Re: The future of PageAnonExclusive

David Hildenbrand
2024-12-11T13:48:37Z

On 11.12.24 14:42, Kirill A. Shutemov wrote:
> On Wed, Dec 11, 2024 at 12:56:11PM +0100, David Hildenbrand wrote:
>>> (C) Encode it in the PTE.
>>>
>>> pte_write() -> PAE
>>>
>>> !pte_write() && pte_dirty() -> PAE
>>>
>>> !pte_write && !pte_dirty() -> !PAE
>
> You are late to the party. On x86, !pte_write() && pte_dirty() is shadow
> stack.
>

Hah, no, it works! :)

On x86 we use this fancy savedirty bit to handle that internally, such
that pte_write/pte_dirty keep working as expected on shadow stacks.