Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752085AbaJ0Bpz (ORCPT ); Sun, 26 Oct 2014 21:45:55 -0400 Received: from mga09.intel.com ([134.134.136.24]:49646 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751816AbaJ0Bpx convert rfc822-to-8bit (ORCPT ); Sun, 26 Oct 2014 21:45:53 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,792,1406617200"; d="scan'208";a="625947589" From: "Ren, Qiaowei" 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 Thread-Topic: [PATCH v9 09/12] x86, mpx: decode MPX instruction to get bound violation information Thread-Index: AQHP5dg7yyhiQxbkmEGH5PJVxeeZs5w+vGAAgASFDTA= Date: Mon, 27 Oct 2014 01:43:00 +0000 Message-ID: <9E0BE1322F2F2246BD820DA9FC397ADE0180ED16@shsmsx102.ccr.corp.intel.com> References: <1413088915-13428-1-git-send-email-qiaowei.ren@intel.com> <1413088915-13428-10-git-send-email-qiaowei.ren@intel.com> In-Reply-To: Accept-Language: zh-CN, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? 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/