From d888eaac4fb1df30320bb1305a8f78efe86524c6 Mon Sep 17 00:00:00 2001 From: Jiri Benc Date: Mon, 27 Sep 2021 18:01:36 +0200 Subject: [PATCH] selftests, bpf: Fix makefile dependencies on libbpf When building bpf selftest with make -j, I'm randomly getting build failures such as this one: In file included from progs/bpf_flow.c:19: [...]/tools/testing/selftests/bpf/tools/include/bpf/bpf_helpers.h:11:10: fatal error: 'bpf_helper_defs.h' file not found #include "bpf_helper_defs.h" ^~~~~~~~~~~~~~~~~~~ The file that fails the build varies between runs but it's always in the progs/ subdir. The reason is a missing make dependency on libbpf for the .o files in progs/. There was a dependency before commit 3ac2e20fba07e but that commit removed it to prevent unneeded rebuilds. However, that only works if libbpf has been built already; the 'wildcard' prerequisite does not trigger when there's no bpf_helper_defs.h generated yet. Keep the libbpf as an order-only prerequisite to satisfy both goals. It is always built before the progs/ objects but it does not trigger unnecessary rebuilds by itself. Fixes: 3ac2e20fba07e ("selftests/bpf: BPF object files should depend only on libbpf headers") Signed-off-by: Jiri Benc Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/ee84ab66436fba05a197f952af23c98d90eb6243.1632758415.git.jbenc@redhat.com --- 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 866531c08e4f..799b88152e9e 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -375,7 +375,8 @@ $(TRUNNER_BPF_OBJS): $(TRUNNER_OUTPUT)/%.o: \ $(TRUNNER_BPF_PROGS_DIR)/%.c \ $(TRUNNER_BPF_PROGS_DIR)/*.h \ $$(INCLUDE_DIR)/vmlinux.h \ - $(wildcard $(BPFDIR)/bpf_*.h) | $(TRUNNER_OUTPUT) + $(wildcard $(BPFDIR)/bpf_*.h) \ + | $(TRUNNER_OUTPUT) $$(BPFOBJ) $$(call $(TRUNNER_BPF_BUILD_RULE),$$<,$$@, \ $(TRUNNER_BPF_CFLAGS)) -- GitLab