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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 448AEC34047 for ; Wed, 19 Feb 2020 16:52:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 182FC2467E for ; Wed, 19 Feb 2020 16:52:00 +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="aPCcJ9zr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726750AbgBSQv6 (ORCPT ); Wed, 19 Feb 2020 11:51:58 -0500 Received: from merlin.infradead.org ([205.233.59.134]:35476 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726450AbgBSQv6 (ORCPT ); Wed, 19 Feb 2020 11:51:58 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.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=aOY3HVNQlxhNJtO2V3TApKHEpYE+w+Db2fWfBxPBg70=; b=aPCcJ9zrRXoUBYVDUKXy3j/k5j yZk9tmPqWFKmqWJQ98hEtRqBOsPIYOIenFwwhHx8m8CYgSGxcMjQzJ3YApVKYLxDgUX8aXH4oQzJf KfZg5wyIDaz2RVRvBCtSBe6T39nda9WAj3V65qNSoEBI5/eA+3hPRpB2ADTKUO/zfZ4q+nOTE78/5 H6ljMA5Pp3zU3gbJ2Duv8QwodNYEKtto+/JcMYkkLWTtPjcY4t4V+YTCkY9VRCLXJAGPxTQpK/ooh c2qx87kmUEOKNEsWjyp/LQ/LKXol9Q8hyI60NtIMd2SzUwABydg/rZARjRJvflIPrQBT/U2mRpItU 1vqZOtTQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1j4SZN-0001JM-FA; Wed, 19 Feb 2020 16:51:29 +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 75EB4300606; Wed, 19 Feb 2020 17:49:35 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id DB88D201E478A; Wed, 19 Feb 2020 17:51:27 +0100 (CET) Date: Wed, 19 Feb 2020 17:51:27 +0100 From: Peter Zijlstra To: Dmitry Vyukov Cc: LKML , linux-arch , Steven Rostedt , Ingo Molnar , Joel Fernandes , Greg Kroah-Hartman , "Gustavo A. R. Silva" , Thomas Gleixner , "Paul E. McKenney" , Josh Triplett , Mathieu Desnoyers , Lai Jiangshan , Andy Lutomirski , tony.luck@intel.com, Frederic Weisbecker , Dan Carpenter , Masami Hiramatsu , Andrey Ryabinin , kasan-dev Subject: Re: [PATCH v3 22/22] x86/int3: Ensure that poke_int3_handler() is not sanitized Message-ID: <20200219165127.GF14946@hirez.programming.kicks-ass.net> References: <20200219144724.800607165@infradead.org> <20200219150745.651901321@infradead.org> <20200219163025.GH18400@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200219163025.GH18400@hirez.programming.kicks-ass.net> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 19, 2020 at 05:30:25PM +0100, Peter Zijlstra wrote: > > It's quite fragile. Tomorrow poke_int3_handler handler calls more of > > fewer functions, and both ways it's not detected by anything. > > Yes; not having tools for this is pretty annoying. In 0/n I asked Dan if > smatch could do at least the normal tracing stuff, the compiler > instrumentation bits are going to be far more difficult because smatch > doesn't work at that level :/ > > (I actually have ... and I stopped typing ... I think I mean to say something like: ... more changes to poke_int3_handler() pending, but they're all quite simple).