selftests/bpf: Improve bpftool changes detection

Detect when bpftool source code changes and trigger rebuild within
selftests/bpf Makefile. Also fix few small formatting problems.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20200124054148.2455060-1-andriin@fb.com

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 5f41f5b..257a1aa 100644 (file)
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -155,16 +155,17 @@ $(OUTPUT)/test_sysctl: cgroup_helpers.c
 
 DEFAULT_BPFTOOL := $(SCRATCH_DIR)/sbin/bpftool
 BPFTOOL ?= $(DEFAULT_BPFTOOL)
-$(DEFAULT_BPFTOOL): $(BPFOBJ) | $(BUILD_DIR)/bpftool
-       $(Q)$(MAKE) $(submake_extras)  -C $(BPFTOOLDIR)                 \
-                   OUTPUT=$(BUILD_DIR)/bpftool/                        \
+$(DEFAULT_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile)    \
+                   $(BPFOBJ) | $(BUILD_DIR)/bpftool
+       $(Q)$(MAKE) $(submake_extras)  -C $(BPFTOOLDIR)                        \
+                   OUTPUT=$(BUILD_DIR)/bpftool/                               \
                    prefix= DESTDIR=$(SCRATCH_DIR)/ install
 
-$(BPFOBJ): $(wildcard $(BPFDIR)/*.c $(BPFDIR)/*.h $(BPFDIR)/Makefile)          \
+$(BPFOBJ): $(wildcard $(BPFDIR)/*.[ch] $(BPFDIR)/Makefile)                    \
           ../../../include/uapi/linux/bpf.h                                   \
           | $(INCLUDE_DIR) $(BUILD_DIR)/libbpf
        $(Q)$(MAKE) $(submake_extras) -C $(BPFDIR) OUTPUT=$(BUILD_DIR)/libbpf/ \
-               DESTDIR=$(SCRATCH_DIR) prefix= all install_headers
+                   DESTDIR=$(SCRATCH_DIR) prefix= all install_headers
 
 $(BUILD_DIR)/libbpf $(BUILD_DIR)/bpftool $(INCLUDE_DIR):
        $(call msg,MKDIR,,$@)