netdev - Re: [PATCH] TX_RING and packet mmap

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]

Message-ID: <20090415071023.GA26986@ioremap.net>
Date:	Wed, 15 Apr 2009 11:10:23 +0400
From:	Evgeniy Polyakov <zbr@...emap.net>
To:	Johann Baudy <johann.baudy@...-log.net>
Cc:	Herbert Xu <herbert@...dor.apana.org.au>, netdev@...r.kernel.org,
	"David S. Miller" <davem@...emloft.net>,
	Patrick McHardy <kaber@...sh.net>, jamal <hadi@...erus.ca>
Subject: Re: [PATCH] TX_RING and packet mmap

Hi Johann.

On Mon, Apr 13, 2009 at 01:31:14AM +0200, Johann Baudy (johann.baudy@...-log.net) wrote:
> So if my understanding is correct, there is no way to get original
> fragment address in destructor using skb fragment page/data.
> 
> Then,
> I can't use fragments due to skb_linearize
> I can't hide pointer into skb data due to skb_copy.
> I can't rely on other fields of skb.
> IMHO, using skb pointer requires too much cpu resources (parsing
> headers to identify the right buffer...)
> 
> So what can I do except using a new field?
> What do you think about adding a new field that is always linked to destructor?
> I mean adding a generic new field skb->destructor_arg.

It can work but do not place it into skb itself, but into shared area,
which is slab allocated and does not suffer from size restrictions.
You can also add shared-info destructor, which could be used by other

-- 
	Evgeniy Polyakov
--
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