[PATCH v10 00/26] Control-flow Enforcement: Shadow Stack

[Yu-cheng Yu <yu-cheng.yu@intel.com>]

Control-flow Enforcement (CET) is a new Intel processor feature that blocks
return/jump-oriented programming attacks.  Details can be found in "Intel
64 and IA-32 Architectures Software Developer's Manual" [1].

This series depends on the XSAVES supervisor state series that was split
out and submitted earlier [2].

I have gone through previous comments, and hope all concerns have been
resolved now.  Please inform me if anything is overlooked.

Changes in v10:

- A shadow stack PTE is (!_PAGE_RW and _PAGE_DIRTY_HW).  In handling page
  faults, previous versions of this series use helpers such as arch_copy_
  pte_mapping() and arch_set_vma_features() to manage the _PAGE_DIRTY_HW
  bit for the copy-on-write logic.  This has been simplified by treating
  shadow stack as logically writable, and shadow stack faults are handled
  similarly as for normal writable data pages.  Functions pte_write(),
  pte_mkwrite(), pte_wrprotect(), maybe_mkwrite() etc. are updated
  accordingly.

- Signal return code is updated according to the XSAVES supervisor state
  changes.

- Other smaller changes are noted in each patch's log.

[1] Intel 64 and IA-32 Architectures Software Developer's Manual:

    https://software.intel.com/en-us/download/intel-64-and-ia-32-
    architectures-sdm-combined-volumes-1-2a-2b-2c-2d-3a-3b-3c-3d-and-4

[2] XSAVES supervisor states patches:
    https://lkml.kernel.org/r/20200328164307.17497-1-yu-cheng.yu@intel.com/

[3] CET Shadow Stack patches v9:

    https://lkml.kernel.org/r/20200205181935.3712-1-yu-cheng.yu@intel.com/

Dave Martin (1):
  ELF: Add ELF program property parsing support

Yu-cheng Yu (25):
  Documentation/x86: Add CET description
  x86/cpufeatures: Add CET CPU feature flags for Control-flow
    Enforcement Technology (CET)
  x86/fpu/xstate: Introduce CET MSR XSAVES supervisor states
  x86/cet: Add control-protection fault handler
  x86/cet/shstk: Add Kconfig option for user-mode Shadow Stack
  x86/mm: Change _PAGE_DIRTY to _PAGE_DIRTY_HW
  x86/mm: Remove _PAGE_DIRTY_HW from kernel RO pages
  x86/mm: Introduce _PAGE_COW
  drm/i915/gvt: Change _PAGE_DIRTY to _PAGE_DIRTY_BITS
  x86/mm: Update pte_modify for _PAGE_COW
  x86/mm: Update ptep_set_wrprotect() and pmdp_set_wrprotect() for
    transition from _PAGE_DIRTY_HW to _PAGE_COW
  mm: Introduce VM_SHSTK for shadow stack memory
  x86/mm: Shadow Stack page fault error checking
  x86/mm: Update maybe_mkwrite() for shadow stack
  mm: Fixup places that call pte_mkwrite() directly
  mm: Add guard pages around a shadow stack.
  mm/mmap: Add shadow stack pages to memory accounting
  mm: Update can_follow_write_pte() for shadow stack
  x86/cet/shstk: User-mode shadow stack support
  x86/cet/shstk: Handle signals for shadow stack
  ELF: UAPI and Kconfig additions for ELF program properties
  ELF: Introduce arch_setup_elf_property()
  x86/cet/shstk: ELF header parsing for shadow stack
  x86/cet/shstk: Handle thread shadow stack
  x86/cet/shstk: Add arch_prctl functions for shadow stack

