[RFC,v4,00/27] Control Flow Enforcement: Shadow Stack

Message

Yu-cheng Yu Sept. 21, 2018, 3:03 p.m. UTC

The previous version of CET patches can be found in the following
link:

  https://lkml.org/lkml/2018/8/30/608

Summary of changes from v3:

  Fixed an issue in page fault handling in do_swap_page().
  Fixed issues in ptep_set_wrprotect/pmdp_set_wrprotect.
  Changed WRUSS fault handling to asm_goto.
  Added shadow stack to memory accounting.
  Added a patch to create a guard gap between VMAs.
  Added a patch to prevent merging of shadow stack areas.
  Other small fixes in ELF header parsing and typos.

Yu-cheng Yu (27):
  x86/cpufeatures: Add CPUIDs for Control-flow Enforcement Technology
    (CET)
  x86/fpu/xstate: Change some names to separate XSAVES system and user
    states
  x86/fpu/xstate: Enable XSAVES system states
  x86/fpu/xstate: Add XSAVES system states for shadow stack
  Documentation/x86: Add CET description
  x86/cet: Control protection exception handler
  x86/cet/shstk: Add Kconfig option for user-mode shadow stack
  mm: Introduce VM_SHSTK for shadow stack memory
  x86/mm: Change _PAGE_DIRTY to _PAGE_DIRTY_HW
  drm/i915/gvt: Update _PAGE_DIRTY to _PAGE_DIRTY_BITS
  x86/mm: Introduce _PAGE_DIRTY_SW
  x86/mm: Modify ptep_set_wrprotect and pmdp_set_wrprotect for
    _PAGE_DIRTY_SW
  x86/mm: Shadow stack page fault error checking
  mm: Handle shadow stack page fault
  mm: Handle THP/HugeTLB shadow stack page fault
  mm: Update can_follow_write_pte/pmd for shadow stack
  mm: Introduce do_mmap_locked()
  x86/cet/shstk: User-mode shadow stack support
  x86/cet/shstk: Introduce WRUSS instruction
  x86/cet/shstk: Signal handling for shadow stack
  x86/cet/shstk: ELF header parsing of Shadow Stack
  x86/cet/shstk: Handle thread shadow stack
  mm/map: Add Shadow stack pages to memory accounting
  mm/mmap: Create a guard area between VMAs
  mm/mmap: Prevent Shadow Stack VMA merges
  x86/cet/shstk: Add arch_prctl functions for Shadow Stack
  x86/cet/shstk: Add Shadow Stack instructions to opcode map

