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: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index b4f7043..afed3b1 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -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.
diff --git a/include/net/dst.h b/include/net/dst.h
index a057319..6aa252c 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -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 {
diff --git a/net/core/dst.c b/net/core/dst.c
index 497ef9b..d16c2c9 100644
--- a/net/core/dst.c
+++ b/net/core/dst.c
@@ -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);
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 243a0c5..843a7a3 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -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;
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index f0d29fc..ba4dc94 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -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);