Re: [PATCH v28 09/32] x86/mm: Introduce _PAGE_COW

From: Borislav Petkov
Date: Sat Aug 21 2021 - 12:27:00 EST


On Wed, Aug 18, 2021 at 09:38:30AM -0700, Yu, Yu-cheng wrote:
> We can visualize the type of a mm area by looking at vma->vm_flags, e.g.

visualize?

> maybe_mkwrite(), and PTE macros as lower-level operatives. These two have
> some relations but not one-to-one. Note that a PTE in a writable area is
> not always pte_write().
>
> I have considered and implemented a shadow stack PTE either pte_write() or
> not. Making shadow stack as pte_write() results in less arch_* macros and
> less confusion in copy-on-write code. That is one more thing to consider.

Ok, even though I'm still not 100% convinced by both amluto's and your
arguments. Let's try it and see what happens...

--
Regards/Gruss,
Boris.

https://people.kernel.org/tglx/notes-about-netiquette