netdev - Re: [PATCH net] bonding: fix arp monitoring with vlan slaves

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]

Message-ID: <51FC40E5.6050809@redhat.com>
Date:	Sat, 03 Aug 2013 01:29:41 +0200
From:	Nikolay Aleksandrov <nikolay@...hat.com>
To:	Eric Dumazet <eric.dumazet@...il.com>
CC:	David Miller <davem@...emloft.net>, netdev@...r.kernel.org,
	andy@...yhouse.net, fubar@...ibm.com
Subject: Re: [PATCH net] bonding: fix arp monitoring with vlan slaves

On 08/03/2013 01:17 AM, Eric Dumazet wrote:
> On Fri, 2013-08-02 at 15:32 -0700, David Miller wrote:
> 
>> Handling this specially in bonding isn't really ideal.
>>
>> Please either hide this detail in dev_trans_start(), or (preferrably)
>> have vlan_dev_hard_start_xmit() set the trans_start timestamp
>> properly thus making this just work for everything.
> 
> vlan is LLTX, so setting the timestamp would incur false sharing on
> multiqueue.
> 
Yeah, this statement actually explains a lot for me, thanks :-)
I knew it was because of the LLTX, but I was wondering about the possible
reasons for the xmit_lock_owner check.
So basically the arp monitoring (or any dev_trans_start code) won't work
with LLTX devices because they don't get their trans_start updated (not the
txq trans_start nor the dev->trans_start), is this correct ?
But what if the txqs get bound to a particular CPU, then the txq
trans_start is okay to be updated I suppose.

Nik
> But it's true we need a helper, because many callers do
> 
> if (dev->priv_flags & IFF_802_1Q_VLAN)
>        dev = vlan_dev_real_dev(dev);
> 
> or the slighly better
> 
> if (is_vlan_dev(dev))
>    dev = vlan_dev_real_dev(dev);
> 
> 
> 

--
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