From: Will Deacon will@kernel.org
[ Upstream commit c71e88c437962c1ec43d4d23a0ebf4c9cf9bee0d ]
KBUILD_CPPFLAGS is defined differently depending on whether the main compiler is clang or not. This means that it is not possible to build the compat vDSO with GCC if the rest of the kernel is built with clang.
Define VDSO_CPPFLAGS directly to break this dependency and allow a clang kernel to build a compat vDSO with GCC:
$ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- \ CROSS_COMPILE_COMPAT=arm-linux-gnueabihf- CC=clang \ COMPATCC=arm-linux-gnueabihf-gcc
Acked-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Will Deacon will@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm64/kernel/vdso32/Makefile | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile index 77aa613403747..aa171b043287b 100644 --- a/arch/arm64/kernel/vdso32/Makefile +++ b/arch/arm64/kernel/vdso32/Makefile @@ -25,11 +25,9 @@ cc32-as-instr = $(call try-run,\ # arm64 one. # As a result we set our own flags here.
-# From top-level Makefile -# NOSTDINC_FLAGS -VDSO_CPPFLAGS := -nostdinc -isystem $(shell $(COMPATCC) -print-file-name=include) +# KBUILD_CPPFLAGS and NOSTDINC_FLAGS from top-level Makefile +VDSO_CPPFLAGS := -D__KERNEL__ -nostdinc -isystem $(shell $(COMPATCC) -print-file-name=include) VDSO_CPPFLAGS += $(LINUXINCLUDE) -VDSO_CPPFLAGS += $(KBUILD_CPPFLAGS)
# Common C and assembly flags # From top-level Makefile