From: Björn Töpel <bjorn.topel@xxxxxxxxx> [ Upstream commit 6016df8fe874e1cf36f6357d71438b384198ce06 ] The selftests/bpf Makefile includes system include directories from the host, when building BPF programs. On RISC-V glibc requires that __riscv_xlen is defined. This is not the case for "clang -target bpf", which messes up __WORDSIZE (errno.h -> ... -> wordsize.h) and breaks the build. By explicitly defining __risc_xlen correctly for riscv, we can workaround this. Fixes: 167381f3eac0 ("selftests/bpf: Makefile fix "missing" headers on build with -idirafter") Signed-off-by: Björn Töpel <bjorn.topel@xxxxxxxxx> Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> Acked-by: Luke Nelson <luke.r.nels@xxxxxxxxx> Link: https://lore.kernel.org/bpf/20201118071640.83773-2-bjorn.topel@xxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- tools/testing/selftests/bpf/Makefile | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 6889c19a628c2..544bd1028baee 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -144,7 +144,8 @@ endif # build would have failed anyways. define get_sys_includes $(shell $(1) -v -E - </dev/null 2>&1 \ - | sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') + | sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') \ +$(shell $(1) -dM -E - </dev/null | grep '#define __riscv_xlen ' | sed 's/#define /-D/' | sed 's/ /=/') endef CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG)) BPF_CFLAGS = -I. -I./include/uapi -I../../../include/uapi \ -- 2.27.0