netdev - Re: Passive OS fingerprint xtables match.

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 for Android: free password hash cracker in your pocket

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

Date:	Mon, 16 Mar 2009 15:40:29 +0100
From:	Patrick McHardy <kaber@...sh.net>
To:	Jesper Dangaard Brouer <hawk@...u.dk>
CC:	Evgeniy Polyakov <zbr@...emap.net>,
	netdev <netdev@...r.kernel.org>,
	David Miller <davem@...emloft.net>,
	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
	Netfilter Development Mailinglist 
	<netfilter-devel@...r.kernel.org>,
	Jan Engelhardt <jengelh@...ozas.de>, hawk@...x.dk
Subject: Re: Passive OS fingerprint xtables match.

Jesper Dangaard Brouer wrote:
> On Tue, 10 Mar 2009, Evgeniy Polyakov wrote:
> 
>> +            call_rcu(&f->rcu_head, ipt_osf_finger_free_rcu);
>> +        }
>> +    }
>> +    rcu_read_unlock();
> 
> Should the list_del_rcu() not be protected by a spinlock?
> 
> 
>> +    rcu_barrier();
> 
> In some of my code I call synchronize_net(), is it enough to call 
> rcu_barrier()?
> 
> What is the difference between:
> 
>  synchronize_rcu()
>  synchronize_net()
>  rcu_barrier()

synchronize_net() is just a call to synchronize_rcu(), so their
functionality is equivalent. synchronize_net() is however only
supposed to synchronize with RX packet processing, which is usually
not enough for netfilter. So I prefer synchronize_rcu() for clarity.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html