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=-1.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham 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 1253FC468BD for ; Fri, 7 Jun 2019 22:27:22 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id BCB4D205ED for ; Fri, 7 Jun 2019 22:27:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=amacapital-net.20150623.gappssmtp.com header.i=@amacapital-net.20150623.gappssmtp.com header.b="fAQwIxWx" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BCB4D205ED Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=amacapital.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4713B6B0274; Fri, 7 Jun 2019 18:27:21 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 420796B0275; Fri, 7 Jun 2019 18:27:21 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2E8516B0276; Fri, 7 Jun 2019 18:27:21 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-pf1-f197.google.com (mail-pf1-f197.google.com [209.85.210.197]) by kanga.kvack.org (Postfix) with ESMTP id E3FD56B0274 for ; Fri, 7 Jun 2019 18:27:20 -0400 (EDT) Received: by mail-pf1-f197.google.com with SMTP id f25so2431564pfk.14 for ; Fri, 07 Jun 2019 15:27:20 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:mime-version:subject:from :in-reply-to:date:cc:content-transfer-encoding:message-id:references :to; bh=hraLxNELwM1NZ3lrrobGX779u9y1WVgm2X9KZ6MnzVU=; b=UHBTAWGqeQ84FzJH5Y8NvxAJaknxVp3MgPSPIsCzeEXCdi1TTRATFVskhrnCYDl0Gv CxzfMFUZmXSnrT2pPSO1ars6KbQuzkuwlkMbt+Sk1w3R6GnIxyzDdPaeXSbNkSN6k+sj 9gITQ2Igj2v6YuSdp+du3JAhYEXd/ViJlUAiBxawDGrAUM+XDTKZ8+3Scjbix01RG8aA GwrOwbgRzHlkBLW2xrNzF/24hFkPb3CIUYj6b2JhnnBukrdN2VeWcqNwXOsR8H5Ed8NG VjQ5IJTY+Q/jzA6bX9FGV60x9WZQS4oi0uDQISpRwCcc333NfREXdQKhNEZYbVov6BPH z4KA== X-Gm-Message-State: APjAAAXCYCHWW3A3mMWuRLDgR3Z0SgRCcX3VCg85qyeND3C0++7jNiGW XcTDId4dHzNEhuojqBESabflpcQb3Qu0W+WiaVnf2Od6ypqcEvX7R6/ZiTNRw5D+QsCjEuJvB76 /opcrP54gnX498kTuuta81rfr4MnjLwYfk31OuSNitdQHo1QkmoZcQ2WYdAHkZyPtjA== X-Received: by 2002:a17:902:6bc8:: with SMTP id m8mr57111130plt.227.1559946440401; Fri, 07 Jun 2019 15:27:20 -0700 (PDT) X-Received: by 2002:a17:902:6bc8:: with SMTP id m8mr57111109plt.227.1559946439796; Fri, 07 Jun 2019 15:27:19 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1559946439; cv=none; d=google.com; s=arc-20160816; b=SINNdcC2F+UqA8rFjuNoQPq1fU5Q3ukDjbzo5VXrnGQIDw5kw90zRnfYSJ5QJiPw+H 0HMND4KY22ajx88uFVmWSqVMQc91ZpNIMbbO2PobkF9ZLemdpVSiXKBDSKoSspyXru7g d4i/VjbjAcHl0NuvJzSnjxQrXpu+d2sDvy+xESspExcSoBGt7GHKVjYPGQjtDmf8OxGf JkQt6nYl3KzbEUx7pNld5m/pf0TeQa+pRHWgH3LwUrZix4B/VOW+wn1jqLhY/cvYjSmD vzjLZcG1OapU4zMA1/LG5emUV6csg68rfnTAlrnSPgbb4YOp3zsRNhbfhxGZDeW5/Mm5 wrCA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=to:references:message-id:content-transfer-encoding:cc:date :in-reply-to:from:subject:mime-version:dkim-signature; bh=hraLxNELwM1NZ3lrrobGX779u9y1WVgm2X9KZ6MnzVU=; b=sVuhR+ZkpHvqzF/Sd3WhfaiohRYU5h+L4Lsg1UO0yya7WjhNXW49e3/BpYpseaH+q5 LvApqpKn6MGZCrP56f3Aq6dIULBDuxSN9eci14SZdI8hZPDPd0JQohm33Jj3Vee+zfob slO2YE+BiTZerV4os031Gyo2jfOXR5gXGK/XUsVfr37bHpFC7qoJI+WcfhFP2AVqYFEX obUX2gd2uxbNljoucDu+HYQbxgrOiWQehjoBDsZWhYvMpAa68gUqJQdf5ZDMr/wgTe4J YYCXyz8To7gyig7yEQ0axOk+4mJaXoMS/YY1v0a84e7G/nc+wJJJS+0lNUhBTP0/vdEv RE6w== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@amacapital-net.20150623.gappssmtp.com header.s=20150623 header.b=fAQwIxWx; spf=pass (google.com: domain of