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    Subject[PATCH v9 00/51] powerpc, mm: Memory Protection Keys
    Date
    Memory protection keys enable applications to protect its
    address space from inadvertent access from or corruption
    by itself.

    These patches along with the pte-bit freeing patch series
    enables the protection key feature on powerpc; 4k and 64k
    hashpage kernels. It also changes the generic and x86
    code to expose memkey features through sysfs. Finally
    testcases and Documentation is updated.

    All patches can be found at --
    https://github.com/rampai/memorykeys.git memkey.v9

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

    This patch series enables the feature on PPC64 HPTE
    platform.

    ISA3.0 section 5.7.13 describes the detailed
    specifications.


    Highlevel view of the design:
    ---------------------------
    When an application associates a key with a address
    address range, program the key in the Linux PTE.
    When the MMU detects a page fault, allocate a hash
    page and program the key into HPTE. And finally
    when the MMU detects a key violation; due to
    invalid application access, invoke the registered
    signal handler and provide the violated key number.


    Testing:
    -------
    This patch series has passed all the protection key
    tests available in the selftest directory.The
    tests are updated to work on both x86 and powerpc.
    The selftests have passed on x86 and powerpc hardware.

    History:
    -------
    version v9:
    (1) used jump-labels to optimize code
    -- Balbir
    (2) fixed a register initialization bug noted
    by Balbir
    (3) fixed inappropriate use of paca to pass
    siginfo and keys to signal handler
    (4) Cleanup of comment style not to be right
    justified -- mpe
    (5) restructured the patches to depend on the
    availability of VM_PKEY_BIT4 in
    include/linux/mm.h
    (6) Incorporated comments from Dave Hansen
    towards changes to selftest and got
    them tested on x86.

    version v8:
    (1) Contents of the AMR register withdrawn from
    the siginfo structure. Applications can always
    read the AMR register.
    (2) AMR/IAMR/UAMOR are now available through
    ptrace system call. -- thanks to Thiago
    (3) code changes to handle legacy power cpus
    that do not support execute-disable.
    (4) incorporates many code improvement
    suggestions.

    version v7:
    (1) refers to device tree property to enable
    protection keys.
    (2) adds 4K PTE support.
    (3) fixes a couple of bugs noticed by Thiago
    (4) decouples this patch series from arch-
    independent code. This patch series can
    now stand by itself, with one kludge
    patch(2).
    version v7:
    (1) refers to device tree property to enable
    protection keys.
    (2) adds 4K PTE support.
    (3) fixes a couple of bugs noticed by Thiago
    (4) decouples this patch series from arch-
    independent code. This patch series can
    now stand by itself, with one kludge
    patch(2).

    version v6:
    (1) selftest changes are broken down into 20
    incremental patches.
    (2) A separate key allocation mask that
    includes PKEY_DISABLE_EXECUTE is
    added for powerpc
    (3) pkey feature is enabled for 64K HPT case
    only. RPT and 4k HPT is disabled.
    (4) Documentation is updated to better
    capture the semantics.
    (5) introduced arch_pkeys_enabled() to find
    if an arch enables pkeys. Correspond-
    ing change the logic that displays
    key value in smaps.
    (6) code rearranged in many places based on
    comments from Dave Hansen, Balbir,
    Anshuman.
    (7) fixed one bug where a bogus key could be
    associated successfully in
    pkey_mprotect().

    version v5:
    (1) reverted back to the old design -- store
    the key in the pte, instead of bypassing
    it. The v4 design slowed down the hash
    page path.
    (2) detects key violation when kernel is told
    to access user pages.
    (3) further refined the patches into smaller
    consumable units
    (4) page faults handlers captures the fault-
    ing key
    from the pte instead of the vma. This
    closes a race between where the key
    update in the vma and a key fault caused
    by the key programmed in the pte.
    (5) a key created with access-denied should
    also set it up to deny write. Fixed it.
    (6) protection-key number is displayed in
    smaps the x86 way.

    version v4:
    (1) patches no more depend on the pte bits
    to program the hpte
    -- comment by Balbir
    (2) documentation updates
    (3) fixed a bug in the selftest.
    (4) unlike x86, powerpc lets signal handler
    change key permission bits; the
    change will persist across signal
    handler boundaries. Earlier we
    allowed the signal handler to
    modify a field in the siginfo
    structure which would than be used
    by the kernel to program the key
    protection register (AMR)
    -- resolves a issue raised by Ben.
    "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".
    (5) these changes enable protection keys on
    4k-page kernel aswell.

    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.


