diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm64/Kconfig | 4 | ||||
| -rw-r--r-- | arch/arm64/Makefile | 37 |
2 files changed, 20 insertions, 21 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 03934808b2ed..be760ad7715d 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1818,7 +1818,7 @@ config ARM64_PTR_AUTH_KERNEL bool "Use pointer authentication for kernel" default y depends on ARM64_PTR_AUTH - depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_PAC + depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_ARMV8_3 # Modern compilers insert a .note.gnu.property section note for PAC # which is only understood by binutils starting with version 2.33.1. depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) @@ -1843,7 +1843,7 @@ config CC_HAS_SIGN_RETURN_ADDRESS # GCC 7, 8 def_bool $(cc-option,-msign-return-address=all) -config AS_HAS_PAC +config AS_HAS_ARMV8_3 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a) config AS_HAS_CFI_NEGATE_RA_STATE diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile index d62bd221828f..e176eb76345b 100644 --- a/arch/arm64/Makefile +++ b/arch/arm64/Makefile @@ -63,11 +63,6 @@ stack_protector_prepare: prepare0 include/generated/asm-offsets.h)) endif -ifeq ($(CONFIG_AS_HAS_ARMV8_2), y) -# make sure to pass the newest target architecture to -march. -asm-arch := armv8.2-a -endif - # Ensure that if the compiler supports branch protection we default it # off, this will be overridden if we are using branch protection. branch-prot-flags-y += $(call cc-option,-mbranch-protection=none) @@ -88,25 +83,29 @@ branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET_BTI) := -mbranch-protectio else branch-prot-flags-$(CONFIG_CC_HAS_BRANCH_PROT_PAC_RET) := -mbranch-protection=$(PACRET-y) endif -# -march=armv8.3-a enables the non-nops instructions for PAC, to avoid the -# compiler to generate them and consequently to break the single image contract -# we pass it only to the assembler. This option is utilized only in case of non -# integrated assemblers. -ifeq ($(CONFIG_AS_HAS_PAC), y) -asm-arch := armv8.3-a -endif endif KBUILD_CFLAGS += $(branch-prot-flags-y) -ifeq ($(CONFIG_AS_HAS_ARMV8_4), y) -# make sure to pass the newest target architecture to -march. -asm-arch := armv8.4-a -endif - +# Tell the assembler to support instructions from the latest target +# architecture. +# +# For non-integrated assemblers we'll pass this on the command line, and for +# integrated assemblers we'll define ARM64_ASM_ARCH and ARM64_ASM_PREAMBLE for +# inline usage. +# +# We cannot pass the same arch flag to the compiler as this would allow it to +# freely generate instructions which are not supported by earlier architecture +# versions, which would prevent a single kernel image from working on earlier +# hardware. ifeq ($(CONFIG_AS_HAS_ARMV8_5), y) -# make sure to pass the newest target architecture to -march. -asm-arch := armv8.5-a + asm-arch := armv8.5-a +else ifeq ($(CONFIG_AS_HAS_ARMV8_4), y) + asm-arch := armv8.4-a +else ifeq ($(CONFIG_AS_HAS_ARMV8_3), y) + asm-arch := armv8.3-a +else ifeq ($(CONFIG_AS_HAS_ARMV8_2), y) + asm-arch := armv8.2-a endif ifdef asm-arch |