sk_msg_memcopy_from_iter
int sk_msg_memcopy_from_iter(struct sock *sk, struct iov_iter *from,
EXPORT_SYMBOL_GPL(sk_msg_memcopy_from_iter);
ret = sk_msg_memcopy_from_iter(sk, &msg->msg_iter, msg_tx,
ret = sk_msg_memcopy_from_iter(sk, &msg->msg_iter,
err = sk_msg_memcopy_from_iter(sk, &pfx_iter, &emsg->skmsg,
err = sk_msg_memcopy_from_iter(sk, &msg->msg_iter, &emsg->skmsg, size);