Also storing tcf_action into struct tcf_skbmod_params makes sure there is no discrepancy in tcf_skbmod_act(). No longer block BH in tcf_skbmod_init() when acquiring tcf_lock. Signed-off-by: Eric Dumazet --- include/net/tc_act/tc_skbmod.h | 1 + net/sched/act_skbmod.c | 26 ++++++++++++-------------- 2 files changed, 13 insertions(+), 14 deletions(-) diff --git a/include/net/tc_act/tc_skbmod.h b/include/net/tc_act/tc_skbmod.h index 7c240d2fed4e3cdf686016588cd78eb52b80765b..626704cd6241b37f20539f9dd1270275ba19e578 100644 --- a/include/net/tc_act/tc_skbmod.h +++ b/include/net/tc_act/tc_skbmod.h @@ -12,6 +12,7 @@ struct tcf_skbmod_params { struct rcu_head rcu; u64 flags; /*up to 64 types of operations; extend if needed */ + int action; u8 eth_dst[ETH_ALEN]; u16 eth_type; u8 eth_src[ETH_ALEN]; diff --git a/net/sched/act_skbmod.c b/net/sched/act_skbmod.c index dc022969346188c17a43f3ef40f3c203272954c4..fce625eafcb2b793cba7bebb740b136bf8498aa1 100644 --- a/net/sched/act_skbmod.c +++ b/net/sched/act_skbmod.c @@ -27,19 +27,18 @@ TC_INDIRECT_SCOPE int tcf_skbmod_act(struct sk_buff *skb, struct tcf_result *res) { struct tcf_skbmod *d = to_skbmod(a); - int action, max_edit_len, err; struct tcf_skbmod_params *p; + int max_edit_len, err; u64 flags; tcf_lastuse_update(&d->tcf_tm); bstats_update(this_cpu_ptr(d->common.cpu_bstats), skb); - action = READ_ONCE(d->tcf_action); - if (unlikely(action == TC_ACT_SHOT)) + p = rcu_dereference_bh(d->skbmod_p); + if (unlikely(p->action == TC_ACT_SHOT)) goto drop; max_edit_len = skb_mac_header_len(skb); - p = rcu_dereference_bh(d->skbmod_p); flags = p->flags; /* tcf_skbmod_init() guarantees "flags" to be one of the following: @@ -85,7 +84,7 @@ TC_INDIRECT_SCOPE int tcf_skbmod_act(struct sk_buff *skb, INET_ECN_set_ce(skb); out: - return action; + return p->action; drop: qstats_overlimit_inc(this_cpu_ptr(d->common.cpu_qstats)); @@ -193,9 +192,9 @@ static int tcf_skbmod_init(struct net *net, struct nlattr *nla, } p->flags = lflags; - + p->action = parm->action; if (ovr) - spin_lock_bh(&d->tcf_lock); + spin_lock(&d->tcf_lock); /* Protected by tcf_lock if overwriting existing action. */ goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); p_old = rcu_dereference_protected(d->skbmod_p, 1); @@ -209,7 +208,7 @@ static int tcf_skbmod_init(struct net *net, struct nlattr *nla, rcu_assign_pointer(d->skbmod_p, p); if (ovr) - spin_unlock_bh(&d->tcf_lock); + spin_unlock(&d->tcf_lock); if (p_old) kfree_rcu(p_old, rcu); @@ -248,10 +247,9 @@ static int tcf_skbmod_dump(struct sk_buff *skb, struct tc_action *a, opt.index = d->tcf_index; opt.refcnt = refcount_read(&d->tcf_refcnt) - ref; opt.bindcnt = atomic_read(&d->tcf_bindcnt) - bind; - spin_lock_bh(&d->tcf_lock); - opt.action = d->tcf_action; - p = rcu_dereference_protected(d->skbmod_p, - lockdep_is_held(&d->tcf_lock)); + rcu_read_lock(); + p = rcu_dereference(d->skbmod_p); + opt.action = p->action; opt.flags = p->flags; if (nla_put(skb, TCA_SKBMOD_PARMS, sizeof(opt), &opt)) goto nla_put_failure; @@ -269,10 +267,10 @@ static int tcf_skbmod_dump(struct sk_buff *skb, struct tc_action *a, if (nla_put_64bit(skb, TCA_SKBMOD_TM, sizeof(t), &t, TCA_SKBMOD_PAD)) goto nla_put_failure; - spin_unlock_bh(&d->tcf_lock); + rcu_read_unlock(); return skb->len; nla_put_failure: - spin_unlock_bh(&d->tcf_lock); + rcu_read_unlock(); nlmsg_trim(skb, b); return -1; } -- 2.51.0.261.g7ce5a0a67e-goog