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 | ||
82b0547c AD |
51 | /* If times==NULL, set access and modification to current time, |
52 | * must be owner or have write permission. | |
53 | * Else, update from *times, must be owner or super user. | |
54 | */ | |
1c710c89 | 55 | long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags) |
82b0547c AD |
56 | { |
57 | int error; | |
58 | struct nameidata nd; | |
1c710c89 UD |
59 | struct dentry *dentry; |
60 | struct inode *inode; | |
82b0547c | 61 | struct iattr newattrs; |
1c710c89 | 62 | struct file *f = NULL; |
74f9fdfa | 63 | struct vfsmount *mnt; |
82b0547c | 64 | |
1c710c89 | 65 | error = -EINVAL; |
043f46f6 MS |
66 | if (times && (!nsec_valid(times[0].tv_nsec) || |
67 | !nsec_valid(times[1].tv_nsec))) { | |
68 | goto out; | |
69 | } | |
70 | ||
1c710c89 | 71 | if (flags & ~AT_SYMLINK_NOFOLLOW) |
82b0547c | 72 | goto out; |
1c710c89 UD |
73 | |
74 | if (filename == NULL && dfd != AT_FDCWD) { | |
75 | error = -EINVAL; | |
76 | if (flags & AT_SYMLINK_NOFOLLOW) | |
77 | goto out; | |
78 | ||
79 | error = -EBADF; | |
80 | f = fget(dfd); | |
81 | if (!f) | |
82 | goto out; | |
83 | dentry = f->f_path.dentry; | |
74f9fdfa | 84 | mnt = f->f_path.mnt; |
1c710c89 UD |
85 | } else { |
86 | error = __user_walk_fd(dfd, filename, (flags & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW, &nd); | |
87 | if (error) | |
88 | goto out; | |
89 | ||
4ac91378 | 90 | dentry = nd.path.dentry; |
74f9fdfa | 91 | mnt = nd.path.mnt; |
1c710c89 UD |
92 | } |
93 | ||
94 | inode = dentry->d_inode; | |
82b0547c | 95 | |
74f9fdfa DH |
96 | error = mnt_want_write(mnt); |
97 | if (error) | |
82b0547c AD |
98 | goto dput_and_out; |
99 | ||
12fd0d30 MK |
100 | if (times && times[0].tv_nsec == UTIME_NOW && |
101 | times[1].tv_nsec == UTIME_NOW) | |
102 | times = NULL; | |
103 | ||
4cca9226 | 104 | /* In most cases, the checks are done in inode_change_ok() */ |
82b0547c AD |
105 | newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME; |
106 | if (times) { | |
107 | error = -EPERM; | |
108 | if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) | |
74f9fdfa | 109 | goto mnt_drop_write_and_out; |
82b0547c | 110 | |
1c710c89 UD |
111 | if (times[0].tv_nsec == UTIME_OMIT) |
112 | newattrs.ia_valid &= ~ATTR_ATIME; | |
113 | else if (times[0].tv_nsec != UTIME_NOW) { | |
114 | newattrs.ia_atime.tv_sec = times[0].tv_sec; | |
115 | newattrs.ia_atime.tv_nsec = times[0].tv_nsec; | |
116 | newattrs.ia_valid |= ATTR_ATIME_SET; | |
117 | } | |
118 | ||
119 | if (times[1].tv_nsec == UTIME_OMIT) | |
120 | newattrs.ia_valid &= ~ATTR_MTIME; | |
121 | else if (times[1].tv_nsec != UTIME_NOW) { | |
122 | newattrs.ia_mtime.tv_sec = times[1].tv_sec; | |
123 | newattrs.ia_mtime.tv_nsec = times[1].tv_nsec; | |
124 | newattrs.ia_valid |= ATTR_MTIME_SET; | |
125 | } | |
02c6be61 | 126 | |
4cca9226 MK |
127 | /* |
128 | * For the UTIME_OMIT/UTIME_NOW and UTIME_NOW/UTIME_OMIT | |
129 | * cases, we need to make an extra check that is not done by | |
