Re: [PATCH 4.9 v2] x86/pti/efi: broken conversion from efi to kernel page table

From: Greg KH
Date: Mon Jan 15 2018 - 12:50:50 EST


On Mon, Jan 15, 2018 at 11:44:14AM -0500, Pavel Tatashin wrote:
> The page table order must be increased for EFI table in order to avoid a
> bug where NMI tries to change the page table to kernel page table, while
> efi page table is active.
>
> For more disccussion about this bug, see this thread:
> http://lkml.iu.edu/hypermail/linux/kernel/1801.1/00951.html
>
> Signed-off-by: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
> Reviewed-by: Steven Sistare <steven.sistare@xxxxxxxxxx>
> Acked-by: Jiri Kosina <jkosina@xxxxxxx>
> ---
> arch/x86/include/asm/pgalloc.h | 11 +++++++++++
> arch/x86/mm/pgtable.c | 7 -------
> arch/x86/platform/efi/efi_64.c | 2 +-
> 3 files changed, 12 insertions(+), 8 deletions(-)
>
> Changelog:
> v1 - v2: Fixed compiling warning

Many thanks for this, now queued up.

greg k-h