Commit 9038c320 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

net: dst: add net device refcount tracking to dst_entry 



We want to track all dev_hold()/dev_put() to ease leak hunting.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 4dbd24f6

include/linux/netdevice.h

+17 −0
Original line number Diff line number Diff line
@@ -3883,6 +3883,23 @@ static inline void dev_put_track(struct net_device *dev, 
	}

}



static inline void dev_replace_track(struct net_device *odev,

				     struct net_device *ndev,

				     netdevice_tracker *tracker,

				     gfp_t gfp)

{

#ifdef CONFIG_NET_DEV_REFCNT_TRACKER

	if (odev)

		ref_tracker_free(&odev->refcnt_tracker, tracker);

#endif

	dev_hold(ndev);

	dev_put(odev);

#ifdef CONFIG_NET_DEV_REFCNT_TRACKER

	if (ndev)

		ref_tracker_alloc(&ndev->refcnt_tracker, tracker, gfp);

#endif

}



/* Carrier loss detection, dial on demand. The functions netif_carrier_on

 * and _off may be called from IRQ context, but it is caller

 * who is responsible for serialization of these calls.

include/net/dst.h

+1 −0
Original line number Diff line number Diff line
@@ -77,6 +77,7 @@ struct dst_entry { 
#ifndef CONFIG_64BIT

	atomic_t		__refcnt;	/* 32-bit offset 64 */

#endif

	netdevice_tracker	dev_tracker;

};



struct dst_metrics {

net/core/dst.c

+4 −4
Original line number Diff line number Diff line
@@ -49,7 +49,7 @@ void dst_init(struct dst_entry *dst, struct dst_ops *ops, 
	      unsigned short flags)

{

	dst->dev = dev;

	dev_hold(dev);

	dev_hold_track(dev, &dst->dev_tracker, GFP_ATOMIC);

	dst->ops = ops;

	dst_init_metrics(dst, dst_default_metrics.metrics, true);

	dst->expires = 0UL;
@@ -117,7 +117,7 @@ struct dst_entry *dst_destroy(struct dst_entry * dst) 


	if (dst->ops->destroy)

		dst->ops->destroy(dst);

	dev_put(dst->dev);

	dev_put_track(dst->dev, &dst->dev_tracker);



	lwtstate_put(dst->lwtstate);
@@ -159,8 +159,8 @@ void dst_dev_put(struct dst_entry *dst) 
	dst->input = dst_discard;

	dst->output = dst_discard_out;

	dst->dev = blackhole_netdev;

	dev_hold(dst->dev);

	dev_put(dev);

	dev_replace_track(dev, blackhole_netdev, &dst->dev_tracker,

			  GFP_ATOMIC);

}

EXPORT_SYMBOL(dst_dev_put);

net/ipv4/route.c

+4 −3
Original line number Diff line number Diff line
@@ -1531,8 +1531,9 @@ void rt_flush_dev(struct net_device *dev) 
			if (rt->dst.dev != dev)

				continue;

			rt->dst.dev = blackhole_netdev;

			dev_hold(rt->dst.dev);

			dev_put(dev);

			dev_replace_track(dev, blackhole_netdev,

					  &rt->dst.dev_tracker,

					  GFP_ATOMIC);

		}

		spin_unlock_bh(&ul->lock);

	}
@@ -2819,7 +2820,7 @@ struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_or 
		new->output = dst_discard_out;



		new->dev = net->loopback_dev;

		dev_hold(new->dev);

		dev_hold_track(new->dev, &new->dev_tracker, GFP_ATOMIC);



		rt->rt_is_input = ort->rt_is_input;

		rt->rt_iif = ort->rt_iif;

net/ipv6/route.c

+3 −2
Original line number Diff line number Diff line
@@ -182,8 +182,9 @@ static void rt6_uncached_list_flush_dev(struct net *net, struct net_device *dev) 


			if (rt_dev == dev) {

				rt->dst.dev = blackhole_netdev;

				dev_hold(rt->dst.dev);

				dev_put(rt_dev);

				dev_replace_track(rt_dev, blackhole_netdev,

						  &rt->dst.dev_tracker,

						  GFP_ATOMIC);

			}

		}

		spin_unlock_bh(&ul->lock);