selftests/bpf: Omit skeleton generation for multi-linked BPF object files

Skip generating individual BPF skeletons for files that are supposed to be
linked together to form the final BPF object file. Very often such files are
"incomplete" BPF object files, which will fail libbpf bpf_object__open() step,
if used individually, thus failing BPF skeleton generation. This is by design,
so skip individual BPF skeletons and only validate them as part of their
linked final BPF object file and skeleton.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210423181348.1801389-15-andrii@kernel.org

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index dd8061069b087792e4e8a48b227bff993aafb8c5..dd3692ec56d365c8f7c49980a6b277aae70b5b44 100644 (file)
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -313,6 +313,8 @@ LINKED_SKELS := test_static_linked.skel.h
 
 test_static_linked.skel.h-deps := test_static_linked1.o test_static_linked2.o
 
+LINKED_BPF_SRCS := $(patsubst %.o,%.c,$(foreach skel,$(LINKED_SKELS),$($(skel)-deps)))
+
 # Set up extra TRUNNER_XXX "temporary" variables in the environment (relies on
 # $eval()) and pass control to DEFINE_TEST_RUNNER_RULES.
 # Parameters:
@@ -331,7 +333,7 @@ TRUNNER_TESTS_HDR := $(TRUNNER_TESTS_DIR)/tests.h
 TRUNNER_BPF_SRCS := $$(notdir $$(wildcard $(TRUNNER_BPF_PROGS_DIR)/*.c))
 TRUNNER_BPF_OBJS := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.o, $$(TRUNNER_BPF_SRCS))
 TRUNNER_BPF_SKELS := $$(patsubst %.c,$$(TRUNNER_OUTPUT)/%.skel.h,      \
-                                $$(filter-out $(SKEL_BLACKLIST),       \
+                                $$(filter-out $(SKEL_BLACKLIST) $(LINKED_BPF_SRCS),\
                                               $$(TRUNNER_BPF_SRCS)))
 TRUNNER_BPF_SKELS_LINKED := $$(addprefix $$(TRUNNER_OUTPUT)/,$(LINKED_SKELS))
 TEST_GEN_FILES += $$(TRUNNER_BPF_OBJS)