The userprog infrastructure links objects files through $(CC). Either explicitly by manually calling $(CC) on multiple object files or implicitly by directly compiling a source file to an executable. The documentation at Documentation/kbuild/llvm.rst indicates that ld.lld would be used for linking if LLVM=1 is specified. However clang instead will use either a globally installed cross linker from $PATH called ${target}-ld or fall back to the system linker, which probably does not support crosslinking. For the normal kernel build this is not an issue because the linker is always executed directly, without the compiler being involved.
Fix this by passing -fuse-lld and let clang find its matching lld.
Fixes: 7f3a59db274c ("kbuild: add infrastructure to build userspace programs") Cc: stable@vger.kernel.org Signed-off-by: Thomas Weißschuh thomas.weissschuh@linutronix.de --- Makefile | 1 + 1 file changed, 1 insertion(+)
diff --git a/Makefile b/Makefile index bb5737ce7f9e79f4023c9c1f578a49a951d1e239..b4c208ae4041c1f4e32c2a158322422ce7353d06 100644 --- a/Makefile +++ b/Makefile @@ -510,6 +510,7 @@ OBJCOPY = $(LLVM_PREFIX)llvm-objcopy$(LLVM_SUFFIX) OBJDUMP = $(LLVM_PREFIX)llvm-objdump$(LLVM_SUFFIX) READELF = $(LLVM_PREFIX)llvm-readelf$(LLVM_SUFFIX) STRIP = $(LLVM_PREFIX)llvm-strip$(LLVM_SUFFIX) +KBUILD_USERLDFLAGS += -fuse-ld=lld else CC = $(CROSS_COMPILE)gcc LD = $(CROSS_COMPILE)ld