Re: [PATCH v5 00/39] Shadow stacks for userspace

From: Mike Rapoport
Date: Sun Jan 22 2023 - 03:20:49 EST

On Thu, Jan 19, 2023 at 01:22:38PM -0800, Rick Edgecombe wrote:
> Hi,
>
> This series implements Shadow Stacks for userspace using x86's Control-flow
> Enforcement Technology (CET). CET consists of two related security features:
> shadow stacks and indirect branch tracking. This series implements just the
> shadow stack part of this feature, and just for userspace.

Acked-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>

> Previous version [1].
>
> [0] https://lore.kernel.org/lkml/20220130211838.8382-1-rick.p.edgecombe@xxxxxxxxx/
> [1] https://lore.kernel.org/lkml/20221203003606.6838-1-rick.p.edgecombe@xxxxxxxxx/
>
> Kirill A. Shutemov (1):
> x86: Introduce userspace API for shadow stack
>
> Mike Rapoport (1):
> x86/shstk: Add ARCH_SHSTK_UNLOCK
>
> Rick Edgecombe (14):
> x86/fpu: Add helper for modifying xstate
> x86/mm: Introduce _PAGE_COW
> x86/mm: Start actually marking _PAGE_COW
> mm: Handle faultless write upgrades for shstk
> mm: Don't allow write GUPs to shadow stack memory
> x86/mm: Introduce MAP_ABOVE4G
> mm: Warn on shadow stack memory in wrong vma
> x86/shstk: Introduce map_shadow_stack syscall
> x86/shstk: Support WRSS for userspace
> x86: Expose thread features in /proc/$PID/status
> x86/shstk: Wire in shadow stack interface
> selftests/x86: Add shadow stack test
> x86/fpu: Add helper for initing features
> x86/shstk: Add ARCH_SHSTK_STATUS
>
> Yu-cheng Yu (23):
> Documentation/x86: Add CET shadow stack description
> x86/shstk: Add Kconfig option for shadow stack
> x86/cpufeatures: Add CPU feature flags for shadow stacks
> x86/cpufeatures: Enable CET CR4 bit for shadow stack
> x86/fpu/xstate: Introduce CET MSR and XSAVES supervisor states
> x86: Add user control-protection fault handler
> x86/mm: Remove _PAGE_DIRTY from kernel RO pages
> x86/mm: Move pmd_write(), pud_write() up in the file
> x86/mm: Update pte_modify for _PAGE_COW
> x86/mm: Update ptep_set_wrprotect() and pmdp_set_wrprotect() for
> transition from _PAGE_DIRTY to _PAGE_COW
> mm: Move VM_UFFD_MINOR_BIT from 37 to 38
> mm: Introduce VM_SHADOW_STACK for shadow stack memory
> x86/mm: Check shadow stack page fault errors
> 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: Re-introduce vm_flags to do_mmap()
> x86/shstk: Add user-mode shadow stack support
> x86/shstk: Handle thread shadow stack
> x86/shstk: Introduce routines modifying shstk
> x86/shstk: Handle signals for shadow stack
> x86: Add PTRACE interface for shadow stack
>
> Documentation/filesystems/proc.rst | 1 +
> Documentation/x86/index.rst | 1 +
> Documentation/x86/shstk.rst | 176 +++++
> arch/arm/kernel/signal.c | 2 +-
> arch/arm64/kernel/signal.c | 2 +-
> arch/arm64/kernel/signal32.c | 2 +-
> arch/sparc/kernel/signal32.c | 2 +-
> arch/sparc/kernel/signal_64.c | 2 +-
