Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753925AbbGXQIw (ORCPT ); Fri, 24 Jul 2015 12:08:52 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:9564 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753574AbbGXQIu (ORCPT ); Fri, 24 Jul 2015 12:08:50 -0400 Date: Fri, 24 Jul 2015 18:08:06 +0200 From: Willy Tarreau To: Steven Rostedt Cc: Andy Lutomirski , Peter Zijlstra , Linus Torvalds , X86 ML , "linux-kernel@vger.kernel.org" , Borislav Petkov , Thomas Gleixner , Brian Gerst Subject: Re: Dealing with the NMI mess Message-ID: <20150724160806.GF3612@1wt.eu> References: <20150723173105.6795c0dc@gandalf.local.home> <20150724081326.GO25159@twins.programming.kicks-ass.net> <20150724120249.1ba0d9de@gandalf.local.home> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150724120249.1ba0d9de@gandalf.local.home> User-Agent: Mutt/1.4.2.3i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 970 Lines: 26 On Fri, Jul 24, 2015 at 12:02:49PM -0400, Steven Rostedt wrote: > On Fri, 24 Jul 2015 08:48:57 -0700 > Andy Lutomirski wrote: > > > So by the time we detect that we've hit a watchpoint, the instruction > > that tripped it is done and we don't need RF. Furthermore, after > > reading 17.3.1.1: I *think* that regs->flags withh have RF *clear* if > > we hit a watchpoint. So this might be as simple as: > > > > if ((dr6 && (0xf * DR_TRAP0) && (regs->flags & (X86_EFLAGS_RF | > > Um, isn't 0xf * DR_TRAP0 same as a constant "true"? For me it's a typo, it should have been : if ((dr6 & (0xf * DR_TRAP0) && (regs->flags & (X86_EFLAGS_RF | (the purpose was to read all 4 lower bits at once). Willy -- 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/