From 15cd0e675f3f76b4d21c313795fe0c23df0ee20f Mon Sep 17 00:00:00 2001 From: Amit Daniel Kachhap Date: Mon, 30 Mar 2020 17:11:39 +0530 Subject: [PATCH] arm64: Kconfig: ptrauth: Add binutils version check to fix mismatch Recent addition of ARM64_PTR_AUTH exposed a mismatch issue with binutils. 9.1+ versions of gcc inserts a section note .note.gnu.property but this can be used properly by binutils version greater than 2.33.1. If older binutils are used then the following warnings are generated, aarch64-linux-ld: warning: arch/arm64/kernel/vdso/vgettimeofday.o: unsupported GNU_PROPERTY_TYPE (5) type: 0xc0000000 aarch64-linux-objdump: warning: arch/arm64/lib/csum.o: unsupported GNU_PROPERTY_TYPE (5) type: 0xc0000000 aarch64-linux-nm: warning: .tmp_vmlinux1: unsupported GNU_PROPERTY_TYPE (5) type: 0xc0000000 This patch enables ARM64_PTR_AUTH when gcc and binutils versions are compatible with each other. Older gcc which do not insert such section continue to work as before. This scenario may not occur with clang as a recent commit 3b446c7d27ddd06 ("arm64: Kconfig: verify binutils support for ARM64_PTR_AUTH") masks binutils version lesser then 2.34. Reported-by: kbuild test robot Suggested-by: Vincenzo Frascino Signed-off-by: Amit Daniel Kachhap [catalin.marinas@arm.com: slight adjustment to the comment] Signed-off-by: Catalin Marinas --- arch/arm64/Kconfig | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index e6712b6818fa..9ba3287bb29d 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1503,7 +1503,10 @@ config ARM64_PTR_AUTH default y depends on !KVM || ARM64_VHE depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_PAC - depends on CC_IS_GCC || (CC_IS_CLANG && AS_HAS_CFI_NEGATE_RA_STATE) + # GCC 9.1 and later inserts a .note.gnu.property section note for PAC + # which is only understood by binutils starting with version 2.33.1. + depends on !CC_IS_GCC || GCC_VERSION < 90100 || LD_VERSION >= 233010000 + depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS) help Pointer authentication (part of the ARMv8.3 Extensions) provides