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

David H. Gutteridge
2018-07-30T07:08:24Z

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@sympatico.ca>

Regards,

Dave