Hi all,
This series implements the Permission Overlay Extension introduced in 2022 VMSA enhancements [1]. It is based on v6.6-rc3.
The Permission Overlay Extension allows to constrain permissions on memory regions. This can be used from userspace (EL0) without a system call or TLB invalidation.
POE is used to implement the Memory Protection Keys [2] Linux syscall.
The first few patches add the basic framework, then the PKEYS interface is implemented, and then the selftests are made to work on arm64.
There was discussion about what the 'default' protection key value should be, I used disallow-all (apart from pkey 0), which matches what x86 does.
Patch 15 contains a call to cpus_have_const_cap(), which I couldn't avoid until Mark's patch to re-order when the alternatives were applied [3] is committed.
The KVM part isn't tested yet.
I have tested the modified protection_keys test on x86_64 [4], but not PPC.
Hopefully I have CC'd everyone correctly.
Thanks, Joey
Joey Gouly (20): arm64/sysreg: add system register POR_EL{0,1} arm64/sysreg: update CPACR_EL1 register arm64: cpufeature: add Permission Overlay Extension cpucap arm64: disable trapping of POR_EL0 to EL2 arm64: context switch POR_EL0 register KVM: arm64: Save/restore POE registers arm64: enable the Permission Overlay Extension for EL0 arm64: add POIndex defines arm64: define VM_PKEY_BIT* for arm64 arm64: mask out POIndex when modifying a PTE arm64: enable ARCH_HAS_PKEYS on arm64 arm64: handle PKEY/POE faults arm64: stop using generic mm_hooks.h arm64: implement PKEYS support arm64: add POE signal support arm64: enable PKEY support for CPUs with S1POE arm64: enable POE and PIE to coexist kselftest/arm64: move get_header() selftests: mm: move fpregs printing selftests: mm: make protection_keys test work on arm64
Documentation/arch/arm64/elf_hwcaps.rst | 3 + arch/arm64/Kconfig | 1 + arch/arm64/include/asm/el2_setup.h | 10 +- arch/arm64/include/asm/hwcap.h | 1 + arch/arm64/include/asm/kvm_host.h | 4 + arch/arm64/include/asm/mman.h | 6 +- arch/arm64/include/asm/mmu.h | 2 + arch/arm64/include/asm/mmu_context.h | 51 ++++++- arch/arm64/include/asm/pgtable-hwdef.h | 10 ++ arch/arm64/include/asm/pgtable-prot.h | 8 +- arch/arm64/include/asm/pgtable.h | 28 +++- arch/arm64/include/asm/pkeys.h | 110 ++++++++++++++ arch/arm64/include/asm/por.h | 33 +++++ arch/arm64/include/asm/processor.h | 1 + arch/arm64/include/asm/sysreg.h | 16 ++ arch/arm64/include/asm/traps.h | 1 + arch/arm64/include/uapi/asm/hwcap.h | 1 + arch/arm64/include/uapi/asm/sigcontext.h | 7 + arch/arm64/kernel/cpufeature.c | 15 ++ arch/arm64/kernel/cpuinfo.c | 1 + arch/arm64/kernel/process.c | 16 ++ arch/arm64/kernel/signal.c | 51 +++++++ arch/arm64/kernel/traps.c | 12 +- arch/arm64/kvm/sys_regs.c | 2 + arch/arm64/mm/fault.c | 44 +++++- arch/arm64/mm/mmap.c | 7 + arch/arm64/mm/mmu.c | 38 +++++ arch/arm64/tools/cpucaps | 1 + arch/arm64/tools/sysreg | 11 +- fs/proc/task_mmu.c | 2 + include/linux/mm.h | 11 +- .../arm64/signal/testcases/testcases.c | 23 --- .../arm64/signal/testcases/testcases.h | 26 +++- tools/testing/selftests/mm/Makefile | 2 +- tools/testing/selftests/mm/pkey-arm64.h | 138 ++++++++++++++++++ tools/testing/selftests/mm/pkey-helpers.h | 8 + tools/testing/selftests/mm/pkey-powerpc.h | 3 + tools/testing/selftests/mm/pkey-x86.h | 4 + tools/testing/selftests/mm/protection_keys.c | 29 ++-- 39 files changed, 685 insertions(+), 52 deletions(-) create mode 100644 arch/arm64/include/asm/pkeys.h create mode 100644 arch/arm64/include/asm/por.h create mode 100644 tools/testing/selftests/mm/pkey-arm64.h