Re: [PATCH 0/3] PTI for x86-32 Fixes
From: David H. Gutteridge
Date: Thu Aug 16 2018 - 22:44:50 EST
On Tue, 2018-08-07 at 12:24 +0200, Joerg Roedel wrote:
> Hi,
>
> here is a small patch-set to fix two small issues in the
> PTI implementation for 32 bit x86. The issues are:
>
> 1) Fix the 32 bit PCID check. I used the wrong
> operator there and this caused false-positive
> warnings.
>
> 2) The other two patches make sure the init-hole is
> not mapped into the user page-table. It is the
> 32 bit counterpart to commit
>
> c40a56a7818c ('x86/mm/init: Remove freed kernel image areas
> from alias mapping')
>
> for the 64 bit PTI implementation.
>
> I tested that no-PAE, PAE and 64 bit kernel all boot and
> have correct user page-tables with identical global mappings
> between user and kernel.
>
> Regards,
>
> Joerg
>
> Joerg Roedel (3):
> x86/mm/pti: Fix 32 bit PCID check
> x86/mm/pti: Don't clear permissions in pti_clone_pmd()
> x86/mm/pti: Clone kernel-image on PTE level for 32 bit
>
> arch/x86/mm/pti.c | 143 ++++++++++++++++++++++++++++++++++++++-------
> ---------
> 1 file changed, 100 insertions(+), 43 deletions(-)
I've tested this in a VM and on an Atom laptop, as usual. No
regressions noted.
Tested-by: David H. Gutteridge <dhgutteridge@xxxxxxxxxxxx>
Regards,
Dave