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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 D31C7C43331 for ; Thu, 26 Mar 2020 18:36:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A0B0020722 for ; Thu, 26 Mar 2020 18:36:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="JQuCPnbn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727446AbgCZSgO (ORCPT ); Thu, 26 Mar 2020 14:36:14 -0400 Received: from mail-pf1-f193.google.com ([209.85.210.193]:40643 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727354AbgCZSgN (ORCPT ); Thu, 26 Mar 2020 14:36:13 -0400 Received: by mail-pf1-f193.google.com with SMTP id c20so674427pfi.7 for ; Thu, 26 Mar 2020 11:36:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=iXlxt2aYlNdrmXy9xrh62320KX+jShx79PK1R5/xAp0=; b=JQuCPnbnMGiAGC1aOyMcC4MmPwZxC6Oi3BG7HdZ54668Q1XbFffRXR0GwZhhSzbFjy 2H+CppEVA/1s0X82dxzmDwfpwkayVvIS3xDh2hcImj75t/xQo9Q93jFRKycRVcxVq7x4 OYRVuQpXPPRZfZpouGVANjeKzLLoTxyHwxTes= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=iXlxt2aYlNdrmXy9xrh62320KX+jShx79PK1R5/xAp0=; b=t9rclE79lOcD++RaPEzJ8Li/VIh9nVjzy7em/4pvt16AcsgJDQPbPxS7u3cbEcE1eg JZyoza7CPVfQ/d1WyUn7sgn9r3ZHqsMHmNjdb4Zq57OGaX1lemGbfwy4lOi0kVSUS7q1 jitLVfalls7UKiAA/Avefc5UQHyzOkvrrQ/RXnUMLBdqJ6krOWUMSXMo+JjRUFSW3rjl IaIA5Eei6UZ/VNJSFBAldhW8IBsuUYy84eGeL6EwFAVVIErsm8yVK3PkCBA34fES3ZbO DsZLQYQ/Z/Umo3WZVC/dPhcSe4QNrWQvg5Oyxea9eDlGPAyqEvBZAIkh5SYKCumizWes ZgRA== X-Gm-Message-State: ANhLgQ2/WuWwfNzl0/NnYwuV+idxck+oYmvchf5iM6moHgNBHTAOeQRi m5dxKu6S1PL34VdehS9FdmJDcA== X-Google-Smtp-Source: ADFU+vuidts8P9YSHqfhFKUIj0CYmlitPay4HIJ1OiYEifPM79lkB188HfB6F4kzetKdTpHlb0KBtw== X-Received: by 2002:aa7:9811:: with SMTP id e17mr9806248pfl.33.1585247772777; Thu, 26 Mar 2020 11:36:12 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id c15sm2242138pfo.139.2020.03.26.11.36.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 26 Mar 2020 11:36:11 -0700 (PDT) Date: Thu, 26 Mar 2020 11:36:10 -0700 From: Kees Cook To: Josh Poimboeuf Cc: Peter Zijlstra , Randy Dunlap , Stephen Rothwell , Linux Next Mailing List , Linux Kernel Mailing List Subject: Re: linux-next: Tree for Mar 18 (objtool) Message-ID: <202003261133.814BEE9F@keescook> References: <20200319173326.oj4qs24x4ly5lrgt@treble> <20200319174028.azzaisoj5gbss7zk@treble> <20200319174550.4wpx4j357nw67nzz@treble> <20200320082613.GA20696@hirez.programming.kicks-ass.net> <202003201131.9B688BC@keescook> <20200324164433.qusyu5h7ykx3f2bu@treble> <202003241105.4707F983@keescook> <20200324222406.zg6hylzqux353jhq@treble> <202003252251.771EF5EC5F@keescook> <20200326163110.n35lxcgkfcar7vd5@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200326163110.n35lxcgkfcar7vd5@treble> Sender: linux-next-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-next@vger.kernel.org On Thu, Mar 26, 2020 at 11:31:10AM -0500, Josh Poimboeuf wrote: > On Wed, Mar 25, 2020 at 10:57:02PM -0700, Kees Cook wrote: > > > In the meantime I can still change objtool to ignore unreachable UD2s if > > > there aren't any better ideas. > > > > It'll still need the objtool change for CONFIG_UBSAN_TRAP, though based on > > the clang bug discussion, I'll probably _also_ be adding CONFIG_UBSAN_WARN > > which won't have an unreachable (and won't bloat the kernel). Testing > > still under way... it is possible that CONFIG_UBSAN_TRAP will go away > > in the future, though. If that happens, should I also remove the change > > at that time? > > I'll go ahead and make the patch and post it soon. It should be pretty > trivial. We can always revert it if CONFIG_UBSAN_TRAP goes away. Awesome, thanks very much. After digging into the WARN-style option, it seems that TRAP is unlikely to go away because it's Clang only; GCC doesn't support the "minimal runtime" option. Yay compilers. Anyway, I'll still get the WARN mode sent out. Thanks for looking at this; can you CC me on the patch? I'm trying to get more familiar with objtool so I don't have to bug you when objtool is angered by crazy stuff I do. ;) -- Kees Cook