static int netlink_dump(struct sock *sk);
static void netlink_skb_destructor(struct sk_buff *skb);
+/* nl_table locking explained:
+ * Lookup and traversal are protected with nl_sk_hash_lock or nl_table_lock
+ * combined with an RCU read-side lock. Insertion and removal are protected
+ * with nl_sk_hash_lock while using RCU list modification primitives and may
+ * run in parallel to nl_table_lock protected lookups. Destruction of the
+ * Netlink socket may only occur *after* nl_table_lock has been acquired
+ * either during or after the socket has been removed from the list.
+ */
DEFINE_RWLOCK(nl_table_lock);
EXPORT_SYMBOL_GPL(nl_table_lock);
static atomic_t nl_table_users = ATOMIC_INIT(0);
DEFINE_MUTEX(nl_sk_hash_lock);
EXPORT_SYMBOL_GPL(nl_sk_hash_lock);
-static int lockdep_nl_sk_hash_is_held(void)
+#ifdef CONFIG_PROVE_LOCKING
+static int lockdep_nl_sk_hash_is_held(void *parent)
{
-#ifdef CONFIG_LOCKDEP
- return (debug_locks) ? lockdep_is_held(&nl_sk_hash_lock) : 1;
-#else
+ if (debug_locks)
+ return lockdep_is_held(&nl_sk_hash_lock) || lockdep_is_held(&nl_table_lock);
return 1;
-#endif
}
+#endif
static ATOMIC_NOTIFIER_HEAD(netlink_chain);
list_add_rcu(&nt->list, &netlink_tap_all);
spin_unlock(&netlink_tap_lock);
- if (nt->module)
- __module_get(nt->module);
+ __module_get(nt->module);
return 0;
}
struct netlink_table *table = &nl_table[protocol];
struct sock *sk;
+ read_lock(&nl_table_lock);
rcu_read_lock();
sk = __netlink_lookup(table, portid, net);
if (sk)
sock_hold(sk);
rcu_read_unlock();
+ read_unlock(&nl_table_lock);
return sk;
}
nlk_sk(sk)->portid = portid;
sock_hold(sk);
- rhashtable_insert(&table->hash, &nlk_sk(sk)->node, GFP_KERNEL);
+ rhashtable_insert(&table->hash, &nlk_sk(sk)->node);
err = 0;
err:
mutex_unlock(&nl_sk_hash_lock);
mutex_lock(&nl_sk_hash_lock);
table = &nl_table[sk->sk_protocol];
- if (rhashtable_remove(&table->hash, &nlk_sk(sk)->node, GFP_KERNEL)) {
+ if (rhashtable_remove(&table->hash, &nlk_sk(sk)->node)) {
WARN_ON(atomic_read(&sk->sk_refcnt) == 1);
__sock_put(sk);
}
}
netlink_table_ungrab();
- /* Wait for readers to complete */
- synchronize_net();
-
kfree(nlk->groups);
nlk->groups = NULL;
retry:
cond_resched();
+ netlink_table_grab();
rcu_read_lock();
if (__netlink_lookup(table, portid, net)) {
/* Bind collision, search negative portid values. */
if (rover > -4097)
rover = -4097;
rcu_read_unlock();
+ netlink_table_ungrab();
goto retry;
}
rcu_read_unlock();
+ netlink_table_ungrab();
err = netlink_insert(sk, net, portid);
if (err == -EADDRINUSE)
return;
for (undo = 0; undo < group; undo++)
- if (test_bit(group, &groups))
+ if (test_bit(undo, &groups))
nlk->netlink_unbind(undo);
}
netlink_insert(sk, net, nladdr->nl_pid) :
netlink_autobind(sock);
if (err) {
- netlink_unbind(nlk->ngroups - 1, groups, nlk);
+ netlink_unbind(nlk->ngroups, groups, nlk);
return err;
}
}
}
skb_reset_transport_header(data_skb);
- err = skb_copy_datagram_iovec(data_skb, 0, msg->msg_iov, copied);
+ err = skb_copy_datagram_msg(data_skb, 0, msg, copied);
if (msg->msg_name) {
DECLARE_SOCKADDR(struct sockaddr_nl *, addr, msg->msg_name);
nl_table[unit].module = module;
if (cfg) {
nl_table[unit].bind = cfg->bind;
+ nl_table[unit].unbind = cfg->unbind;
nl_table[unit].flags = cfg->flags;
if (cfg->compare)
nl_table[unit].compare = cfg->compare;
}
static void *netlink_seq_start(struct seq_file *seq, loff_t *pos)
- __acquires(RCU)
+ __acquires(nl_table_lock) __acquires(RCU)
{
+ read_lock(&nl_table_lock);
rcu_read_lock();
return *pos ? netlink_seq_socket_idx(seq, *pos - 1) : SEQ_START_TOKEN;
}
static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
+ struct rhashtable *ht;
struct netlink_sock *nlk;
struct nl_seq_iter *iter;
struct net *net;
iter = seq->private;
nlk = v;
- rht_for_each_entry_rcu(nlk, nlk->node.next, node)
+ i = iter->link;
+ ht = &nl_table[i].hash;
+ rht_for_each_entry(nlk, nlk->node.next, ht, node)
if (net_eq(sock_net((struct sock *)nlk), net))
return nlk;
- i = iter->link;
j = iter->hash_idx + 1;
do {
- struct rhashtable *ht = &nl_table[i].hash;
const struct bucket_table *tbl = rht_dereference_rcu(ht->tbl, ht);
for (; j < tbl->size; j++) {
- rht_for_each_entry_rcu(nlk, tbl->buckets[j], node) {
+ rht_for_each_entry(nlk, tbl->buckets[j], ht, node) {
if (net_eq(sock_net((struct sock *)nlk), net)) {
iter->link = i;
iter->hash_idx = j;
}
static void netlink_seq_stop(struct seq_file *seq, void *v)
- __releases(RCU)
+ __releases(RCU) __releases(nl_table_lock)
{
rcu_read_unlock();
+ read_unlock(&nl_table_lock);
}
.max_shift = 16, /* 64K */
.grow_decision = rht_grow_above_75,
.shrink_decision = rht_shrink_below_30,
+#ifdef CONFIG_PROVE_LOCKING
.mutex_is_held = lockdep_nl_sk_hash_is_held,
+#endif
};
if (err != 0)