From: Nick Desaulniers ndesaulniers@google.com
commit 3e6f8d1fa18457d54b20917bd9174d27daf09ab9 upstream.
Similar to commit 231ad7f409f1 ("Makefile: infer --target from ARCH for CC=clang") There really is no point in setting --target based on $CROSS_COMPILE_COMPAT for clang when the integrated assembler is being used, since commit ef94340583ee ("arm64: vdso32: drop -no-integrated-as flag").
Allows COMPAT_VDSO to be selected without setting $CROSS_COMPILE_COMPAT when using clang and lld together.
Before: $ ARCH=arm64 CROSS_COMPILE_COMPAT=arm-linux-gnueabi- make -j72 LLVM=1 defconfig $ grep CONFIG_COMPAT_VDSO .config CONFIG_COMPAT_VDSO=y $ ARCH=arm64 make -j72 LLVM=1 defconfig $ grep CONFIG_COMPAT_VDSO .config $
After: $ ARCH=arm64 CROSS_COMPILE_COMPAT=arm-linux-gnueabi- make -j72 LLVM=1 defconfig $ grep CONFIG_COMPAT_VDSO .config CONFIG_COMPAT_VDSO=y $ ARCH=arm64 make -j72 LLVM=1 defconfig $ grep CONFIG_COMPAT_VDSO .config CONFIG_COMPAT_VDSO=y
Reviewed-by: Nathan Chancellor nathan@kernel.org Suggested-by: Nathan Chancellor nathan@kernel.org Tested-by: Nathan Chancellor nathan@kernel.org Signed-off-by: Nick Desaulniers ndesaulniers@google.com Reviewed-by: Vincenzo Frascino vincenzo.frascino@arm.com Link: https://lore.kernel.org/r/20211019223646.1146945-5-ndesaulniers@google.com Signed-off-by: Will Deacon will@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm64/Kconfig | 3 ++- arch/arm64/kernel/vdso32/Makefile | 17 +++++------------ 2 files changed, 7 insertions(+), 13 deletions(-)
--- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -1264,7 +1264,8 @@ config KUSER_HELPERS
config COMPAT_VDSO bool "Enable vDSO for 32-bit applications" - depends on !CPU_BIG_ENDIAN && "$(CROSS_COMPILE_COMPAT)" != "" + depends on !CPU_BIG_ENDIAN + depends on (CC_IS_CLANG && LD_IS_LLD) || "$(CROSS_COMPILE_COMPAT)" != "" select GENERIC_COMPAT_VDSO default y help --- a/arch/arm64/kernel/vdso32/Makefile +++ b/arch/arm64/kernel/vdso32/Makefile @@ -10,18 +10,15 @@ include $(srctree)/lib/vdso/Makefile
# Same as cc-*option, but using CC_COMPAT instead of CC ifeq ($(CONFIG_CC_IS_CLANG), y) -CC_COMPAT_CLANG_FLAGS := --target=$(notdir $(CROSS_COMPILE_COMPAT:%-=%)) - CC_COMPAT ?= $(CC) -CC_COMPAT += $(CC_COMPAT_CLANG_FLAGS) - -ifneq ($(LLVM),) -LD_COMPAT ?= $(LD) +CC_COMPAT += --target=arm-linux-gnueabi else -LD_COMPAT ?= $(CROSS_COMPILE_COMPAT)ld +CC_COMPAT ?= $(CROSS_COMPILE_COMPAT)gcc endif + +ifeq ($(CONFIG_LD_IS_LLD), y) +LD_COMPAT ?= $(LD) else -CC_COMPAT ?= $(CROSS_COMPILE_COMPAT)gcc LD_COMPAT ?= $(CROSS_COMPILE_COMPAT)ld endif
@@ -47,10 +44,6 @@ VDSO_CPPFLAGS += $(LINUXINCLUDE) # Common C and assembly flags # From top-level Makefile VDSO_CAFLAGS := $(VDSO_CPPFLAGS) -ifneq ($(shell $(CC_COMPAT) --version 2>&1 | head -n 1 | grep clang),) -VDSO_CAFLAGS += --target=$(notdir $(CROSS_COMPILE_COMPAT:%-=%)) -endif - VDSO_CAFLAGS += $(call cc32-option,-fno-PIE) ifdef CONFIG_DEBUG_INFO VDSO_CAFLAGS += -g