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

From: Yu-cheng Yu
Date: Wed Apr 29 2020 - 18:08:41 EST

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@xxxxxxxxx/

[3] CET Shadow Stack patches v9:

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

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