
203 times[1].tv_usec >= 1000000 || times[1].tv_usec < 0)
204 return -EINVAL;
205
206 tstimes[0].tv_sec = times[0].tv_sec;
207 tstimes[0].tv_nsec = 1000 * times[0].tv_usec;
208 tstimes[1].tv_sec = times[1].tv_sec;
209 tstimes[1].tv_nsec = 1000 * times[1].tv_usec;
210 }
211
212 return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0);
213}
214
215
216SYSCALL_DEFINE3(futimesat, int, dfd, const char __user *, filename,
217 struct timeval __user *, utimes)
218{
219 return do_futimesat(dfd, filename, utimes);
220}
221
222SYSCALL_DEFINE2(utimes, char __user *, filename,
223 struct timeval __user *, utimes)
224{
225 return do_futimesat(AT_FDCWD, filename, utimes);
226}
227
228#ifdef CONFIG_COMPAT
229/*
230 * Not all architectures have sys_utime, so implement this in terms
231 * of sys_utimes.
232 */
233COMPAT_SYSCALL_DEFINE2(utime, const char __user *, filename,
234 struct compat_utimbuf __user *, t)
235{
236 struct timespec64 tv[2];
237
238 if (t) {
239 if (get_user(tv[0].tv_sec, &t->actime) ||
240 get_user(tv[1].tv_sec, &t->modtime))
241 return -EFAULT;
242 tv[0].tv_nsec = 0;
243 tv[1].tv_nsec = 0;
244 }
245 return do_utimes(AT_FDCWD, filename, t ? tv : NULL, 0);
246}
247
248COMPAT_SYSCALL_DEFINE4(utimensat, unsigned int, dfd, const char __user *, filename, struct compat_timespec __user *, t, int, flags)
249{
250 struct timespec64 tv[2];
251
252 if (t) {
253 if (compat_get_timespec64(&tv[0], &t[0]) ||
254 compat_get_timespec64(&tv[1], &t[1]))
255 return -EFAULT;
256
257 if (tv[0].tv_nsec == UTIME_OMIT && tv[1].tv_nsec == UTIME_OMIT)
258 return 0;
259 }
260 return do_utimes(dfd, filename, t ? tv : NULL, flags);
261}
262
263static long do_compat_futimesat(unsigned int dfd, const char __user *filename,
264 struct compat_timeval __user *t)
265{
266 struct timespec64 tv[2];
267
268 if (t) {
269 if (get_user(tv[0].tv_sec, &t[0].tv_sec) ||
270 get_user(tv[0].tv_nsec, &t[0].tv_usec) ||
271 get_user(tv[1].tv_sec, &t[1].tv_sec) ||
272 get_user(tv[1].tv_nsec, &t[1].tv_usec))
273 return -EFAULT;
274 if (tv[0].tv_nsec >= 1000000 || tv[0].tv_nsec < 0 ||
275 tv[1].tv_nsec >= 1000000 || tv[1].tv_nsec < 0)
276 return -EINVAL;
277 tv[0].tv_nsec *= 1000;
278 tv[1].tv_nsec *= 1000;
279 }
280 return do_utimes(dfd, filename, t ? tv : NULL, 0);
281}
282
283COMPAT_SYSCALL_DEFINE3(futimesat, unsigned int, dfd,
284 const char __user *, filename,
285 struct compat_timeval __user *, t)
286{
287 return do_compat_futimesat(dfd, filename, t);
288}
289
290COMPAT_SYSCALL_DEFINE2(utimes, const char __user *, filename, struct compat_timeval __user *, t)
291{
292 return do_compat_futimesat(AT_FDCWD, filename, t);
293}
294#endif