Re: [PATCH v23 07/28] x86/mm: Remove _PAGE_DIRTY from kernel RO pages

[Yu, Yu-cheng]

On 3/22/2021 2:13 AM, Kirill A. Shutemov wrote:
> On Tue, Mar 16, 2021 at 08:10:33AM -0700, Yu-cheng Yu wrote:
> > The x86 family of processors do not directly create read-only and Dirty
> > PTEs.  These PTEs are created by software.  One such case is that kernel
> > read-only pages are historically setup as Dirty.
> >
> > New processors that support Shadow Stack regard read-only and Dirty PTEs as
> > shadow stack pages.  This results in ambiguity between shadow stack and
> > kernel read-only pages.  To resolve this, removed Dirty from kernel read-
> > only pages.
> >
> > Signed-off-by: Yu-cheng Yu <yu-cheng.yu@xxxxxxxxx>
> > Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
> > Cc: Kees Cook <keescook@xxxxxxxxxxxx>
> > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> > Cc: Christoph Hellwig <hch@xxxxxx>
> > Cc: Andy Lutomirski <luto@xxxxxxxxxx>
> > Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> > Cc: Borislav Petkov <bp@xxxxxxxxx>
> > Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
>
> Looks good to me.
>
> Reviewed-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>

Thanks for reviewing.

Yu-cheng