Received: by 10.223.185.116 with SMTP id b49csp2452339wrg; Thu, 22 Feb 2018 14:06:19 -0800 (PST) X-Google-Smtp-Source: AH8x224FaOHgQhVZuu7VQotONs2KphGuVCVzg4VsWtWPC+xTAuYU+zFUjPTQR7eKG+Yk077ZSe0Q X-Received: by 2002:a17:902:bc86:: with SMTP id bb6-v6mr1814479plb.313.1519337179879; Thu, 22 Feb 2018 14:06:19 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1519337179; cv=none; d=google.com; s=arc-20160816; b=NGKNQ7bs1cIWyHx7Po1kuQiy4URt4kfWrDXikSMkOtRzN+wqsfLd4dQMpfJ4tnbpvB 4n+mRq9USN+K1Mxahp9PFUycSIKw7xWJGM7f4koTub8gqJfAhDWDGRnV4F+yU6Vs2ysv 76cmbUJCfOGOLgl7+XD2OX4cnnDZUN5y1NTo5gszrgR2EKPVNokbNs6WYVjWY3BZP9Kw EwH0qFlkGKCxZ1qYfVJMJPK1/kJgfpvmzt7dC2dvrmy1B7ZCF3xtS54VSaUdiF8gTw7v Lt1qq32x11vMn4Q5zbZIOD2ts97+f8FudEA4TONxFSKIur8wJwiqnTYDz+te81DhJsGm 58WA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding :content-language:in-reply-to:mime-version:user-agent:date :message-id:from:cc:references:to:subject:arc-authentication-results; bh=9jFQUa0SO2gIKPyOl9UZHrRVT1KObYIBhdKqvbjAUiI=; b=Qmf6g/r0gv7sumZAnBT+NX+NlSVGuMcXjbujsvl2C6uNvuT9x8m+jsvLZZnuPbXenj bPMkCtI5zBpoPQ/C2Pnwl/+gvZV5EFe/9WwXQ4BfyURsV/246gezz1O7dgPt779cAS4m NqPSpAqlVJlFzjuzIeW476LUFRgQeIdDq/0Sj2zk/VlUdv4ZojPqgJe7a2VqXDIIQpP9 FrOyHKfkq6pVMEbrdg3TCUz/9dkmV7U7RTv64aKkCmpRNvI+4APJ0ynPfe+H0brRwvIS cGnxPMyb6DyybYw5AHXeHskU+rFox82+QPetOcntshCbwUymwoAyxebymoFwQbFe3keY VWIQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id e4si545598pgp.516.2018.02.22.14.06.03; Thu, 22 Feb 2018 14:06:19 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751608AbeBVWFW (ORCPT + 99 others); Thu, 22 Feb 2018 17:05:22 -0500 Received: from mga06.intel.com ([134.134.136.31]:37697 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751502AbeBVWFV (ORCPT ); Thu, 22 Feb 2018 17:05:21 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 22 Feb 2018 14:05:21 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.47,380,1515484800"; d="scan'208";a="19721303" Received: from lkannan-mobl3.amr.corp.intel.com (HELO [10.254.100.148]) ([10.254.100.148]) by fmsmga008.fm.intel.com with ESMTP; 22 Feb 2018 14:05:20 -0800 Subject: Re: [RFC][PATCH 04/10] x86/espfix: use kernel-default PTE mask To: Andy Lutomirski References: <20180222203651.B776810C@viggo.jf.intel.com> <20180222203658.80705136@viggo.jf.intel.com> <93613F56-C778-4EA0-8945-A0B8ABC1A5FD@vmware.com> Cc: Nadav Amit , "linux-kernel@vger.kernel.org" , "aarcange@redhat.com" , "torvalds@linux-foundation.org" , "keescook@google.com" , "hughd@google.com" , "jgross@suse.com" , "x86@kernel.org" From: Dave Hansen Message-ID: <8fca2faa-1bac-2252-3719-8d393e2f2661@linux.intel.com> Date: Thu, 22 Feb 2018 14:05:19 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/22/2018 01:59 PM, Andy Lutomirski wrote: >> I think it's good practice to just expose only the *minimal* amount of >> data necessary. It's easier to audit and less likely to expose things >> accidentall. > But espfix64 is geniunely global. I'm confused. I'm the confused one. In my *first* set of patches to do this, I missed making the espfix64 area global. This new code apparently got it right, but I assumed the "new" global area that showed up was a mistake, thus this patch. I'll change this patch into a commenting patch that calls out the need for keeping _PAGE_GLOBAL.