Linux and aliasing?

[Joern Rennecke]

> Also some of the datastructures one would need to change are included
> by userspace applications, especially for some of the networking
> instances, and thus one would have ABI issues to concern themselves
> about if they were to go and perform these transformations.  Much more
> is it than a tedious chore.  One could certainly create another header
> file, leave the old one alone with the same name, and use only the new
> one inside the kernel, but does it make sense to have two copies and
> maintain them?

No.  You could still have a single header file, and control the variant
portions with #ifdef __KERNEL__ / #else / #endif .
Or if you have some recurring common type mix, you could use some macros
in the declarations that are definied differently for kernel and user space.