From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] NET: fix kernel panic from no dev->hard_header_len space Date: Mon, 31 Jul 2006 13:23:24 -0700 (PDT) Message-ID: <20060731.132324.65197403.davem@davemloft.net> References: <20060730.153004.45876935.davem@davemloft.net> <20060731153948.GB17540@ms2.inr.ac.ru> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: kuznet@ms2.inr.ac.ru, netdev@vger.kernel.org Return-path: Received: from dsl027-180-168.sfo1.dsl.speakeasy.net ([216.27.180.168]:15283 "EHLO sunset.davemloft.net") by vger.kernel.org with ESMTP id S932510AbWGaUX0 (ORCPT ); Mon, 31 Jul 2006 16:23:26 -0400 To: khc@pm.waw.pl In-Reply-To: Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Krzysztof Halasa Date: Mon, 31 Jul 2006 22:04:33 +0200 > Alexey Kuznetsov writes: > > > All the rest of places just check, that there is enough space > > for their immediate needs. If dev->hard_header() is NULL, it means that > > stack does not need any space at all, so that it does not need to worry. > > Why do you think dev->hard_header == NULL means there is no need for > header space? Isn't it dev->hard_header_len = 0? Why would a device > set hard_header_len to non-zero if it doesn't need header space? If you have headers to prepend for your device, why do you set the header building function to NULL? :-)