commit 7f58b487e9ff3ff0f5f29a57172295a41f08a6b5
author Masahiro Yamada <masahiroy@kernel.org> Wed Jul 01 00:06:25 2020 +0900
committer Masahiro Yamada <masahiroy@kernel.org> Thu Jul 02 00:58:00 2020 +0900
tree d4912fafbd144b54679f7c4d4e8f15a9ccd75c72
parent b816b3db15f68690ee72a4a414624f8e82942b25

kbuild: make Clang build userprogs for target architecture

Programs added 'userprogs' should be compiled for the target
architecture i.e. the same architecture as the kernel.

GCC does this correctly since the target architecture is implied
by the toolchain prefix.

Clang builds userspace programs always for the host architecture
because the target triple is currently missing.

Fix this.

Fixes: 7f3a59db274c ("kbuild: add infrastructure to build userspace programs")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>

Makefile

diff --git a/Makefile b/Makefile
index ac2c61c..bc48810 100644
--- a/Makefile
+++ b/Makefile
@@ -970,8 +970,8 @@
 endif
 
 # Align the bit size of userspace programs with the kernel
-KBUILD_USERCFLAGS  += $(filter -m32 -m64, $(KBUILD_CFLAGS))
-KBUILD_USERLDFLAGS += $(filter -m32 -m64, $(KBUILD_CFLAGS))
+KBUILD_USERCFLAGS  += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
+KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CFLAGS))
 
 # make the checker run with the right architecture
 CHECKFLAGS += --arch=$(ARCH)