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 9A2F8C433F5 for ; Tue, 4 Oct 2022 08:36:32 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 018436B0072; Tue, 4 Oct 2022 04:36:32 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id F15666B0073; Tue, 4 Oct 2022 04:36:31 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DAA118E0001; Tue, 4 Oct 2022 04:36:31 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id C80046B0072 for ; Tue, 4 Oct 2022 04:36:31 -0400 (EDT) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 803E11C5337 for ; Tue, 4 Oct 2022 08:36:31 +0000 (UTC) X-FDA: 79982610582.06.8BEAED5 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf08.hostedemail.com (Postfix) with ESMTP id EE4AE16001D for ; Tue, 4 Oct 2022 08:36:30 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 0D64B612B3; Tue, 4 Oct 2022 08:36:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 59C95C433D6; Tue, 4 Oct 2022 08:36:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1664872589; bh=Vta9NNBr6nkHrzFHJhf3d1KXNnH13ptRWqXqAZ9UuEA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=fd64pqzS0vr1Ay1lpgWB0pzIJx/pan0dcKrQm+bEESTb6QvXN8YvuzOiuxvO9KTVb ek5+IBL+J9KydBy0BbecAAwU/jxjdjCx56Ix+M4Fx5jiW8JCShwS8lw8EgWGDBZ39w imMW7YzBADcIahbEZlNGpHe/fwLHm0MzdExPXLojDaBIOxijF18NtWIpX3cjiXiq14 fdUAAFs6aJtZBqP0tmFC061PEhUaAjdIpRo1lbbVrBDU1hH8c4ylTSdv75dGF/t0Pp B31dqnsqa4pOzRFODOizMXWBrH8EJlmGGC1zGaiWCUjHcwYrfuGNdzIQZsvIT/Y5jX 31+AYNaAKcBkQ== Date: Tue, 4 Oct 2022 11:36:05 +0300 From: Mike Rapoport To: Dave Hansen Cc: Kees Cook , 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 , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , Peter Zijlstra , Randy Dunlap , "Ravi V . Shankar" , Weijiang Yang , "Kirill A . Shutemov" , joao.moreira@intel.com, John Allen , kcc@google.com, eranian@google.com, jamorris@linux.microsoft.com, dethoma@microsoft.com, Tom Lendacky , "Moger, Babu" Subject: Re: [PATCH v2 33/39] x86/cpufeatures: Limit shadow stack to Intel CPUs Message-ID: References: <20220929222936.14584-1-rick.p.edgecombe@intel.com> <20220929222936.14584-34-rick.p.edgecombe@intel.com> <202210031656.23FAA3195@keescook> <559f937f-cab4-d408-6d95-fc85b4809aa9@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <559f937f-cab4-d408-6d95-fc85b4809aa9@intel.com> ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1664872591; 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=1yU1aKED1/HjRjYTJVlFFIKo8iwHYsppTCUk78I3q2M=; b=5WhsYIu+NVxepiIZ029SYYFtSYf3Yvb5CWJuyR4oKM3Bd2CmWyV2U5AzvfW8efTTOWTs6Y OA28PQ4+0c1iIOuq8h8t+/kq8DnZnpWmJT07jrEEMI0O+65t+9eA72GvKlfaYQx+qCuvnw f8k5A4vWMC/6+14lj/dvWdaZ47aRVmA= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=fd64pqzS; spf=pass (imf08.hostedemail.com: domain of rppt@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=none) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1664872591; a=rsa-sha256; cv=none; b=Qu6rfCSwO8REdWXbhgs6bIK17kZpsdyd2J/G8tpF2k8CTKQz8Ls8NWZ3c0OIFJcISDJJVC /IseNSJL2vEZPYgYScywrjeUX3a/2AtqaEzfK4vVFLJZT2Cm+olBok1wh3wnRI9H1SpQ8E Q1hR0NIqAeQOEFjMebkRimKRRff8y40= X-Stat-Signature: 6s7mfuow333pasznpj9d6aor8k1racz4 X-Rspamd-Queue-Id: EE4AE16001D Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=fd64pqzS; spf=pass (imf08.hostedemail.com: domain of rppt@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=rppt@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-Rspamd-Server: rspam07 X-Rspam-User: X-HE-Tag: 1664872590-666221 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 Mon, Oct 03, 2022 at 05:09:04PM -0700, Dave Hansen wrote: > On 10/3/22 16:57, Kees Cook wrote: > > On Thu, Sep 29, 2022 at 03:29:30PM -0700, Rick Edgecombe wrote: > >> Shadow stack is supported on newer AMD processors, but the kernel > >> implementation has not been tested on them. Prevent basic issues from > >> showing up for normal users by disabling shadow stack on all CPUs except > >> Intel until it has been tested. At which point the limitation should be > >> removed. > >> > >> Signed-off-by: Rick Edgecombe > > So running the selftests on an AMD system is sufficient to drop this > > patch? > > Yes, that's enough. > > I _thought_ the AMD folks provided some tested-by's at some point in the > past. But, maybe I'm confusing this for one of the other shared > features. Either way, I'm sure no tested-by's were dropped on purpose. > > I'm sure Rick is eager to trim down his series and this would be a great > patch to drop. Does anyone want to make that easy for Rick? FWIW, I've run CRIU test suite with the previous version of this set on an AMD machine. > -- Sincerely yours, Mike.