Root/
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 | */ |
27 | SYSCALL_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 | |
43 | static 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 | |
51 | static 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 | * 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. |
86 | */ |
87 | newattrs.ia_valid |= ATTR_TIMES_SET; |
88 | } else { |
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 | */ |
94 | error = -EACCES; |
95 | if (IS_IMMUTABLE(inode)) |
96 | goto mnt_drop_write_and_out; |
97 | |
98 | if (!inode_owner_or_capable(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 | |
108 | mnt_drop_write_and_out: |
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, const char __user *filename, struct timespec *times, |
130 | int flags) |
131 | { |
132 | int error = -EINVAL; |
133 | |
134 | if (times && (!nsec_valid(times[0].tv_nsec) || |
135 | !nsec_valid(times[1].tv_nsec))) { |
136 | goto out; |
137 | } |
138 | |
139 | if (flags & ~AT_SYMLINK_NOFOLLOW) |
140 | goto out; |
141 | |
142 | if (filename == NULL && dfd != AT_FDCWD) { |
143 | int fput_needed; |
144 | struct file *file; |
145 | |
146 | if (flags & AT_SYMLINK_NOFOLLOW) |
147 | goto out; |
148 | |
149 | file = fget_light(dfd, &fput_needed); |
150 | error = -EBADF; |
151 | if (!file) |
152 | goto out; |
153 | |
154 | error = utimes_common(&file->f_path, times); |
155 | fput_light(file, fput_needed); |
156 | } else { |
157 | struct path path; |
158 | int lookup_flags = 0; |
159 | |
160 | if (!(flags & AT_SYMLINK_NOFOLLOW)) |
161 | lookup_flags |= LOOKUP_FOLLOW; |
162 | |
163 | error = user_path_at(dfd, filename, lookup_flags, &path); |
164 | if (error) |
165 | goto out; |
166 | |
167 | error = utimes_common(&path, times); |
168 | path_put(&path); |
169 | } |
170 | |
171 | out: |
172 | return error; |
173 | } |
174 | |
175 | SYSCALL_DEFINE4(utimensat, int, dfd, const char __user *, filename, |
176 | struct timespec __user *, utimes, int, flags) |
177 | { |
178 | struct timespec tstimes[2]; |
179 | |
180 | if (utimes) { |
181 | if (copy_from_user(&tstimes, utimes, sizeof(tstimes))) |
182 | return -EFAULT; |
183 | |
184 | /* Nothing to do, we must not even check the path. */ |
185 | if (tstimes[0].tv_nsec == UTIME_OMIT && |
186 | tstimes[1].tv_nsec == UTIME_OMIT) |
187 | return 0; |
188 | } |
189 | |
190 | return do_utimes(dfd, filename, utimes ? tstimes : NULL, flags); |
191 | } |
192 | |
193 | SYSCALL_DEFINE3(futimesat, int, dfd, const char __user *, filename, |
194 | struct timeval __user *, utimes) |
195 | { |
196 | struct timeval times[2]; |
197 | struct timespec tstimes[2]; |
198 | |
199 | if (utimes) { |
200 | if (copy_from_user(×, utimes, sizeof(times))) |
201 | return -EFAULT; |
202 | |
203 | /* This test is needed to catch all invalid values. If we |
204 | would test only in do_utimes we would miss those invalid |
205 | values truncated by the multiplication with 1000. Note |
206 | that we also catch UTIME_{NOW,OMIT} here which are only |
207 | valid for utimensat. */ |
208 | if (times[0].tv_usec >= 1000000 || times[0].tv_usec < 0 || |
209 | times[1].tv_usec >= 1000000 || times[1].tv_usec < 0) |
210 | return -EINVAL; |
211 | |
212 | tstimes[0].tv_sec = times[0].tv_sec; |
213 | tstimes[0].tv_nsec = 1000 * times[0].tv_usec; |
214 | tstimes[1].tv_sec = times[1].tv_sec; |
215 | tstimes[1].tv_nsec = 1000 * times[1].tv_usec; |
216 | } |
217 | |
218 | return do_utimes(dfd, filename, utimes ? tstimes : NULL, 0); |
219 | } |
220 | |
221 | SYSCALL_DEFINE2(utimes, char __user *, filename, |
222 | struct timeval __user *, utimes) |
223 | { |
224 | return sys_futimesat(AT_FDCWD, filename, utimes); |
225 | } |
226 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9