From 9038c320001dd07f60736018edf608ac5baca0ab Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sat, 4 Dec 2021 20:22:03 -0800 Subject: [PATCH] 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 Signed-off-by: Jakub Kicinski --- include/linux/netdevice.h | 17 +++++++++++++++++ include/net/dst.h | 1 + net/core/dst.c | 8 ++++---- net/ipv4/route.c | 7 ++++--- net/ipv6/route.c | 5 +++-- 5 files changed, 29 insertions(+), 9 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index b4f704337f65..afed3b10491b 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 a057319aabef..6aa252c3fc55 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 497ef9b3fc6a..d16c2c9bfebd 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 243a0c52be42..843a7a3699fe 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 f0d29fcb2094..ba4dc94d76d6 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); -- 2.11.0