Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751720AbWBQWON (ORCPT ); Fri, 17 Feb 2006 17:14:13 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751813AbWBQWON (ORCPT ); Fri, 17 Feb 2006 17:14:13 -0500 Received: from smtp.osdl.org ([65.172.181.4]:23779 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1751720AbWBQWON (ORCPT ); Fri, 17 Feb 2006 17:14:13 -0500 Date: Fri, 17 Feb 2006 14:14:06 -0800 (PST) From: Linus Torvalds To: Chuck Ebbert <76306.1226@compuserve.com> cc: linux-kernel Subject: Re: [patch] i386: another possible singlestep fix In-Reply-To: <200602171652_MC3-1-B8AC-373E@compuserve.com> Message-ID: References: <200602171652_MC3-1-B8AC-373E@compuserve.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 843 Lines: 25 On Fri, 17 Feb 2006, Chuck Ebbert wrote: > > When entering kernel via int80, TIF_SINGLESTEP is not set > when TF has been set in eflags by the user. This patch > does that. This really shouldn't matter. When we enter the kernel through "int 0x80", we don't need to do anything about TIF_SINGLESTEP, because unlike the "sysenter" path, the "int" instruction will automatically do the right thing (save old eflags on the stack). So afaik, this won't actually do anything (except make _the_ most timing-critical path in the kernel slower). Have you actually seen any effects of it? Linus - 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/