 .../admin-guide/kernel-parameters.txt         |   6 +
 Documentation/x86/index.rst                   |   1 +
 Documentation/x86/intel_cet.rst               | 129 +++++++
 arch/x86/Kconfig                              |  36 ++
 arch/x86/entry/entry_64.S                     |   2 +-
 arch/x86/ia32/ia32_signal.c                   |  17 +
 arch/x86/include/asm/cet.h                    |  40 ++
 arch/x86/include/asm/cpufeatures.h            |   2 +
 arch/x86/include/asm/disabled-features.h      |   8 +-
 arch/x86/include/asm/elf.h                    |  13 +
 arch/x86/include/asm/fpu/internal.h           |  10 +
 arch/x86/include/asm/fpu/types.h              |  22 ++
 arch/x86/include/asm/fpu/xstate.h             |   5 +-
 arch/x86/include/asm/mmu_context.h            |   3 +
 arch/x86/include/asm/msr-index.h              |  18 +
 arch/x86/include/asm/pgtable.h                | 209 +++++++++-
 arch/x86/include/asm/pgtable_types.h          |  58 ++-
 arch/x86/include/asm/processor.h              |  15 +
 arch/x86/include/asm/special_insns.h          |  32 ++
 arch/x86/include/asm/traps.h                  |   7 +
 arch/x86/include/uapi/asm/prctl.h             |   5 +
 arch/x86/include/uapi/asm/processor-flags.h   |   2 +
 arch/x86/include/uapi/asm/sigcontext.h        |   9 +
 arch/x86/kernel/Makefile                      |   2 +
 arch/x86/kernel/cet.c                         | 356 ++++++++++++++++++
 arch/x86/kernel/cet_prctl.c                   |  87 +++++
 arch/x86/kernel/cpu/common.c                  |  28 ++
 arch/x86/kernel/cpu/cpuid-deps.c              |   2 +
 arch/x86/kernel/fpu/signal.c                  | 101 +++++
 arch/x86/kernel/fpu/xstate.c                  |  25 +-
 arch/x86/kernel/idt.c                         |   4 +
 arch/x86/kernel/process.c                     |  12 +-
 arch/x86/kernel/process_64.c                  |  29 ++
 arch/x86/kernel/relocate_kernel_64.S          |   2 +-
 arch/x86/kernel/signal.c                      |  10 +
 arch/x86/kernel/signal_compat.c               |   2 +-
 arch/x86/kernel/traps.c                       |  59 +++
 arch/x86/kvm/vmx/vmx.c                        |   2 +-
 arch/x86/mm/fault.c                           |  19 +
 arch/x86/mm/mmap.c                            |   2 +
 arch/x86/mm/pat/set_memory.c                  |   2 +-
 arch/x86/mm/pgtable.c                         |  25 ++
 drivers/gpu/drm/i915/gvt/gtt.c                |   2 +-
 fs/Kconfig.binfmt                             |   3 +
 fs/binfmt_elf.c                               | 131 +++++++
 fs/compat_binfmt_elf.c                        |   4 +
 fs/proc/task_mmu.c                            |   3 +
 include/asm-generic/pgtable.h                 |  35 ++
 include/linux/elf.h                           |  33 ++
 include/linux/mm.h                            |  34 +-
 include/uapi/asm-generic/siginfo.h            |   3 +-
 include/uapi/linux/elf.h                      |  12 +
 mm/gup.c                                      |   8 +-
 mm/huge_memory.c                              |  10 +-
 mm/memory.c                                   |   5 +-
 mm/migrate.c                                  |   3 +-
 mm/mmap.c                                     |   5 +
 mm/mprotect.c                                 |   2 +-
 scripts/as-x86_64-has-shadow-stack.sh         |   4 +
 .../arch/x86/include/asm/disabled-features.h  |   8 +-
 60 files changed, 1670 insertions(+), 53 deletions(-)
 create mode 100644 Documentation/x86/intel_cet.rst
 create mode 100644 arch/x86/include/asm/cet.h
 create mode 100644 arch/x86/kernel/cet.c
 create mode 100644 arch/x86/kernel/cet_prctl.c
 create mode 100755 scripts/as-x86_64-has-shadow-stack.sh

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2.21.0