Re: [GIT PULL] xen: Check NX state before setting up GDT mapping

[Ingo Molnar <mingo@elte.hu>]

* Jeremy Fitzhardinge <jeremy@goop.org> wrote:

> Hi Ingo,
> 
> This is a little followup fix to the previous Xen stack-protector
> patches to deal with the case of a 64-bit processor without NX support
> (either old Intel or disabled in BIOS).  Before creating the mapping for
> the GDT we need to make sure that NX is actually supported or the
> processor will fault on us.
> 
> This ends up making mm/init.o non-stack-protected.  Given that this file
> has some fairly complex functions with local arrays, I've made an
> additional change to move the NX setup into its own file to limit the
> non-stack-protected code.  I added it as a later delta so that the pure
> bugfix can be applied to stable, and the cleanup can go on top into
> mainline.
> 
> Thanks,
>     J
> 
> The following changes since commit 79b520e87e1214cfa107bdc8528b5d6c055a8b82:
>   Linus Torvalds (1):
>         Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfs
> 
> are available in the git repository at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen.git bugfix
> 
> Jeremy Fitzhardinge (2):
>       xen: check EFER for NX before setting up GDT mapping
>       x86: split NX setup into separate file to limit unstack-protected code
> 
>  arch/x86/include/asm/pgtable_types.h |    1 +
>  arch/x86/mm/Makefile                 |    3 +-
>  arch/x86/mm/init.c                   |   63 -------------------------------
>  arch/x86/mm/setup_nx.c               |   69 ++++++++++++++++++++++++++++++++++
>  arch/x86/xen/enlighten.c             |   10 ++--
>  5 files changed, 77 insertions(+), 69 deletions(-)
>  create mode 100644 arch/x86/mm/setup_nx.c

Pulled, thanks Jeremy!

	Ingo