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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 626B3C7618D for ; Mon, 20 Mar 2023 11:01:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229783AbjCTLBR (ORCPT ); Mon, 20 Mar 2023 07:01:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33378 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229904AbjCTLAw (ORCPT ); Mon, 20 Mar 2023 07:00:52 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CE8C79008 for ; Mon, 20 Mar 2023 03:55:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1679309732; 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=hZyCMxGpcR0S73UtYylnn7dYqSGpGJubntx2gaRzXj0=; b=hN3mNu4yEf2xkfj4or3ogFG6HVzJReytpvfqTslXSta/D7lHv2cAn5XgyPErzy/G9FPBCw 0I3LCYS5Rm5SMszITLcOY6u+OaYJyLSgLJkadAMlBdUfFLOswbz5uKgHR2/4Pdm2uG8++z NP11k1jSZJIsoS/DqXuW7CZ7Z5TJqzU= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-296-n2BhCl7bOKeb2TmwZHKxEw-1; Mon, 20 Mar 2023 06:55:31 -0400 X-MC-Unique: n2BhCl7bOKeb2TmwZHKxEw-1 Received: by mail-wr1-f70.google.com with SMTP id g7-20020a5d6987000000b002cea7acd26fso1357784wru.5 for ; Mon, 20 Mar 2023 03:55:31 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1679309730; 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=hZyCMxGpcR0S73UtYylnn7dYqSGpGJubntx2gaRzXj0=; b=xVfMCIGnhbPe+cZB8l43E84Om/rP+OzqjLpctWahNcH7rhHHuk9mDV7hBFmoMDkAr5 sQaRLgim5t+DDo2j+8xZkpXRxyw+Vvysj30geDi4jErj+6UYUpF9gqlhdTPJbd0DxUo4 cpP1Z50PlxnBlzu5ReyprpuVsZPTiQobjSx/h7dNeBwsECbtycrcwFXwbtSQg4aJcdLJ PHqFfZ3ZzeDWXmzWGexKuLffZuNThUZbc4fgvVHw0NBBCNmzKQ+giK/8Zv0rBvXAGtYl STgVhja8a2yS55DQJ6mfChPNWFefd85Tt82GfEnxzMLcyqpC9f55mzin5I/uQoZnaDoV k/Rg== X-Gm-Message-State: AO0yUKXOEyXGQUp4zEr4u5+eTXjk8Q8d7oDormeVm0RoPoZI0dFWfEgV 03p8BqS84j+LJFtn5TKOnXsG/UnBBH3rh1pai5uK6U/GvaBLy5ON6YcDgR/jM15NIZhsLgbgCAB 1pufICd50M5Y1pPNP0DvjYTpf X-Received: by 2002:a5d:4d10:0:b0:2d1:7ade:aad with SMTP id z16-20020a5d4d10000000b002d17ade0aadmr11360083wrt.31.1679309730068; Mon, 20 Mar 2023 03:55:30 -0700 (PDT) X-Google-Smtp-Source: AK7set93CzdZEb3DYvK+1MT2JxGK+OwqrYFwweBrtleHk/IXtONusAqG4ZSXQvD5FA52RfO37i3ukA== X-Received: by 2002:a5d:4d10:0:b0:2d1:7ade:aad with SMTP id z16-20020a5d4d10000000b002d17ade0aadmr11360062wrt.31.1679309729712; Mon, 20 Mar 2023 03:55:29 -0700 (PDT) Received: from ?IPV6:2003:cb:c702:4100:a064:1ded:25ec:cf2f? (p200300cbc7024100a0641ded25eccf2f.dip0.t-ipconnect.de. [2003:cb:c702:4100:a064:1ded:25ec:cf2f]) by smtp.gmail.com with ESMTPSA id v7-20020a5d4b07000000b002c56af32e8csm8555317wrq.35.2023.03.20.03.55.27 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 20 Mar 2023 03:55:29 -0700 (PDT) Message-ID: Date: Mon, 20 Mar 2023 11:55:27 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.8.0 Subject: Re: [PATCH v8 17/40] mm: Move VM_UFFD_MINOR_BIT from 37 to 38 Content-Language: en-US To: Rick Edgecombe , 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 , Kees Cook , 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, szabolcs.nagy@arm.com Cc: Yu-cheng Yu References: <20230319001535.23210-1-rick.p.edgecombe@intel.com> <20230319001535.23210-18-rick.p.edgecombe@intel.com> From: David Hildenbrand Organization: Red Hat In-Reply-To: <20230319001535.23210-18-rick.p.edgecombe@intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 19.03.23 01:15, Rick Edgecombe wrote: > From: Yu-cheng Yu > > 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. > > Future patches will introduce a new VM flag VM_SHADOW_STACK that will be > VM_HIGH_ARCH_BIT_5. VM_HIGH_ARCH_BIT_1 through VM_HIGH_ARCH_BIT_4 are > bits 32-36, and bit 37 is the unrelated VM_UFFD_MINOR_BIT. For the sake > of order, make all VM_HIGH_ARCH_BITs stay together by moving > VM_UFFD_MINOR_BIT from 37 to 38. This will allow VM_SHADOW_STACK to be > introduced as 37. > > Co-developed-by: Rick Edgecombe > Signed-off-by: Yu-cheng Yu > Signed-off-by: Rick Edgecombe > Reviewed-by: Kees Cook > Reviewed-by: Axel Rasmussen > Acked-by: Mike Rapoport (IBM) > Acked-by: Peter Xu > Tested-by: Pengfei Xu > Tested-by: John Allen > Tested-by: Kees Cook > --- Reviewed-by: David Hildenbrand -- Thanks, David / dhildenb