lkml.org 
[lkml]   [2023]   [Jun]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RESUBMIT][PATCH] x86/mm: Fix PAT bit missing from page protection modify mask
On Thu, Jun 01, 2023 at 10:47:39AM +0200, Juergen Gross wrote:
> As described in the commit message, this only works on bare metal due to the
> PAT bit not being needed for WC mappings.
>
> Making this patch Xen specific would try to cure the symptoms without fixing
> the underlying problem: _PAGE_PAT should be regarded the same way as the bits
> for caching mode (_PAGE_CHG_MASK).

So why isn't _PAGE_PAT part of _PAGE_CHG_MASK?

It says above it "Set of bits not changed in pte_modify."

And I don't see pte_modify() changing that bit either.

Right now this "fix" looks like, "let's OR these two masks so that we
can take care of _PAGE_PAT too". But it doesn't make a whole lotta sense
to me...

--
Regards/Gruss,
Boris.

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

\
 
 \ /
  Last update: 2023-06-02 16:44    [W:0.063 / U:0.032 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site