From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: Change in alloc_skb() behavior in 3.2+ kernels?
Date: Wed, 06 Jun 2012 11:51:30 -0700 (PDT)
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From: Grant Edwards <grant.b.edwards@gmail.com>
Date: Wed, 6 Jun 2012 18:32:57 +0000 (UTC)

> The kernel module that's started failing fills the allocated sk_buff
> until tailroom() indicates it is full and then sends it.  The problem
> is that sending a packet with a length of 1850 won't work (it's a
> MAC-layer Ethernet packet).

The amount of tailroom an SKB has is implementation dependent.

It's incredibly poor form to rely upon it to determine whether a fully
sized frame has been constructed or not.

Please fix the code that does this.