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

[David H. Gutteridge]

On Wed, 2018-07-25 at 17:48 +0200, Joerg Roedel wrote:
> Hi,
> 
> here are three patches on-top of tip/x86/pti to update the
> vmallo_fault() fix and also with another important fix.
> 
> The first two patches remove the WARN_ON_ONCE(in_nmi) from
> the vmalloc_fault() function and revert the previous fix, as
> discussed at the last patch-set.
> 
> The third patch is an important fix for a silent memory
> corruption issue found by the trinity fuzzer, which did take
> a while to track down. But I found it and with the fix the
> fuzzer already runs for couple of hours now and the VM is
> still alive.
> 
> Regards,
> 
> 	Joerg
> 
> Joerg Roedel (3):
>   x86/mm: Remove in_nmi() warning from vmalloc_fault()
>   Revert "perf/core: Make sure the ring-buffer is mapped in all
>     page-tables"
>   x86/kexec: Allocate 8k PGDs for PTI
> 
>  arch/x86/kernel/machine_kexec_32.c |  5 +++--
>  arch/x86/mm/fault.c                |  2 --
>  kernel/events/ring_buffer.c        | 16 ----------------
>  3 files changed, 3 insertions(+), 20 deletions(-)

Hi Joerg,

I've found no significant issues in my testing of this patch set.
The only minor thing I noted is that in your previous "v8" patch set
([PATCH 38/39] x86/mm/pti: Add Warning when booting on a PCID capable
CPU), it reports the warning on non-PCID capable CPUs: I think you
intended a bitwise "&", not a logical "&&" in the if statement?

Tested-by: David H. Gutteridge <dhgutteridge@xxxxxxxxxxxx>

Regards,

Dave