130 | * inode_change_ok(). | |
131 | */ | |
132 | if (((times[0].tv_nsec == UTIME_NOW && | |
133 | times[1].tv_nsec == UTIME_OMIT) | |
134 | || | |
135 | (times[0].tv_nsec == UTIME_OMIT && | |
136 | times[1].tv_nsec == UTIME_NOW)) | |
137 | && !is_owner_or_cap(inode)) | |
138 | goto mnt_drop_write_and_out; | |
139 | } else { | |
140 | ||
141 | /* | |
142 | * If times is NULL (or both times are UTIME_NOW), | |
143 | * then we need to check permissions, because | |
144 | * inode_change_ok() won't do it. | |
145 | */ | |
82b0547c AD |
146 | error = -EACCES; |
147 | if (IS_IMMUTABLE(inode)) | |
74f9fdfa | 148 | goto mnt_drop_write_and_out; |
82b0547c | 149 | |
3bd858ab | 150 | if (!is_owner_or_cap(inode)) { |
c70f8441 MK |
151 | error = permission(inode, MAY_WRITE, NULL); |
152 | if (error) | |
153 | goto mnt_drop_write_and_out; | |
1e5de283 | 154 | } |
82b0547c AD |
155 | } |
156 | mutex_lock(&inode->i_mutex); | |
1c710c89 | 157 | error = notify_change(dentry, &newattrs); |
82b0547c | 158 | mutex_unlock(&inode->i_mutex); |
74f9fdfa DH |
159 | mnt_drop_write_and_out: |
160 | mnt_drop_write(mnt); | |
82b0547c | 161 | dput_and_out: |
1c710c89 UD |
162 | if (f) |
163 | fput(f); | |
164 | else | |
1d957f9b | 165 | path_put(&nd.path); |
82b0547c AD |
166 | out: |
167 | return error; | |
168 | } | |
169 | ||
1c710c89 UD |
170 | asmlinkage long sys_utimensat(int dfd, char __user *filename, struct timespec __user *utimes, int flags) |
171 | { | |
172 | struct timespec tstimes[2]; | |
173 | ||
174 | if (utimes) { | |
175 | if (copy_from_user(&tstimes, utimes, sizeof(tstimes))) | |
176 | return -EFAULT; | |
1c710c89 UD |
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 | ||
82b0547c AD |
187 | asmlinkage long sys_futimesat(int dfd, char __user *filename, struct timeval __user *utimes) |
188 | { | |
189 | struct timeval times[2]; | |
1c710c89 UD |
190 | struct timespec tstimes[2]; |
191 | ||
192 | if (utimes) { | |
193 | if (copy_from_user(×, utimes, sizeof(times))) | |
194 | return -EFAULT; | |
195 | ||
196 | /* This test is needed to catch all invalid values. If we | |
197 | would test only in do_utimes we would miss those invalid | |
198 | values truncated by the multiplication with 1000. Note | |
199 | that we also catch UTIME_{NOW,OMIT} here which are only | |
200 | valid for utimensat. */ | |
201 | if (times[0].tv_usec >= 1000000 || times[0].tv_usec < 0 || | |
202 | times[1].tv_usec >= 1000000 || times[1].tv_usec < 0) | |
203 | return -EINVAL; | |
204 | ||
205 | tstimes[0].tv_sec = times[0].tv_sec; | |
206 | tstimes[0].tv_nsec = 1000 * times[0].tv_usec; | |
207 | tstimes[1].tv_sec = times[1].tv_sec; | |
208 | tstimes[1].tv_nsec = 1000 * times[1].tv_usec; | |
209 | } | |
82b0547c | 210 | |
1c710c89 | 211 | return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0); |
82b0547c AD |
212 | } |
213 | ||
214 | asmlinkage long sys_utimes(char __user *filename, struct timeval __user *utimes) | |
215 | { | |
216 | return sys_futimesat(AT_FDCWD, filename, utimes); | |
217 | } |