The current selftests Makefile construct result in cgroup_helpers.c
gets compiled together with all the TEST_GEN_PROGS. And it also result
in invoking the libbpf Makefile two times (tools/lib/bpf).
These issues were introduced in commit 9d1f15941967 ("bpf: move
cgroup_helpers from samples/bpf/ to tools/testing/selftesting/bpf/").
The only test program that requires the cgroup helpers is 'test_dev_cgroup'.
Thus, create a make target $(OUTPUT)/test_dev_cgroup that extend[1]
the 'prerequisite' for the 'stem' %-style pattern in ../lib.mk,
for this particular test program.
Reviewers notice the make-rules in tools/testing/selftests/lib.mk
differ from the normal kernel kbuild rules, and it is practical
to use 'make -p' to follow how these 'Implicit/static pattern stem'
gets expanded.
[1] https://www.gnu.org/software/make/manual/html_node/Static-Usage.html
Fixes: 9d1f15941967 ("bpf: move cgroup_helpers from samples/bpf/ to
tools/testing/selftesting/bpf/")
Signed-off-by: Jesper Dangaard Brouer <bro...@redhat.com>
---
tools/testing/selftests/bpf/Makefile | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/Makefile
b/tools/testing/selftests/bpf/Makefile
index 5c43c187f27c..8567a858b789 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -35,12 +35,14 @@ TEST_GEN_PROGS_EXTENDED = test_libbpf_open
include ../lib.mk
-BPFOBJ := $(OUTPUT)/libbpf.a cgroup_helpers.c
+BPFOBJ := $(OUTPUT)/libbpf.a
$(TEST_GEN_PROGS): $(BPFOBJ)
$(TEST_GEN_PROGS_EXTENDED): $(OUTPUT)/libbpf.a
+$(OUTPUT)/test_dev_cgroup: cgroup_helpers.c
+
.PHONY: force
# force a rebuild of BPFOBJ when its dependencies are updated
