From: Vlad Buslov <vladbu@mellanox.com>
Date: Fri, 10 Aug 2018 17:51:48 +0000 (+0300)
Subject: net: sched: act_simple: remove dependency on rtnl lock
X-Git-Tag: v4.19-rc1~140^2~41^2~7
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=5e48180ed8bcfa60e02887ba801307caf14bbe40;p=linux.git

net: sched: act_simple: remove dependency on rtnl lock

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

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/sched/act_simple.c b/net/sched/act_simple.c
index aa51152e0066..18e4452574cd 100644
--- a/net/sched/act_simple.c
+++ b/net/sched/act_simple.c
@@ -156,10 +156,11 @@ static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a,
 		.index   = d->tcf_index,
 		.refcnt  = refcount_read(&d->tcf_refcnt) - ref,
 		.bindcnt = atomic_read(&d->tcf_bindcnt) - bind,
-		.action  = d->tcf_action,
 	};
 	struct tcf_t t;
 
+	spin_lock_bh(&d->tcf_lock);
+	opt.action = d->tcf_action;
 	if (nla_put(skb, TCA_DEF_PARMS, sizeof(opt), &opt) ||
 	    nla_put_string(skb, TCA_DEF_DATA, d->tcfd_defdata))
 		goto nla_put_failure;
@@ -167,9 +168,12 @@ static int tcf_simp_dump(struct sk_buff *skb, struct tc_action *a,
 	tcf_tm_dump(&t, &d->tcf_tm);
 	if (nla_put_64bit(skb, TCA_DEF_TM, sizeof(t), &t, TCA_DEF_PAD))
 		goto nla_put_failure;
+	spin_unlock_bh(&d->tcf_lock);
+
 	return skb->len;
 
 nla_put_failure:
+	spin_unlock_bh(&d->tcf_lock);
 	nlmsg_trim(skb, b);
 	return -1;
 }