From: Björn Töpel bjorn@rivosinc.com

The BPF Makefile in net/bpf did incorrect path substitution for O=dir builds, e.g.

make O=/tmp/kselftest headers make O=/tmp/kselftest -C tools/testing/selftests

would fail in selftest builds [1] net/ with

clang-16: error: no such file or directory: 'kselftest/net/bpf/nat6to4.c' clang-16: error: no input files

Add a pattern prerequisite and an order-only-prerequisite (for creating the directory), to resolve the issue.

[1] https://lore.kernel.org/all/202212060009.34CkQmCN-lkp@intel.com/

Reported-by: kernel test robot lkp@intel.com Fixes: 837a3d66d698 ("selftests: net: Add cross-compilation support for BPF programs") Signed-off-by: Björn Töpel bjorn@rivosinc.com --- tools/testing/selftests/net/bpf/Makefile | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/net/bpf/Makefile b/tools/testing/selftests/net/bpf/Makefile index a26cb94354f6..4abaf16d2077 100644 --- a/tools/testing/selftests/net/bpf/Makefile +++ b/tools/testing/selftests/net/bpf/Makefile @@ -12,7 +12,7 @@ CCINCLUDE += -I$(SCRATCH_DIR)/include

BPFOBJ := $(BUILD_DIR)/libbpf/libbpf.a

-MAKE_DIRS := $(BUILD_DIR)/libbpf +MAKE_DIRS := $(BUILD_DIR)/libbpf $(OUTPUT)/bpf $(MAKE_DIRS): mkdir -p $@

@@ -37,8 +37,8 @@ endif

CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH))

-$(TEST_CUSTOM_PROGS): $(BPFOBJ) - $(CLANG) -O2 -target bpf -c $(@:.o=.c) $(CCINCLUDE) $(CLANG_SYS_INCLUDES) -o $@ +$(TEST_CUSTOM_PROGS): $(OUTPUT)/%.o: %.c $(BPFOBJ) | $(MAKE_DIRS) + $(CLANG) -O2 -target bpf -c $< $(CCINCLUDE) $(CLANG_SYS_INCLUDES) -o $@

$(BPFOBJ): $(wildcard $(BPFDIR)/*.[ch] $(BPFDIR)/Makefile) \ $(APIDIR)/linux/bpf.h \

base-commit: c9f8d73645b6f76c8d14f49bc860f7143d001cb7