kern_readv
error = kern_readv(td, uap->fd, auio);
error = kern_readv(td, uap->fd, auio);
error = kern_readv(td, uap->fd, &auio);
error = kern_readv(td, uap->fd, auio);
int kern_readv(struct thread *td, int fd, struct uio *auio);