From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f174.google.com (mail-wi0-f174.google.com [209.85.212.174]) by kanga.kvack.org (Postfix) with ESMTP id 6EA316B0069 for ; Fri, 24 Oct 2014 08:36:24 -0400 (EDT) Received: by mail-wi0-f174.google.com with SMTP id q5so1092374wiv.7 for ; Fri, 24 Oct 2014 05:36:23 -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 l2si1780931wix.39.2014.10.24.05.36.22 for (version=TLSv1.2 cipher=RC4-SHA bits=128/128); Fri, 24 Oct 2014 05:36:22 -0700 (PDT) Date: Fri, 24 Oct 2014 14:36:10 +0200 (CEST) From: Thomas Gleixner Subject: Re: [PATCH v9 09/12] x86, mpx: decode MPX instruction to get bound violation information In-Reply-To: <1413088915-13428-10-git-send-email-qiaowei.ren@intel.com> Message-ID: References: <1413088915-13428-1-git-send-email-qiaowei.ren@intel.com> <1413088915-13428-10-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, linux-ia64@vger.kernel.org, linux-mips@linux-mips.org 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. 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