--- /dev/null
+From foo@baz Tue Dec 11 16:07:42 CET 2018
+From: Stefan Agner <stefan@agner.ch>
+Date: Wed, 5 Dec 2018 16:45:26 -0800
+Subject: kbuild: allow to use GCC toolchain not in Clang search path
+
+From: Stefan Agner <stefan@agner.ch>
+
+(commit ef8c4ed9db80261f397f0c0bf723684601ae3b52 upstream)
+
+When using a GCC cross toolchain which is not in a compiled in
+Clang search path, Clang reverts to the system assembler and
+linker. This leads to assembler or linker errors, depending on
+which tool is first used for a given architecture.
+
+It seems that Clang is not searching $PATH for a matching
+assembler or linker.
+
+Make sure that Clang picks up the correct assembler or linker by
+passing the cross compilers bin directory as search path.
+
+This allows to use Clang provided by distributions with GCC
+toolchains not in /usr/bin.
+
+Link: https://github.com/ClangBuiltLinux/linux/issues/78
+Signed-off-by: Stefan Agner <stefan@agner.ch>
+Reviewed-and-tested-by: Nick Desaulniers <ndesaulniers@google.com>
+Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
+[ND: adjusted to context, due to adjusting the context of my previous
+backport of upstream's ae6b289a3789]
+Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ Makefile | 8 +++++---
+ 1 file changed, 5 insertions(+), 3 deletions(-)
+
+--- a/Makefile
++++ b/Makefile
+@@ -512,13 +512,15 @@ endif
+ ifeq ($(cc-name),clang)
+ ifneq ($(CROSS_COMPILE),)
+ CLANG_TARGET := -target $(notdir $(CROSS_COMPILE:%-=%))
+-GCC_TOOLCHAIN := $(realpath $(dir $(shell which $(LD)))/..)
++GCC_TOOLCHAIN_DIR := $(dir $(shell which $(LD)))
++CLANG_PREFIX := --prefix=$(GCC_TOOLCHAIN_DIR)
++GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..)
+ endif
+ ifneq ($(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_CFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX)
++KBUILD_AFLAGS += $(CLANG_TARGET) $(CLANG_GCC_TC) $(CLANG_PREFIX)
+ KBUILD_CPPFLAGS += $(call cc-option,-Qunused-arguments,)
+ KBUILD_CFLAGS += $(call cc-disable-warning, unused-variable)
+ KBUILD_CFLAGS += $(call cc-disable-warning, format-invalid-specifier)
--- /dev/null
+From foo@baz Tue Dec 11 16:07:42 CET 2018
+From: Nick Desaulniers <ndesaulniers@google.com>
+Date: Tue, 4 Dec 2018 15:39:42 -0800
+Subject: kbuild: fix linker feature test macros when cross compiling with Clang
+
+From: Nick Desaulniers <ndesaulniers@google.com>
+
+(commit 86a9df597cdd564d2d29c65897bcad42519e3678 upstream)
+
+I was not seeing my linker flags getting added when using ld-option when
+cross compiling with Clang. Upon investigation, this seems to be due to
+a difference in how GCC vs Clang handle cross compilation.
+
+GCC is configured at build time to support one backend, that is implicit
+when compiling. Clang is explicit via the use of `-target <triple>` and
+ships with all supported backends by default.
+
+GNU Make feature test macros that compile then link will always fail
+when cross compiling with Clang unless Clang's triple is passed along to
+the compiler. For example:
+
+$ clang -x c /dev/null -c -o temp.o
+$ aarch64-linux-android/bin/ld -E temp.o
+aarch64-linux-android/bin/ld:
+unknown architecture of input file `temp.o' is incompatible with
+aarch64 output
+aarch64-linux-android/bin/ld:
+warning: cannot find entry symbol _start; defaulting to
+0000000000400078
+$ echo $?
+1
+
+$ clang -target aarch64-linux-android- -x c /dev/null -c -o temp.o
+$ aarch64-linux-android/bin/ld -E temp.o
+aarch64-linux-android/bin/ld:
+warning: cannot find entry symbol _start; defaulting to 00000000004002e4
+$ echo $?
+0
+
+This causes conditional checks that invoke $(CC) without the target
+triple, then $(LD) on the result, to always fail.
+
+Suggested-by: Masahiro Yamada <yamada.masahiro@socionext.com>
+Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
+Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
+Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
+[ND: readjusted for context]
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ scripts/Kbuild.include | 5 +++--
+ 1 file changed, 3 insertions(+), 2 deletions(-)
+
+--- a/scripts/Kbuild.include
++++ b/scripts/Kbuild.include
+@@ -162,12 +162,13 @@ cc-ifversion = $(shell [ $(cc-version) $
+ # cc-ldoption
+ # Usage: ldflags += $(call cc-ldoption, -Wl$(comma)--hash-style=both)
+ cc-ldoption = $(call try-run,\
+- $(CC) $(1) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
++ $(CC) $(1) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -nostdlib -x c /dev/null -o "$$TMP",$(1),$(2))
+
+ # ld-option
+ # Usage: LDFLAGS += $(call ld-option, -X)
+ ld-option = $(call try-run,\
+- $(CC) -x c /dev/null -c -o "$$TMPO" ; $(LD) $(1) "$$TMPO" -o "$$TMP",$(1),$(2))
++ $(CC) $(KBUILD_CPPFLAGS) $(CC_OPTION_CFLAGS) -x c /dev/null -c -o "$$TMPO"; \
++ $(LD) $(LDFLAGS) $(1) "$$TMPO" -o "$$TMP",$(1),$(2))
+
+ # ar-option
+ # Usage: KBUILD_ARFLAGS := $(call ar-option,D)