On 1/8/23 10:43, Jakub Kicinski wrote:

On Sun, 30 Jul 2023 19:49:50 +0800 Leon Hwang wrote:

quoted

@@ -9472,6 +9473,7 @@ int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
 	struct bpf_link_primer link_primer;
 	struct bpf_xdp_link *link;
 	struct net_device *dev;
+	struct netlink_ext_ack extack;

This is not initialized. Also, while fixing that, move it up 
to maintain the line order by decreasing line length.

Thank you for your reviewing.

I'll fix it by initializing extack and moving the line to its appropriate position.

Thanks,
Leon

quoted

 	int err, fd;
 
 	rtnl_lock();

@@ -9497,12 +9499,13 @@ int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
 		goto unlock;
 	}
 
-	err = dev_xdp_attach_link(dev, NULL, link);
+	err = dev_xdp_attach_link(dev, &extack, link);
 	rtnl_unlock();
 
 	if (err) {
 		link->dev = NULL;
 		bpf_link_cleanup(&link_primer);
+		trace_bpf_xdp_link_attach_failed(extack._msg);