Re: [PATCH v17 11/26] x86/mm: Update ptep_set_wrprotect() and pmdp_set_wrprotect() for transition from _PAGE_DIRTY to _PAGE_COW

[Borislav Petkov]

On Mon, Jan 25, 2021 at 01:27:51PM -0800, Yu, Yu-cheng wrote:
> > Maybe I'm missing something but those two can happen outside of the
> > loop, no? Or is *ptep somehow changing concurrently while the loop is
> > doing the CMPXCHG and you need to recreate it each time?
> > 
> > IOW, you can generate upfront and do the empty loop...
> 
> *ptep can change concurrently.

Care to elaborate?

-- 
Regards/Gruss,
    Boris.

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