From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753978AbcEIWJ3 (ORCPT ); Mon, 9 May 2016 18:09:29 -0400 Received: from mga02.intel.com ([134.134.136.20]:7863 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753869AbcEIWJX (ORCPT ); Mon, 9 May 2016 18:09:23 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,602,1455004800"; d="scan'208";a="949544716" Subject: Re: [PATCH v5 04/13] x86/xsaves: Introduce a new check that allows correct xstates copy from kernel to user directly To: Yu-cheng Yu , linux-kernel@vger.kernel.org, x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Ingo Molnar References: <1655fc17bc9b8f5eeca1b2bbeac55bdbce0646a0.1462816638.git.yu-cheng.yu@intel.com> Cc: Andy Lutomirski , Borislav Petkov , Sai Praneeth Prakhya , "Ravi V. Shankar" , Fenghua Yu From: Dave Hansen Message-ID: <57310A8F.8060508@linux.intel.com> Date: Mon, 9 May 2016 15:09:19 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <1655fc17bc9b8f5eeca1b2bbeac55bdbce0646a0.1462816638.git.yu-cheng.yu@intel.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/09/2016 01:46 PM, Yu-cheng Yu wrote: > XSAVES is a kernel instruction and uses a compacted format. When working > with user space, the kernel should provide standard-format, non-supervisor > state data. We cannot do __copy_to_user() from a compacted- format kernel > xstate area to a signal frame. Looks good now: Reviewed-by: Dave Hansen