Make the addrs_lock be per port, not per ipvlan dev. This appears to be a very minor problem though. Since it's highly unlikely that ipvlan_add_addr() will be called on 2 CPU simultaneously. But nevertheless, this may cause: 1. False-negative of ipvlan_addr_busy(): one interface iterated through all port->ipvlans + ipvlan->addrs under some ipvlan spinlock, and another added IP under its own lock. Though this is only possible for IPv6, since looks like only ipvlan_addr6_event() can be called without rtnl_lock. 2. Race since ipvlan_ht_addr_add(port) is called under different ipvlan->addrs_lock locks This should not affect performance, since add/remove IP is a rare situation and spinlock is not locked on fast paths. Fixes: 8230819494b3 ("ipvlan: use per device spinlock to protect addrs list updates") Signed-off-by: Dmitry Skorodumov CC: Paolo Abeni --- drivers/net/ipvlan/ipvlan.h | 2 +- drivers/net/ipvlan/ipvlan_main.c | 20 ++++++++++---------- 2 files changed, 11 insertions(+), 11 deletions(-) diff --git a/drivers/net/ipvlan/ipvlan.h b/drivers/net/ipvlan/ipvlan.h index 50de3ee204db..80f84fc87008 100644 --- a/drivers/net/ipvlan/ipvlan.h +++ b/drivers/net/ipvlan/ipvlan.h @@ -69,7 +69,6 @@ struct ipvl_dev { DECLARE_BITMAP(mac_filters, IPVLAN_MAC_FILTER_SIZE); netdev_features_t sfeatures; u32 msg_enable; - spinlock_t addrs_lock; }; struct ipvl_addr { @@ -90,6 +89,7 @@ struct ipvl_port { struct net_device *dev; possible_net_t pnet; struct hlist_head hlhead[IPVLAN_HASH_SIZE]; + spinlock_t addrs_lock; /* guards hash-table and addrs */ struct list_head ipvlans; u16 mode; u16 flags; diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c index 660f3db11766..c390f4241621 100644 --- a/drivers/net/ipvlan/ipvlan_main.c +++ b/drivers/net/ipvlan/ipvlan_main.c @@ -75,6 +75,7 @@ static int ipvlan_port_create(struct net_device *dev) for (idx = 0; idx < IPVLAN_HASH_SIZE; idx++) INIT_HLIST_HEAD(&port->hlhead[idx]); + spin_lock_init(&port->addrs_lock); skb_queue_head_init(&port->backlog); INIT_WORK(&port->wq, ipvlan_process_multicast); ida_init(&port->ida); @@ -579,7 +580,6 @@ int ipvlan_link_new(struct net_device *dev, struct rtnl_newlink_params *params, if (!tb[IFLA_MTU]) ipvlan_adjust_mtu(ipvlan, phy_dev); INIT_LIST_HEAD(&ipvlan->addrs); - spin_lock_init(&ipvlan->addrs_lock); /* TODO Probably put random address here to be presented to the * world but keep using the physical-dev address for the outgoing @@ -657,13 +657,13 @@ void ipvlan_link_delete(struct net_device *dev, struct list_head *head) struct ipvl_dev *ipvlan = netdev_priv(dev); struct ipvl_addr *addr, *next; - spin_lock_bh(&ipvlan->addrs_lock); + spin_lock_bh(&ipvlan->port->addrs_lock); list_for_each_entry_safe(addr, next, &ipvlan->addrs, anode) { ipvlan_ht_addr_del(addr); list_del_rcu(&addr->anode); kfree_rcu(addr, rcu); } - spin_unlock_bh(&ipvlan->addrs_lock); + spin_unlock_bh(&ipvlan->port->addrs_lock); ida_free(&ipvlan->port->ida, dev->dev_id); list_del_rcu(&ipvlan->pnode); @@ -847,16 +847,16 @@ static void ipvlan_del_addr(struct ipvl_dev *ipvlan, void *iaddr, bool is_v6) { struct ipvl_addr *addr; - spin_lock_bh(&ipvlan->addrs_lock); + spin_lock_bh(&ipvlan->port->addrs_lock); addr = ipvlan_find_addr(ipvlan, iaddr, is_v6); if (!addr) { - spin_unlock_bh(&ipvlan->addrs_lock); + spin_unlock_bh(&ipvlan->port->addrs_lock); return; } ipvlan_ht_addr_del(addr); list_del_rcu(&addr->anode); - spin_unlock_bh(&ipvlan->addrs_lock); + spin_unlock_bh(&ipvlan->port->addrs_lock); kfree_rcu(addr, rcu); } @@ -878,14 +878,14 @@ static int ipvlan_add_addr6(struct ipvl_dev *ipvlan, struct in6_addr *ip6_addr) { int ret = -EINVAL; - spin_lock_bh(&ipvlan->addrs_lock); + spin_lock_bh(&ipvlan->port->addrs_lock); if (ipvlan_addr_busy(ipvlan->port, ip6_addr, true)) netif_err(ipvlan, ifup, ipvlan->dev, "Failed to add IPv6=%pI6c addr for %s intf\n", ip6_addr, ipvlan->dev->name); else ret = ipvlan_add_addr(ipvlan, ip6_addr, true); - spin_unlock_bh(&ipvlan->addrs_lock); + spin_unlock_bh(&ipvlan->port->addrs_lock); return ret; } @@ -946,14 +946,14 @@ static int ipvlan_add_addr4(struct ipvl_dev *ipvlan, struct in_addr *ip4_addr) { int ret = -EINVAL; - spin_lock_bh(&ipvlan->addrs_lock); + spin_lock_bh(&ipvlan->port->addrs_lock); if (ipvlan_addr_busy(ipvlan->port, ip4_addr, false)) netif_err(ipvlan, ifup, ipvlan->dev, "Failed to add IPv4=%pI4 on %s intf.\n", ip4_addr, ipvlan->dev->name); else ret = ipvlan_add_addr(ipvlan, ip4_addr, false); - spin_unlock_bh(&ipvlan->addrs_lock); + spin_unlock_bh(&ipvlan->port->addrs_lock); return ret; } -- 2.25.1 It was forgotten to lock addrs in ipvlan_open(). Seems that code was initially written in assumption that any address change occurs under rtnl_lock(). But it's not true for the ipv6 case. So, we have to take addr_lock in ipvlan_open(). Also, take the addrs_lock in ipvlan_close() Fixes: 8230819494b3 ("ipvlan: use per device spinlock to protect addrs list updates") Signed-off-by: Dmitry Skorodumov CC: Paolo Abeni --- drivers/net/ipvlan/ipvlan_main.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/drivers/net/ipvlan/ipvlan_main.c b/drivers/net/ipvlan/ipvlan_main.c index c390f4241621..53d311af2f44 100644 --- a/drivers/net/ipvlan/ipvlan_main.c +++ b/drivers/net/ipvlan/ipvlan_main.c @@ -182,18 +182,18 @@ static void ipvlan_uninit(struct net_device *dev) static int ipvlan_open(struct net_device *dev) { struct ipvl_dev *ipvlan = netdev_priv(dev); + struct ipvl_port *port = ipvlan->port; struct ipvl_addr *addr; - if (ipvlan->port->mode == IPVLAN_MODE_L3 || - ipvlan->port->mode == IPVLAN_MODE_L3S) + if (port->mode == IPVLAN_MODE_L3 || port->mode == IPVLAN_MODE_L3S) dev->flags |= IFF_NOARP; else dev->flags &= ~IFF_NOARP; - rcu_read_lock(); + spin_lock_bh(&port->addrs_lock); list_for_each_entry_rcu(addr, &ipvlan->addrs, anode) ipvlan_ht_addr_add(ipvlan, addr); - rcu_read_unlock(); + spin_unlock_bh(&port->addrs_lock); return 0; } @@ -207,10 +207,10 @@ static int ipvlan_stop(struct net_device *dev) dev_uc_unsync(phy_dev, dev); dev_mc_unsync(phy_dev, dev); - rcu_read_lock(); + spin_lock_bh(&ipvlan->port->addrs_lock); list_for_each_entry_rcu(addr, &ipvlan->addrs, anode) ipvlan_ht_addr_del(addr); - rcu_read_unlock(); + spin_unlock_bh(&ipvlan->port->addrs_lock); return 0; } @@ -817,6 +817,8 @@ static int ipvlan_add_addr(struct ipvl_dev *ipvlan, void *iaddr, bool is_v6) { struct ipvl_addr *addr; + assert_spin_locked(&ipvlan->port->addrs_lock); + addr = kzalloc(sizeof(struct ipvl_addr), GFP_ATOMIC); if (!addr) return -ENOMEM; -- 2.25.1