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 E5F8FC4332F for ; Fri, 14 Oct 2022 19:44:48 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 718946B0075; Fri, 14 Oct 2022 15:44:48 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6C7DE8E0002; Fri, 14 Oct 2022 15:44:48 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 542098E0001; Fri, 14 Oct 2022 15:44:48 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 451A46B0075 for ; Fri, 14 Oct 2022 15:44:48 -0400 (EDT) Received: from smtpin10.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 149F71C5EFD for ; Fri, 14 Oct 2022 19:44:48 +0000 (UTC) X-FDA: 80020582656.10.821934C Received: from mail.skyhub.de (mail.skyhub.de [5.9.137.197]) by imf19.hostedemail.com (Postfix) with ESMTP id 91AB01A002C for ; Fri, 14 Oct 2022 19:44:40 +0000 (UTC) Received: from zn.tnic (p200300ea9733e7ed329c23fffea6a903.dip0.t-ipconnect.de [IPv6:2003:ea:9733:e7ed:329c:23ff:fea6:a903]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 936011EC0745; Fri, 14 Oct 2022 21:44:34 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1665776674; 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:in-reply-to:in-reply-to: references:references; bh=/V95RNDyG4C0aXVPfYmbPIz3FOBoOTs+eKl5UB9vPKs=; b=CH3Dw0F6sUBootIDepy8xu8SZlUqfyEbs1sZrwlg3E7dKOz34Nr41iAjSyzAvqEtP6IfFj H+Hv4B1TcCVGKnzMjTjy0r+KM7Pq05/PjJWMKOrsBw7qD+sz+QE1gmondjrULUrTc/BDJn ly1DXRZkoOd6GwlsHRLdAYjL+jHXVJE= Date: Fri, 14 Oct 2022 21:44:34 +0200 From: Borislav Petkov To: "Edgecombe, Rick P" Cc: "bsingharora@gmail.com" , "hpa@zytor.com" , "Syromiatnikov, Eugene" , "peterz@infradead.org" , "rdunlap@infradead.org" , "keescook@chromium.org" , "Yu, Yu-cheng" , "dave.hansen@linux.intel.com" , "kirill.shutemov@linux.intel.com" , "Eranian, Stephane" , "linux-mm@kvack.org" , "fweimer@redhat.com" , "nadav.amit@gmail.com" , "jannh@google.com" , "dethoma@microsoft.com" , "linux-arch@vger.kernel.org" , "kcc@google.com" , "pavel@ucw.cz" , "oleg@redhat.com" , "hjl.tools@gmail.com" , "linux-doc@vger.kernel.org" , "Lutomirski, Andy" , "arnd@arndb.de" , "jamorris@linux.microsoft.com" , "Moreira, Joao" , "tglx@linutronix.de" , "mike.kravetz@oracle.com" , "x86@kernel.org" , "Yang, Weijiang" , "john.allen@amd.com" , "rppt@kernel.org" , "mingo@redhat.com" , "Shankar, Ravi V" , "corbet@lwn.net" , "linux-kernel@vger.kernel.org" , "linux-api@vger.kernel.org" , "gorcunov@gmail.com" Subject: Re: [PATCH v2 04/39] x86/cpufeatures: Enable CET CR4 bit for shadow stack Message-ID: References: <20220929222936.14584-1-rick.p.edgecombe@intel.com> <20220929222936.14584-5-rick.p.edgecombe@intel.com> <1f9e89ae13b49ffbcc947bf6bdee0303387c5cd4.camel@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1f9e89ae13b49ffbcc947bf6bdee0303387c5cd4.camel@intel.com> ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1665776687; a=rsa-sha256; cv=none; b=2qgl8SKxosvlPtExaQwWHt3niZYUQHKR4uD/mXboPHO6pzrP9QyyLi2t1KYk/qQDRwwIEr lw+Lw768NvnbFyXgoowgHIXIwhtTwM1iOqPhWqefFI4OXYatUxFV29ROgfGXAsOV+eQE6l r0FpOsKx+ovEDXEl+rcvDI0XM68A62E= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=temperror ("DNS error when getting key") header.d=alien8.de header.s=dkim header.b=CH3Dw0F6; spf=pass (imf19.hostedemail.com: domain of bp@alien8.de designates 5.9.137.197 as permitted sender) smtp.mailfrom=bp@alien8.de; dmarc=temperror reason="server fail" header.from=alien8.de (policy=temperror) ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1665776687; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=/V95RNDyG4C0aXVPfYmbPIz3FOBoOTs+eKl5UB9vPKs=; b=bJWY5CdW7z7aACWTfmWPd5JcWRXbn6LyLGjEbHyH3FBpg/eN4Pazf0D34ierzTrGAV1K5a Pn5yHWma6s2zUCPAwU3teoyUhI35Fk8Z/BSjt8wHXx6siQeFBDUOQ65pVxZMXXUN1HyLdx YlsiahyvNHnUhDlM29Dn9Q1QbxihQW8= X-Rspam-User: X-Stat-Signature: dqwbedezdtos44hef139xqsbxx1zhamj X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 91AB01A002C Authentication-Results: imf19.hostedemail.com; dkim=temperror ("DNS error when getting key") header.d=alien8.de header.s=dkim header.b=CH3Dw0F6; spf=pass (imf19.hostedemail.com: domain of bp@alien8.de designates 5.9.137.197 as permitted sender) smtp.mailfrom=bp@alien8.de; dmarc=temperror reason="server fail" header.from=alien8.de (policy=temperror) X-HE-Tag: 1665776680-669490 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 Fri, Oct 14, 2022 at 06:15:30PM +0000, Edgecombe, Rick P wrote: > Andrew Cooper has suggested to create some software cpu features to > differentiate user/supervisor CET feature use. It could replace > HAS_KERNEL_IBT. Any objections to that versus Kconfig symbols? Sure, except you can't use them in arch/x86/include/asm/idtentry.h:8:#define IDT_ALIGN (8 * (1 + HAS_KERNEL_IBT)) as that gets used in asm code. But you don't have to do this in this patchset - it is huge already anyway. I have this thing on my todo so I'll get to it eventually. Unless you're itching to remove it yourself - then I won't stay in the way. :-) Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette