From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [PATCH] netpoll: Fix skb tail pointer in netpoll_send_udp()
Date: Tue, 12 Jun 2012 15:34:09 +0200
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To: Bogdan Hamciuc <bogdan.hamciuc@freescale.com>
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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