netdev - Re: [PATCH net-next 12/14] net: sched: act_mirred: remove dependency on rtnl lock

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 08 Aug 2018 10:40:35 +0300
From:   Vlad Buslov <vladbu@...lanox.com>
To:     Jiri Pirko <jiri@...nulli.us>
Cc:     netdev@...r.kernel.org, davem@...emloft.net, jhs@...atatu.com,
        xiyou.wangcong@...il.com, pablo@...filter.org,
        kadlec@...ckhole.kfki.hu, fw@...len.de, ast@...nel.org,
        daniel@...earbox.net, edumazet@...gle.com, keescook@...omium.org,
        marcelo.leitner@...il.com
Subject: Re: [PATCH net-next 12/14] net: sched: act_mirred: remove dependency on rtnl lock


On Tue 07 Aug 2018 at 16:36, Jiri Pirko <jiri@...nulli.us> wrote:
> Mon, Aug 06, 2018 at 08:54:23AM CEST, vladbu@...lanox.com wrote:
>
> [...]
>
>>diff --git a/include/net/tc_act/tc_tunnel_key.h b/include/net/tc_act/tc_tunnel_key.h
>>index 46b8c7f1c8d5..e6e475d788c6 100644
>>--- a/include/net/tc_act/tc_tunnel_key.h
>>+++ b/include/net/tc_act/tc_tunnel_key.h
>>@@ -30,26 +30,47 @@ struct tcf_tunnel_key {
>> 
>> static inline bool is_tcf_tunnel_set(const struct tc_action *a)
>> {
>>+	bool ret = false;
>> #ifdef CONFIG_NET_CLS_ACT
>> 	struct tcf_tunnel_key *t = to_tunnel_key(a);
>>-	struct tcf_tunnel_key_params *params = rtnl_dereference(t->params);
>>+	struct tcf_tunnel_key_params *params;
>> 
>>+	rcu_read_lock();
>>+	params = rcu_dereference(t->params);
>> 	if (a->ops && a->ops->type == TCA_ACT_TUNNEL_KEY)
>>-		return params->tcft_action == TCA_TUNNEL_KEY_ACT_SET;
>>+		ret = params->tcft_action == TCA_TUNNEL_KEY_ACT_SET;
>>+	rcu_read_unlock();
>> #endif
>>-	return false;
>>+	return ret;
>> }
>> 
>> static inline bool is_tcf_tunnel_release(const struct tc_action *a)
>
> Why are these tunnel things in a mirred patch?

Mistake during re-slit. Will move those to tunnel_key patch.

>
>
> [...]
>
>
>> static struct net_device *tcf_mirred_get_dev(const struct tc_action *a)
>> {
>> 	struct tcf_mirred *m = to_mirred(a);
>>+	struct net_device *dev;
>>+
>>+	rcu_read_lock();
>>+	dev = rcu_dereference(m->tcfm_dev);
>>+	if (dev)
>>+		dev_hold(dev);
>>+	rcu_read_unlock();
>> 
>>-	return rtnl_dereference(m->tcfm_dev);
>>+	return dev;
>> }
>> 
>> static int tcf_mirred_delete(struct net *net, u32 index)
>>diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
>>index e8b0bbd0883f..0cce0eadc28b 100644
>>--- a/net/sched/cls_api.c
>>+++ b/net/sched/cls_api.c
>>@@ -2167,6 +2167,7 @@ static int tc_exts_setup_cb_egdev_call(struct tcf_exts *exts,
>> 		if (!dev)
>> 			continue;
>> 		ret = tc_setup_cb_egdev_call(dev, type, type_data, err_stop);
>>+		dev_put(dev);
>
> This looks really odd. a->ops->put_dev is needed.

Got it. Will implement put_dev in v2.

>
>
>> 		if (ret < 0)
>> 			return ret;
>> 		ok_count += ret;
>>-- 
>>2.7.5
>>

Thanks for reviewing my code!