Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752745AbbGXPed (ORCPT ); Fri, 24 Jul 2015 11:34:33 -0400 Received: from smtprelay0211.hostedemail.com ([216.40.44.211]:39524 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751027AbbGXPe3 (ORCPT ); Fri, 24 Jul 2015 11:34:29 -0400 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::::::::::::::,RULES_HIT:41:355:379:541:599:960:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1538:1593:1594:1711:1730:1747:1777:1792:2393:2553:2559:2562:2736:3138:3139:3140:3141:3142:3352:3622:3865:3867:3868:3870:3871:3872:3874:4321:5007:6117:6261:7875:7903:10004:10400:10848:10967:11232:11658:11914:12517:12519:12663:12740:13069:13161:13229:13311:13357:21080,0,RBL:none,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:none,Custom_rules:0:0:0 X-HE-Tag: crowd29_9e381f581d12 X-Filterd-Recvd-Size: 2113 Date: Fri, 24 Jul 2015 11:34:26 -0400 From: Steven Rostedt To: Willy Tarreau Cc: Peter Zijlstra , Linus Torvalds , Andy Lutomirski , X86 ML , "linux-kernel@vger.kernel.org" , Borislav Petkov , Thomas Gleixner , Brian Gerst Subject: Re: Dealing with the NMI mess Message-ID: <20150724113426.3b0d3706@gandalf.local.home> In-Reply-To: <20150724152637.GC3612@1wt.eu> References: <20150724081326.GO25159@twins.programming.kicks-ass.net> <20150724075841.40f209f4@gandalf.local.home> <20150724124304.GH19282@twins.programming.kicks-ass.net> <20150724090342.6d11e16d@gandalf.local.home> <20150724132128.GA3612@1wt.eu> <20150724103127.3c3f4693@gandalf.local.home> <20150724145901.GB3612@1wt.eu> <20150724111621.34713023@gandalf.local.home> <20150724152637.GC3612@1wt.eu> X-Mailer: Claws Mail 3.11.1 (GTK+ 2.24.28; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 811 Lines: 23 On Fri, 24 Jul 2015 17:26:37 +0200 Willy Tarreau wrote: > > The point is, if we trigger a #DB on an instruction breakpoint > > while !IF, then we simply disable that breakpoint and do the RET. > > Yes but the breakpoint remains disabled then. Or I'm missing > something. Do we care? If it was an instruction breakpoint with !IF set, then it had to have happened in the kernel. And kgdb or whatever added it there needs to deal with that. There should be no instances in the kernel where we execute userspace code with interrupts disabled. -- Steve -- 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/