From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755021AbbCCAYP (ORCPT ); Mon, 2 Mar 2015 19:24:15 -0500 Received: from mga11.intel.com ([192.55.52.93]:15614 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750960AbbCCAYO (ORCPT ); Mon, 2 Mar 2015 19:24:14 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.09,678,1418112000"; d="scan'208";a="692999763" Message-ID: <54F4FF2C.7030200@intel.com> Date: Mon, 02 Mar 2015 16:24:12 -0800 From: Dave Hansen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: "Yu, Fenghua" , LKML , the arch/x86 maintainers Subject: Re: xsaves support broken? References: <54F4F964.5030701@intel.com> <3E5A0FA7E9CA944F9D5414FEC6C712205A7061FB@ORSMSX106.amr.corp.intel.com> In-Reply-To: <3E5A0FA7E9CA944F9D5414FEC6C712205A7061FB@ORSMSX106.amr.corp.intel.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/02/2015 04:09 PM, Yu, Fenghua wrote: > Xsaves has been tested by QA since 3.17 with or without MPX. I'm not > aware of reported issues. > > But MPX is the only code to call the get_xsave_addr kernel API. > Though it has been tested before on upstream MPX code. Has it? I'm fairly sure I've never explicitly tested it. I'm also doubting now that I've *ever* seen it work without booting with 'noxsaves'. > What changes in your new MPX code? I just discovered it when adding a new feature. I actually backed out all of my changes before reporting this issue. I'm running a completely untouched 4.0-rc1 kernel with the config I attached a moment ago. If I boot with 'noxsaves', MPX works fine. If I boot without it, the kernel never sees the values that userspace sets in the "bndcsr" register.