validate_ns
ret = validate_ns(nsset, &user_ns->ns);
ret = validate_ns(nsset, from_mnt_ns(nsp->mnt_ns));
ret = validate_ns(nsset, &nsp->uts_ns->ns);
ret = validate_ns(nsset, &nsp->ipc_ns->ns);
ret = validate_ns(nsset, &pid_ns->ns);
ret = validate_ns(nsset, &nsp->cgroup_ns->ns);
ret = validate_ns(nsset, &nsp->net_ns->ns);
ret = validate_ns(nsset, &nsp->time_ns->ns);
err = validate_ns(&nsset, ns);