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From: Eric Dumazet <eric.dumazet@gmail.com>
To: Bogdan Hamciuc <bogdan.hamciuc@freescale.com>
Cc: davem@davemloft.net, netdev@vger.kernel.org
Subject: Re: [PATCH] netpoll: Fix skb tail pointer in netpoll_send_udp()
Date: Tue, 12 Jun 2012 15:34:09 +0200	[thread overview]
Message-ID: <1339508049.22704.143.camel@edumazet-glaptop> (raw)
In-Reply-To: <1339506917.22704.134.camel@edumazet-glaptop>

On Tue, 2012-06-12 at 15:15 +0200, Eric Dumazet wrote:
> On Tue, 2012-06-12 at 14:22 +0200, Eric Dumazet wrote:

> > Hmm, real question is why skb_realloc_headroom() is even necessary...
> > 
> > I suspect we need to reserve more bytes.
> > 
> > 	total_len = ip_len + ETH_HLEN + NET_IP_ALIGN + NET_SKB_PAD;
> > 
> > or something like that ?
> > 
> > Which driver triggers the bug ?
> > 

In case you wonder why I try so hard to avoid the
skb_realloc_headroom() :

netpoll has complicated^Wspecial^Wnice skb cache, to make sure it can
work even if memory is exhausted.

But if we trigger skb_realloc_headroom() the whole thing is useless. 

Thanks

  reply	other threads:[~2012-06-12 13:34 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-12 10:26 [PATCH] netpoll: Fix skb tail pointer in netpoll_send_udp() Bogdan Hamciuc
2012-06-12 10:26 ` [PATCH] netpoll: Add support for hardware checksumming on egress Bogdan Hamciuc
2012-06-12 12:43   ` Eric Dumazet
2012-06-12 12:22 ` [PATCH] netpoll: Fix skb tail pointer in netpoll_send_udp() Eric Dumazet
2012-06-12 13:15   ` Eric Dumazet
2012-06-12 13:34     ` Eric Dumazet [this message]
2012-06-12 15:08       ` Hamciuc Bogdan-BHAMCIU1

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