Re: [PATCH 0/3] PTI for x86-32 Fixes

[David H. Gutteridge]

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