From 54d54d2e02c7b6ab7c447e16237d9d8e08f2b54c Mon Sep 17 00:00:00 2001
From: Jiri Benc <jbenc@redhat.com>
Date: Mon, 27 Sep 2021 18:01:36 +0200
Subject: [PATCH] selftests, bpf: Fix makefile dependencies on libbpf
Git-commit: d888eaac4fb1df30320bb1305a8f78efe86524c6
Patch-mainline: v5.15-rc4
References: stable-5.14.10
[ Upstream commit d888eaac4fb1df30320bb1305a8f78efe86524c6 ]
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 <jbenc@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/ee84ab66436fba05a197f952af23c98d90eb6243.1632758415.git.jbenc@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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 f405b20c1e6c..93f1f124ef89 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -374,7 +374,8 @@ $(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))
--
2.26.2