From owner-freebsd-stable@FreeBSD.ORG Sun Feb 18 20:51:09 2007 Return-Path: X-Original-To: stable@freebsd.org Delivered-To: freebsd-stable@FreeBSD.ORG Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 9325816A400; Sun, 18 Feb 2007 20:51:09 +0000 (UTC) (envelope-from dmitry@atlantis.dp.ua) Received: from postman.atlantis.dp.ua (postman.atlantis.dp.ua [193.108.47.1]) by mx1.freebsd.org (Postfix) with ESMTP id C0BD413C4B3; Sun, 18 Feb 2007 20:51:08 +0000 (UTC) (envelope-from dmitry@atlantis.dp.ua) Received: from smtp.atlantis.dp.ua (smtp.atlantis.dp.ua [193.108.46.231]) by postman.atlantis.dp.ua (8.13.1/8.13.1) with ESMTP id l1IKovmY045956; Sun, 18 Feb 2007 22:50:58 +0200 (EET) (envelope-from dmitry@atlantis.dp.ua) Date: Sun, 18 Feb 2007 22:50:57 +0200 (EET) From: Dmitry Pryanishnikov To: Kris Kennaway In-Reply-To: <20070218193845.GA54412@xor.obsecurity.org> Message-ID: <20070218220725.K986@atlantis.atlantis.dp.ua> References: <200702071933.35688.lofi@freebsd.org> <20070208075657.GA98754@xor.obsecurity.org> <20070218192903.E47137@atlantis.atlantis.dp.ua> <20070218193845.GA54412@xor.obsecurity.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: stable@freebsd.org, Ian Smith , Joe Vender , Michael Nottebrock Subject: Re: pppd crashes, was: kde-freebsd] Question about KPPP on FreeBSD X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 18 Feb 2007 20:51:09 -0000 On Sun, 18 Feb 2007, Kris Kennaway wrote: >> http://www.freebsd.org/cgi/query-pr.cgi?pr=109277 >> >> The problem looks like a lack of proper locking during the operations with >> clist (specifically, this causes multiple entry to cblock_alloc()). >> I'm ready to provide further debugging information on this issue. >> Unfortunately, I'm not familiar enough with the locking concepts >> in modern FreeBSD kernels (and in tty subsystem particularly) >> in order to make the fix myself. > > ...and that's the problem :) You could do this additional work, but > you'd be wasting your time. I don't believe that nobody _knows_ how to serialize clist-related work within ppp(4) properly. I would rather believe that nobody (at least, among the src-commiters) _cares_ about it. Well, given the presence of working alternatives to ppp(4), this situation seems to be quite explainable. OTOH I still think that my PR could be useful in two aspects: 1) it clearly documents ppp(4) as broken in it's current state so wise people won't use it in production environment; 2) it can be useful for some hypothetical courageous person who will try to fix the problem. > Kris Sincerely, Dmitry -- Atlantis ISP, System Administrator e-mail: dmitry@atlantis.dp.ua nic-hdl: LYNX-RIPE