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Diffstat (limited to 'net/netlink/af_netlink.c')
-rw-r--r--net/netlink/af_netlink.c63
1 files changed, 39 insertions, 24 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 7a186e74b1b3..ef5f77b44ec7 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -96,6 +96,14 @@ static DECLARE_WAIT_QUEUE_HEAD(nl_table_wait);
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);
@@ -106,14 +114,14 @@ 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);
@@ -134,8 +142,7 @@ int netlink_add_tap(struct netlink_tap *nt)
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;
}
@@ -1028,11 +1035,13 @@ static struct sock *netlink_lookup(struct net *net, int protocol, u32 portid)
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;
}
@@ -1082,7 +1091,7 @@ static int netlink_insert(struct sock *sk, struct net *net, u32 portid)
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);
@@ -1095,7 +1104,7 @@ static void netlink_remove(struct sock *sk)
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);
}
@@ -1257,9 +1266,6 @@ static int netlink_release(struct socket *sock)
}
netlink_table_ungrab();
- /* Wait for readers to complete */
- synchronize_net();
-
kfree(nlk->groups);
nlk->groups = NULL;
@@ -1281,6 +1287,7 @@ static int netlink_autobind(struct socket *sock)
retry:
cond_resched();
+ netlink_table_grab();
rcu_read_lock();
if (__netlink_lookup(table, portid, net)) {
/* Bind collision, search negative portid values. */
@@ -1288,9 +1295,11 @@ retry:
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)
@@ -1430,7 +1439,7 @@ static void netlink_unbind(int group, long unsigned int groups,
return;
for (undo = 0; undo < group; undo++)
- if (test_bit(group, &groups))
+ if (test_bit(undo, &groups))
nlk->netlink_unbind(undo);
}
@@ -1482,7 +1491,7 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr,
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;
}
}
@@ -2296,7 +2305,7 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
}
if (netlink_tx_is_mmaped(sk) &&
- msg->msg_iov->iov_base == NULL) {
+ msg->msg_iter.iov->iov_base == NULL) {
err = netlink_mmap_sendmsg(sk, msg, dst_portid, dst_group,
siocb);
goto out;
@@ -2316,7 +2325,7 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
NETLINK_CB(skb).flags = netlink_skb_flags;
err = -EFAULT;
- if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {
+ if (memcpy_from_msg(skb_put(skb, len), msg, len)) {
kfree_skb(skb);
goto out;
}
@@ -2391,7 +2400,7 @@ static int netlink_recvmsg(struct kiocb *kiocb, struct socket *sock,
}
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);
@@ -2499,6 +2508,7 @@ __netlink_kernel_create(struct net *net, int unit, struct module *module,
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;
@@ -2921,14 +2931,16 @@ static struct sock *netlink_seq_socket_idx(struct seq_file *seq, loff_t pos)
}
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;
@@ -2943,19 +2955,19 @@ static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
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;
@@ -2971,9 +2983,10 @@ static void *netlink_seq_next(struct seq_file *seq, void *v, loff_t *pos)
}
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);
}
@@ -3116,11 +3129,13 @@ static int __init netlink_proto_init(void)
.head_offset = offsetof(struct netlink_sock, node),
.key_offset = offsetof(struct netlink_sock, portid),
.key_len = sizeof(u32), /* portid */
- .hashfn = arch_fast_hash,
+ .hashfn = jhash,
.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)
generated by cgit v1.2.3 (git 2.39.0) at 2025-02-01 02:07:44 +0300