From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CDE54C433E0 for ; Thu, 14 May 2020 09:33:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A2E012065D for ; Thu, 14 May 2020 09:33:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="RcKHDjZA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726033AbgENJdR (ORCPT ); Thu, 14 May 2020 05:33:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45658 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1725878AbgENJdR (ORCPT ); Thu, 14 May 2020 05:33:17 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 75859C061A0C for ; Thu, 14 May 2020 02:33:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=cVHXoLB2mKPJ84h2fIyDOysMGSEkFTC+SjVjPPzZLB4=; b=RcKHDjZAzs8ZFQuurs9chdvEMs Ug3zPq0RzbPHbGa65zKp4w3X5G10dMdyurJesgWwc/d5hzxl8wAX1JAIpAOcGvsToBopebGu2j8ar LErFASg53ubd4FBnlXOHGsaCgGS3nYRcN7Fl9CtlB3mfLAmApp3uaFU30NFMRax4h+MyphZK5Rxk+ 3UVOHv4Xb+HC/Kdjoru9eIptT2B0k1G/At6rkuDumsIDsv7BbRmSC1xHAMOdz6eKdDUJ1Ems0l/Nb AqggijEUCueqTIqbh3Pn7UxLijTGh+ZxjPWj0i3PK5bQ9TFz83TIgs9yUvwWrwjFJHuUiWzltxKQV rof4KKPg==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jZAEe-0002Vl-Np; Thu, 14 May 2020 09:33:00 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 229B0301A66; Thu, 14 May 2020 11:32:57 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id CF06D213C8B59; Thu, 14 May 2020 11:32:57 +0200 (CEST) Date: Thu, 14 May 2020 11:32:57 +0200 From: Peter Zijlstra To: Andy Lutomirski Cc: Thomas Gleixner , LKML , X86 ML , "Paul E. McKenney" , Alexandre Chartre , Frederic Weisbecker , Paolo Bonzini , Sean Christopherson , Masami Hiramatsu , Petr Mladek , Steven Rostedt , Joel Fernandes , Boris Ostrovsky , Juergen Gross , Brian Gerst , Mathieu Desnoyers , Josh Poimboeuf , Will Deacon Subject: Re: [patch V4 part 4 02/24] x86/int3: Avoid atomic instrumentation Message-ID: <20200514093257.GT2978@hirez.programming.kicks-ass.net> References: <20200505134926.578885807@linutronix.de> <20200505135313.517429268@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 13, 2020 at 09:57:52PM -0700, Andy Lutomirski wrote: > On Tue, May 5, 2020 at 7:15 AM Thomas Gleixner wrote: > > > > From: Peter Zijlstra > > > > Use arch_atomic_*() and READ_ONCE_NOCHECK() to ensure nothing untoward > > creeps in and ruins things. > > > > That is; this is the INT3 text poke handler, strictly limit the code > > that runs in it, lest it inadvertenly hits yet another INT3. > > > Acked-by: Andy Lutomirski > > Does objtool catch this error? It does not. I'll put it on the (endless) todo list..