Which architectures are currently making their pre-page execute permissions
depend upon VM_EXEC? Would additional arch patches be needed for this?
Yes, they would need some straight forward minor patches e.g. in the
32bit emulation. IA64 would be a candidate I guess.
i386 could do it on NX capable CPUs with PAE kernels (but it would require backporting some fixes from x86-64). However currently it doesn't make
much sense because all x86 CPUs that support NX (AMD K8 currently only) support 64bit kernels and people can as well run 64bit kernels.
Doing it on i386 would only make sense if non 64bit capable CPUs ever get
NX. I heard VIA may be planning that, but so far there is nothing in their
shipping CPUs, so I guess we can skip that for now.