From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161135AbXCAW5X (ORCPT ); Thu, 1 Mar 2007 17:57:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161132AbXCAW5X (ORCPT ); Thu, 1 Mar 2007 17:57:23 -0500 Received: from moutng.kundenserver.de ([212.227.126.177]:60008 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161135AbXCAW5W (ORCPT ); Thu, 1 Mar 2007 17:57:22 -0500 From: Arnd Bergmann To: cbe-oss-dev@ozlabs.org, michael@ellerman.id.au Subject: Re: [Cbe-oss-dev] [PATCH 14/22] spufs: use SPU master control to prevent =?iso-8859-15?q?wild=09SPU?= execution Date: Thu, 1 Mar 2007 14:50:50 +0100 User-Agent: KMail/1.9.6 Cc: linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org References: <20061120174454.067872000@arndb.de> <20061120180525.281408000@arndb.de> <1172729890.5852.40.camel@concordia.ozlabs.ibm.com> In-Reply-To: <1172729890.5852.40.camel@concordia.ozlabs.ibm.com> X-Face: >j"dOR3XO=^3iw?0`(E1wZ/&le9!.ok[JrI=S~VlsF~}"P\+jx.GT@=?utf-8?q?=0A=09-oaEG?=,9Ba>v;3>:kcw#yO5?B:l{(Ln.2)=?utf-8?q?=27=7Dfw07+4-=26=5E=7CScOpE=3F=5D=5EXdv=5B/zWkA7=60=25M!DxZ=0A=09?= =?utf-8?q?8MJ=2EU5?="hi+2yT(k`PF~Zt;tfT,i,JXf=x@eLP{7B:"GyA\=UnN) =?utf-8?q?=26=26qdaA=3A=7D-Y*=7D=3A3YvzV9=0A=09=7E=273a=7E7I=7CWQ=5D?=<50*%U-6Ewmxfzdn/CK_E/ouMU(r?FAQG/ev^JyuX.%(By`" =?utf-8?q?L=5F=0A=09H=3Dbj?=)"y7*XOqz|SS"mrZ$`Q_syCd MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200703011450.50935.arnd@arndb.de> X-Provags-ID: kundenserver.de abuse@kundenserver.de login:c48f057754fc1b1a557605ab9fa6da41 X-Provags-ID2: V01U2FsdGVkX18xtYZGF9qXkiAFu5sRL8wvI1nPQZhhyip50GV o5PkuLlJ5rRsrjWW+J7Z+qJb9Hj/XMA4NsjeXeIiQEDZ5ZPyyL krbo0CnVJnpuZMq2r3VSg== Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thursday 01 March 2007, Michael Ellerman wrote: > On Mon, 2006-11-20 at 18:45 +0100, Arnd Bergmann wrote: > > plain text document attachment (spufs-master-control.diff) > > When the user changes the runcontrol register, an SPU might be > > running without a process being attached to it and waiting for > > events. In order to prevent this, make sure we always disable > > the priv1 master control when we're not inside of spu_run. > > Hi Arnd, > > Sorry I didn't comment on this when you sent it, I wasn't paying enough > attention. This patch confuses me, you say we should make sure we always > disable the master control when we're not inside spu_run, but I see > several exit paths where we leave the master run bit enabled - or maybe > I'm reading it wrong. I think you're right, there is at least one path that I now saw getting out of spufs_run_spu incorrectly. In particular, when spu_reacquire_runnable() fails, we never call the master stop, which is a bug, but should happen very infrequently in practice. Do you see another case where we end up with the same problem? If not, I'll prepare a patch to fix this one case. Arnd <><