| Message ID | 20201209222320.1724-3-yu-cheng.yu@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Control-flow Enforcement: Shadow Stack | expand |
On Wed, Dec 09, 2020 at 02:22:56PM -0800, Yu-cheng Yu wrote: > Shadow Stack provides protection against function return address > corruption. It is active when the processor supports it, the kernel has > CONFIG_X86_CET_USER, and the application is built for the feature. ^ enabled. > This is only implemented for the 64-bit kernel. When it is enabled, legacy > non-Shadow Stack applications continue to work, but without protection. > > Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> > --- > arch/x86/Kconfig | 22 ++++++++++++++++++++++ > arch/x86/Kconfig.assembler | 5 +++++ > 2 files changed, 27 insertions(+) Rest looks good, thanks.
On 12/29/2020 4:39 AM, Borislav Petkov wrote: > On Wed, Dec 09, 2020 at 02:22:56PM -0800, Yu-cheng Yu wrote: >> Shadow Stack provides protection against function return address >> corruption. It is active when the processor supports it, the kernel has >> CONFIG_X86_CET_USER, and the application is built for the feature. > ^ > enabled. > >> This is only implemented for the 64-bit kernel. When it is enabled, legacy >> non-Shadow Stack applications continue to work, but without protection. >> >> Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> >> --- >> arch/x86/Kconfig | 22 ++++++++++++++++++++++ >> arch/x86/Kconfig.assembler | 5 +++++ >> 2 files changed, 27 insertions(+) > > Rest looks good, thanks. > Thanks! I will re-base to v5.11-rc1 and send out a new version. -- Yu-cheng
On Tue, Dec 29, 2020 at 08:34:51AM -0800, Yu, Yu-cheng wrote:
> Thanks! I will re-base to v5.11-rc1 and send out a new version.
You don't have to if it still applies and there are no changes pending.
On 12/29/2020 10:54 AM, Borislav Petkov wrote: > On Tue, Dec 29, 2020 at 08:34:51AM -0800, Yu, Yu-cheng wrote: >> Thanks! I will re-base to v5.11-rc1 and send out a new version. > > You don't have to if it still applies and there are no changes pending. > There are some small conflicts, so I will send a new version. -- Yu-cheng
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index fbf26e0f7a6a..78b4b5bb1272 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1931,6 +1931,28 @@ config X86_INTEL_TSX_MODE_AUTO side channel attacks- equals the tsx=auto command line parameter. endchoice +config ARCH_HAS_SHADOW_STACK + def_bool n + +config X86_CET_USER + prompt "Intel Control-flow protection for user-mode" + def_bool n + depends on CPU_SUP_INTEL && X86_64 + depends on AS_WRUSS + select ARCH_USES_HIGH_VMA_FLAGS + select ARCH_HAS_SHADOW_STACK + help + Control-flow protection is a hardware security hardening feature + that detects function-return address or jump target changes by + malicious code. Applications must be enabled to use it, and old + userspace does not get protection "for free". + Support for this feature is present on processors released in + 2020 or later. Enabling this feature increases kernel text size + by 3.7 KB. + See Documentation/x86/intel_cet.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 26b8c08e2fc4..00c79dd93651 100644 --- a/arch/x86/Kconfig.assembler +++ b/arch/x86/Kconfig.assembler @@ -19,3 +19,8 @@ config AS_TPAUSE def_bool $(as-instr,tpause %ecx) help Supported by binutils >= 2.31.1 and LLVM integrated assembler >= V7 + +config AS_WRUSS + def_bool $(as-instr,wrussq %rax$(comma)(%rbx)) + help + Supported by binutils >= 2.31 and LLVM integrated assembler
Shadow Stack provides protection against function return address corruption. It is active when the processor supports it, the kernel has CONFIG_X86_CET_USER, 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. Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com> --- arch/x86/Kconfig | 22 ++++++++++++++++++++++ arch/x86/Kconfig.assembler | 5 +++++ 2 files changed, 27 insertions(+)