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