Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752506AbbGXObe (ORCPT ); Fri, 24 Jul 2015 10:31:34 -0400 Received: from smtprelay0189.hostedemail.com ([216.40.44.189]:42242 "EHLO smtprelay.hostedemail.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751126AbbGXObb (ORCPT ); Fri, 24 Jul 2015 10:31:31 -0400 X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Spam-Summary: 2,0,0,,d41d8cd98f00b204,rostedt@goodmis.org,:::::::::::::::::,RULES_HIT:41:355:379:541:599:960:973:988:989:1260:1277:1311:1313:1314:1345:1359:1437:1515:1516:1518:1534:1539:1593:1594:1711:1730:1747:1777:1792:2393:2553:2559:2562:2693:3138:3139:3140:3141:3142:3352:3622:3865:3866:3867:3868:3870:3871:3872:3874:4250:4321:5007:6261:7875:7903:8784:10004:10400:10848:10967:11232:11658:11914:12517:12519:12740:13069:13311:13357:21063:21080,0,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: dress86_2a2c1d860410d X-Filterd-Recvd-Size: 2285 Date: Fri, 24 Jul 2015 10:31:27 -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: <20150724103127.3c3f4693@gandalf.local.home> In-Reply-To: <20150724132128.GA3612@1wt.eu> References: <20150723173105.6795c0dc@gandalf.local.home> <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> 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: 883 Lines: 23 On Fri, 24 Jul 2015 15:21:28 +0200 Willy Tarreau wrote: > My understanding is that by using RET we can't set the RF flag and #DB But the RF flag is only set for instruction (executing) breakpoints. It is not set for data (RW) ones. -- Steve > will immediately strike again when the operation is attempted again. Thus > we have to completely disable the breakpoints on leaving after the first > one strikes, resulting in some userland breakpoints being missed. Maybe > it can be accepted as a limitation when perf is running. I don't know if > the output of perf is that relevant when a debugger is present BTW. > > 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/