[PATCH 00/13] [v4] x86, pkeys: two protection keys bug fixes

[Dave Hansen <dave.hansen@linux.intel.com>]

Hi x86 maintainers,

This set has been seen quite a few changes and additions since the
last post.  Details below.

Changes from v3:
 * Reordered patches following Ingo's recommendations: Introduce
   failing selftests first, then the kernel code to fix the test
   failure.
 * Increase verbosity and accuracy of do_not_expect_pk_fault()
   messages.
 * Removed abort() use from tests.  Crashing is not nice.
 * Remove some dead debugging code, fixing dprint_in_signal.
 * Fix deadlocks from using printf() and friends in signal
   handlers.

Changes from v2:
 * Clarified commit message in patch 1/9 taking some feedback from
   Shuah.

Changes from v1:
 * Added Fixes: and cc'd stable.  No code changes.

--

This fixes two bugs, and adds selftests to make sure they stay fixed:

1. pkey 0 was not usable via mprotect_pkey() because it had never
   been explicitly allocated.
2. mprotect(PROT_EXEC) memory could sometimes be left with the
   implicit exec-only protection key assigned.

I already posted #1 previously.  I'm including them both here because
I don't think it's been picked up in case folks want to pull these
all in a single bundle.

Dave Hansen (13):
      x86/pkeys/selftests: give better unexpected fault error messages
      x86/pkeys/selftests: Stop using assert()
      x86/pkeys/selftests: remove dead debugging code, fix dprint_in_signal
      x86/pkeys/selftests: avoid printf-in-signal deadlocks
      x86/pkeys/selftests: Allow faults on unknown keys
      x86/pkeys/selftests: Factor out "instruction page"
      x86/pkeys/selftests: Add PROT_EXEC test
      x86/pkeys/selftests: Fix pkey exhaustion test off-by-one
      x86/pkeys: Override pkey when moving away from PROT_EXEC
      x86/pkeys/selftests: Fix pointer math
      x86/pkeys/selftests: Save off 'prot' for allocations
      x86/pkeys/selftests: Add a test for pkey 0
      x86/pkeys: Do not special case protection key 0

 arch/x86/include/asm/mmu_context.h            |   2 +-
 arch/x86/include/asm/pkeys.h                  |  18 +-
 arch/x86/mm/pkeys.c                           |  21 +-
 tools/testing/selftests/x86/pkey-helpers.h    |  20 +-
 tools/testing/selftests/x86/protection_keys.c | 187 +++++++++++++-----
 5 files changed, 173 insertions(+), 75 deletions(-)

Cc: Ram Pai <linuxram@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Michael Ellermen <mpe@ellerman.id.au>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>p
Cc: Shuah Khan <shuah@kernel.org>
Cc: Shakeel Butt <shakeelb@google.com>