From 47be03a28cc6c80e3aa2b3e8ed6d960ff0c5c0af Mon Sep 17 00:00:00 2001 From: Amerigo Wang Date: Fri, 10 Aug 2012 01:24:37 +0000 Subject: netpoll: use GFP_ATOMIC in slave_enable_netpoll() and __netpoll_setup() slave_enable_netpoll() and __netpoll_setup() may be called with read_lock() held, so should use GFP_ATOMIC to allocate memory. Eric suggested to pass gfp flags to __netpoll_setup(). Cc: Eric Dumazet Cc: "David S. Miller" Reported-by: Dan Carpenter Signed-off-by: Eric Dumazet Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- net/bridge/br_device.c | 12 ++++++------ net/bridge/br_if.c | 2 +- net/bridge/br_private.h | 4 ++-- 3 files changed, 9 insertions(+), 9 deletions(-) (limited to 'net/bridge') diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c index 33348453760..ed0e0f9dc78 100644 --- a/net/bridge/br_device.c +++ b/net/bridge/br_device.c @@ -213,7 +213,8 @@ static void br_netpoll_cleanup(struct net_device *dev) } } -static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni) +static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni, + gfp_t gfp) { struct net_bridge *br = netdev_priv(dev); struct net_bridge_port *p, *n; @@ -222,8 +223,7 @@ static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni) list_for_each_entry_safe(p, n, &br->port_list, list) { if (!p->dev) continue; - - err = br_netpoll_enable(p); + err = br_netpoll_enable(p, gfp); if (err) goto fail; } @@ -236,17 +236,17 @@ fail: goto out; } -int br_netpoll_enable(struct net_bridge_port *p) +int br_netpoll_enable(struct net_bridge_port *p, gfp_t gfp) { struct netpoll *np; int err = 0; - np = kzalloc(sizeof(*p->np), GFP_KERNEL); + np = kzalloc(sizeof(*p->np), gfp); err = -ENOMEM; if (!np) goto out; - err = __netpoll_setup(np, p->dev); + err = __netpoll_setup(np, p->dev, gfp); if (err) { kfree(np); goto out; diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c index e1144e1617b..171fd6b9bfe 100644 --- a/net/bridge/br_if.c +++ b/net/bridge/br_if.c @@ -361,7 +361,7 @@ int br_add_if(struct net_bridge *br, struct net_device *dev) if (err) goto err2; - if (br_netpoll_info(br) && ((err = br_netpoll_enable(p)))) + if (br_netpoll_info(br) && ((err = br_netpoll_enable(p, GFP_KERNEL)))) goto err3; err = netdev_set_master(dev, br->dev); diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index a768b2408ed..f507d2af964 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -316,7 +316,7 @@ static inline void br_netpoll_send_skb(const struct net_bridge_port *p, netpoll_send_skb(np, skb); } -extern int br_netpoll_enable(struct net_bridge_port *p); +extern int br_netpoll_enable(struct net_bridge_port *p, gfp_t gfp); extern void br_netpoll_disable(struct net_bridge_port *p); #else static inline struct netpoll_info *br_netpoll_info(struct net_bridge *br) @@ -329,7 +329,7 @@ static inline void br_netpoll_send_skb(const struct net_bridge_port *p, { } -static inline int br_netpoll_enable(struct net_bridge_port *p) +static inline int br_netpoll_enable(struct net_bridge_port *p, gfp_t gfp) { return 0; } -- cgit v1.2.3 From 38e6bc185d9544dfad1774b3f8902a0b061aea25 Mon Sep 17 00:00:00 2001 From: Amerigo Wang Date: Fri, 10 Aug 2012 01:24:38 +0000 Subject: netpoll: make __netpoll_cleanup non-block Like the previous patch, slave_disable_netpoll() and __netpoll_cleanup() may be called with read_lock() held too, so we should make them non-block, by moving the cleanup and kfree() to call_rcu_bh() callbacks. Cc: "David S. Miller" Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- net/bridge/br_device.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'net/bridge') diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c index ed0e0f9dc78..f41ba4048c9 100644 --- a/net/bridge/br_device.c +++ b/net/bridge/br_device.c @@ -267,11 +267,7 @@ void br_netpoll_disable(struct net_bridge_port *p) p->np = NULL; - /* Wait for transmitting packets to finish before freeing. */ - synchronize_rcu_bh(); - - __netpoll_cleanup(np); - kfree(np); + __netpoll_free_rcu(np); } #endif -- cgit v1.2.3 From d30362c0712eb567334b3b66de7c40d4372f2c6f Mon Sep 17 00:00:00 2001 From: Amerigo Wang Date: Fri, 10 Aug 2012 01:24:43 +0000 Subject: bridge: add some comments for NETDEV_RELEASE Add comments on why we don't notify NETDEV_RELEASE. Cc: David Miller Cc: Stephen Hemminger Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- net/bridge/br_if.