On Wed, Aug 19, 2009 at 03:00:34PM +1000, Benjamin Herrenschmidt wrote: > This is an attempt at cleaning up a bit the way we handle execute > permission on powerpc. _PAGE_HWEXEC is gone, _PAGE_EXEC is now only > defined by CPUs that can do something with it, and the myriad of > #ifdef's in the I$/D$ coherency code is reduced to 2 cases that > hopefully should cover everything. > > The logic on BookE is a little bit different than what it was though > not by much. Since now, _PAGE_EXEC will be set by the generic code > for executable pages, we need to filter out if they are unclean and > recover it. However, I don't expect the code to be more bloated than > it already was in that area due to that change. > > I could boast that this brings proper enforcing of per-page execute > permissions to all BookE and 40x but in fact, we've had that now for > some time as a side effect of my previous rework in that area (and > I didn't even know it :-) We would only enable execute permission if > the page was cache clean and we would only cache clean it if we took > and exec fault. Since we now enforce that the later only work if > VM_EXEC is part of the VMA flags, we de-fact already enforce per-page > execute permissions... Unless I missed something > > Signed-off-by: Benjamin Herrenschmidt <b...@kernel.crashing.org> Acked-by: David Gibson <da...@gibson.dropbear.id.au>
-- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev