From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759931Ab1JGLyv (ORCPT ); Fri, 7 Oct 2011 07:54:51 -0400 Received: from mail7.hitachi.co.jp ([133.145.228.42]:43900 "EHLO mail7.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752427Ab1JGLyu (ORCPT ); Fri, 7 Oct 2011 07:54:50 -0400 X-AuditID: b753bd60-a14abba0000019f4-0e-4e8ee887594d X-AuditID: b753bd60-a14abba0000019f4-0e-4e8ee887594d Message-ID: <4E8EE885.9040703@hitachi.com> Date: Fri, 07 Oct 2011 20:54:45 +0900 From: Masami Hiramatsu Organization: Systems Development Lab., Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:7.0.1) Gecko/20110929 Thunderbird/7.0.1 MIME-Version: 1.0 To: Peter Zijlstra Cc: Stephane Eranian , Andi Kleen , linux-kernel@vger.kernel.org, mingo@elte.hu, acme@redhat.com, ming.m.lin@intel.com, robert.richter@amd.com, ravitillo@lbl.gov Subject: Re: [PATCH 07/12] perf_events: add LBR software filter support for Intel X86 References: <1317912555-9559-1-git-send-email-eranian@google.com> <1317912555-9559-8-git-send-email-eranian@google.com> <20111006153229.GJ14482@one.firstfloor.org> <1317984122.31132.6.camel@twins> <1317986519.31132.13.camel@twins> In-Reply-To: <1317986519.31132.13.camel@twins> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org (2011/10/07 20:21), Peter Zijlstra wrote: > On Fri, 2011-10-07 at 13:18 +0200, Peter Zijlstra wrote: >>> Yeah, depending on the depth of the LBR. But then what happens, you >>> decode an instruction that is not what was executed. >> >> Right, and Andi's concern is that this might cause our instruction >> decoder to blow up, or worse. > > That is, we have a fair confidence that its capable of correctly > decoding correct streams, but I understood from Masami that they haven't > actually tried feeding it crap. OK, I'll do hardening it. Thanks, -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com