Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266786AbUIVTxX (ORCPT ); Wed, 22 Sep 2004 15:53:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266833AbUIVTxX (ORCPT ); Wed, 22 Sep 2004 15:53:23 -0400 Received: from mail.aknet.ru ([217.67.122.194]:19470 "EHLO mail.aknet.ru") by vger.kernel.org with ESMTP id S266786AbUIVTw5 (ORCPT ); Wed, 22 Sep 2004 15:52:57 -0400 Message-ID: <4151DA79.7000804@aknet.ru> Date: Thu, 23 Sep 2004 00:03:05 +0400 From: Stas Sergeev User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040510 X-Accept-Language: ru, en-us, en MIME-Version: 1.0 To: root@chaos.analogic.com Cc: Petr Vandrovec , Linux kernel Subject: Re: ESP corruption bug - what CPUs are affected? References: <3BFF2F87096@vcnet.vc.cvut.cz> <414C662D.5090607@aknet.ru> <20040918165932.GA15570@vana.vc.cvut.cz> <414C8924.1070701@aknet.ru> <20040918203529.GA4447@vana.vc.cvut.cz> <4151C949.1080807@aknet.ru> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-AV-Checked: ClamAV using ClamSMTP Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2353 Lines: 65 Hi, Richard B. Johnson wrote: > What problem is this supposed to fix? Richard, it will really help if you read the whole thread. I was answering this to Denis Vlasenko already - he agreed. Do I have to repeat the explanations? > ESP is __not__ corrupted Right, but is not properly restored either, while it have to be. > when returning to protected-mode or a different privilege level. It gets "corrupted" (not properly restored) exactly when returning to *protected mode* from another priv level. Please refer to the Intel docs I pointed to in that thread earlier. > You don't 'return' to protected mode from a virtual-8086 mode, Noone was speaking about v86. I don't see why you pick that up. > The so-called bug is that when in real mode or in virtual-8086 > mode, the high word of ESP is not changed. In short: Wrong. The complete explanations are easily locateable in that thread. And it have nothing to do with the real mode either. > It is not a bug > because the high word doesn't even exist when in VM-86 mode!! Noone was speaking about v86, sorry. I am bypassing that part. > It is possible to use the 32-bit prefix, when in 16-bit mode, That's not about the prefixes either, sorry. We were talking about the 32bit PM code. > Please, somebody from Intel tell these guys to leave the thing > alone. Thanks many, they already left that alone once:) Maybe enough of leaving the bugs alone? I have lots of the DOS progs here that do not work under dosemu without that patch, and work perfectly with it. It should be enough. If you need an examples - well, OpenCubicPlayer for one. It will start, but crash as soon as the music is attempted to play. The patch fixes it. Other progs you'll have problems downloading anyway, but let me know if you need these. > I, for one, don't want a bunch of "fixes" that do nothing > except consume valuable RAM, making it near impossible to > use later versions of Linux in embedded systems. Well, my patch is purely in asm. How many valueable bytes does it take from you? As for performance - 8 asm insns on a generic path. Not too much either, as for me. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/