From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f72.google.com (mail-pg0-f72.google.com [74.125.83.72]) by kanga.kvack.org (Postfix) with ESMTP id 28C2F6B049D for ; Fri, 5 Jan 2018 01:29:56 -0500 (EST) Received: by mail-pg0-f72.google.com with SMTP id o9so1963649pgv.3 for ; Thu, 04 Jan 2018 22:29:56 -0800 (PST) Received: from mga14.intel.com (mga14.intel.com. [192.55.52.115]) by mx.google.com with ESMTPS id i75si178762pgc.392.2018.01.04.22.29.54 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 04 Jan 2018 22:29:55 -0800 (PST) Subject: Re: [PATCH 05/23] x86, kaiser: unmap kernel from userspace page tables (core patch) References: <20171123003438.48A0EEDE@viggo.jf.intel.com> <20171123003447.1DB395E3@viggo.jf.intel.com> <93776eb2-b6d4-679a-280c-8ba558a69c34@linux.intel.com> From: Dave Hansen Message-ID: <20a54a5f-f4e5-2126-fb73-6a995d13d52d@linux.intel.com> Date: Thu, 4 Jan 2018 22:29:53 -0800 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Yisheng Xie , linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org, richard.fellner@student.tugraz.at, moritz.lipp@iaik.tugraz.at, daniel.gruss@iaik.tugraz.at, michael.schwarz@iaik.tugraz.at, luto@kernel.org, torvalds@linux-foundation.org, keescook@google.com, hughd@google.com, x86@kernel.org, Andrea Arcangeli On 01/04/2018 10:16 PM, Yisheng Xie wrote: > BTW, we have just reported a bug caused by kaiser[1], which looks like > caused by SMEP. Could you please help to have a look? > > [1] https://lkml.org/lkml/2018/1/5/3 Please report that to your kernel vendor. Your EFI page tables have the NX bit set on the low addresses. There have been a bunch of iterations of this, but you need to make sure that the EFI kernel mappings don't get _PAGE_NX set on them. Look at what __pti_set_user_pgd() does in mainline. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org