net_sched: act_tunnel_key: use RCU in tunnel_key_dump()

Also storing tcf_action into struct tcf_tunnel_key_params
makes sure there is no discrepancy in tunnel_key_act().

No longer block BH in tunnel_key_init() when acquiring tcf_lock.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250827125349.3505302-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Eric Dumazet
2025-08-27 12:53:48 +00:00
committed by Jakub Kicinski
parent 48b5e5dbdb
commit e97ae74297
2 changed files with 10 additions and 11 deletions

View File

@@ -14,6 +14,7 @@
struct tcf_tunnel_key_params {
struct rcu_head rcu;
int tcft_action;
int action;
struct metadata_dst *tcft_enc_metadata;
};

View File

@@ -29,13 +29,11 @@ TC_INDIRECT_SCOPE int tunnel_key_act(struct sk_buff *skb,
{
struct tcf_tunnel_key *t = to_tunnel_key(a);
struct tcf_tunnel_key_params *params;
int action;
params = rcu_dereference_bh(t->params);
tcf_lastuse_update(&t->tcf_tm);
tcf_action_update_bstats(&t->common, skb);
action = READ_ONCE(t->tcf_action);
switch (params->tcft_action) {
case TCA_TUNNEL_KEY_ACT_RELEASE:
@@ -51,7 +49,7 @@ TC_INDIRECT_SCOPE int tunnel_key_act(struct sk_buff *skb,
break;
}
return action;
return params->action;
}
static const struct nla_policy
@@ -532,11 +530,12 @@ static int tunnel_key_init(struct net *net, struct nlattr *nla,
params_new->tcft_action = parm->t_action;
params_new->tcft_enc_metadata = metadata;
spin_lock_bh(&t->tcf_lock);
params_new->action = parm->action;
spin_lock(&t->tcf_lock);
goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
params_new = rcu_replace_pointer(t->params, params_new,
lockdep_is_held(&t->tcf_lock));
spin_unlock_bh(&t->tcf_lock);
spin_unlock(&t->tcf_lock);
tunnel_key_release_params(params_new);
if (goto_ch)
tcf_chain_put_by_act(goto_ch);
@@ -726,10 +725,9 @@ static int tunnel_key_dump(struct sk_buff *skb, struct tc_action *a,
};
struct tcf_t tm;
spin_lock_bh(&t->tcf_lock);
params = rcu_dereference_protected(t->params,
lockdep_is_held(&t->tcf_lock));
opt.action = t->tcf_action;
rcu_read_lock();
params = rcu_dereference(t->params);
opt.action = params->action;
opt.t_action = params->tcft_action;
if (nla_put(skb, TCA_TUNNEL_KEY_PARMS, sizeof(opt), &opt))
@@ -766,12 +764,12 @@ static int tunnel_key_dump(struct sk_buff *skb, struct tc_action *a,
if (nla_put_64bit(skb, TCA_TUNNEL_KEY_TM, sizeof(tm),
&tm, TCA_TUNNEL_KEY_PAD))
goto nla_put_failure;
spin_unlock_bh(&t->tcf_lock);
rcu_read_unlock();
return skb->len;
nla_put_failure:
spin_unlock_bh(&t->tcf_lock);
rcu_read_unlock();
nlmsg_trim(skb, b);
return -1;
}