From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f176.google.com (mail-wi0-f176.google.com [209.85.212.176]) by kanga.kvack.org (Postfix) with ESMTP id 8A2856B003A for ; Thu, 11 Sep 2014 18:18:26 -0400 (EDT) Received: by mail-wi0-f176.google.com with SMTP id ex7so1751204wid.3 for ; Thu, 11 Sep 2014 15:18:25 -0700 (PDT) Received: from Galois.linutronix.de (Galois.linutronix.de. [2001:470:1f0b:db:abcd:42:0:1]) by mx.google.com with ESMTPS id j6si3996631wjn.116.2014.09.11.15.18.24 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Thu, 11 Sep 2014 15:18:24 -0700 (PDT) Date: Fri, 12 Sep 2014 00:18:15 +0200 (CEST) From: Thomas Gleixner Subject: Re: [PATCH v8 07/10] x86, mpx: decode MPX instruction to get bound violation information In-Reply-To: <1410425210-24789-8-git-send-email-qiaowei.ren@intel.com> Message-ID: References: <1410425210-24789-1-git-send-email-qiaowei.ren@intel.com> <1410425210-24789-8-git-send-email-qiaowei.ren@intel.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: Qiaowei Ren Cc: "H. Peter Anvin" , Ingo Molnar , Dave Hansen , x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Thu, 11 Sep 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. And why is that an argument to add another special purpose decoder? If a bound violation happens it is completely irrelevant whether the decoder is heavyweight or not. So unless you come up with a convincing argument why the generic decoder is the wrong place, this won't happen. Thanks, tglx -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org