    version v1: Initial version

    Ram Pai (47):
    mm, powerpc, x86: define VM_PKEY_BITx bits if CONFIG_ARCH_HAS_PKEYS
    is enabled
    mm, powerpc, x86: introduce an additional vma bit for powerpc pkey
    powerpc: initial pkey plumbing
    powerpc: track allocation status of all pkeys
    powerpc: helper function to read,write AMR,IAMR,UAMOR registers
    powerpc: helper functions to initialize AMR, IAMR and UAMOR registers
    powerpc: cleanup AMR, IAMR when a key is allocated or freed
    powerpc: implementation for arch_set_user_pkey_access()
    powerpc: ability to create execute-disabled pkeys
    powerpc: store and restore the pkey state across context switches
    powerpc: introduce execute-only pkey
    powerpc: ability to associate pkey to a vma
    powerpc: implementation for arch_override_mprotect_pkey()
    powerpc: map vma key-protection bits to pte key bits.
    powerpc: Program HPTE key protection bits
    powerpc: helper to validate key-access permissions of a pte
    powerpc: check key protection for user page access
    powerpc: implementation for arch_vma_access_permitted()
    powerpc: Handle exceptions caused by pkey violation
    powerpc: introduce get_mm_addr_key() helper
    powerpc: Deliver SEGV signal on pkey violation
    powerpc: Enable pkey subsystem
    powerpc: sys_pkey_alloc() and sys_pkey_free() system calls
    powerpc: sys_pkey_mprotect() system call
    powerpc: add sys_pkey_modify() system call
    mm, x86 : introduce arch_pkeys_enabled()
    mm: display pkey in smaps if arch_pkeys_enabled() is true
    Documentation/x86: Move protecton key documentation to arch neutral
    directory
    Documentation/vm: PowerPC specific updates to memory protection keys
    selftest/x86: Move protecton key selftest to arch neutral directory
    selftest/vm: rename all references to pkru to a generic name
    selftest/vm: move generic definitions to header file
    selftest/vm: typecast the pkey register
    selftest/vm: generic function to handle shadow key register
    selftest/vm: fix the wrong assert in pkey_disable_set()
    selftest/vm: fixed bugs in pkey_disable_clear()
    selftest/vm: clear the bits in shadow reg when a pkey is freed.
    selftest/vm: fix alloc_random_pkey() to make it really random
    selftest/vm: introduce two arch independent abstraction
    selftest/vm: pkey register should match shadow pkey
    selftest/vm: generic cleanup
    selftest/vm: powerpc implementation for generic abstraction
    selftest/vm: fix an assertion in test_pkey_alloc_exhaust()
    selftest/vm: associate key on a mapped page and detect access
    violation
    selftest/vm: associate key on a mapped page and detect write
    violation
    selftest/vm: detect write violation on a mapped access-denied-key
    page
    selftest/vm: sub-page allocator

    Thiago Jung Bauermann (4):
    powerpc/ptrace: Add memory protection key regset
    mm/mprotect, powerpc/mm/pkeys, x86/mm/pkeys: Add sysfs interface
    selftests/powerpc: Add ptrace tests for Protection Key register
    selftests/powerpc: Add core file test for Protection Key register

    Documentation/vm/protection-keys.txt | 161 +++
    Documentation/x86/protection-keys.txt | 85 --
    arch/powerpc/Kconfig | 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 | 42 +-
    arch/powerpc/include/asm/bug.h | 1 +
    arch/powerpc/include/asm/cputable.h | 15 +-
    arch/powerpc/include/asm/mman.h | 13 +-
    arch/powerpc/include/asm/mmu.h | 9 +
    arch/powerpc/include/asm/mmu_context.h | 24 +
    arch/powerpc/include/asm/pkeys.h | 247 ++++
    arch/powerpc/include/asm/processor.h | 5 +
    arch/powerpc/include/asm/systbl.h | 4 +
    arch/powerpc/include/asm/unistd.h | 6 +-
    arch/powerpc/include/uapi/asm/elf.h | 1 +
    arch/powerpc/include/uapi/asm/mman.h | 6 +
    arch/powerpc/include/uapi/asm/unistd.h | 4 +
    arch/powerpc/kernel/entry_64.S | 9 +
    arch/powerpc/kernel/process.c | 7 +
    arch/powerpc/kernel/prom.c | 18 +
    arch/powerpc/kernel/ptrace.c | 66 +
    arch/powerpc/kernel/traps.c | 19 +-
    arch/powerpc/mm/Makefile | 1 +
    arch/powerpc/mm/fault.c | 49 +-
    arch/powerpc/mm/hash_utils_64.c | 29 +
    arch/powerpc/mm/mmu_context_book3s64.c | 2 +
    arch/powerpc/mm/pkeys.c | 463 +++++++
    arch/x86/include/asm/mmu_context.h | 4 +-
    arch/x86/include/asm/pkeys.h | 2 +
    arch/x86/kernel/fpu/xstate.c | 5 +
    arch/x86/kernel/setup.c | 8 -
    arch/x86/mm/pkeys.c | 9 +
    fs/proc/task_mmu.c | 16 +-
    include/linux/mm.h | 12 +-
    include/linux/pkeys.h | 7 +-
    include/uapi/linux/elf.h | 1 +
    mm/mprotect.c | 88 ++
    tools/testing/selftests/powerpc/include/reg.h | 1 +
    tools/testing/selftests/powerpc/ptrace/Makefile | 5 +-
    tools/testing/selftests/powerpc/ptrace/core-pkey.c | 438 ++++++
    .../testing/selftests/powerpc/ptrace/ptrace-pkey.c | 443 ++++++
    tools/testing/selftests/vm/Makefile | 1 +
    tools/testing/selftests/vm/pkey-helpers.h | 405 ++++++
    tools/testing/selftests/vm/protection_keys.c | 1464 ++++++++++++++++++++
    tools/testing/selftests/x86/Makefile | 2 +-
    tools/testing/selftests/x86/pkey-helpers.h | 220 ---
    tools/testing/selftests/x86/protection_keys.c | 1395 -------------------
    48 files changed, 4095 insertions(+), 1747 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/powerpc/ptrace/core-pkey.c
    create mode 100644 tools/testing/selftests/powerpc/ptrace/ptrace-pkey.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

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