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 <eric.duma...@gmail.com>
Signed-off-by: Kirill Tkhai <ktk...@virtuozzo.com>
---
include/net/net_namespace.h | 8 ++++----
net/core/net-sysfs.c | 6 +++---
net/core/net_namespace.c | 8 ++++----
net/ipv4/inet_timewait_sock.c | 4 ++--
net/ipv4/tcp_metrics.c | 2 +-
5 files changed, 14 insertions(+), 14 deletions(-)
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 @@ void inet_twsk_purge(struct inet_hashinfo *hashinfo, int
family)
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);
