mmap(), #PF handler and EADD interaction

[Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>]

I did some backtracking today how the permission flow worked.

With the maximum VM flags defined for a page, what if EADD is done after
mmap()?  E.g. we first do mmap() with RWX and later EADD with lets say
RW.

The first thing that comes to mind is that the #PF handler should caught
this corner case.

Now the code correctly validates when you do either mmap() and
mprotect() after EADD(s) but I think "other way around" is missing.

/Jarkko