Compile all functions with two ptrauth instructions: paciasp in the prologue to sign the return address, and autiasp in the epilogue to authenticate the return address. This should help protect the kernel against attacks using return-oriented programming. CONFIG_ARM64_PTR_AUTH enables pointer auth for both userspace and the kernel. Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx> Signed-off-by: Kristina Martsenko <kristina.martsenko@xxxxxxx> --- arch/arm64/Makefile | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index 106039d25e2f..dbcd43ea99d8 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -56,6 +56,10 @@ KBUILD_AFLAGS += $(lseinstr) $(brokengasinst) KBUILD_CFLAGS += $(call cc-option,-mabi=lp64) KBUILD_AFLAGS += $(call cc-option,-mabi=lp64) +ifeq ($(CONFIG_ARM64_PTR_AUTH),y) +KBUILD_CFLAGS += -msign-return-address=all +endif + ifeq ($(CONFIG_CPU_BIG_ENDIAN), y) KBUILD_CPPFLAGS += -mbig-endian CHECKFLAGS += -D__AARCH64EB__ -- 2.11.0
