diff options
| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2025-05-12 11:27:32 +0200 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2025-05-15 15:23:31 +0200 |
| commit | 20d677d389e7df6963ca9a41cd0f88954a65ba7b (patch) | |
| tree | ab81613bd38af3422eb39e5435d547c2894f260a | |
| parent | 7fe70c06a182a140be9996b02256d907e114479a (diff) | |
net/sched: Use nested-BH locking for sch_frag_data_storage
sch_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 local_lock_t to the struct 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: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20250512092736.229935-12-bigeasy@linutronix.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
| -rw-r--r-- | net/sched/sch_frag.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/net/sched/sch_frag.c b/net/sched/sch_frag.c index ce63414185fd..d1d87dce7f3f 100644 --- a/net/sched/sch_frag.c +++ b/net/sched/sch_frag.c @@ -16,14 +16,18 @@ struct sch_frag_data { unsigned int l2_len; u8 l2_data[VLAN_ETH_HLEN]; int (*xmit)(struct sk_buff *skb); + local_lock_t bh_lock; }; -static DEFINE_PER_CPU(struct sch_frag_data, sch_frag_data_storage); +static DEFINE_PER_CPU(struct sch_frag_data, sch_frag_data_storage) = { + .bh_lock = INIT_LOCAL_LOCK(bh_lock), +}; static int sch_frag_xmit(struct net *net, struct sock *sk, struct sk_buff *skb) { struct sch_frag_data *data = this_cpu_ptr(&sch_frag_data_storage); + lockdep_assert_held(&data->bh_lock); if (skb_cow_head(skb, data->l2_len) < 0) { kfree_skb(skb); return -ENOMEM; @@ -95,6 +99,7 @@ static int sch_fragment(struct net *net, struct sk_buff *skb, struct rtable sch_frag_rt = { 0 }; unsigned long orig_dst; + local_lock_nested_bh(&sch_frag_data_storage.bh_lock); sch_frag_prepare_frag(skb, xmit); dst_init(&sch_frag_rt.dst, &sch_frag_dst_ops, NULL, DST_OBSOLETE_NONE, DST_NOCOUNT); @@ -105,11 +110,13 @@ static int sch_fragment(struct net *net, struct sk_buff *skb, IPCB(skb)->frag_max_size = mru; ret = ip_do_fragment(net, skb->sk, skb, sch_frag_xmit); + local_unlock_nested_bh(&sch_frag_data_storage.bh_lock); refdst_drop(orig_dst); } else if (skb_protocol(skb, true) == htons(ETH_P_IPV6)) { unsigned long orig_dst; struct rt6_info sch_frag_rt; + local_lock_nested_bh(&sch_frag_data_storage.bh_lock); sch_frag_prepare_frag(skb, xmit); memset(&sch_frag_rt, 0, sizeof(sch_frag_rt)); dst_init(&sch_frag_rt.dst, &sch_frag_dst_ops, NULL, @@ -122,6 +129,7 @@ static int sch_fragment(struct net *net, struct sk_buff *skb, ret = ipv6_stub->ipv6_fragment(net, skb->sk, skb, sch_frag_xmit); + local_unlock_nested_bh(&sch_frag_data_storage.bh_lock); refdst_drop(orig_dst); } else { net_warn_ratelimited("Fail frag %s: eth=%x, MRU=%d, MTU=%d\n", |