diff options
| author | Rick Edgecombe <rick.p.edgecombe@intel.com> | 2023-06-12 17:10:32 -0700 |
|---|---|---|
| committer | Rick Edgecombe <rick.p.edgecombe@intel.com> | 2023-07-11 14:12:18 -0700 |
| commit | 18e66b695e787374ca762ecdeaa1ab5e3772af94 (patch) | |
| tree | fe0c977a5b99541f1cb81dc32f97758d2b5ce799 /arch | |
| parent | fb47a799cc5ccc469c63e9174f2ad555a21ba2a1 (diff) | |
x86/shstk: Add Kconfig option for shadow stack
Shadow stack provides protection for applications against function return
address corruption. It is active when the processor supports it, the
kernel has CONFIG_X86_SHADOW_STACK enabled, and the application is built
for the feature. This is only implemented for the 64-bit kernel. When it
is enabled, legacy non-shadow stack applications continue to work, but
without protection.
Since there is another feature that utilizes CET (Kernel IBT) that will
share implementation with shadow stacks, create CONFIG_CET to signify
that at least one CET feature is configured.
Co-developed-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Tested-by: John Allen <john.allen@amd.com>
Tested-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/all/20230613001108.3040476-7-rick.p.edgecombe%40intel.com
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/Kconfig | 24 | ||||
| -rw-r--r-- | arch/x86/Kconfig.assembler | 5 |
2 files changed, 29 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 7422db409770..e860f805199f 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1849,6 +1849,11 @@ config CC_HAS_IBT (CC_IS_CLANG && CLANG_VERSION >= 140000)) && \ $(as-instr,endbr64) +config X86_CET + def_bool n + help + CET features configured (Shadow stack or IBT) + config X86_KERNEL_IBT prompt "Indirect Branch Tracking" def_bool y @@ -1856,6 +1861,7 @@ config X86_KERNEL_IBT # https://github.com/llvm/llvm-project/commit/9d7001eba9c4cb311e03cd8cdc231f9e579f2d0f depends on !LD_IS_LLD || LLD_VERSION >= 140000 select OBJTOOL + select X86_CET help Build the kernel with support for Indirect Branch Tracking, a hardware support course-grain forward-edge Control Flow Integrity @@ -1949,6 +1955,24 @@ config X86_SGX If unsure, say N. +config X86_USER_SHADOW_STACK + bool "X86 userspace shadow stack" + depends on AS_WRUSS + depends on X86_64 + select ARCH_USES_HIGH_VMA_FLAGS + select X86_CET + help + Shadow stack protection is a hardware feature that detects function + return address corruption. This helps mitigate ROP attacks. + Applications must be enabled to use it, and old userspace does not + get protection "for free". + + CPUs supporting shadow stacks were first released in 2020. + + See Documentation/x86/shstk.rst for more information. + + If unsure, say N. + config EFI bool "EFI runtime service support" depends on ACPI diff --git a/arch/x86/Kconfig.assembler b/arch/x86/Kconfig.assembler index b88f784cb02e..8ad41da301e5 100644 --- a/arch/x86/Kconfig.assembler +++ b/arch/x86/Kconfig.assembler @@ -24,3 +24,8 @@ config AS_GFNI def_bool $(as-instr,vgf2p8mulb %xmm0$(comma)%xmm1$(comma)%xmm2) help Supported by binutils >= 2.30 and LLVM integrated assembler + +config AS_WRUSS + def_bool $(as-instr,wrussq %rax$(comma)(%rbx)) + help + Supported by binutils >= 2.31 and LLVM integrated assembler |