fs: change return values from -EACCES to -EPERM
[linux-3.10.git] / fs / proc / self.c
1 #include <linux/proc_fs.h>
2 #include <linux/sched.h>
3 #include <linux/namei.h>
4
5 /*
6  * /proc/self:
7  */
8 static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
9                               int buflen)
10 {
11         struct pid_namespace *ns = dentry->d_sb->s_fs_info;
12         pid_t tgid = task_tgid_nr_ns(current, ns);
13         char tmp[PROC_NUMBUF];
14         if (!tgid)
15                 return -ENOENT;
16         sprintf(tmp, "%d", tgid);
17         return vfs_readlink(dentry,buffer,buflen,tmp);
18 }
19
20 static void *proc_self_follow_link(struct dentry *dentry, struct nameidata *nd)
21 {
22         struct pid_namespace *ns = dentry->d_sb->s_fs_info;
23         pid_t tgid = task_tgid_nr_ns(current, ns);
24         char *name = ERR_PTR(-ENOENT);
25         if (tgid) {
26                 /* 11 for max length of signed int in decimal + NULL term */
27                 name = kmalloc(12, GFP_KERNEL);
28                 if (!name)
29                         name = ERR_PTR(-ENOMEM);
30                 else
31                         sprintf(name, "%d", tgid);
32         }
33         nd_set_link(nd, name);
34         return NULL;
35 }
36
37 static void proc_self_put_link(struct dentry *dentry, struct nameidata *nd,
38                                 void *cookie)
39 {
40         char *s = nd_get_link(nd);
41         if (!IS_ERR(s))
42                 kfree(s);
43 }
44
45 static const struct inode_operations proc_self_inode_operations = {
46         .readlink       = proc_self_readlink,
47         .follow_link    = proc_self_follow_link,
48         .put_link       = proc_self_put_link,
49 };
50
51 void __init proc_self_init(void)
52 {
53         struct proc_dir_entry *proc_self_symlink;
54         mode_t mode;
55
56         mode = S_IFLNK | S_IRWXUGO;
57         proc_self_symlink = proc_create("self", mode, NULL, NULL );
58         proc_self_symlink->proc_iops = &proc_self_inode_operations;
59 }