Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754008AbbGXPeo (ORCPT ); Fri, 24 Jul 2015 11:34:44 -0400 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:9455 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752850AbbGXPej (ORCPT ); Fri, 24 Jul 2015 11:34:39 -0400 Date: Fri, 24 Jul 2015 17:33:57 +0200 From: Willy Tarreau To: Peter Zijlstra Cc: Steven Rostedt , 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: <20150724153357.GD3612@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> <20150724153054.GK19282@twins.programming.kicks-ass.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150724153054.GK19282@twins.programming.kicks-ass.net> 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: 847 Lines: 23 On Fri, Jul 24, 2015 at 05:30:54PM +0200, Peter Zijlstra wrote: > On Fri, Jul 24, 2015 at 05:26:37PM +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. > > http://marc.info/?l=linux-kernel&m=143773601130974 > > We re-enable before going back to userspace. Ah OK thanks Peter. I'm sorry if I'm adding more noise than anything here, it's hard to follow and it becomes a bit complex. 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/