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> --- 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 c1708ffa6b1c..9d48769ad268 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -219,7 +219,8 @@ $(RESOLVE_BTFIDS): $(BPFOBJ) | $(BUILD_DIR)/resolve_btfids \ # 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 # Determine target endianness. -- 2.27.0