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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57A5FC05027 for ; Mon, 20 Feb 2023 11:17:20 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 8D44C6B0071; Mon, 20 Feb 2023 06:17:19 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 85D026B0072; Mon, 20 Feb 2023 06:17:19 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6D6B66B0073; Mon, 20 Feb 2023 06:17:19 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 522E16B0071 for ; Mon, 20 Feb 2023 06:17:19 -0500 (EST) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 1C41714011F for ; Mon, 20 Feb 2023 11:17:19 +0000 (UTC) X-FDA: 80487418998.11.D7303BC Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf07.hostedemail.com (Postfix) with ESMTP id 8F4F840005 for ; Mon, 20 Feb 2023 11:17:16 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=f5eV9Sfb; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf07.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1676891836; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=4EQNfPCKlm/dnqlucYMgfhMhQeV8s6OOHLtd2gYWnSc=; b=N3fiVaYdrZJIaWnHzQSbgKsBf8ohJU0FTHsYxizCEIMdMloDEpkt7f+EQv83nyV5a4ojyD oVECSU5G28CGfA32/L6dI9u3JOoEokiVIiiW7GNkSr//dcGUX2jV5VbA9Goa1lC9AzWfWj sIDK4XxvR8+5RC8YSet7QwLRLHjaQPI= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=f5eV9Sfb; dmarc=pass (policy=none) header.from=redhat.com; spf=pass (imf07.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1676891836; a=rsa-sha256; cv=none; b=KPn466W1pOBuo2uOCyKqxqpdIY9pSLo5yzxCJCphTN8RKDLhIrXqPN4zViqfqqNB+ftm4J 4V2M4q3VAMVE0fkZBH/VHiTfszJbxklXb+gCyDSjLgU1ecvwgHbqZNqpmj6tHWSv35Fqjx /tYhcRFbmV1eW23Qp20bQTbBtEwqkIQ= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1676891835; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=4EQNfPCKlm/dnqlucYMgfhMhQeV8s6OOHLtd2gYWnSc=; b=f5eV9Sfbr5eRqRvVqV/ovfHcekpO2Q/V577M8avaT5ismeNOqdCWVi44Y8ZYG++qTywQ0p KYs//XZIwwa8KnOZcK2MpVbaBdR+q+OGo1bXSoRZG6oBXILL+rvuipEycjtXKsQl9bSnYV PfaN0gonGx9WuR0vzeFEPGp67C4DTZM= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-384-tq7w-bJyNYCDn96VA8X-hA-1; Mon, 20 Feb 2023 06:17:14 -0500 X-MC-Unique: tq7w-bJyNYCDn96VA8X-hA-1 Received: by mail-wm1-f72.google.com with SMTP id n15-20020a05600c500f00b003dd07ce79c8so437008wmr.1 for ; Mon, 20 Feb 2023 03:17:14 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:organization:from:references :cc:to:content-language:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=4EQNfPCKlm/dnqlucYMgfhMhQeV8s6OOHLtd2gYWnSc=; b=ItLx/smu2aFnjV7MuLcttYNoJvp6dXZ38D7KQemRwzllTJTco4ciz9E8Jk8D0HYUw+ I6GcMaompOcknTCyGoMo0fwxxz8VAAY4V8g/Vsao+1SvI+w/4WItdNdr8YXCa1JBN65d qzfnTsvSPm8iWT7sBcbkK9iNFXfCw4FwapZ5SM96Oru0VflLHkr4KX9XBy1y6yUQarvg /oHxs2mE19chFvCBMkmVMYZ+xF3bAg5AMwn0t1I2IwTXgAfGIyvmrbZYpN/gHmUsgAx0 H6eE7B4vO9zatwJTt9MqouB1DkdNNImVGIbrrfq9qWT3072SGj2JFNHKkJfTn7coz1Lg IvlQ== X-Gm-Message-State: AO0yUKVyQTYOmvTH11fxTXjL7Z2bt3J0ooIqnW2ZvOB5nZEmcCh5SQEg lzJb4N3U2tdh4spNbrU1khPgz3pjA9ss+Bb3V+QCzfP1ubSOuI0uGCiz+igx8Y0mioGLRv534yX 1p6P1G/HtZBw= X-Received: by 2002:a05:600c:4d89:b0:3e0:1a9:b1e0 with SMTP id v9-20020a05600c4d8900b003e001a9b1e0mr578767wmp.25.1676891833523; Mon, 20 Feb 2023 03:17:13 -0800 (PST) X-Google-Smtp-Source: AK7set8S0E2hPJcQfDWwVBHJ827trXEDgyAecAtZgO3tsbPQgMPJ2pfBI07ijKz0qUw/7N5br62ouQ== X-Received: by 2002:a05:600c:4d89:b0:3e0:1a9:b1e0 with SMTP id v9-20020a05600c4d8900b003e001a9b1e0mr578749wmp.25.1676891833134; Mon, 20 Feb 2023 03:17:13 -0800 (PST) Received: from ?IPV6:2003:cb:c705:8300:e519:4218:a8b5:5bec? (p200300cbc7058300e5194218a8b55bec.dip0.t-ipconnect.de. [2003:cb:c705:8300:e519:4218:a8b5:5bec]) by smtp.gmail.com with ESMTPSA id c128-20020a1c3586000000b003e21558ee9dsm331492wma.2.2023.02.20.03.17.10 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 20 Feb 2023 03:17:12 -0800 (PST) Message-ID: Date: Mon, 20 Feb 2023 12:17:09 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.7.2 Subject: Re: [PATCH v6 11/41] mm: Introduce pte_mkwrite_kernel() To: Kees Cook , Rick Edgecombe Cc: 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 , Andy Lutomirski , Balbir Singh , Borislav Petkov , Cyrill Gorcunov , Dave Hansen , Eugene Syromiatnikov , Florian Weimer , "H . J . Lu" , Jann Horn , Jonathan Corbet , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , Weijiang Yang , "Kirill A . Shutemov" , John Allen , kcc@google.com, eranian@google.com, rppt@kernel.org, jamorris@linux.microsoft.com, dethoma@microsoft.com, akpm@linux-foundation.org, Andrew.Cooper3@citrix.com, christina.schimpe@intel.com, debug@rivosinc.com, linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org, xen-devel@lists.xenproject.org References: <20230218211433.26859-1-rick.p.edgecombe@intel.com> <20230218211433.26859-12-rick.p.edgecombe@intel.com> <63f288cc.a70a0220.5558c.3c92@mx.google.com> From: David Hildenbrand Organization: Red Hat In-Reply-To: <63f288cc.a70a0220.5558c.3c92@mx.google.com> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 8F4F840005 X-Rspamd-Server: rspam09 X-Rspam-User: X-Stat-Signature: rh8aon9csmzpogem37xns18r57qaxa9c X-HE-Tag: 1676891836-213391 X-HE-Meta: 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 dPF7vERY 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 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 19.02.23 21:38, Kees Cook wrote: > On Sat, Feb 18, 2023 at 01:14:03PM -0800, Rick Edgecombe wrote: >> The x86 Control-flow Enforcement Technology (CET) feature includes a new >> type of memory called shadow stack. This shadow stack memory has some >> unusual properties, which requires some core mm changes to function >> properly. >> >> One of these changes is to allow for pte_mkwrite() to create different >> types of writable memory (the existing conventionally writable type and >> also the new shadow stack type). Future patches will convert pte_mkwrite() >> to take a VMA in order to facilitate this, however there are places in the >> kernel where pte_mkwrite() is called outside of the context of a VMA. >> These are for kernel memory. So create a new variant called >> pte_mkwrite_kernel() and switch the kernel users over to it. Have >> pte_mkwrite() and pte_mkwrite_kernel() be the same for now. Future patches >> will introduce changes to make pte_mkwrite() take a VMA. >> >> Only do this for architectures that need it because they call pte_mkwrite() >> in arch code without an associated VMA. Since it will only currently be >> used in arch code, so do not include it in arch_pgtable_helpers.rst. >> >> Cc: linux-doc@vger.kernel.org >> Cc: linux-arm-kernel@lists.infradead.org >> Cc: linux-s390@vger.kernel.org >> Cc: xen-devel@lists.xenproject.org >> Cc: linux-arch@vger.kernel.org >> Cc: linux-mm@kvack.org >> Tested-by: Pengfei Xu >> Suggested-by: David Hildenbrand >> Signed-off-by: Rick Edgecombe > > I think it's a little weird that it's the only PTE helper taking a vma, > but it does seem like the right approach. Right. We could pass the vm flags instead, but not sure if that really improves the situation. So unless someone has a better idea, this LGTM. -- Thanks, David / dhildenb