[PATCH v2 bpf-next] selftests/bpf: fix dependency ordering for attach_probe test

[PATCH v2 bpf-next] selftests/bpf: fix dependency ordering for attach_probe test

[Andrii Nakryiko]

Current Makefile dependency chain is not strict enough and allows
test_attach_probe.o to be built before test_progs's
prog_test/attach_probe.o is built, which leads to assembler complaining
about missing included binary.

This patch is a minimal fix to fix this issue by enforcing that
test_attach_probe.o (BPF object file) is built before
prog_tests/attach_probe.c is attempted to be compiled.

Fixes: 928ca75e59d7 ("selftests/bpf: switch tests to new bpf_object__open_{file, mem}() APIs")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
---
 tools/testing/selftests/bpf/Makefile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index b59fb4e8afaf..771a4e82128b 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -164,7 +164,7 @@ $(OUTPUT)/test_queue_map.o: test_queue_stack_map.h
 $(OUTPUT)/test_stack_map.o: test_queue_stack_map.h
 
 $(OUTPUT)/flow_dissector_load.o: flow_dissector_load.h
-$(OUTPUT)/test_progs.o: flow_dissector_load.h $(OUTPUT)/test_attach_probe.o
+$(OUTPUT)/test_progs.o: flow_dissector_load.h
 
 BTF_LLC_PROBE := $(shell $(LLC) -march=bpf -mattr=help 2>&1 | grep dwarfris)
 BTF_PAHOLE_PROBE := $(shell $(BTF_PAHOLE) --help 2>&1 | grep BTF)
@@ -275,7 +275,7 @@ PROG_TESTS_H := $(PROG_TESTS_DIR)/tests.h
 PROG_TESTS_FILES := $(wildcard prog_tests/*.c)
 test_progs.c: $(PROG_TESTS_H)
 $(OUTPUT)/test_progs: CFLAGS += $(TEST_PROGS_CFLAGS)
-$(OUTPUT)/test_progs: test_progs.c $(PROG_TESTS_FILES) | $(PROG_TESTS_H)
+$(OUTPUT)/test_progs: test_progs.c $(PROG_TESTS_FILES) | $(OUTPUT)/test_attach_probe.o $(PROG_TESTS_H)
 $(PROG_TESTS_H): $(PROG_TESTS_FILES) | $(PROG_TESTS_DIR)
 	$(shell ( cd prog_tests/; \
 		  echo '/* Generated header, do not edit */'; \
-- 
2.17.1

Re: [PATCH v2 bpf-next] selftests/bpf: fix dependency ordering for attach_probe test

[Alexei Starovoitov]

On Mon, Oct 7, 2019 at 1:42 PM Andrii Nakryiko <andriin@fb.com> wrote:
>
> Current Makefile dependency chain is not strict enough and allows
> test_attach_probe.o to be built before test_progs's
> prog_test/attach_probe.o is built, which leads to assembler complaining
> about missing included binary.
>
> This patch is a minimal fix to fix this issue by enforcing that
> test_attach_probe.o (BPF object file) is built before
> prog_tests/attach_probe.c is attempted to be compiled.
>
> Fixes: 928ca75e59d7 ("selftests/bpf: switch tests to new bpf_object__open_{file, mem}() APIs")
> Signed-off-by: Andrii Nakryiko <andriin@fb.com>

This time the fix is actually fixing the build in my setup.
Thanks. Applied.