luto@amacapital.net designates 209.85.220.65 as permitted sender) smtp.mailfrom=luto@amacapital.net Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id x189sor3485833pfx.37.2019.06.07.15.27.19 for (Google Transport Security); Fri, 07 Jun 2019 15:27:19 -0700 (PDT) Received-SPF: pass (google.com: domain of luto@amacapital.net designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; Authentication-Results: mx.google.com; dkim=pass header.i=@amacapital-net.20150623.gappssmtp.com header.s=20150623 header.b=fAQwIxWx; spf=pass (google.com: domain of luto@amacapital.net designates 209.85.220.65 as permitted sender) smtp.mailfrom=luto@amacapital.net DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amacapital-net.20150623.gappssmtp.com; s=20150623; h=mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=hraLxNELwM1NZ3lrrobGX779u9y1WVgm2X9KZ6MnzVU=; b=fAQwIxWx36GcX9oIEt7f+jVMHginM+LONwFdfMNqwIhko+8c0QHYbEF8bNlyIqbI9j NQNEvOKC/rk/tH80WaLOxYfIeLrNuLs39w+NLcIj3q54Q271veY67rrkNFKpfdqfZfj7 zJroDKjRWmVDQ90XGnNScGmFaTzL9du1I7zDspqbrM6NsrWdM1i+JbmO4PVz/elLIgeu 6BrmpgiXUF9dz/S6HaFuV5ThOeSRhvAkGNBoMZMOPzaVaIgbNw2niqpkC+G9ce07EdDH qP3J8OITji6PPDgyiEOb7pbi42mIE/z0MQOvU/LZER5Na/CvkkoUFll6uwuMASm3splg LFTQ== X-Google-Smtp-Source: APXvYqwFO3Q0DLnvBTYrA6mi0dVS8BZ1iVqUNQ4tJLNaZqwnxT+p/ehoHtcdu1qHh/Y6c+cHQmyQLA== X-Received: by 2002:a62:3287:: with SMTP id y129mr55579697pfy.101.1559946439420; Fri, 07 Jun 2019 15:27:19 -0700 (PDT) Received: from ?IPv6:2600:1012:b018:c314:403f:c95d:60d3:b732? ([2600:1012:b018:c314:403f:c95d:60d3:b732]) by smtp.gmail.com with ESMTPSA id 2sm3147331pfo.41.2019.06.07.15.27.18 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 07 Jun 2019 15:27:18 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (1.0) Subject: Re: [PATCH v7 03/14] x86/cet/ibt: Add IBT legacy code bitmap setup function From: Andy Lutomirski X-Mailer: iPhone Mail (16F203) In-Reply-To: Date: Fri, 7 Jun 2019 15:27:16 -0700 Cc: Yu-cheng Yu , Peter Zijlstra , x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org, Arnd Bergmann , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Randy Dunlap , "Ravi V. Shankar" , Vedvyas Shanbhogue , Dave Martin Content-Transfer-Encoding: quoted-printable Message-Id: <4F7D0C3C-F239-4B67-BB05-31350F809293@amacapital.net> References: <20190606200926.4029-1-yu-cheng.yu@intel.com> <20190606200926.4029-4-yu-cheng.yu@intel.com> <20190607080832.GT3419@hirez.programming.kicks-ass.net> <20190607174336.GM3436@hirez.programming.kicks-ass.net> <34E0D316-552A-401C-ABAA-5584B5BC98C5@amacapital.net> <7e0b97bf1fbe6ff20653a8e4e147c6285cc5552d.camel@intel.com> <4b448cde-ee4e-1c95-0f7f-4fe694be7db6@intel.com> <0e505563f7dae3849b57fb327f578f41b760b6f7.camel@intel.com> To: Dave Hansen X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: > On Jun 7, 2019, at 2:09 PM, Dave Hansen wrote: >=20 > On 6/7/19 1:06 PM, Yu-cheng Yu wrote: >>> Huh, how does glibc know about all possible past and future legacy code >>> in the application? >> When dlopen() gets a legacy binary and the policy allows that, it will ma= nage >> the bitmap: >>=20 >> If a bitmap has not been created, create one. >> Set bits for the legacy code being loaded. >=20 > I was thinking about code that doesn't go through GLIBC like JITs. CRIU is another consideration: it would be rather annoying if CET programs c= an=E2=80=99t migrate between LA57 and normal machines.=