> We could turn ->msg_control/->msg_controllen into another > iov_iter, but seeing that we never do scatter-gather for those > IMO that would be a massive overkill. A flag controlling whether > ->msg_control is kernel or userland pointer would do, especially > since we already have a flag for "do we want a native or compat > layout for cmsg" in there. While your current hack seems like a nice short term improvement I think we need an iov_iter or iov_iter-light there in the long run. Same for ioctl so that we can pass properly typed kernel or user buffers through without all these set_fs hacks.