/*
* /proc/self:
*/
static int proc_self_readlink(struct dentry *dentry, char __user *buffer,
int buflen)
{
struct pid_namespace *ns = dentry->d_sb->s_fs_info;
pid_t tgid = task_tgid_nr_ns(current, ns);
char tmp[PROC_NUMBUF];
if (!tgid)
return -ENOENT;
sprintf(tmp, "%d", tgid);
return readlink_copy(buffer, buflen, tmp);
}
int
xfs_readlink_by_handle(
struct file *parfilp,
xfs_fsop_handlereq_t *hreq)
{
struct dentry *dentry;
__u32 olen;
void *link;
int error;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
dentry = xfs_handlereq_to_dentry(parfilp, hreq);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
/* Restrict this handle operation to symlinks only. */
if (!d_is_symlink(dentry)) {
error = -EINVAL;
goto out_dput;
}
if (copy_from_user(&olen, hreq->ohandlen, sizeof(__u32))) {
error = -EFAULT;
goto out_dput;
}
link = kmalloc(MAXPATHLEN+1, GFP_KERNEL);
if (!link) {
error = -ENOMEM;
goto out_dput;
}
error = xfs_readlink(XFS_I(d_inode(dentry)), link);
if (error)
goto out_kfree;
error = readlink_copy(hreq->ohandle, olen, link);
if (error)
goto out_kfree;
out_kfree:
kfree(link);
out_dput:
dput(dentry);
return error;
}
static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int buflen)
{
struct inode *inode = d_inode(dentry);
const struct proc_ns_operations *ns_ops = PROC_I(inode)->ns_ops;
struct task_struct *task;
char name[50];
int res = -EACCES;
task = get_proc_task(inode);
if (!task)
return res;
if (ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
res = ns_get_name(name, sizeof(name), task, ns_ops);
if (res >= 0)
res = readlink_copy(buffer, buflen, name);
}
put_task_struct(task);
return res;
}
