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 7D4C7C433FE for ; Tue, 4 Oct 2022 00:09:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230001AbiJDAJP (ORCPT ); Mon, 3 Oct 2022 20:09:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230005AbiJDAJI (ORCPT ); Mon, 3 Oct 2022 20:09:08 -0400 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7CA182339B; Mon, 3 Oct 2022 17:09:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1664842147; x=1696378147; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=aa9xL1h4AcH+tfPWyZLVKtFOv8x6EYzjVZIOkGJl5EU=; b=k1wsmHsff3H5IzKJNzpXQzzG05jYB1/xZ9MviwOep9TmP0O33QDKYoZt U7F0NtG6pAODqA3U2nv963lV8hb0vWVG7j1UKkmERLjiUJQpY5cfGoY7c 3TQvIhfujHOFIYTA1+Ngp0PYgKhZmttUyOpH2oYNAUhgzBMw2hrKx55nz RnTemRMBQ+NTxc5Dl+U2yVMaYILqjxr8uUz9eDddFrLyo3OgpjrylDoIF lVXe0hSM3Ygwa28Zmtr48lEqxKxgLpbAU5ZgpbGp0TmXlyM12SDpOhiaP ltaCr2307uMO5DHbzKkAh0PL2sMwmrMehBQPXEaVOA/oq8BHA4txaEZKn w==; X-IronPort-AV: E=McAfee;i="6500,9779,10489"; a="290011189" X-IronPort-AV: E=Sophos;i="5.93,366,1654585200"; d="scan'208";a="290011189" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Oct 2022 17:09:07 -0700 X-IronPort-AV: E=McAfee;i="6500,9779,10489"; a="952574919" X-IronPort-AV: E=Sophos;i="5.93,366,1654585200"; d="scan'208";a="952574919" Received: from akashred-mobl.amr.corp.intel.com (HELO [10.212.139.217]) ([10.212.139.217]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Oct 2022 17:09:04 -0700 Message-ID: <559f937f-cab4-d408-6d95-fc85b4809aa9@intel.com> Date: Mon, 3 Oct 2022 17:09:04 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH v2 33/39] x86/cpufeatures: Limit shadow stack to Intel CPUs Content-Language: en-US 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 , "Ravi V . Shankar" , Weijiang Yang , "Kirill A . Shutemov" , joao.moreira@intel.com, John Allen , kcc@google.com, eranian@google.com, rppt@kernel.org, jamorris@linux.microsoft.com, dethoma@microsoft.com, Tom Lendacky , "Moger, Babu" References: <20220929222936.14584-1-rick.p.edgecombe@intel.com> <20220929222936.14584-34-rick.p.edgecombe@intel.com> <202210031656.23FAA3195@keescook> From: Dave Hansen In-Reply-To: <202210031656.23FAA3195@keescook> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org 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?