Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933559AbaJ1GBa (ORCPT ); Tue, 28 Oct 2014 02:01:30 -0400 Received: from mga11.intel.com ([192.55.52.93]:42252 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753171AbaJ1GB1 (ORCPT ); Tue, 28 Oct 2014 02:01:27 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,862,1389772800"; d="scan'208";a="407085163" Message-ID: <544F307D.7090701@intel.com> Date: Tue, 28 Oct 2014 13:58:21 +0800 From: Ren Qiaowei User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Thomas Gleixner CC: "H. Peter Anvin" , Ingo Molnar , "Hansen, Dave" , "x86@kernel.org" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "linux-ia64@vger.kernel.org" , "linux-mips@linux-mips.org" Subject: Re: [PATCH v9 09/12] x86, mpx: decode MPX instruction to get bound violation information References: <1413088915-13428-1-git-send-email-qiaowei.ren@intel.com> <1413088915-13428-10-git-send-email-qiaowei.ren@intel.com> <9E0BE1322F2F2246BD820DA9FC397ADE0180ED16@shsmsx102.ccr.corp.intel.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/28/2014 04:36 AM, Thomas Gleixner wrote: > On Mon, 27 Oct 2014, Ren, Qiaowei wrote: >> On 2014-10-24, Thomas Gleixner wrote: >>> On Sun, 12 Oct 2014, Qiaowei Ren wrote: >>> >>>> This patch sets bound violation fields of siginfo struct in #BR >>>> exception handler by decoding the user instruction and constructing >>>> the faulting pointer. >>>> >>>> This patch does't use the generic decoder, and implements a limited >>>> special-purpose decoder to decode MPX instructions, simply because >>>> the generic decoder is very heavyweight not just in terms of >>>> performance but in terms of interface -- because it has to. >>> >>> My question still stands why using the existing decoder is an issue. >>> Performance is a complete non issue in case of a bounds violation and >>> the interface argument is just silly, really. >>> >> >> As hpa said, we only need to decode several mpx instructions >> including BNDCL/BNDCU, and general decoder looks like a little >> heavy. Peter, what do you think about it? > > You're repeating yourself. Care to read the discussion about this from > the last round of review again? > Ok. I will go through it again. Thanks. - Qiaowei -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/