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
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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
57 error = mnt_want_write(path->mnt);
58 if (error)
59 goto out;
60
61 if (times && times[0].tv_nsec == UTIME_NOW &&
62 times[1].tv_nsec == UTIME_NOW)
63 times = NULL;
64
65 newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
66 if (times) {
67 if (times[0].tv_nsec == UTIME_OMIT)
68 newattrs.ia_valid &= ~ATTR_ATIME;
69 else if (times[0].tv_nsec != UTIME_NOW) {
70 newattrs.ia_atime.tv_sec = times[0].tv_sec;
71 newattrs.ia_atime.tv_nsec = times[0].tv_nsec;
72 newattrs.ia_valid |= ATTR_ATIME_SET;
73 }
74
75 if (times[1].tv_nsec == UTIME_OMIT)
76 newattrs.ia_valid &= ~ATTR_MTIME;
77 else if (times[1].tv_nsec != UTIME_NOW) {
78 newattrs.ia_mtime.tv_sec = times[1].tv_sec;
79 newattrs.ia_mtime.tv_nsec = times[1].tv_nsec;
80 newattrs.ia_valid |= ATTR_MTIME_SET;
81 }
82
83
84
85
86
87 newattrs.ia_valid |= ATTR_TIMES_SET;
88 } else {
89
90
91
92
93
94 error = -EACCES;
95 if (IS_IMMUTABLE(inode))
96 goto mnt_drop_write_and_out;
97
98 if (!is_owner_or_cap(inode)) {
99 error = inode_permission(inode, MAY_WRITE);
100 if (error)
101 goto mnt_drop_write_and_out;
102 }
103 }
104 mutex_lock(&inode->i_mutex);
105 error = notify_change(path->dentry, &newattrs);
106 mutex_unlock(&inode->i_mutex);
107
108mnt_drop_write_and_out:
109 mnt_drop_write(path->mnt);
110out:
111 return error;
112}
113
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127
128
129long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags)
130{
131 int error = -EINVAL;
132
133 if (times && (!nsec_valid(times[0].tv_nsec) ||
134 !nsec_valid(times[1].tv_nsec))) {
135 goto out;
136 }
137
138 if (flags & ~AT_SYMLINK_NOFOLLOW)
139 goto out;
140
141 if (filename == NULL && dfd != AT_FDCWD) {
142 struct file *file;
143
144 if (flags & AT_SYMLINK_NOFOLLOW)
145 goto out;
146
147 file = fget(dfd);
148 error = -EBADF;
149 if (!file)
150 goto out;
151
152 error = utimes_common(&file->f_path, times);
153 fput(file);
154 } else {
155 struct path path;
156 int lookup_flags = 0;
157
158 if (!(flags & AT_SYMLINK_NOFOLLOW))
159 lookup_flags |= LOOKUP_FOLLOW;
160
161 error = user_path_at(dfd, filename, lookup_flags, &path);
162 if (error)
163 goto out;
164
165 error = utimes_common(&path, times);
166 path_put(&path);
167 }
168
169out:
170 return error;
171}
172
173SYSCALL_DEFINE4(utimensat, int, dfd, char __user *, filename,
174 struct timespec __user *, utimes, int, flags)
175{
176 struct timespec tstimes[2];
177
178 if (utimes) {
179 if (copy_from_user(&tstimes, utimes, sizeof(tstimes)))
180 return -EFAULT;
181
182
183 if (tstimes[0].tv_nsec == UTIME_OMIT &&
184 tstimes[1].tv_nsec == UTIME_OMIT)
185 return 0;
186 }
187
188 return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags);
189}
190
191SYSCALL_DEFINE3(futimesat, int, dfd, char __user *, filename,
192 struct timeval __user *, utimes)
193{
194 struct timeval times[2];
195 struct timespec tstimes[2];
196
197 if (utimes) {
198 if (copy_from_user(×, utimes, sizeof(times)))
199 return -EFAULT;
200
201
202
203
204
205
206 if (times[0].tv_usec >= 1000000 || times[0].tv_usec < 0 ||
207 times[1].tv_usec >= 1000000 || times[1].tv_usec < 0)
208 return -EINVAL;
209
210 tstimes[0].tv_sec = times[0].tv_sec;
211 tstimes[0].tv_nsec = 1000 * times[0].tv_usec;
212 tstimes[1].tv_sec = times[1].tv_sec;
213 tstimes[1].tv_nsec = 1000 * times[1].tv_usec;
214 }
215
216 return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0);
217}
218
219SYSCALL_DEFINE2(utimes, char __user *, filename,
220 struct timeval __user *, utimes)
221{
222 return sys_futimesat(AT_FDCWD, filename, utimes);
223}
224