From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Barkowski Subject: Re: hdlc_ppp: why no detach()? Date: Mon, 12 Apr 2010 10:34:34 -0400 Message-ID: <4BC32F7A.4040809@ruggedcom.com> References: <4BC32B00.1030600@ruggedcom.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Cc: "David S. Miller" , Julia Lawall , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" To: Krzysztof Halasa Return-path: In-Reply-To: <4BC32B00.1030600@ruggedcom.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Michael Barkowski wrote: > Hello Krzyztof, > > I am looking at your hdlc_ppp code and I don't understand: why is there > not the equivalent of fr_detach() in there? > > pc8300_drv:cpc_remove_one() frees netdevs quite confidently but I wonder > how it can be so sure that there are not skbs in hdlc_ppp's tx_queue > associated with those devices before freeing them.... > the above is the real danger I see - free the netdev, then ppp's timer comes along and dequeues from tx_queue an skb with invalid device. > Even if you wanted to switch a device from PPP to Frame Relay, I don't > see the method right now. If I may ask, please, what am I missing? > Ok - this part was a momentary lapse on my part - please strike from the record :) > If you agree there is a need for detach(), I would be happy to work on > it and make a submission. > > thanks for your time, > -- Michael Barkowski 905-482-4577