Re: [PATCH v2 00/10] x86/module: rework ROX cache to avoid writable copy

[Peter Zijlstra]

On Tue, Jan 21, 2025 at 01:36:47PM +0100, Peter Zijlstra wrote:
> On Tue, Jan 21, 2025 at 11:57:29AM +0200, Mike Rapoport wrote:
> 
> > Kirill A. Shutemov (1):
> >   x86/mm/pat: restore large ROX pages after fragmentation
> 
> The duplication between pmd and pud collapse is a bit annoying, but so
> be it.
> 
> > Mike Rapoport (Microsoft) (9):
> >   x86/mm/pat: cpa-test: fix length for CPA_ARRAY test
> >   x86/mm/pat: drop duplicate variable in cpa_flush()
> >   execmem: don't remove ROX cache from the direct map
> >   execmem: add API for temporal remapping as RW and restoring ROX afterwards
> >   module: introduce MODULE_STATE_GONE
> >   module: switch to execmem API for remapping as RW and restoring ROX
> >   Revert "x86/module: prepare module loading for ROX allocations of text"
> >   module: drop unused module_writable_address()
> >   x86: re-enable EXECMEM_ROX support
> 
> All these look good on a first reading, let me go build and test the
> various options.

I've tested:

GCC:  ibt=off
      ibt=on
LLVM: ibt-off,cfi=off
      ibt=off,cfi=kcfi
      ibt=on,cfi=off
      ibt=on,cfi=kcfi
      ibt=on,cfi=fineibt

And all of them were able to load a module, so yay!

My plan is to merge these patches into tip/x86/mm once we have -rc1.