sk_ioctl
int sk_ioctl(struct sock *sk, unsigned int cmd, void __user *arg);
EXPORT_SYMBOL(sk_ioctl);
return sk_ioctl(sk, cmd, (void __user *)arg);
err = sk_ioctl(sk, cmd, (void __user *)arg);
return sk_ioctl(sk, cmd, (void __user *)arg);
return sk_ioctl(sk, cmd, (void __user *)arg);