Commit 2142236b authored by Vlad Buslov's avatar Vlad Buslov Committed by David S. Miller
Browse files

net: sched: act_bpf: remove dependency on rtnl lock 



Use tcf spinlock to protect bpf action private data from concurrent
modification during dump and init. Remove rtnl lock assertion that is no
longer necessary.

Signed-off-by: default avatarVlad Buslov <vladbu@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2b14e1ea

net/sched/act_bpf.c

+7 −3
Original line number Diff line number Diff line
@@ -143,11 +143,12 @@ static int tcf_bpf_dump(struct sk_buff *skb, struct tc_action *act, 
		.index   = prog->tcf_index,

		.refcnt  = refcount_read(&prog->tcf_refcnt) - ref,

		.bindcnt = atomic_read(&prog->tcf_bindcnt) - bind,

		.action  = prog->tcf_action,

	};

	struct tcf_t tm;

	int ret;



	spin_lock(&prog->tcf_lock);

	opt.action = prog->tcf_action;

	if (nla_put(skb, TCA_ACT_BPF_PARMS, sizeof(opt), &opt))

		goto nla_put_failure;
@@ -163,9 +164,11 @@ static int tcf_bpf_dump(struct sk_buff *skb, struct tc_action *act, 
			  TCA_ACT_BPF_PAD))

		goto nla_put_failure;



	spin_unlock(&prog->tcf_lock);

	return skb->len;



nla_put_failure:

	spin_unlock(&prog->tcf_lock);

	nlmsg_trim(skb, tp);

	return -1;

}
@@ -264,7 +267,7 @@ static void tcf_bpf_prog_fill_cfg(const struct tcf_bpf *prog, 
{

	cfg->is_ebpf = tcf_bpf_is_ebpf(prog);

	/* updates to prog->filter are prevented, since it's called either

	 * with rtnl lock or during final cleanup in rcu callback

	 * with tcf lock or during final cleanup in rcu callback

	 */

	cfg->filter = rcu_dereference_protected(prog->filter, 1);
@@ -336,8 +339,8 @@ static int tcf_bpf_init(struct net *net, struct nlattr *nla, 
		goto out;



	prog = to_bpf(*act);

	ASSERT_RTNL();



	spin_lock(&prog->tcf_lock);

	if (res != ACT_P_CREATED)

		tcf_bpf_prog_fill_cfg(prog, &old);
@@ -349,6 +352,7 @@ static int tcf_bpf_init(struct net *net, struct nlattr *nla, 


	prog->tcf_action = parm->action;

	rcu_assign_pointer(prog->filter, cfg.filter);

	spin_unlock(&prog->tcf_lock);



	if (res == ACT_P_CREATED) {

		tcf_idr_insert(tn, *act);