From 122bb046bcfb8f3d2d94d9f7f6b74da187a740f2 Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Tue, 26 Jun 2012 06:52:45 +0000 Subject: team: fix team_adjust_ops with regard to enabled ports team_adjust_ops should check for enabled ports, not all ports. This may lead to division by zero. This patch fixes this. Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- drivers/net/team/team.c | 30 +++++++++++++++++++----------- 1 file changed, 19 insertions(+), 11 deletions(-) (limited to 'drivers/net/team/team.c') diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c index 3a4a74be52d9..6b4cf6eca238 100644 --- a/drivers/net/team/team.c +++ b/drivers/net/team/team.c @@ -508,26 +508,31 @@ static void team_set_no_mode(struct team *team) team->mode = &__team_no_mode; } -static void team_adjust_ops(struct team *team) +static void __team_adjust_ops(struct team *team, int en_port_count) { /* * To avoid checks in rx/tx skb paths, ensure here that non-null and * correct ops are always set. */ - if (list_empty(&team->port_list) || - !team_is_mode_set(team) || !team->mode->ops->transmit) + if (!en_port_count || !team_is_mode_set(team) || + !team->mode->ops->transmit) team->ops.transmit = team_dummy_transmit; else team->ops.transmit = team->mode->ops->transmit; - if (list_empty(&team->port_list) || - !team_is_mode_set(team) || !team->mode->ops->receive) + if (!en_port_count || !team_is_mode_set(team) || + !team->mode->ops->receive) team->ops.receive = team_dummy_receive; else team->ops.receive = team->mode->ops->receive; } +static void team_adjust_ops(struct team *team) +{ + __team_adjust_ops(team, team->en_port_count); +} + /* * We can benefit from the fact that it's ensured no port is present * at the time of mode change. Therefore no packets are in fly so there's no @@ -687,6 +692,7 @@ static void team_port_enable(struct team *team, port->index = team->en_port_count++; hlist_add_head_rcu(&port->hlist, team_port_index_hash(team, port->index)); + team_adjust_ops(team); if (team->ops.port_enabled) team->ops.port_enabled(team, port); } @@ -708,16 +714,20 @@ static void __reconstruct_port_hlist(struct team *team, int rm_index) static void team_port_disable(struct team *team, struct team_port *port) { - int rm_index = port->index; - if (!team_port_enabled(port)) return; if (team->ops.port_disabled) team->ops.port_disabled(team, port); hlist_del_rcu(&port->hlist); - __reconstruct_port_hlist(team, rm_index); - team->en_port_count--; + __reconstruct_port_hlist(team, port->index); port->index = -1; + __team_adjust_ops(team, team->en_port_count - 1); + /* + * Wait until readers see adjusted ops. This ensures that + * readers never see team->en_port_count == 0 + */ + synchronize_rcu(); + team->en_port_count--; } #define TEAM_VLAN_FEATURES (NETIF_F_ALL_CSUM | NETIF_F_SG | \ @@ -874,7 +884,6 @@ static int team_port_add(struct team *team, struct net_device *port_dev) port->index = -1; team_port_enable(team, port); list_add_tail_rcu(&port->list, &team->port_list); - team_adjust_ops(team); __team_compute_features(team); __team_port_change_check(port, !!netif_carrier_ok(port_dev)); __team_options_change_check(team); @@ -928,7 +937,6 @@ static int team_port_del(struct team *team, struct net_device *port_dev) __team_port_change_check(port, false); team_port_disable(team, port); list_del_rcu(&port->list); - team_adjust_ops(team); netdev_rx_handler_unregister(port_dev); netdev_set_master(port_dev, NULL); vlan_vids_del_by_dev(port_dev, dev); -- cgit v1.2.3-58-ga151