From: Kirill Tkhai Date: Fri, 12 Jan 2018 15:28:31 +0000 (+0300) Subject: net: Convert atomic_t net::count to refcount_t X-Git-Tag: microblaze-4.16-rc6~157^2~163 X-Git-Url: http://git.monstr.eu/?a=commitdiff_plain;h=273c28bc57ca9672f7b70bed764ecdfb964930c8;p=linux-2.6-microblaze.git net: Convert atomic_t net::count to refcount_t Since net could be obtained from RCU lists, and there is a race with net destruction, the patch converts net::count to refcount_t. This provides sanity checks for the cases of incrementing counter of already dead net, when maybe_get_net() has to used instead of get_net(). Drivers: allyesconfig and allmodconfig are OK. Suggested-by: Eric Dumazet Signed-off-by: Kirill Tkhai Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller --- diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index 10f99dafd5ac..f8a84a2c2341 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -51,7 +51,7 @@ struct net { refcount_t passive; /* To decided when the network * namespace should be freed. */ - atomic_t count; /* To decided when the network + refcount_t count; /* To decided when the network * namespace should be shut down. */ spinlock_t rules_mod_lock; @@ -195,7 +195,7 @@ void __put_net(struct net *net); static inline struct net *get_net(struct net *net) { - atomic_inc(&net->count); + refcount_inc(&net->count); return net; } @@ -206,14 +206,14 @@ static inline struct net *maybe_get_net(struct net *net) * exists. If the reference count is zero this * function fails and returns NULL. */ - if (!atomic_inc_not_zero(&net->count)) + if (!refcount_inc_not_zero(&net->count)) net = NULL; return net; } static inline void put_net(struct net *net) { - if (atomic_dec_and_test(&net->count)) + if (refcount_dec_and_test(&net->count)) __put_net(net); } diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 799b75268291..7bf8b85ade16 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -961,7 +961,7 @@ net_rx_queue_update_kobjects(struct net_device *dev, int old_num, int new_num) while (--i >= new_num) { struct kobject *kobj = &dev->_rx[i].kobj; - if (!atomic_read(&dev_net(dev)->count)) + if (!refcount_read(&dev_net(dev)->count)) kobj->uevent_suppress = 1; if (dev->sysfs_rx_queue_group) sysfs_remove_group(kobj, dev->sysfs_rx_queue_group); @@ -1367,7 +1367,7 @@ netdev_queue_update_kobjects(struct net_device *dev, int old_num, int new_num) while (--i >= new_num) { struct netdev_queue *queue = dev->_tx + i; - if (!atomic_read(&dev_net(dev)->count)) + if (!refcount_read(&dev_net(dev)->count)) queue->kobj.uevent_suppress = 1; #ifdef CONFIG_BQL sysfs_remove_group(&queue->kobj, &dql_group); @@ -1558,7 +1558,7 @@ void netdev_unregister_kobject(struct net_device *ndev) { struct device *dev = &ndev->dev; - if (!atomic_read(&dev_net(ndev)->count)) + if (!refcount_read(&dev_net(ndev)->count)) dev_set_uevent_suppress(dev, 1); kobject_get(&dev->kobj); diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index 60a71be75aea..2213d45fcafd 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -35,7 +35,7 @@ LIST_HEAD(net_namespace_list); EXPORT_SYMBOL_GPL(net_namespace_list); struct net init_net = { - .count = ATOMIC_INIT(1), + .count = REFCOUNT_INIT(1), .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head), }; EXPORT_SYMBOL(init_net); @@ -224,10 +224,10 @@ int peernet2id_alloc(struct net *net, struct net *peer) bool alloc; int id; - if (atomic_read(&net->count) == 0) + if (refcount_read(&net->count) == 0) return NETNSA_NSID_NOT_ASSIGNED; spin_lock_bh(&net->nsid_lock); - alloc = atomic_read(&peer->count) == 0 ? false : true; + alloc = refcount_read(&peer->count) == 0 ? false : true; id = __peernet2id_alloc(net, peer, &alloc); spin_unlock_bh(&net->nsid_lock); if (alloc && id >= 0) @@ -284,7 +284,7 @@ static __net_init int setup_net(struct net *net, struct user_namespace *user_ns) int error = 0; LIST_HEAD(net_exit_list); - atomic_set(&net->count, 1); + refcount_set(&net->count, 1); refcount_set(&net->passive, 1); net->dev_base_seq = 1; net->user_ns = user_ns; diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c index 277ff69a312d..c3ea4906d237 100644 --- a/net/ipv4/inet_timewait_sock.c +++ b/net/ipv4/inet_timewait_sock.c @@ -270,14 +270,14 @@ restart: continue; tw = inet_twsk(sk); if ((tw->tw_family != family) || - atomic_read(&twsk_net(tw)->count)) + refcount_read(&twsk_net(tw)->count)) continue; if (unlikely(!refcount_inc_not_zero(&tw->tw_refcnt))) continue; if (unlikely((tw->tw_family != family) || - atomic_read(&twsk_net(tw)->count))) { + refcount_read(&twsk_net(tw)->count))) { inet_twsk_put(tw); goto restart; } diff --git a/net/ipv4/tcp_metrics.c b/net/ipv4/tcp_metrics.c index 759e6bc8327b..03b51cdcc731 100644 --- a/net/ipv4/tcp_metrics.c +++ b/net/ipv4/tcp_metrics.c @@ -892,7 +892,7 @@ static void tcp_metrics_flush_all(struct net *net) pp = &hb->chain; for (tm = deref_locked(*pp); tm; tm = deref_locked(*pp)) { match = net ? net_eq(tm_net(tm), net) : - !atomic_read(&tm_net(tm)->count); + !refcount_read(&tm_net(tm)->count); if (match) { *pp = tm->tcpm_next; kfree_rcu(tm, rcu_head);