From owner-cvs-all@FreeBSD.ORG Tue Aug 12 15:15:49 2008 Return-Path: Delivered-To: cvs-all@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id C0F021065680; Tue, 12 Aug 2008 15:15:49 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from server.baldwin.cx (bigknife-pt.tunnel.tserv9.chi1.ipv6.he.net [IPv6:2001:470:1f10:75::2]) by mx1.freebsd.org (Postfix) with ESMTP id 69DE78FC23; Tue, 12 Aug 2008 15:15:49 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from localhost.corp.yahoo.com (john@localhost [IPv6:::1]) (authenticated bits=0) by server.baldwin.cx (8.14.2/8.14.2) with ESMTP id m7CFFIbI079614; Tue, 12 Aug 2008 11:15:42 -0400 (EDT) (envelope-from jhb@freebsd.org) From: John Baldwin To: Bruce Evans Date: Tue, 12 Aug 2008 11:15:00 -0400 User-Agent: KMail/1.9.7 References: <200808081343.m78DhwYE068477@repoman.freebsd.org> <20080812014937.E21092@besplex.bde.org> <20080812231130.D760@besplex.bde.org> In-Reply-To: <20080812231130.D760@besplex.bde.org> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200808121115.01483.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH authentication, not delayed by milter-greylist-2.0.2 (server.baldwin.cx [IPv6:::1]); Tue, 12 Aug 2008 11:15:43 -0400 (EDT) X-Virus-Scanned: ClamAV 0.93.1/8018/Tue Aug 12 04:36:31 2008 on server.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-2.6 required=4.2 tests=AWL,BAYES_00,NO_RELAYS autolearn=ham version=3.1.3 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on server.baldwin.cx Cc: cvs-src@freebsd.org, src-committers@freebsd.org, Ed Schouten , cvs-all@freebsd.org Subject: Re: cvs commit: src/sys/dev/io iodev.c X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: CVS commit messages for the entire tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 12 Aug 2008 15:15:49 -0000 On Tuesday 12 August 2008 10:07:43 am Bruce Evans wrote: > I checked that bpf panics (even under UP) due to the obvious bugs in > its d_close(): > > # Generate lots of network activity using something like: > sysctl net.inet.icmp.icmplim=0; ping -fq localhost & > > # Race to panic eventually: > while :; do tcpdump -i lo0 & sleep 0.001; revoke /dev/bpf0 > > Most or all device drivers have obvious bugs in their d_close(); bpf > is just a bit easier to understand and more likely to cause a panic > than most device drivers, since it is simple and frees resources. A > panic is very likely when si_drv1 is freed, and si_drv1 is only locked > accidentally. I think revoke(2) should EINVAL (or ENOTTY) for non-ttys. Of course bpf is broken with revoke, but nobody uses revoke with bpf. What people do do in the normal course of using bpf is lots of concurrent bpf accesses, and w/o D_TRACKCLOSE, bpf devices don't get closed. -- John Baldwin