Commit 99e44f39 authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

netdev: depend on netdev->lock for xdp features 



Writes to XDP features are now protected by netdev->lock.
Other things we report are based on ops which don't change
once device has been registered. It is safe to stop taking
rtnl_lock, and depend on netdev->lock instead.

Reviewed-by: default avatarJoe Damato <jdamato@fastly.com>
Acked-by: default avatarStanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250408195956.412733-7-kuba@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 03df156d

net/core/netdev-genl.c

+12 −14
Original line number Diff line number Diff line
@@ -38,6 +38,8 @@ netdev_nl_dev_fill(struct net_device *netdev, struct sk_buff *rsp, 
	u64 xdp_rx_meta = 0;

	void *hdr;



	netdev_assert_locked(netdev); /* note: rtnl_lock may not be held! */



	hdr = genlmsg_iput(rsp, info);

	if (!hdr)

		return -EMSGSIZE;
@@ -122,15 +124,14 @@ int netdev_nl_dev_get_doit(struct sk_buff *skb, struct genl_info *info) 
	if (!rsp)

		return -ENOMEM;



	rtnl_lock();



	netdev = __dev_get_by_index(genl_info_net(info), ifindex);

	if (netdev)

		err = netdev_nl_dev_fill(netdev, rsp, info);

	else

	netdev = netdev_get_by_index_lock(genl_info_net(info), ifindex);

	if (!netdev) {

		err = -ENODEV;

		goto err_free_msg;

	}



	rtnl_unlock();

	err = netdev_nl_dev_fill(netdev, rsp, info);

	netdev_unlock(netdev);



	if (err)

		goto err_free_msg;
@@ -146,18 +147,15 @@ int netdev_nl_dev_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb) 
{

	struct netdev_nl_dump_ctx *ctx = netdev_dump_ctx(cb);

	struct net *net = sock_net(skb->sk);

	struct net_device *netdev;

	int err = 0;

	int err;



	rtnl_lock();

	for_each_netdev_dump(net, netdev, ctx->ifindex) {

	for_each_netdev_lock_scoped(net, netdev, ctx->ifindex) {

		err = netdev_nl_dev_fill(netdev, skb, genl_info_dump(cb));

		if (err < 0)

			break;

			return err;

	}

	rtnl_unlock();



	return err;

	return 0;

}



static int