[RFC PATCH 0/7 v1] powerpc: Memory Protection Keys

[Ram Pai]

Memory protection keys enable applications to protect its
address space from inadvertent access or corruption from
itself.

The overall idea:

 A process allocates a   key  and associates it with
 a  address  range  within    its   address   space.
 The process  than  can  dynamically  set read/write 
 permissions on  the   key   without  involving  the 
 kernel. Any  code that  violates   the  permissions
 off the address space; as defined by its associated
 key, will receive a segmentation fault.

This patch series enables the feature on PPC64.
It is enabled on HPTE 64K-page platform.

ISA3.0 section 5.7.13 describes the detailed specifications.

Testing:
	This patch series has passed all the protection key
	tests available in  the selftests directory. Though
	the test are written  for x86, I  have updated  the
	tests to  cater  to  powerpc. Will  send  the patch
	separately, along with documentation updates.

Thanks-to: Dave Hansen, Aneesh, Paul Mackerras,
	   Michael Ellermen  :)

Ram Pai (7):
  Free up four PTE bits to accommadate memory keys
  Implement sys_pkey_alloc and sys_pkey_free system call.
  store and restore the key state across context switches.
  Implementation for sys_mprotect_pkey() system call.
  Program HPTE key protection bits.
  Handle exceptions caused by violation of key protection.
  Deliver SEGV signal on protection key violation.

 arch/powerpc/Kconfig                          |  15 ++
 arch/powerpc/include/asm/book3s/64/hash-4k.h  |  12 ++
 arch/powerpc/include/asm/book3s/64/hash-64k.h |  38 ++--
 arch/powerpc/include/asm/book3s/64/hash.h     |   8 +-
 arch/powerpc/include/asm/book3s/64/mmu-hash.h |  10 +
 arch/powerpc/include/asm/book3s/64/mmu.h      |  10 +
 arch/powerpc/include/asm/book3s/64/pgtable.h  |  84 +++++++-
 arch/powerpc/include/asm/mman.h               |  29 +--
 arch/powerpc/include/asm/mmu_context.h        |  12 ++
 arch/powerpc/include/asm/pkeys.h              | 159 +++++++++++++++
 arch/powerpc/include/asm/processor.h          |   5 +
 arch/powerpc/include/asm/reg.h                |  10 +-
 arch/powerpc/include/asm/systbl.h             |   3 +
 arch/powerpc/include/asm/unistd.h             |   6 +-
 arch/powerpc/include/uapi/asm/ptrace.h        |   5 +-
 arch/powerpc/include/uapi/asm/unistd.h        |   3 +
 arch/powerpc/kernel/asm-offsets.c             |   1 +
 arch/powerpc/kernel/exceptions-64s.S          |  10 +-
 arch/powerpc/kernel/process.c                 |  18 ++
 arch/powerpc/kernel/signal_32.c               |  18 +-
 arch/powerpc/kernel/signal_64.c               |  11 ++
 arch/powerpc/kernel/traps.c                   |  49 +++++
 arch/powerpc/mm/Makefile                      |   1 +
 arch/powerpc/mm/dump_linuxpagetables.c        |   3 +-
 arch/powerpc/mm/fault.c                       |  21 +-
 arch/powerpc/mm/hash64_4k.c                   |  12 +-
 arch/powerpc/mm/hash64_64k.c                  |  73 +++----
 arch/powerpc/mm/hash_utils_64.c               |  43 ++++-
 arch/powerpc/mm/hugetlbpage-hash64.c          |  16 +-
 arch/powerpc/mm/mmu_context_book3s64.c        |   5 +
 arch/powerpc/mm/pkeys.c                       | 267 ++++++++++++++++++++++++++
 include/linux/mm.h                            |  32 +--
 include/uapi/asm-generic/mman-common.h        |   2 +-
 33 files changed, 856 insertions(+), 135 deletions(-)
 create mode 100644 arch/powerpc/include/asm/pkeys.h
 create mode 100644 arch/powerpc/mm/pkeys.c

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1.8.3.1