From: Vlad Buslov <vladbu@mellanox.com>
Date: Fri, 10 Aug 2018 20:51:55 +0300
Subject: net: sched: act_police: remove dependency on rtnl lock
Patch-mainline: v4.19-rc1
Git-commit: e329bc427395e2d74f2bb685ef3dddda91a6695f
References: bsc#1109837

Use tcf spinlock to protect police action private data from concurrent
modification during dump. (init already uses tcf spinlock when changing
police action state)

Pass tcf spinlock as estimator lock argument to gen_replace_estimator()
during action init.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/sched/act_police.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

--- a/net/sched/act_police.c
+++ b/net/sched/act_police.c
@@ -274,14 +274,15 @@ static int tcf_act_police_dump(struct sk
 	struct tcf_police *police = to_police(a);
 	struct tc_police opt = {
 		.index = police->tcf_index,
-		.action = police->tcf_action,
-		.mtu = police->tcfp_mtu,
-		.burst = PSCHED_NS2TICKS(police->tcfp_burst),
 		.refcnt = refcount_read(&police->tcf_refcnt) - ref,
 		.bindcnt = atomic_read(&police->tcf_bindcnt) - bind,
 	};
 	struct tcf_t t;
 
+	spin_lock_bh(&police->tcf_lock);
+	opt.action = police->tcf_action;
+	opt.mtu = police->tcfp_mtu;
+	opt.burst = PSCHED_NS2TICKS(police->tcfp_burst);
 	if (police->rate_present)
 		psched_ratecfg_getrate(&opt.rate, &police->rate);
 	if (police->peak_present)
@@ -301,10 +302,12 @@ static int tcf_act_police_dump(struct sk
 	t.expires = jiffies_to_clock_t(police->tcf_tm.expires);
 	if (nla_put_64bit(skb, TCA_POLICE_TM, sizeof(t), &t, TCA_POLICE_PAD))
 		goto nla_put_failure;
+	spin_unlock_bh(&police->tcf_lock);
 
 	return skb->len;
 
 nla_put_failure:
+	spin_unlock_bh(&police->tcf_lock);
 	nlmsg_trim(skb, b);
 	return -1;
 }