bpf/preload: Make sure Makefile cleans up after itself, and add .gitignore

The Makefile in bpf/preload builds a local copy of libbpf, but does not
properly clean up after itself. This can lead to subsequent compilation
failures, since the feature detection cache is kept around which can lead
subsequent detection to fail.

Fix this by properly setting clean-files, and while we're at it, also add a
.gitignore for the directory to ignore the build artifacts.

Fixes: d71fa5c9763c ("bpf: Add kernel module with user mode driver that populates bpffs.")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200927193005.8459-1-toke@redhat.com

diff --git a/kernel/bpf/preload/.gitignore b/kernel/bpf/preload/.gitignore
new file mode 100644 (file)
index 0000000..856a4c5
--- /dev/null
+++ b/kernel/bpf/preload/.gitignore
@@ -0,0 +1,4 @@
+/FEATURE-DUMP.libbpf
+/bpf_helper_defs.h
+/feature
+/bpf_preload_umd

diff --git a/kernel/bpf/preload/Makefile b/kernel/bpf/preload/Makefile
index 12c7b62..23ee310 100644 (file)
--- a/kernel/bpf/preload/Makefile
+++ b/kernel/bpf/preload/Makefile
@@ -12,6 +12,8 @@ userccflags += -I $(srctree)/tools/include/ -I $(srctree)/tools/include/uapi \
 
 userprogs := bpf_preload_umd
 
+clean-files := $(userprogs) bpf_helper_defs.h FEATURE-DUMP.libbpf staticobjs/ feature/
+
 bpf_preload_umd-objs := iterators/iterators.o
 bpf_preload_umd-userldlibs := $(LIBBPF_A) -lelf -lz