6.8-stable review patch. If anyone has any objections, please let me know.
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From: Valentin Obst kernel@valentinobst.de
[ Upstream commit d4e6fbd245c48b272cc591d1c5e7c07aedd7f071 ]
Align the behavior for gcc and clang builds by interpreting unset `ARCH` and `CROSS_COMPILE` variables in `LLVM` builds as a sign that the user wants to build for the host architecture.
This patch preserves the properties that setting the `ARCH` variable to an unknown value will trigger an error that complains about insufficient information, and that a set `CROSS_COMPILE` variable will override the target triple that is determined based on presence/absence of `ARCH`.
When compiling with clang, i.e., `LLVM` is set, an unset `ARCH` variable in combination with an unset `CROSS_COMPILE` variable, i.e., compiling for the host architecture, leads to compilation failures since `lib.mk` can not determine the clang target triple. In this case, the following error message is displayed for each subsystem that does not set `ARCH` in its own Makefile before including `lib.mk` (lines wrapped at 75 chrs):
make[1]: Entering directory '/mnt/build/linux/tools/testing/selftests/ sysctl' ../lib.mk:33: *** Specify CROSS_COMPILE or add '--target=' option to lib.mk. Stop. make[1]: Leaving directory '/mnt/build/linux/tools/testing/selftests/ sysctl'
In the same scenario a gcc build would default to the host architecture, i.e., it would use plain `gcc`.
Fixes: 795285ef2425 ("selftests: Fix clang cross compilation") Reviewed-by: Mark Brown broonie@kernel.org Signed-off-by: Valentin Obst kernel@valentinobst.de Reviewed-by: John Hubbard jhubbard@nvidia.com Signed-off-by: Shuah Khan skhan@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/testing/selftests/lib.mk | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/lib.mk b/tools/testing/selftests/lib.mk index aa646e0661f36..a8f0442a36bca 100644 --- a/tools/testing/selftests/lib.mk +++ b/tools/testing/selftests/lib.mk @@ -7,6 +7,8 @@ else ifneq ($(filter -%,$(LLVM)),) LLVM_SUFFIX := $(LLVM) endif
+CLANG := $(LLVM_PREFIX)clang$(LLVM_SUFFIX) + CLANG_TARGET_FLAGS_arm := arm-linux-gnueabi CLANG_TARGET_FLAGS_arm64 := aarch64-linux-gnu CLANG_TARGET_FLAGS_hexagon := hexagon-linux-musl @@ -18,7 +20,13 @@ CLANG_TARGET_FLAGS_riscv := riscv64-linux-gnu CLANG_TARGET_FLAGS_s390 := s390x-linux-gnu CLANG_TARGET_FLAGS_x86 := x86_64-linux-gnu CLANG_TARGET_FLAGS_x86_64 := x86_64-linux-gnu -CLANG_TARGET_FLAGS := $(CLANG_TARGET_FLAGS_$(ARCH)) + +# Default to host architecture if ARCH is not explicitly given. +ifeq ($(ARCH),) +CLANG_TARGET_FLAGS := $(shell $(CLANG) -print-target-triple) +else +CLANG_TARGET_FLAGS := $(CLANG_TARGET_FLAGS_$(ARCH)) +endif
ifeq ($(CROSS_COMPILE),) ifeq ($(CLANG_TARGET_FLAGS),) @@ -30,7 +38,7 @@ else CLANG_FLAGS += --target=$(notdir $(CROSS_COMPILE:%-=%)) endif # CROSS_COMPILE
-CC := $(LLVM_PREFIX)clang$(LLVM_SUFFIX) $(CLANG_FLAGS) -fintegrated-as +CC := $(CLANG) $(CLANG_FLAGS) -fintegrated-as else CC := $(CROSS_COMPILE)gcc endif # LLVM