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 X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 47B91C5CFEB for ; Wed, 11 Jul 2018 16:18:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F395620C0C for ; Wed, 11 Jul 2018 16:18:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F395620C0C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389674AbeGKQXx (ORCPT ); Wed, 11 Jul 2018 12:23:53 -0400 Received: from mga12.intel.com ([192.55.52.136]:42440 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733247AbeGKQXx (ORCPT ); Wed, 11 Jul 2018 12:23:53 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Jul 2018 09:18:49 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,338,1526367600"; d="scan'208";a="71471984" Received: from 2b52.sc.intel.com ([143.183.136.52]) by fmsmga001.fm.intel.com with ESMTP; 11 Jul 2018 09:18:38 -0700 Message-ID: <1531325701.13297.32.camel@intel.com> Subject: Re: [RFC PATCH v2 08/27] mm: Introduce VM_SHSTK for shadow stack memory From: Yu-cheng Yu To: Peter Zijlstra 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 , Cyrill Gorcunov , Dave Hansen , Florian Weimer , "H.J. Lu" , Jann Horn , Jonathan Corbet , Kees Cook , Mike Kravetz , Nadav Amit , Oleg Nesterov , Pavel Machek , "Ravi V. Shankar" , Vedvyas Shanbhogue Date: Wed, 11 Jul 2018 09:15:01 -0700 In-Reply-To: <20180711083412.GP2476@hirez.programming.kicks-ass.net> References: <20180710222639.8241-1-yu-cheng.yu@intel.com> <20180710222639.8241-9-yu-cheng.yu@intel.com> <20180711083412.GP2476@hirez.programming.kicks-ass.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.18.5.2-0ubuntu3.2 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2018-07-11 at 10:34 +0200, Peter Zijlstra wrote: > On Tue, Jul 10, 2018 at 03:26:20PM -0700, Yu-cheng Yu wrote: > > > > VM_SHSTK indicates a shadow stack memory area. > > > > A shadow stack PTE must be read-only and dirty.  For non shadow > > stack, we use a spare bit of the 64-bit PTE for dirty.  The PTE > > changes are in the next patch. > This doesn't make any sense.. the $subject and the patch seem > completely > unrelated to this Changelog. I was trying to say why this is only defined for 64-bit.  I will fix it. Yu-cheng