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Message-ID: <20240607070427.1379327-8-bigeasy@linutronix.de>
Date: Fri, 7 Jun 2024 08:53:10 +0200
From: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
To: linux-kernel@...r.kernel.org,
netdev@...r.kernel.org
Cc: "David S. Miller" <davem@...emloft.net>,
Daniel Bristot de Oliveira <bristot@...nel.org>,
Boqun Feng <boqun.feng@...il.com>,
Daniel Borkmann <daniel@...earbox.net>,
Eric Dumazet <edumazet@...gle.com>,
Frederic Weisbecker <frederic@...nel.org>,
Ingo Molnar <mingo@...hat.com>,
Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>,
Peter Zijlstra <peterz@...radead.org>,
Thomas Gleixner <tglx@...utronix.de>,
Waiman Long <longman@...hat.com>,
Will Deacon <will@...nel.org>,
Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
Florian Westphal <fw@...len.de>,
Jozsef Kadlecsik <kadlec@...filter.org>,
Nikolay Aleksandrov <razor@...ckwall.org>,
Pablo Neira Ayuso <pablo@...filter.org>,
Roopa Prabhu <roopa@...dia.com>,
bridge@...ts.linux.dev,
coreteam@...filter.org,
netfilter-devel@...r.kernel.org
Subject: [PATCH v5 net-next 07/15] netfilter: br_netfilter: Use nested-BH locking for brnf_frag_data_storage.
brnf_frag_data_storage is a per-CPU variable and relies on disabled BH
for its locking. Without per-CPU locking in local_bh_disable() on
PREEMPT_RT this data structure requires explicit locking.
Add a local_lock_t to the data structure and use local_lock_nested_bh()
for locking. This change adds only lockdep coverage and does not alter
the functional behaviour for !PREEMPT_RT.
Cc: Florian Westphal <fw@...len.de>
Cc: Jozsef Kadlecsik <kadlec@...filter.org>
Cc: Nikolay Aleksandrov <razor@...ckwall.org>
Cc: Pablo Neira Ayuso <pablo@...filter.org>
Cc: Roopa Prabhu <roopa@...dia.com>
Cc: bridge@...ts.linux.dev
Cc: coreteam@...filter.org
Cc: netfilter-devel@...r.kernel.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
---
net/bridge/br_netfilter_hooks.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c
index bf30c50b56895..3c9f6538990ea 100644
--- a/net/bridge/br_netfilter_hooks.c
+++ b/net/bridge/br_netfilter_hooks.c
@@ -137,6 +137,7 @@ static inline bool is_pppoe_ipv6(const struct sk_buff *skb,
#define NF_BRIDGE_MAX_MAC_HEADER_LENGTH (PPPOE_SES_HLEN + ETH_HLEN)
struct brnf_frag_data {
+ local_lock_t bh_lock;
char mac[NF_BRIDGE_MAX_MAC_HEADER_LENGTH];
u8 encap_size;
u8 size;
@@ -144,7 +145,9 @@ struct brnf_frag_data {
__be16 vlan_proto;
};
-static DEFINE_PER_CPU(struct brnf_frag_data, brnf_frag_data_storage);
+static DEFINE_PER_CPU(struct brnf_frag_data, brnf_frag_data_storage) = {
+ .bh_lock = INIT_LOCAL_LOCK(bh_lock),
+};
static void nf_bridge_info_free(struct sk_buff *skb)
{
@@ -850,6 +853,7 @@ static int br_nf_dev_queue_xmit(struct net *net, struct sock *sk, struct sk_buff
{
struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb);
unsigned int mtu, mtu_reserved;
+ int ret;
mtu_reserved = nf_bridge_mtu_reduction(skb);
mtu = skb->dev->mtu;
@@ -882,6 +886,7 @@ static int br_nf_dev_queue_xmit(struct net *net, struct sock *sk, struct sk_buff
IPCB(skb)->frag_max_size = nf_bridge->frag_max_size;
+ local_lock_nested_bh(&brnf_frag_data_storage.bh_lock);
data = this_cpu_ptr(&brnf_frag_data_storage);
if (skb_vlan_tag_present(skb)) {
@@ -897,7 +902,9 @@ static int br_nf_dev_queue_xmit(struct net *net, struct sock *sk, struct sk_buff
skb_copy_from_linear_data_offset(skb, -data->size, data->mac,
data->size);
- return br_nf_ip_fragment(net, sk, skb, br_nf_push_frag_xmit);
+ ret = br_nf_ip_fragment(net, sk, skb, br_nf_push_frag_xmit);
+ local_unlock_nested_bh(&brnf_frag_data_storage.bh_lock);
+ return ret;
}
if (IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) &&
skb->protocol == htons(ETH_P_IPV6)) {
@@ -909,6 +916,7 @@ static int br_nf_dev_queue_xmit(struct net *net, struct sock *sk, struct sk_buff
IP6CB(skb)->frag_max_size = nf_bridge->frag_max_size;
+ local_lock_nested_bh(&brnf_frag_data_storage.bh_lock);
data = this_cpu_ptr(&brnf_frag_data_storage);
data->encap_size = nf_bridge_encap_header_len(skb);
data->size = ETH_HLEN + data->encap_size;
@@ -916,8 +924,12 @@ static int br_nf_dev_queue_xmit(struct net *net, struct sock *sk, struct sk_buff
skb_copy_from_linear_data_offset(skb, -data->size, data->mac,
data->size);
- if (v6ops)
- return v6ops->fragment(net, sk, skb, br_nf_push_frag_xmit);
+ if (v6ops) {
+ ret = v6ops->fragment(net, sk, skb, br_nf_push_frag_xmit);
+ local_unlock_nested_bh(&brnf_frag_data_storage.bh_lock);
+ return ret;
+ }
+ local_unlock_nested_bh(&brnf_frag_data_storage.bh_lock);
kfree_skb(skb);
return -EMSGSIZE;
--
2.45.1
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