Fix _GNU_SOURCE redefined warning

diff --git a/src/cc/libbpf.c b/src/cc/libbpf.c
index 0da8e2c..928d7d7 100644 (file)
--- a/src/cc/libbpf.c
+++ b/src/cc/libbpf.c
@@ -13,7 +13,9 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+#ifndef _GNU_SOURCE
 #define _GNU_SOURCE
+#endif
 
 #include <arpa/inet.h>
 #include <errno.h>