8 files changed, 19 insertions, 28 deletions

diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index 0eed0b7ab2df..1dd075eda595 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -88,9 +88,8 @@ struct nf_sockopt_ops
         int (*compat_get)(struct sock *sk, int optval,
                         void __user *user, int *len);
 
-        /* Number of users inside set() or get(). */
-        unsigned int use;
-        struct task_struct *cleanup_task;
+        /* Use the module struct to lock set/get code in place */
+        struct module *owner;
 };
 
 /* Each queued (to userspace) skbuff has one of these. */
diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 4169a2a89a39..6018d0e51938 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -1513,6 +1513,7 @@ static struct nf_sockopt_ops ebt_sockopts =
         .get_optmin     = EBT_BASE_CTL,
         .get_optmax     = EBT_SO_GET_MAX + 1,
         .get            = do_ebt_get_ctl,
+        .owner          = THIS_MODULE,
 };
 
 static int __init ebtables_init(void)
diff --git a/net/ipv4/ipvs/ip_vs_ctl.c b/net/ipv4/ipvs/ip_vs_ctl.c
index 902fd578aa3c..f656d41d8d41 100644
--- a/net/ipv4/ipvs/ip_vs_ctl.c
+++ b/net/ipv4/ipvs/ip_vs_ctl.c
@@ -2339,6 +2339,7 @@ static struct nf_sockopt_ops ip_vs_sockopts = {
         .get_optmin     = IP_VS_BASE_CTL,
         .get_optmax     = IP_VS_SO_GET_MAX+1,
         .get            = do_ip_vs_get_ctl,
+        .owner          = THIS_MODULE,
 };
 
 
diff --git a/net/ipv4/netfilter/arp_tables.c b/net/ipv4/netfilter/arp_tables.c
index d1149aba9351..29114a9ccd1d 100644
--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -1161,6 +1161,7 @@ static struct nf_sockopt_ops arpt_sockopts = {
         .get_optmin     = ARPT_BASE_CTL,
         .get_optmax     = ARPT_SO_GET_MAX+1,
         .get            = do_arpt_get_ctl,
+        .owner          = THIS_MODULE,
 };
 
 static int __init arp_tables_init(void)
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index e1b402c6b855..6486894f450c 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -2296,6 +2296,7 @@ static struct nf_sockopt_ops ipt_sockopts = {
 #ifdef CONFIG_COMPAT
         .compat_get     = compat_do_ipt_get_ctl,
 #endif
+        .owner          = THIS_MODULE,
 };
 
 static struct xt_match icmp_matchstruct __read_mostly = {
diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
index 53cb1772f38f..f813e02aab30 100644
--- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
+++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c
@@ -399,6 +399,7 @@ static struct nf_sockopt_ops so_getorigdst = {
         .get_optmin     = SO_ORIGINAL_DST,
         .get_optmax     = SO_ORIGINAL_DST+1,
         .get            = &getorigdst,
+        .owner          = THIS_MODULE,
 };
 
 struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv4 __read_mostly = {
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index aeda617246b7..cd9df02bb85c 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -1462,6 +1462,7 @@ static struct nf_sockopt_ops ip6t_sockopts = {
         .get_optmin     = IP6T_BASE_CTL,
         .get_optmax     = IP6T_SO_GET_MAX+1,
         .get            = do_ip6t_get_ctl,
+        .owner          = THIS_MODULE,
 };
 
 static struct xt_match icmp6_matchstruct __read_mostly = {
diff --git a/net/netfilter/nf_sockopt.c b/net/netfilter/nf_sockopt.c
index 8b8ece750313..e32761ce260c 100644
--- a/net/netfilter/nf_sockopt.c
+++ b/net/netfilter/nf_sockopt.c
@@ -55,18 +55,7 @@ EXPORT_SYMBOL(nf_register_sockopt);
 
 void nf_unregister_sockopt(struct nf_sockopt_ops *reg)
 {
-        /* No point being interruptible: we're probably in cleanup_module() */
- restart:
         mutex_lock(&nf_sockopt_mutex);
-        if (reg->use != 0) {
-                /* To be woken by nf_sockopt call... */
-                /* FIXME: Stuart Young's name appears gratuitously. */
-                set_current_state(TASK_UNINTERRUPTIBLE);
-                reg->cleanup_task = current;
-                mutex_unlock(&nf_sockopt_mutex);
-                schedule();
-                goto restart;
-        }
         list_del(&reg->list);
         mutex_unlock(&nf_sockopt_mutex);
 }
@@ -86,10 +75,11 @@ static int nf_sockopt(struct sock *sk, int pf, int val,
         list_for_each(i, &nf_sockopts) {
                 ops = (struct nf_sockopt_ops *)i;
                 if (ops->pf == pf) {
+                        if (!try_module_get(ops->owner))
+                                goto out_nosup;
                         if (get) {
                                 if (val >= ops->get_optmin
                                     && val < ops->get_optmax) {
-                                        ops->use++;
                                         mutex_unlock(&nf_sockopt_mutex);
                                         ret = ops->get(sk, val, opt, len);
                                         goto out;
@@ -97,23 +87,20 @@ static int nf_sockopt(struct sock *sk, int pf, int val,
                         } else {
                                 if (val >= ops->set_optmin
                                     && val < ops->set_optmax) {
-                                        ops->use++;
                                         mutex_unlock(&nf_sockopt_mutex);
                                         ret = ops->set(sk, val, opt, *len);
                                         goto out;
                                 }
                         }
+                        module_put(ops->owner);
                 }
         }
+ out_nosup:
         mutex_unlock(&nf_sockopt_mutex);
         return -ENOPROTOOPT;
 
  out:
-        mutex_lock(&nf_sockopt_mutex);
-        ops->use--;
-        if (ops->cleanup_task)
-                wake_up_process(ops->cleanup_task);
-        mutex_unlock(&nf_sockopt_mutex);
+        module_put(ops->owner);
         return ret;
 }
 
@@ -144,10 +131,12 @@ static int compat_nf_sockopt(struct sock *sk, int pf, int val,
         list_for_each(i, &nf_sockopts) {
                 ops = (struct nf_sockopt_ops *)i;
                 if (ops->pf == pf) {
+                        if (!try_module_get(ops->owner))
+                                goto out_nosup;
+
                         if (get) {
                                 if (val >= ops->get_optmin
                                     && val < ops->get_optmax) {
-                                        ops->use++;
                                         mutex_unlock(&nf_sockopt_mutex);
                                         if (ops->compat_get)
                                                 ret = ops->compat_get(sk,
@@ -160,7 +149,6 @@ static int compat_nf_sockopt(struct sock *sk, int pf, int val,
                         } else {
                                 if (val >= ops->set_optmin
                                     && val < ops->set_optmax) {
-                                        ops->use++;
                                         mutex_unlock(&nf_sockopt_mutex);
                                         if (ops->compat_set)
                                                 ret = ops->compat_set(sk,
@@ -171,17 +159,15 @@ static int compat_nf_sockopt(struct sock *sk, int pf, int val,
                                         goto out;
                                 }
                         }
+                        module_put(ops->owner);
                 }
         }
+ out_nosup:
         mutex_unlock(&nf_sockopt_mutex);
         return -ENOPROTOOPT;
 
  out:
-        mutex_lock(&nf_sockopt_mutex);
-        ops->use--;
-        if (ops->cleanup_task)
-                wake_up_process(ops->cleanup_task);
-        mutex_unlock(&nf_sockopt_mutex);
+        module_put(ops->owner);
         return ret;
 }