[PATCH net-next 07/24] netfilter: br_netfilter: Use nested-BH locking for brnf_frag_data_storage.
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: 2023-12-15 17:10:37
Also in:
bridge, lkml, netfilter-devel
Subsystem:
ethernet bridge, netfilter, networking [general], the rest · Maintainers:
Nikolay Aleksandrov, Ido Schimmel, Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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@strlen.de> Cc: Jozsef Kadlecsik <redacted> Cc: Nikolay Aleksandrov <razor@blackwall.org> Cc: Pablo Neira Ayuso <pablo@netfilter.org> Cc: Roopa Prabhu <redacted> Cc: bridge@lists.linux.dev Cc: coreteam@netfilter.org Cc: netfilter-devel@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> --- net/bridge/br_netfilter_hooks.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c
index 6adcb45bca75d..c06f498c5f1b3 100644
--- a/net/bridge/br_netfilter_hooks.c
+++ b/net/bridge/br_netfilter_hooks.c@@ -133,6 +133,7 @@ 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;
@@ -140,7 +141,9 @@ 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) {
@@ -768,6 +771,7 @@ 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; + guard(local_lock_nested_bh)(&brnf_frag_data_storage.bh_lock); data = this_cpu_ptr(&brnf_frag_data_storage); if (skb_vlan_tag_present(skb)) {
@@ -795,6 +799,7 @@ 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; + guard(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;
--
2.43.0