 .../admin-guide/kernel-parameters.txt         |   6 +
 Documentation/index.rst                       |   1 +
 Documentation/x86/index.rst                   |  11 +
 Documentation/x86/intel_cet.rst               | 259 +++++++++++++
 arch/x86/Kconfig                              |  28 ++
 arch/x86/Makefile                             |   7 +
 arch/x86/entry/entry_64.S                     |   2 +-
 arch/x86/ia32/ia32_signal.c                   |  13 +
 arch/x86/include/asm/cet.h                    |  42 +++
 arch/x86/include/asm/cpufeatures.h            |   2 +
 arch/x86/include/asm/disabled-features.h      |   8 +-
 arch/x86/include/asm/elf.h                    |   5 +
 arch/x86/include/asm/fpu/internal.h           |   6 +-
 arch/x86/include/asm/fpu/types.h              |  22 ++
 arch/x86/include/asm/fpu/xstate.h             |  31 +-
 arch/x86/include/asm/mmu_context.h            |   3 +
 arch/x86/include/asm/msr-index.h              |  14 +
 arch/x86/include/asm/pgtable.h                | 191 ++++++++--
 arch/x86/include/asm/pgtable_types.h          |  31 +-
 arch/x86/include/asm/processor.h              |   5 +
 arch/x86/include/asm/sighandling.h            |   5 +
 arch/x86/include/asm/special_insns.h          |  32 ++
 arch/x86/include/asm/traps.h                  |   5 +
 arch/x86/include/uapi/asm/elf_property.h      |  15 +
 arch/x86/include/uapi/asm/prctl.h             |   5 +
 arch/x86/include/uapi/asm/processor-flags.h   |   2 +
 arch/x86/include/uapi/asm/sigcontext.h        |  17 +
 arch/x86/kernel/Makefile                      |   4 +
 arch/x86/kernel/cet.c                         | 285 +++++++++++++++
 arch/x86/kernel/cet_prctl.c                   |  79 ++++
 arch/x86/kernel/cpu/common.c                  |  24 ++
 arch/x86/kernel/cpu/scattered.c               |   1 +
 arch/x86/kernel/elf.c                         | 340 ++++++++++++++++++
 arch/x86/kernel/fpu/core.c                    |  11 +-
 arch/x86/kernel/fpu/init.c                    |  10 -
 arch/x86/kernel/fpu/signal.c                  |   6 +-
 arch/x86/kernel/fpu/xstate.c                  | 152 +++++---
 arch/x86/kernel/idt.c                         |   4 +
 arch/x86/kernel/process.c                     |   8 +
 arch/x86/kernel/process_64.c                  |   7 +
 arch/x86/kernel/relocate_kernel_64.S          |   2 +-
 arch/x86/kernel/signal.c                      |  96 +++++
 arch/x86/kernel/traps.c                       |  58 +++
 arch/x86/kvm/vmx.c                            |   2 +-
 arch/x86/lib/x86-opcode-map.txt               |  26 +-
 arch/x86/mm/fault.c                           |  27 ++
 arch/x86/mm/pgtable.c                         |  42 +++
 drivers/gpu/drm/i915/gvt/gtt.c                |   2 +-
 fs/binfmt_elf.c                               |  15 +
 fs/proc/task_mmu.c                            |   3 +
 include/asm-generic/pgtable.h                 |  14 +
 include/linux/mm.h                            |  56 ++-
 include/uapi/linux/elf.h                      |   1 +
 mm/gup.c                                      |   8 +-
 mm/huge_memory.c                              |  12 +-
 mm/memory.c                                   |   7 +-
 mm/mmap.c                                     |  11 +
 tools/objtool/arch/x86/lib/x86-opcode-map.txt |  26 +-
 58 files changed, 1946 insertions(+), 161 deletions(-)
 create mode 100644 Documentation/x86/index.rst
 create mode 100644 Documentation/x86/intel_cet.rst
 create mode 100644 arch/x86/include/asm/cet.h
 create mode 100644 arch/x86/include/uapi/asm/elf_property.h
 create mode 100644 arch/x86/kernel/cet.c
 create mode 100644 arch/x86/kernel/cet_prctl.c
 create mode 100644 arch/x86/kernel/elf.c

Comments

Dave Hansen Sept. 21, 2018, 10:53 p.m. UTC | #1

On 09/21/2018 08:03 AM, Yu-cheng Yu wrote:
> The previous version of CET patches can be found in the following
> link:
> 
>   https://lkml.org/lkml/2018/8/30/608

So, this is an RFC, but there no mention of what you want comments *on*. :)

What do you want folks to review?  What needs to get settled before this
is merged?

Yu-cheng Yu Sept. 24, 2018, 3:25 p.m. UTC | #2

On Fri, 2018-09-21 at 15:53 -0700, Dave Hansen wrote:
> On 09/21/2018 08:03 AM, Yu-cheng Yu wrote:
> > The previous version of CET patches can be found in the following
> > link:
> > 
> >   https://lkml.org/lkml/2018/8/30/608
> 
> So, this is an RFC, but there no mention of what you want comments *on*. :)
> 
> What do you want folks to review?  What needs to get settled before this
> is merged?

Thanks, Dave!

These patches passed GLIBC built-in tests and more tests HJ and I put together
at https://github.com/hjl-tools/cet-smoke-test.

I made some changes since V3 as outlined in the cover letter.
In particular there are two new patches for the VMA guard and preventing shadow
stack merging.  Does anyone have comments on those and the whole Shadow
Stack/IBT series in general?

Thanks,
Yu-cheng