Re: [REGRESSION] Re: [PATCH v7 8/8] x86/module: enable ROX caches for module text on 64 bit

[Peter Zijlstra]

On Sun, Jan 12, 2025 at 08:07:55PM +0100, Borislav Petkov wrote:
> On Sun, Jan 12, 2025 at 08:42:05PM +0200, Ville Syrjälä wrote:
> > On Wed, Oct 23, 2024 at 07:27:11PM +0300, Mike Rapoport wrote:
> > > From: "Mike Rapoport (Microsoft)" <rppt@xxxxxxxxxx>
> > > 
> > > Enable execmem's cache of PMD_SIZE'ed pages mapped as ROX for module
> > > text allocations on 64 bit.
> > 
> > Hi,
> > 
> > This breaks resume from hibernation on my Alderlake laptop.
> > 
> > Fortunately this still reverts cleanly.
> 
> Does that hunk in the mail here fix it?
> 
> https://lore.kernel.org/all/Z4DwPkcYyZ-tDKwY@xxxxxxxxxx/

There's definiltely breakage with that module_writable_address()
nonsense in alternative.c that will not be fixed by that patch.

The very simplest thing at this point is to remove:

     select ARCH_HAS_EXECMEM_ROX             if X86_64

and try again next cycle.