[PATCHv4 0/8] Linear Address Masking enabling

[Kirill A. Shutemov]

Linear Address Masking[1] (LAM) modifies the checking that is applied to
64-bit linear addresses, allowing software to use of the untranslated
address bits for metadata.

The patchset brings support for LAM for userspace addresses.

LAM_U48 enabling is controversial since it competes for bits with
5-level paging. Its enabling isolated into an optional last patch that
can be applied at maintainer's discretion.

Please review and consider applying.

v4:
  - Fix untagged_addr() for LAM_U48;
  - Remove no-threads restriction on LAM enabling;
  - Fix mm_struct access from /proc/$PID/arch_status
  - Fix LAM handling in initialize_tlbstate_and_flush()
  - Pack tlb_state better;
  - Comments and commit messages;
v3:
  - Rebased onto v5.19-rc1
  - Per-process enabling;
  - API overhaul (again);
  - Avoid branches and costly computations in the fast path;
  - LAM_U48 is in optional patch.
v2:
  - Rebased onto v5.18-rc1
  - New arch_prctl(2)-based API
  - Expose status of LAM (or other thread features) in
    /proc/$PID/arch_status

[1] ISE, Chapter 14.
https://software.intel.com/content/dam/develop/external/us/en/documents-tps/architecture-instruction-set-extensions-programming-reference.pdf

Kirill A. Shutemov (8):
  x86/mm: Fix CR3_ADDR_MASK
  x86: CPUID and CR3/CR4 flags for Linear Address Masking
  mm: Pass down mm_struct to untagged_addr()
  x86/mm: Handle LAM on context switch
  x86/uaccess: Provide untagged_addr() and remove tags before address
    check
  x86/mm: Provide ARCH_GET_UNTAG_MASK and ARCH_ENABLE_TAGGED_ADDR
  x86: Expose untagging mask in /proc/$PID/arch_status
  x86/mm: Extend LAM to support to LAM_U48

 arch/arm64/include/asm/memory.h               |  4 +-
 arch/arm64/include/asm/signal.h               |  2 +-
 arch/arm64/include/asm/uaccess.h              |  4 +-
 arch/arm64/kernel/hw_breakpoint.c             |  2 +-
 arch/arm64/kernel/traps.c                     |  4 +-
 arch/arm64/mm/fault.c                         | 10 +--
 arch/sparc/include/asm/pgtable_64.h           |  2 +-
 arch/sparc/include/asm/uaccess_64.h           |  2 +
 arch/x86/include/asm/cpufeatures.h            |  1 +
 arch/x86/include/asm/elf.h                    |  3 +-
 arch/x86/include/asm/mmu.h                    |  2 +
 arch/x86/include/asm/mmu_context.h            | 58 ++++++++++++++
 arch/x86/include/asm/processor-flags.h        |  2 +-
 arch/x86/include/asm/tlbflush.h               |  4 +
 arch/x86/include/asm/uaccess.h                | 42 +++++++++-
 arch/x86/include/uapi/asm/prctl.h             |  3 +
 arch/x86/include/uapi/asm/processor-flags.h   |  6 ++
 arch/x86/kernel/Makefile                      |  2 +
 arch/x86/kernel/fpu/xstate.c                  | 47 -----------
 arch/x86/kernel/proc.c                        | 60 ++++++++++++++
 arch/x86/kernel/process.c                     |  3 +
 arch/x86/kernel/process_64.c                  | 78 ++++++++++++++++++-
 arch/x86/kernel/sys_x86_64.c                  |  5 +-
 arch/x86/mm/hugetlbpage.c                     |  6 +-
 arch/x86/mm/mmap.c                            |  9 ++-
 arch/x86/mm/tlb.c                             | 68 ++++++++++++----
 .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c  |  2 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c       |  2 +-
 drivers/gpu/drm/radeon/radeon_gem.c           |  2 +-
 drivers/infiniband/hw/mlx4/mr.c               |  2 +-
 drivers/media/common/videobuf2/frame_vector.c |  2 +-
 drivers/media/v4l2-core/videobuf-dma-contig.c |  2 +-
 .../staging/media/atomisp/pci/hmm/hmm_bo.c    |  2 +-
 drivers/tee/tee_shm.c                         |  2 +-
 drivers/vfio/vfio_iommu_type1.c               |  2 +-
 fs/proc/task_mmu.c                            |  2 +-
 include/linux/mm.h                            | 11 ---
 include/linux/uaccess.h                       | 15 ++++
 lib/strncpy_from_user.c                       |  2 +-
 lib/strnlen_user.c                            |  2 +-
 mm/gup.c                                      |  6 +-
 mm/madvise.c                                  |  2 +-
 mm/mempolicy.c                                |  6 +-
 mm/migrate.c                                  |  2 +-
 mm/mincore.c                                  |  2 +-
 mm/mlock.c                                    |  4 +-
 mm/mmap.c                                     |  2 +-
 mm/mprotect.c                                 |  2 +-
 mm/mremap.c                                   |  2 +-
 mm/msync.c                                    |  2 +-
 virt/kvm/kvm_main.c                           |  2 +-
 51 files changed, 385 insertions(+), 126 deletions(-)
 create mode 100644 arch/x86/kernel/proc.c

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2.35.1