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Commit | Line | Data |
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82b0547c | 1 | #include <linux/compiler.h> |
1c710c89 | 2 | #include <linux/file.h> |
82b0547c AD |
3 | #include <linux/fs.h> |
4 | #include <linux/linkage.h> | |
74f9fdfa | 5 | #include <linux/mount.h> |
82b0547c | 6 | #include <linux/namei.h> |
914e2637 | 7 | #include <linux/sched.h> |
1c710c89 | 8 | #include <linux/stat.h> |
82b0547c | 9 | #include <linux/utime.h> |
12c2ab5e | 10 | #include <linux/syscalls.h> |
82b0547c AD |
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 | */ | |
1c710c89 | 27 | asmlinkage long sys_utime(char __user *filename, struct utimbuf __user *times) |
82b0547c | 28 | { |
1c710c89 | 29 | struct timespec tv[2]; |
82b0547c | 30 | |
82b0547c | 31 | if (times) { |
1c710c89 UD |
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; | |
82b0547c | 37 | } |
1c710c89 | 38 | return do_utimes(AT_FDCWD, filename, times ? tv : NULL, 0); |
82b0547c AD |
39 | } |
40 | ||
41 | #endif | |
42 | ||
043f46f6 MS |
43 | static bool nsec_valid(long nsec) |
44 | { | |
4cca9226 | 45 | if (nsec == UTIME_OMIT || nsec == UTIME_NOW) |
043f46f6 MS |
46 | return true; |
47 | ||
48 | return nsec >= 0 && nsec <= 999999999; | |
49 | } | |
50 | ||
e9b76fed | 51 | static int utimes_common(struct path *path, struct timespec *times) |
82b0547c AD |
52 | { |
53 | int error; | |
82b0547c | 54 | struct iattr newattrs; |
e9b76fed | 55 | struct inode *inode = path->dentry->d_inode; |
82b0547c | 56 | |
e9b76fed | 57 | error = mnt_want_write(path->mnt); |
74f9fdfa | 58 | if (error) |
e9b76fed | 59 | goto out; |
82b0547c | 60 | |
12fd0d30 MK |
61 | if (times && times[0].tv_nsec == UTIME_NOW && |
62 | times[1].tv_nsec == UTIME_NOW) | |
63 | times = NULL; | |
64 | ||
82b0547c AD |
65 | newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME; |
66 | if (times) { | |
1c710c89 UD |
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 | } | |
4cca9226 | 82 | /* |
9767d749 MS |
83 | * Tell inode_change_ok(), that this is an explicit time |
84 | * update, even if neither ATTR_ATIME_SET nor ATTR_MTIME_SET | |
85 | * were used. | |
4cca9226 | 86 | */ |
9767d749 | 87 | newattrs.ia_valid |= ATTR_TIMES_SET; |
4cca9226 | 88 | } else { |
4cca9226 MK |
89 | /* |
90 | * If times is NULL (or both times are UTIME_NOW), | |
91 | * then we need to check permissions, because | |
92 | * inode_change_ok() won't do it. | |
93 | */ | |
82b0547c AD |
94 | error = -EACCES; |
95 | if (IS_IMMUTABLE(inode)) | |
74f9fdfa | 96 | goto mnt_drop_write_and_out; |
82b0547c | 97 | |
3bd858ab | 98 | if (!is_owner_or_cap(inode)) { |
f419a2e3 | 99 | error = inode_permission(inode, MAY_WRITE); |
c70f8441 MK |
100 | if (error) |
101 | goto mnt_drop_write_and_out; | |
1e5de283 | 102 | } |
82b0547c AD |
103 | } |
104 | mutex_lock(&inode->i_mutex); | |
e9b76fed | 105 | error = notify_change(path->dentry, &newattrs); |
82b0547c | 106 | mutex_unlock(&inode->i_mutex); |
e9b76fed | 107 | |
74f9fdfa | 108 | mnt_drop_write_and_out: |
e9b76fed MS |
109 | mnt_drop_write(path->mnt); |
110 | out: | |
111 | return error; | |
112 | } | |
113 | ||
114 | /* | |
115 | * do_utimes - change times on filename or file descriptor | |
116 | * @dfd: open file descriptor, -1 or AT_FDCWD | |
117 | * @filename: path name or NULL | |
118 | * @times: new times or NULL | |
119 | * @flags: zero or more flags (only AT_SYMLINK_NOFOLLOW for the moment) | |
120 | * | |
121 | * If filename is NULL and dfd refers to an open file, then operate on | |
122 | * the file. Otherwise look up filename, possibly using dfd as a | |
123 | * starting point. | |
124 | * | |
125 | * If times==NULL, set access and modification to current time, | |
126 | * must be owner or have write permission. | |
127 | * Else, update from *times, must be owner or super user. | |
128 | */ | |
129 | long 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 { | |
2d8f3038 | 155 | struct path path; |
e9b76fed MS |
156 | int lookup_flags = 0; |
157 | ||
158 | if (!(flags & AT_SYMLINK_NOFOLLOW)) | |
159 | lookup_flags |= LOOKUP_FOLLOW; | |
160 | ||
2d8f3038 | 161 | error = user_path_at(dfd, filename, lookup_flags, &path); |
e9b76fed MS |
162 | if (error) |
163 | goto out; | |
164 | ||
2d8f3038 AV |
165 | error = utimes_common(&path, times); |
166 | path_put(&path); | |
e9b76fed MS |
167 | } |
168 | ||
82b0547c AD |
169 | out: |
170 | return error; | |
171 | } | |
172 | ||
1c710c89 UD |
173 | asmlinkage long sys_utimensat(int dfd, char __user *filename, struct timespec __user *utimes, int flags) |
174 | { | |
175 | struct timespec tstimes[2]; | |
176 | ||
177 | if (utimes) { | |
178 | if (copy_from_user(&tstimes, utimes, sizeof(tstimes))) | |
179 | return -EFAULT; | |
1c710c89 UD |
180 | |
181 | /* Nothing to do, we must not even check the path. */ | |
182 | if (tstimes[0].tv_nsec == UTIME_OMIT && | |
183 | tstimes[1].tv_nsec == UTIME_OMIT) | |
184 | return 0; | |
185 | } | |
186 | ||
187 | return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags); | |
188 | } | |
189 | ||
82b0547c AD |
190 | asmlinkage long sys_futimesat(int dfd, char __user *filename, struct timeval __user *utimes) |
191 | { | |
192 | struct timeval times[2]; | |
1c710c89 UD |
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 | } | |
82b0547c | 213 | |
1c710c89 | 214 | return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0); |
82b0547c AD |
215 | } |
216 | ||
217 | asmlinkage long sys_utimes(char __user *filename, struct timeval __user *utimes) | |
218 | { | |
219 | return sys_futimesat(AT_FDCWD, filename, utimes); | |
220 | } |