samples/bpf: fix in-source build of samples with clang
in-source build of 'make samples/bpf/' was incorrectly
using default compiler instead of invoking clang/llvm.
out-of-source build was ok.
Fixes: a80857822b0c ("samples: bpf: trivial eBPF program in C")
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 76e3458..8fdbd73 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -44,7 +44,7 @@
# point this to your LLVM backend with bpf support
LLC=$(srctree)/tools/bpf/llvm/bld/Debug+Asserts/bin/llc
-%.o: %.c
+$(obj)/%.o: $(src)/%.c
clang $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) \
-D__KERNEL__ -Wno-unused-value -Wno-pointer-sign \
-O2 -emit-llvm -c $< -o -| $(LLC) -march=bpf -filetype=obj -o $@