diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 6b39f37f769a..7e76b6316425 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -1162,6 +1162,28 @@ config RANDOMIZE_BASE If unsure, say N. +config RISCV_USER_CFI + def_bool y + bool "riscv userspace control flow integrity" + depends on 64BIT && MMU && \ + $(cc-option,-mabi=lp64 -march=rv64ima_zicfiss_zicfilp -fcf-protection=full) + depends on RISCV_ALTERNATIVE + select RISCV_SBI + select ARCH_HAS_USER_SHADOW_STACK + select ARCH_USES_HIGH_VMA_FLAGS + select DYNAMIC_SIGFRAME + help + Provides CPU-assisted control flow integrity to userspace tasks. + Control flow integrity is provided by implementing shadow stack for + backward edge and indirect branch tracking for forward edge. + Shadow stack protection is a hardware feature that detects function + return address corruption. This helps mitigate ROP attacks. + Indirect branch tracking enforces that all indirect branches must land + on a landing pad instruction else CPU will fault. This mitigates against + JOP / COP attacks. Applications must be enabled to use it, and old userspace + does not get protection "for free". + default y. + endmenu # "Kernel features" menu "Boot options" diff --git a/arch/riscv/configs/hardening.config b/arch/riscv/configs/hardening.config new file mode 100644 index 000000000000..089f4cee82f4 --- /dev/null +++ b/arch/riscv/configs/hardening.config @@ -0,0 +1,4 @@ +# RISCV specific kernel hardening options + +# Enable control flow integrity support for usermode. +CONFIG_RISCV_USER_CFI=y