selftests/bpf: Re-generate vmlinux.h and BPF skeletons if bpftool changed

BugLink: https://bugs.launchpad.net/bugs/1929455
[ Upstream commit cab62c37be057379a2a17b1b2eacd9dcba1e14dc ]

Trigger vmlinux.h and BPF skeletons re-generation if detected that bpftool was
re-compiled. Otherwise full `make clean` is required to get updated skeletons,
if bpftool is modified.

Fixes: acbd06206bbb ("selftests/bpf: Add vmlinux.h selftest exercising tracing of syscalls")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210318194036.3521577-11-andrii@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index c51df6b91befe50b6740e6f25c05d503885b7c1f..d47dd8a24a6f69bb43c75929c3439ad9e02bea1e 100644 (file)
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -202,7 +202,7 @@ $(BUILD_DIR)/libbpf $(BUILD_DIR)/bpftool $(BUILD_DIR)/resolve_btfids $(INCLUDE_D
        $(call msg,MKDIR,,$@)
        $(Q)mkdir -p $@
 
-$(INCLUDE_DIR)/vmlinux.h: $(VMLINUX_BTF) | $(BPFTOOL) $(INCLUDE_DIR)
+$(INCLUDE_DIR)/vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL) | $(INCLUDE_DIR)
 ifeq ($(VMLINUX_H),)
        $(call msg,GEN,,$@)
        $(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF) format c > $@
@@ -326,7 +326,8 @@ $(TRUNNER_BPF_OBJS): $(TRUNNER_OUTPUT)/%.o:                         \
 
 $(TRUNNER_BPF_SKELS): $(TRUNNER_OUTPUT)/%.skel.h:                      \
                      $(TRUNNER_OUTPUT)/%.o                             \
-                     | $(BPFTOOL) $(TRUNNER_OUTPUT)
+                     $(BPFTOOL)                                        \
+                     | $(TRUNNER_OUTPUT)
        $$(call msg,GEN-SKEL,$(TRUNNER_BINARY),$$@)
        $(Q)$$(BPFTOOL) gen skeleton $$< > $$@
 endif