Re: [PATCH v6 14/41] x86/mm: Introduce _PAGE_SAVED_DIRTY

[Edgecombe, Rick P]

On Tue, 2023-02-21 at 09:38 +0100, David Hildenbrand wrote:
> Again, I'd not specialize on COW in all patches to much (IMHO, it 
> creates more confusion than it actually helps for understanding
> what's 
> happening) and just call it a read-only PTE that is dirty. Simple as 
> that. And it's easy to see why that's problematic, because read-only 
> PTEs that are dirty would be identified as shadow stack PTEs, which
> we 
> want to work around.
> 
> Again, just my 2 cents. I'm not an x86 maintainer ;)

Right, I see the point. Let's see if they have any opinion. There is a
bit of a historical reason for the focus on COW. As you well know the
dirty bit used to be important for that case. But I think it's still
not a terrible example. It covers some typical cases, but yes we don't
want to mislead the reader that it is a Cow only scenario.