Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262550AbVDGSK1 (ORCPT ); Thu, 7 Apr 2005 14:10:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262551AbVDGSK0 (ORCPT ); Thu, 7 Apr 2005 14:10:26 -0400 Received: from mail.aknet.ru ([217.67.122.194]:48655 "EHLO mail.aknet.ru") by vger.kernel.org with ESMTP id S262548AbVDGSKK (ORCPT ); Thu, 7 Apr 2005 14:10:10 -0400 Message-ID: <42557786.8090502@aknet.ru> Date: Thu, 07 Apr 2005 22:10:14 +0400 From: Stas Sergeev User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.3) Gecko/20041020 X-Accept-Language: ru, en-us, en MIME-Version: 1.0 To: Linus Torvalds Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Andrew Morton , Petr Vandrovec Subject: Re: crash in entry.S restore_all, 2.6.12-rc2, x86, PAGEALLOC References: <20050405065544.GA21360@elte.hu> <4252E2C9.9040809@aknet.ru> <4252EA01.7000805@aknet.ru> <425403F6.409@aknet.ru> <20050407080004.GA27252@elte.hu> <42555BBF.6090704@aknet.ru> <425563D6.30108@aknet.ru> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1073 Lines: 31 Hi Linus. Linus Torvalds wrote: > The NMI code had better be really careful, and yeah, I suspect it needs > fixing. And since the NMI return will need a ESP fixup too, it will require the "branched" version of the restore_all checks I suppose. >> 2. How can one be sure there are no more >> of the like places where the stack is left >> empty? > That's a good argument, and may be the strongest reason for _not_ doing > the speculation. I haven't said that explicitly, only implied:) My another idea was to adjust the tss.esp0 to always point 8 bytes below the real top of the stack, so that even in case of an NMI we are still safe. And in case of another such instance - too. This may look more like a hack than shifting the "sti", but it is probably more reliable. At least something to consider as soon as we are at it. - 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/