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=-8.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL 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 D6921C35E01 for ; Tue, 25 Feb 2020 20:37:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A3BCE20675 for ; Tue, 25 Feb 2020 20:37:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="LQ3s5JsG" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731821AbgBYUhi (ORCPT ); Tue, 25 Feb 2020 15:37:38 -0500 Received: from mail-pj1-f52.google.com ([209.85.216.52]:55576 "EHLO mail-pj1-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731297AbgBYUhi (ORCPT ); Tue, 25 Feb 2020 15:37:38 -0500 Received: by mail-pj1-f52.google.com with SMTP id d5so229929pjz.5 for ; Tue, 25 Feb 2020 12:37:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=v1XIiBi4oFqFORFlQSNw7k0aiV4sK296qJvfGhGJwdw=; b=LQ3s5JsGiE5C/5QwAaBVAvmcQzFSZQV/cq37pLIqqZoS3kr5rWHIeVPeJi0QSbm7dU O7s4jzwksIiWqBJl3RfEfyT4PA4Nj/Vtkwy64hhxX4FdUhNGyRFAINXPapkhR1QhuKld l6+1XX+FTFlbm9z3wgR6d6GVBMsl7z+jf2myRX5SR6V7qPuYrz77DbG6ScEQXzWT0IAT ib4+WM9ZvKKuzoqe96C5ctW3XxDOjZn1POfDRcLHx9jYZF6z2LihbFkU44SdtUsDvdIl mVW632toRtCJCwzWCcBKjACtoXBm/Smx194+Sm3i8GOjCdsRkPNKzWG1A688jczm79dY Gj6A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=v1XIiBi4oFqFORFlQSNw7k0aiV4sK296qJvfGhGJwdw=; b=YvXNQm8Evyv2IlFtQUiS7515uJEf4vX1rmVjtR2ZLWye8RYosQJ74lH6zOzY25x+wX il9q8YO6tlCeZAB0gM+3cHp/3aSOyW+rCGGvGj9XzwMtNmb/kdsfnosyt9WnoxCDPHge 1eks2lVm+0lgwbe8Y3+23sKuSASpbwkCu4LBU2OsxU4iVt85z0EPuZb9l98XSoJ3Oj3l /9cejRUSDKag9kvLLNojTZNriMza1c4sgVaqY1OE67l42wCDpbyky0ElRSTdtSF/LKPp sOCdMMKaa95b4nRfm0O8YzucJ/1muwdjvSPiu35WQT4ARHdvK2STDO8himdhi+onXcDt /0nA== X-Gm-Message-State: APjAAAWolLf9ZiIma0cX/Z1uCDOs7vi8ghuxewhtYsPrXYy8aGXuWOqb qYXx0h1UxXX/3GsjCXbOaXRRNnkU4Uv6cWwzl/LmXg== X-Google-Smtp-Source: APXvYqwA9l5PA1pH+Ecx/QO7gbcCcyQIT07mu96WcqOtKhnbLmxVjht2OHC1qkLLWoQLn5YC4KnOfLbelRCE2tYsDCc= X-Received: by 2002:a17:90a:7784:: with SMTP id v4mr955101pjk.134.1582663057319; Tue, 25 Feb 2020 12:37:37 -0800 (PST) MIME-Version: 1.0 References: <20200109150218.16544-2-nivedita@alum.mit.edu> <20200222050845.GA19912@ubuntu-m2-xlarge-x86> <20200222065521.GA11284@zn.tnic> <20200222070218.GA27571@ubuntu-m2-xlarge-x86> <20200222072144.asqaxlv364s6ezbv@google.com> <20200222074254.GB11284@zn.tnic> <20200222162225.GA3326744@rani.riverdale.lan> <202002242122.AA4D1B8@keescook> <20200225182951.GA1179890@rani.riverdale.lan> <202002251140.4F28F0A4F@keescook> In-Reply-To: <202002251140.4F28F0A4F@keescook> From: Nick Desaulniers Date: Tue, 25 Feb 2020 12:37:26 -0800 Message-ID: Subject: Re: --orphan-handling=warn To: Kees Cook Cc: Arvind Sankar , Fangrui Song , Borislav Petkov , Nathan Chancellor , Thomas Gleixner , "maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)" , LKML , clang-built-linux , Michael Matz , Kristen Carlson Accardi Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 25, 2020 at 11:43 AM Kees Cook wrote: > > On Tue, Feb 25, 2020 at 01:29:51PM -0500, Arvind Sankar wrote: > > On Mon, Feb 24, 2020 at 09:35:04PM -0800, Kees Cook wrote: > > > Note that cheating and doing the 1-to-1 mapping by handy with a 40,000 > > > entry linker script ... made ld.lld take about 15 minutes to do the > > > final link. :( > > > > Out of curiosity, how long does ld.bfd take on that linker script :) > > A single CPU at 100% for 15 minutes. :) I can see the implementers of linker script handling thinking "surely no one would ever have >10k entries." Then we invented things like -ffunction-sections, -fdata-sections, (per basic block equivalents: https://reviews.llvm.org/D68049) and then finally FGKASLR. "640k ought to be enough for anybody" and such. -- Thanks, ~Nick Desaulniers