This is a note to let you know that I've just added the patch titled
selftests, bpf: Fix makefile dependencies on libbpf
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
selftests-bpf-fix-makefile-dependencies-on-libbpf.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 98252a14c8bbc7f9c5bd0a1e4959a80e90a7569b
Author: Jiri Benc <jbenc@xxxxxxxxxx>
Date: Mon Sep 27 18:01:36 2021 +0200
selftests, bpf: Fix makefile dependencies on libbpf
[ 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@xxxxxxxxxx>
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/bpf/ee84ab66436fba05a197f952af23c98d90eb6243.1632758415.git.jbenc@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index b5322d60068c..1d9155533360 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -326,7 +326,8 @@ $(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), \
$(TRUNNER_BPF_LDFLAGS))
