4.9-stable review patch. If anyone has any objections, please let me know.
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From: Behan Webster behanw@converseincode.com
commit 785f11aa595bc3d4e74096cbd598ada54ecc0d81 upstream.
Add cross target to CC if using clang. Also add custom gcc toolchain path for fallback gcc tools.
Clang will fallback to using things like ld, as, and libgcc if (respectively) one of the llvm linkers isn't available, the integrated assembler is turned off, or an appropriately cross-compiled version of compiler-rt isn't available. To this end, you can specify the path to this fallback gcc toolchain with GCC_TOOLCHAIN.
Signed-off-by: Behan Webster behanw@converseincode.com Reviewed-by: Jan-Simon Möller dl9pf@gmx.de Reviewed-by: Mark Charlebois charlebm@gmail.com Signed-off-by: Greg Hackmann ghackmann@google.com Signed-off-by: Matthias Kaehlcke mka@chromium.org Signed-off-by: Masahiro Yamada yamada.masahiro@socionext.com Signed-off-by: Nick Desaulniers ndesaulniers@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- Makefile | 9 +++++++++ 1 file changed, 9 insertions(+)
--- a/Makefile +++ b/Makefile @@ -704,6 +704,15 @@ endif KBUILD_CFLAGS += $(stackp-flag)
ifeq ($(cc-name),clang) +ifneq ($(CROSS_COMPILE),) +CLANG_TARGET := -target $(notdir $(CROSS_COMPILE:%-=%)) +GCC_TOOLCHAIN := $(realpath $(dir $(shell which $(LD)))/..) +endif +ifneq ($(GCC_TOOLCHAIN),) +CLANG_GCC_TC := -gcc-toolchain $(GCC_TOOLCHAIN) +endif +KBUILD_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) +KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,) KBUILD_CPPFLAGS += $(call cc-option,-Wno-unknown-warning-option,) KBUILD_CFLAGS += $(call cc-disable-warning, unused-variable)