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'net/bridge') diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c index 171fd6b9bfe..1c8fdc3558c 100644 --- a/net/bridge/br_if.c +++ b/net/bridge/br_if.c @@ -427,6 +427,10 @@ int br_del_if(struct net_bridge *br, struct net_device *dev) if (!p || p->br != br) return -EINVAL; + /* Since more than one interface can be attached to a bridge, + * there still maybe an alternate path for netconsole to use; + * therefore there is no reason for a NETDEV_RELEASE event. + */ del_nbp(p); spin_lock_bh(&br->lock); -- cgit v1.2.3 From 4e3828c4bfd90b00a951cad7c8da27d1966beefe Mon Sep 17 00:00:00 2001 From: Amerigo Wang Date: Fri, 10 Aug 2012 01:24:44 +0000 Subject: bridge: use list_for_each_entry() in netpoll functions We don't delete 'p' from the list in the loop, so we can just use list_for_each_entry(). Cc: David Miller Cc: Stephen Hemminger Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- net/bridge/br_device.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) (limited to 'net/bridge') diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c index f41ba4048c9..32211fa5b50 100644 --- a/net/bridge/br_device.c +++ b/net/bridge/br_device.c @@ -206,21 +206,20 @@ static void br_poll_controller(struct net_device *br_dev) static void br_netpoll_cleanup(struct net_device *dev) { struct net_bridge *br = netdev_priv(dev); - struct net_bridge_port *p, *n; + struct net_bridge_port *p; - list_for_each_entry_safe(p, n, &br->port_list, list) { + list_for_each_entry(p, &br->port_list, list) br_netpoll_disable(p); - } } static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni, gfp_t gfp) { struct net_bridge *br = netdev_priv(dev); - struct net_bridge_port *p, *n; + struct net_bridge_port *p; int err = 0; - list_for_each_entry_safe(p, n, &br->port_list, list) { + list_for_each_entry(p, &br->port_list, list) { if (!p->dev) continue; err = br_netpoll_enable(p, gfp); -- cgit v1.2.3 From e15c3c2294605f09f9b336b2f3b97086ab4b8145 Mon Sep 17 00:00:00 2001 From: Amerigo Wang Date: Fri, 10 Aug 2012 01:24:45 +0000 Subject: netpoll: check netpoll tx status on the right device Although this doesn't matter actually, because netpoll_tx_running() doesn't use the parameter, the code will be more readable. For team_dev_queue_xmit() we have to move it down to avoid compile errors. Cc: David Miller Signed-off-by: Jiri Pirko Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- net/bridge/br_forward.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/bridge') diff --git a/net/bridge/br_forward.c b/net/bridge/br_forward.c index e9466d41270..02015a505d2 100644 --- a/net/bridge/br_forward.c +++ b/net/bridge/br_forward.c @@ -65,7 +65,7 @@ static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb) { skb->dev = to->dev; - if (unlikely(netpoll_tx_running(to->dev))) { + if (unlikely(netpoll_tx_running(to->br->dev))) { if (packet_length(skb) > skb->dev->mtu && !skb_is_gso(skb)) kfree_skb(skb); else { -- cgit v1.2.3 From c03307eab68d583ea6db917681afa14ed1fb3b84 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Tue, 14 Aug 2012 08:19:33 -0700 Subject: bridge: fix rcu dereference outside of rcu_read_lock Alternative solution for problem found by Linux Driver Verification project (linuxtesting.org). As it noted in the comment before the br_handle_frame_finish function, this function should be called under rcu_read_lock. The problem callgraph: br_dev_xmit -> br_nf_pre_routing_finish_bridge_slow -> -> br_handle_frame_finish -> br_port_get_rcu -> rcu_dereference And in this case there is no read-lock section. Reported-by: Denis Efremov Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- net/bridge/br_device.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'net/bridge') diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c index 32211fa5b50..070e8a68cfc 100644 --- a/net/bridge/br_device.c +++ b/net/bridge/br_device.c @@ -31,9 +31,11 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) struct net_bridge_mdb_entry *mdst; struct br_cpu_netstats *brstats = this_cpu_ptr(br->stats); + rcu_read_lock(); #ifdef CONFIG_BRIDGE_NETFILTER if (skb->nf_bridge && (skb->nf_bridge->mask & BRNF_BRIDGED_DNAT)) { br_nf_pre_routing_finish_bridge_slow(skb); + rcu_read_unlock(); return NETDEV_TX_OK; } #endif @@ -48,7 +50,6 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) skb_reset_mac_header(skb); skb_pull(skb, ETH_HLEN); - rcu_read_lock(); if (is_broadcast_ether_addr(dest)) br_flood_deliver(br, skb); else if (is_multicast_ether_addr(dest)) { -- cgit v1.2.3