> arch/x86/Kconfig | 24 +
> arch/x86/Kconfig.assembler | 5 +
> arch/x86/entry/syscalls/syscall_64.tbl | 1 +
> arch/x86/include/asm/cpufeatures.h | 2 +
> arch/x86/include/asm/disabled-features.h | 16 +-
> arch/x86/include/asm/fpu/api.h | 9 +
> arch/x86/include/asm/fpu/regset.h | 7 +-
> arch/x86/include/asm/fpu/sched.h | 3 +-
> arch/x86/include/asm/fpu/types.h | 16 +-
> arch/x86/include/asm/fpu/xstate.h | 6 +-
> arch/x86/include/asm/idtentry.h | 2 +-
> arch/x86/include/asm/mmu_context.h | 2 +
> arch/x86/include/asm/msr.h | 11 +
> arch/x86/include/asm/pgtable.h | 338 ++++++++-
> arch/x86/include/asm/pgtable_types.h | 65 +-
> arch/x86/include/asm/processor.h | 8 +
> arch/x86/include/asm/shstk.h | 40 ++
> arch/x86/include/asm/special_insns.h | 13 +
> arch/x86/include/asm/tlbflush.h | 3 +-
> arch/x86/include/asm/trap_pf.h | 2 +
> arch/x86/include/asm/traps.h | 12 +
> arch/x86/include/uapi/asm/mman.h | 4 +
> arch/x86/include/uapi/asm/prctl.h | 12 +
> arch/x86/kernel/Makefile | 4 +
> arch/x86/kernel/cet.c | 152 ++++
> arch/x86/kernel/cpu/common.c | 35 +-
> arch/x86/kernel/cpu/cpuid-deps.c | 1 +
> arch/x86/kernel/cpu/proc.c | 23 +
> arch/x86/kernel/fpu/core.c | 59 +-
> arch/x86/kernel/fpu/regset.c | 87 +++
> arch/x86/kernel/fpu/xstate.c | 148 ++--
> arch/x86/kernel/fpu/xstate.h | 6 +
> arch/x86/kernel/idt.c | 2 +-
> arch/x86/kernel/process.c | 18 +-
> arch/x86/kernel/process_64.c | 9 +-
> arch/x86/kernel/ptrace.c | 12 +
> arch/x86/kernel/shstk.c | 492 +++++++++++++
> arch/x86/kernel/signal.c | 1 +
> arch/x86/kernel/signal_32.c | 2 +-
> arch/x86/kernel/signal_64.c | 8 +-
> arch/x86/kernel/sys_x86_64.c | 6 +-
> arch/x86/kernel/traps.c | 87 ---
> arch/x86/mm/fault.c | 38 +
> arch/x86/mm/pat/set_memory.c | 2 +-
> arch/x86/mm/pgtable.c | 6 +
> arch/x86/xen/enlighten_pv.c | 2 +-
> arch/x86/xen/xen-asm.S | 2 +-
> fs/aio.c | 2 +-
> fs/proc/array.c | 6 +
> fs/proc/task_mmu.c | 3 +
> include/linux/mm.h | 59 +-
> include/linux/mman.h | 4 +
> include/linux/pgtable.h | 35 +
> include/linux/proc_fs.h | 2 +
> include/linux/syscalls.h | 1 +
> include/uapi/asm-generic/siginfo.h | 3 +-
> include/uapi/asm-generic/unistd.h | 2 +-
> include/uapi/linux/elf.h | 2 +
> ipc/shm.c | 2 +-
> kernel/sys_ni.c | 1 +
> mm/gup.c | 2 +-
> mm/huge_memory.c | 12 +-
> mm/memory.c | 7 +-
> mm/migrate_device.c | 4 +-
> mm/mmap.c | 12 +-
> mm/nommu.c | 4 +-
> mm/userfaultfd.c | 10 +-
> mm/util.c | 2 +-
> tools/testing/selftests/x86/Makefile | 4 +-
> .../testing/selftests/x86/test_shadow_stack.c | 667 ++++++++++++++++++
> 78 files changed, 2578 insertions(+), 259 deletions(-)
> create mode 100644 Documentation/x86/shstk.rst
> create mode 100644 arch/x86/include/asm/shstk.h
> create mode 100644 arch/x86/kernel/cet.c
> create mode 100644 arch/x86/kernel/shstk.c
> create mode 100644 tools/testing/selftests/x86/test_shadow_stack.c
>
> --
> 2.17.1
>