selftests, powerpc, x86: Memory Protection Keys

Memory protection keys enables an application to protect its address space from inadvertent access by its own code.

This feature is now enabled on powerpc and has been available since 4.16-rc1. The patches move the selftests to arch neutral directory and enhance their test coverage.

Testing
-------
Verified for correctness on powerpc. Need help with x86 testing as I do not have access to a Skylake server. Client platforms like Coffee Lake do not have the required feature bits set in CPUID.

Changelog
---------
Link to previous version (v14):
https://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=55981&state=*

v15:
(1) Rebased on top of latest master.
(2) Addressed review comments from Dave Hansen.
(3) Moved code for getting or setting pkey bits to new helpers. These changes replace patch 7 of v14.
(4) Added a fix which ensures that the correct count of reserved keys is used across different platforms.
(5) Added a fix which ensures that the correct page size is used as powerpc supports both 4K and 64K pages.

v14:
(1) Incorporated another round of comments from Dave Hansen.

v13:
(1) Incorporated comments for Dave Hansen.
(2) Added one more test for correct pkey-0 behavior.

v12:
(1) Fixed the offset of pkey field in the siginfo structure for x86_64 and powerpc. And tries to use the actual field if the headers have it defined.

v11:
(1) Fixed a deadlock in the ptrace testcase.

v10 and prior:
(1) Moved the testcase to arch neutral directory.
(2) Split the changes into incremental patches.

Desnes A. Nunes do Rosario (1):
selftests/vm/pkeys: Fix number of reserved powerpc pkeys

Ram Pai (17):
selftests/x86/pkeys: Move selftests to arch-neutral directory selftests/vm/pkeys: Rename all references to pkru to a generic name selftests/vm/pkeys: Move generic definitions to header file selftests/vm/pkeys: Typecast the pkey register selftests/vm/pkeys: Fix pkey_disable_clear() selftests/vm/pkeys: Fix assertion in pkey_disable_set/clear() selftests/vm/pkeys: Fix alloc_random_pkey() to make it really random selftests/vm/pkeys: Introduce generic pkey abstractions selftests/vm/pkeys: Introduce powerpc support selftests/vm/pkeys: Fix assertion in test_pkey_alloc_exhaust() selftests/vm/pkeys: Improve checks to determine pkey support selftests/vm/pkeys: Associate key on a mapped page and detect access
violation
selftests/vm/pkeys: Associate key on a mapped page and detect write
violation
selftests/vm/pkeys: Detect write violation on a mapped
access-denied-key page
selftests/vm/pkeys: Introduce a sub-page allocator selftests/vm/pkeys: Test correct behaviour of pkey-0 selftests/vm/pkeys: Override access right definitions on powerpc

Sandipan Das (3):
selftests: vm: pkeys: Add helpers for pkey bits
selftests: vm: pkeys: Use the correct huge page size
selftests: vm: pkeys: Use the correct page size on powerpc

Thiago Jung Bauermann (2):
selftests/vm/pkeys: Move some definitions to arch-specific header selftests/vm/pkeys: Make gcc check arguments of sigsafe_printf()

 tools/testing/selftests/vm/.gitignore         |   1 +
 tools/testing/selftests/vm/Makefile           |   5 +
 tools/testing/selftests/vm/pkey-helpers.h     | 226 ++++++
 tools/testing/selftests/vm/pkey-powerpc.h     | 138 ++++
 tools/testing/selftests/vm/pkey-x86.h         | 183 +++++
 .../selftests/{x86 => vm}/protection_keys.c   | 688 ++++++++++--------
 tools/testing/selftests/x86/.gitignore        |   1 -
 tools/testing/selftests/x86/pkey-helpers.h    | 219 ------
 8 files changed, 931 insertions(+), 530 deletions(-)
 create mode 100644 tools/testing/selftests/vm/pkey-helpers.h
 create mode 100644 tools/testing/selftests/vm/pkey-powerpc.h
 create mode 100644 tools/testing/selftests/vm/pkey-x86.h
 rename tools/testing/selftests/{x86 => vm}/protection_keys.c (74%)
 delete mode 100644 tools/testing/selftests/x86/pkey-helpers.h

2.17.1