[PATCH v3 0/5] fix device-dax pud crash and fixup {pte, pmd, pud}_write

[Dan Williams <dan.j.williams@intel.com>]

Changes since v2 [1]:
* Switch from the "#define __HAVE_ARCH_PUD_WRITE" to "#define
  pud_write". This incidentally fixes a powerpc compile error.
  (Stephen)

* Add a cleanup patch to align pmd_write to the pud_write definition
  scheme.

---

Andrew,

Here is another attempt at the pud_write() fix [2], and some follow-on
patches to use the '_access_permitted' helpers in fault and
get_user_pages() paths where we are checking if the thread has access to
write. I explicitly omit conversions for places where the kernel is
checking the _PAGE_RW flag for kernel purposes, not for userspace
access.

Beyond fixing the crash, this series also fixes get_user_pages() and
fault paths to honor protection keys in the same manner as
get_user_pages_fast(). Only the crash fix is tagged for -stable as the
protection key check is done just for consistency reasons since
userspace can change protection keys at will.

These have received a build success notification from the 0day robot.

[1]: https://lists.01.org/pipermail/linux-nvdimm/2017-November/013254.html
[2]: https://lists.01.org/pipermail/linux-nvdimm/2017-November/013237.html

---

Dan Williams (5):
      mm: fix device-dax pud write-faults triggered by get_user_pages()
      mm: switch to 'define pmd_write' instead of __HAVE_ARCH_PMD_WRITE
      mm: replace pud_write with pud_access_permitted in fault + gup paths
      mm: replace pmd_write with pmd_access_permitted in fault + gup paths
      mm: replace pte_write with pte_access_permitted in fault + gup paths


 arch/arm/include/asm/pgtable-3level.h        |    1 -
 arch/arm64/include/asm/pgtable.h             |    1 -
 arch/mips/include/asm/pgtable.h              |    2 +-
 arch/powerpc/include/asm/book3s/64/pgtable.h |    1 -
 arch/s390/include/asm/pgtable.h              |    8 +++++++-
 arch/sparc/include/asm/pgtable_64.h          |    2 +-
 arch/sparc/mm/gup.c                          |    4 ++--
 arch/tile/include/asm/pgtable.h              |    1 -
 arch/x86/include/asm/pgtable.h               |    8 +++++++-
 fs/dax.c                                     |    3 ++-
 include/asm-generic/pgtable.h                |   12 ++++++++++--
 include/linux/hugetlb.h                      |    8 --------
 mm/gup.c                                     |    2 +-
 mm/hmm.c                                     |    8 ++++----
 mm/huge_memory.c                             |    6 +++---
 mm/memory.c                                  |    8 ++++----
 16 files changed, 42 insertions(+), 33 deletions(-)

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