Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752166AbWCOXhO (ORCPT ); Wed, 15 Mar 2006 18:37:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752170AbWCOXhO (ORCPT ); Wed, 15 Mar 2006 18:37:14 -0500 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:52401 "EHLO amd.ucw.cz") by vger.kernel.org with ESMTP id S1752166AbWCOXhM (ORCPT ); Wed, 15 Mar 2006 18:37:12 -0500 Date: Thu, 16 Mar 2006 00:37:03 +0100 From: Pavel Machek To: Zachary Amsden Cc: Linux Kernel Mailing List Subject: Re: VMI Interface Proposal Documentation for I386, Part 4 Message-ID: <20060315233703.GE1919@elf.ucw.cz> References: <4415CE1C.1060608@vmware.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4415CE1C.1060608@vmware.com> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1032 Lines: 39 Hi! > 6) Interrupts must always be enabled when running code in userspace. I'd say this breaks userspace. This code used to work when ran as root: void main(void) { int i; iopl(3); while (1) { asm volatile("cli"); // for (i=0; i<20000000; i++) for (i=0; i<1000000000; i++) asm volatile(""); asm volatile("sti"); sleep(1); } } ...and was actually useful. > 7) IOPL semantics for userspace are changed; although userspace may be > granted port access, it can not affect the interrupt flag. I'm not sure how will X like this. Pavel -- 57: MD5CryptoServiceProvider MD5 = new MD5CryptoServiceProvider(); - 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/