[GIT PULL] devmem fix for v4.11-rc7

[Kees Cook]

Hi,

Please pull this devmem change for v4.11-rc7. Tommi tested this successfully
and no one appears to have objected to the RFC patch, so here's the fix. :)

Thanks!

-Kees

The following changes since commit b9b3322f13f350587f17f0a76f008830e3a420d3:

  Merge branch 'stable-4.11' of git://git.infradead.org/users/pcmoore/audit (2017-04-12 00:02:33 -0700)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git tags/devmem-v4.11-rc7

for you to fetch changes up to a4866aa812518ed1a37d8ea0c881dc946409de94:

  mm: Tighten x86 /dev/mem with zeroing reads (2017-04-12 11:40:23 -0700)

----------------------------------------------------------------
Fixes /dev/mem to read back zeros for System RAM areas in the 1MB exception
area on x86 to avoid exposing RAM or tripping hardened usercopy.

----------------------------------------------------------------
Kees Cook (1):
      mm: Tighten x86 /dev/mem with zeroing reads

 arch/x86/mm/init.c | 41 +++++++++++++++++++--------
 drivers/char/mem.c | 82 ++++++++++++++++++++++++++++++++++--------------------
 2 files changed, 82 insertions(+), 41 deletions(-)

-- 
Kees Cook
Pixel Security