From cec7a5c6c695ba2226b6120dc330e3bea3ea96f8 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 9 Jul 2025 09:02:02 +0000 Subject: [PATCH] net_sched: act_police: use RCU in tcf_police_dump() Also storing tcf_action into struct tcf_police_params makes sure there is no discrepancy in tcf_police_act(). Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20250709090204.797558-11-edumazet@google.com Signed-off-by: Jakub Kicinski --- include/net/tc_act/tc_police.h | 3 ++- net/sched/act_police.c | 18 +++++++++--------- 2 files changed, 11 insertions(+), 10 deletions(-) diff --git a/include/net/tc_act/tc_police.h b/include/net/tc_act/tc_police.h index 490d88cb52338..a89fc8e68b1e4 100644 --- a/include/net/tc_act/tc_police.h +++ b/include/net/tc_act/tc_police.h @@ -5,10 +5,11 @@ #include struct tcf_police_params { + int action; int tcfp_result; u32 tcfp_ewma_rate; - s64 tcfp_burst; u32 tcfp_mtu; + s64 tcfp_burst; s64 tcfp_mtu_ptoks; s64 tcfp_pkt_burst; struct psched_ratecfg rate; diff --git a/net/sched/act_police.c b/net/sched/act_police.c index a214ed6811420..0e1c611833790 100644 --- a/net/sched/act_police.c +++ b/net/sched/act_police.c @@ -198,6 +198,7 @@ static int tcf_police_init(struct net *net, struct nlattr *nla, psched_ppscfg_precompute(&new->ppsrate, pps); } + new->action = parm->action; spin_lock_bh(&police->tcf_lock); spin_lock_bh(&police->tcfp_lock); police->tcfp_t_c = ktime_get_ns(); @@ -254,8 +255,8 @@ TC_INDIRECT_SCOPE int tcf_police_act(struct sk_buff *skb, tcf_lastuse_update(&police->tcf_tm); bstats_update(this_cpu_ptr(police->common.cpu_bstats), skb); - ret = READ_ONCE(police->tcf_action); p = rcu_dereference_bh(police->params); + ret = p->action; if (p->tcfp_ewma_rate) { struct gnet_stats_rate_est64 sample; @@ -338,9 +339,9 @@ static void tcf_police_stats_update(struct tc_action *a, static int tcf_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref) { + const struct tcf_police *police = to_police(a); unsigned char *b = skb_tail_pointer(skb); - struct tcf_police *police = to_police(a); - struct tcf_police_params *p; + const struct tcf_police_params *p; struct tc_police opt = { .index = police->tcf_index, .refcnt = refcount_read(&police->tcf_refcnt) - ref, @@ -348,10 +349,9 @@ static int tcf_police_dump(struct sk_buff *skb, struct tc_action *a, }; struct tcf_t t; - spin_lock_bh(&police->tcf_lock); - opt.action = police->tcf_action; - p = rcu_dereference_protected(police->params, - lockdep_is_held(&police->tcf_lock)); + rcu_read_lock(); + p = rcu_dereference(police->params); + opt.action = p->action; opt.mtu = p->tcfp_mtu; opt.burst = PSCHED_NS2TICKS(p->tcfp_burst); if (p->rate_present) { @@ -392,12 +392,12 @@ static int tcf_police_dump(struct sk_buff *skb, struct tc_action *a, tcf_tm_dump(&t, &police->tcf_tm); if (nla_put_64bit(skb, TCA_POLICE_TM, sizeof(t), &t, TCA_POLICE_PAD)) goto nla_put_failure; - spin_unlock_bh(&police->tcf_lock); + rcu_read_unlock(); return skb->len; nla_put_failure: - spin_unlock_bh(&police->tcf_lock); + rcu_read_unlock(); nlmsg_trim(skb, b); return -1; } -- 2.47.2