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.
The tests are updated to work on both x86 and powerpc.
version v3:
(1) split the patches into smaller consumable
patches.
(2) added the ability to disable execute permission
on a key at creation.
(3) rename calc_pte_to_hpte_pkey_bits() to
pte_to_hpte_pkey_bits() -- suggested by Anshuman
(4) some code optimization and clarity in
do_page_fault()
(5) A bug fix while invalidating a hpte slot in
__hash_page_4K() -- noticed by Aneesh
version v2:
(1) documentation and selftest added
(2) fixed a bug in 4k hpte backed 64k pte where page
invalidation was not done correctly, and
initialization of second-part-of-the-pte was not
done correctly if the pte was not yet Hashed
with a hpte. Reported by Aneesh.
(3) Fixed ABI breakage caused in siginfo structure.
Reported by Anshuman.
Outstanding known issue:
Calls to sys_swapcontext with a made-up context will end
up with a crap AMR if done by code who didn't know about
that register. -- Reported by Ben.
version v1: Initial version
Thanks-to: Dave Hansen, Aneesh, Paul Mackerras,
Michael Ellermen
Ram Pai (23):
powerpc: Free up four 64K PTE bits in 4K backed HPTE pages
powerpc: introduce set_hidx_slot helper
powerpc: introduce get_hidx_gslot helper
powerpc: Free up four 64K PTE bits in 64K backed HPTE pages
powerpc: capture the PTE format changes in the dump pte report
powerpc: use helper functions in __hash_page_4K() for 64K PTE
powerpc: use helper functions in __hash_page_4K() for 4K PTE
powerpc: use helper functions in flush_hash_page()
mm: introduce an additional vma bit for powerpc pkey
mm: provide the ability to disable execute on a key at creation
x86: key creation with PKEY_DISABLE_EXECUTE is disallowed
powerpc: Implement sys_pkey_alloc and sys_pkey_free system call
powerpc: store and restore the pkey state across context switches
powerpc: Implementation for sys_mprotect_pkey() system call
powerpc: Program HPTE key protection bits
powerpc: Macro the mask used for checking DSI exception
powerpc: Handle exceptions caused by violation of pkey protection
powerpc: Deliver SEGV signal on pkey violation
selftest: Move protecton key selftest to arch neutral directory
selftest: PowerPC specific test updates to memory protection keys
Documentation: Move protecton key documentation to arch neutral
directory
Documentation: PowerPC specific updates to memory protection keys
procfs: display the protection-key number associated with a vma
Documentation/filesystems/proc.txt | 3 +-
Documentation/vm/protection-keys.txt | 110 ++
Documentation/x86/protection-keys.txt | 85 --
arch/powerpc/Kconfig | 15 +
arch/powerpc/include/asm/book3s/64/hash-4k.h | 14 +
arch/powerpc/include/asm/book3s/64/hash-64k.h | 53 +-
arch/powerpc/include/asm/book3s/64/hash.h | 15 +-
arch/powerpc/include/asm/book3s/64/mmu-hash.h | 5 +
arch/powerpc/include/asm/book3s/64/mmu.h | 10 +
arch/powerpc/include/asm/book3s/64/pgtable.h | 84 +-
arch/powerpc/include/asm/mman.h | 14 +-
arch/powerpc/include/asm/mmu_context.h | 12 +
arch/powerpc/include/asm/paca.h | 1 +
arch/powerpc/include/asm/pkeys.h | 159 +++
arch/powerpc/include/asm/processor.h | 5 +
arch/powerpc/include/asm/reg.h | 7 +-
arch/powerpc/include/asm/systbl.h | 3 +
arch/powerpc/include/asm/unistd.h | 6 +-
arch/powerpc/include/uapi/asm/ptrace.h | 3 +-
arch/powerpc/include/uapi/asm/unistd.h | 3 +
arch/powerpc/kernel/asm-offsets.c | 5 +
arch/powerpc/kernel/exceptions-64s.S | 18 +-
arch/powerpc/kernel/process.c | 18 +
arch/powerpc/kernel/signal_32.c | 14 +
arch/powerpc/kernel/signal_64.c | 14 +
arch/powerpc/kernel/traps.c | 49 +
arch/powerpc/mm/Makefile | 1 +
arch/powerpc/mm/dump_linuxpagetables.c | 3 +-
arch/powerpc/mm/fault.c | 22 +
arch/powerpc/mm/hash64_4k.c | 14 +-
arch/powerpc/mm/hash64_64k.c | 111 +-
arch/powerpc/mm/hash_utils_64.c | 36 +-
arch/powerpc/mm/hugetlbpage-hash64.c | 16 +-
arch/powerpc/mm/mmu_context_book3s64.c | 5 +
arch/powerpc/mm/pkeys.c | 267 +++++
arch/x86/kernel/fpu/xstate.c | 3 +
fs/proc/task_mmu.c | 18 +-
include/linux/mm.h | 18 +-
include/uapi/asm-generic/mman-common.h | 4 +-
tools/testing/selftests/vm/Makefile | 1 +
tools/testing/selftests/vm/pkey-helpers.h | 365 ++++++
tools/testing/selftests/vm/protection_keys.c | 1483 +++++++++++++++++++++++++
tools/testing/selftests/x86/Makefile | 2 +-
tools/testing/selftests/x86/pkey-helpers.h | 219 ----
tools/testing/selftests/x86/protection_keys.c | 1395 -----------------------
45 files changed, 2868 insertions(+), 1840 deletions(-)
create mode 100644 Documentation/vm/protection-keys.txt
delete mode 100644 Documentation/x86/protection-keys.txt
create mode 100644 arch/powerpc/include/asm/pkeys.h
create mode 100644 arch/powerpc/mm/pkeys.c
create mode 100644 tools/testing/selftests/vm/pkey-helpers.h
create mode 100644 tools/testing/selftests/vm/protection_keys.c
delete mode 100644 tools/testing/selftests/x86/pkey-helpers.h
delete mode 100644 tools/testing/selftests/x86/protection_keys.c
--
1.8.3.1
