netfilter: Remove explicit rcu_read_lock in nf_hook_slow
All of the callers of nf_hook_slow already hold the rcu_read_lock, so this
cleanup removes the recursive call. This is just a cleanup, as the locking
code gracefully handles this situation.
Signed-off-by: Aaron Conole <aconole@bytheb.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
diff --git a/net/netfilter/core.c b/net/netfilter/core.c
index f39276d..c8faf81 100644
--- a/net/netfilter/core.c
+++ b/net/netfilter/core.c
@@ -291,16 +291,13 @@
/* Returns 1 if okfn() needs to be executed by the caller,
- * -EPERM for NF_DROP, 0 otherwise. */
+ * -EPERM for NF_DROP, 0 otherwise. Caller must hold rcu_read_lock. */
int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state)
{
struct nf_hook_ops *elem;
unsigned int verdict;
int ret = 0;
- /* We may already have this, but read-locks nest anyway */
- rcu_read_lock();
-
elem = list_entry_rcu(state->hook_list, struct nf_hook_ops, list);
next_hook:
verdict = nf_iterate(state->hook_list, skb, state, &elem);
@@ -321,7 +318,6 @@
kfree_skb(skb);
}
}
- rcu_read_unlock();
return ret;
}
EXPORT_SYMBOL(nf_hook_slow);
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index 8d1ddb9..c94ec19 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1275,7 +1275,7 @@
skb->nfct = NULL;
}
- /* rcu_read_lock()ed by nf_hook_slow */
+ /* rcu_read_lock()ed by nf_hook_thresh */
l3proto = __nf_ct_l3proto_find(pf);
ret = l3proto->get_l4proto(skb, skb_network_offset(skb),
&dataoff, &protonum);
diff --git a/net/netfilter/nf_conntrack_h323_main.c b/net/netfilter/nf_conntrack_h323_main.c
index 5c0db5c..f65d9363 100644
--- a/net/netfilter/nf_conntrack_h323_main.c
+++ b/net/netfilter/nf_conntrack_h323_main.c
@@ -736,7 +736,7 @@
const struct nf_afinfo *afinfo;
int ret = 0;
- /* rcu_read_lock()ed by nf_hook_slow() */
+ /* rcu_read_lock()ed by nf_hook_thresh */
afinfo = nf_get_afinfo(family);
if (!afinfo)
return 0;
diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c
index 4ffe388..336e215 100644
--- a/net/netfilter/nf_conntrack_helper.c
+++ b/net/netfilter/nf_conntrack_helper.c
@@ -346,7 +346,7 @@
/* Called from the helper function, this call never fails */
help = nfct_help(ct);
- /* rcu_read_lock()ed by nf_hook_slow */
+ /* rcu_read_lock()ed by nf_hook_thresh */
helper = rcu_dereference(help->helper);
nf_log_packet(nf_ct_net(ct), nf_ct_l3num(ct), 0, skb, NULL, NULL, NULL,
diff --git a/net/netfilter/nfnetlink_cthelper.c b/net/netfilter/nfnetlink_cthelper.c
index e924e95..3b79f34 100644
--- a/net/netfilter/nfnetlink_cthelper.c
+++ b/net/netfilter/nfnetlink_cthelper.c
@@ -43,7 +43,7 @@
if (help == NULL)
return NF_DROP;
- /* rcu_read_lock()ed by nf_hook_slow */
+ /* rcu_read_lock()ed by nf_hook_thresh */
helper = rcu_dereference(help->helper);
if (helper == NULL)
return NF_DROP;
diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c
index 6577db5..eb086a1 100644
--- a/net/netfilter/nfnetlink_log.c
+++ b/net/netfilter/nfnetlink_log.c
@@ -442,7 +442,9 @@
if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSINDEV,
htonl(indev->ifindex)) ||
/* this is the bridge group "brX" */
- /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
+ /* rcu_read_lock()ed by nf_hook_thresh or
+ * nf_log_packet.
+ */
nla_put_be32(inst->skb, NFULA_IFINDEX_INDEV,
htonl(br_port_get_rcu(indev)->br->dev->ifindex)))
goto nla_put_failure;
@@ -477,7 +479,9 @@
if (nla_put_be32(inst->skb, NFULA_IFINDEX_PHYSOUTDEV,
htonl(outdev->ifindex)) ||
/* this is the bridge group "brX" */
- /* rcu_read_lock()ed by nf_hook_slow or nf_log_packet */
+ /* rcu_read_lock()ed by nf_hook_thresh or
+ * nf_log_packet.
+ */
nla_put_be32(inst->skb, NFULA_IFINDEX_OUTDEV,
htonl(br_port_get_rcu(outdev)->br->dev->ifindex)))
goto nla_put_failure;
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index 808da34..7caa8b0 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -740,7 +740,7 @@
struct net *net = entry->state.net;
struct nfnl_queue_net *q = nfnl_queue_pernet(net);
- /* rcu_read_lock()ed by nf_hook_slow() */
+ /* rcu_read_lock()ed by nf_hook_thresh */
queue = instance_lookup(q, queuenum);
if (!queue)
return -ESRCH;
diff --git a/net/netfilter/xt_helper.c b/net/netfilter/xt_helper.c
index 805c9f6..f679dd4 100644
--- a/net/netfilter/xt_helper.c
+++ b/net/netfilter/xt_helper.c
@@ -41,7 +41,7 @@
if (!master_help)
return ret;
- /* rcu_read_lock()ed by nf_hook_slow */
+ /* rcu_read_lock()ed by nf_hook_thresh */
helper = rcu_dereference(master_help->helper);
if (!helper)
return ret;