Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765323AbZDAWOQ (ORCPT ); Wed, 1 Apr 2009 18:14:16 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756153AbZDAWN7 (ORCPT ); Wed, 1 Apr 2009 18:13:59 -0400 Received: from one.firstfloor.org ([213.235.205.2]:41839 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756097AbZDAWN6 (ORCPT ); Wed, 1 Apr 2009 18:13:58 -0400 Date: Thu, 2 Apr 2009 00:15:40 +0200 From: Andi Kleen To: Masami Hiramatsu Cc: Andi Kleen , Ingo Molnar , Arnaldo Carvalho de Melo , Steven Rostedt , Ananth N Mavinakayanahalli , Frederic Weisbecker , Linux Kernel Mailing List , systemtap-ml , Andrew Morton , Jim Keniston Subject: Re: [PATCH -tip 0/4 V3] tracing: kprobe-based event tracer Message-ID: <20090401221540.GX11935@one.firstfloor.org> References: <49CC08A2.5030602@redhat.com> <20090401133654.GB18677@elte.hu> <49D37584.50208@redhat.com> <873acsm8qp.fsf@basil.nowhere.org> <49D3D3B4.4060702@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <49D3D3B4.4060702@redhat.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1531 Lines: 37 On Wed, Apr 01, 2009 at 04:51:00PM -0400, Masami Hiramatsu wrote: > Andi Kleen wrote: > > Masami Hiramatsu writes: > >> I agreed. Fortunately, Jim Keniston and I wrote an x86 instruction > >> decoder :-) which has been made originally for uprobe andd kprobes > >> jump-optimizer. > >> > >> https://www.redhat.com/archives/utrace-devel/2009-March/msg00031.html > > > > An alternative would be to adapt the x86 interpreter in KVM. > > I thought for some time that that one should be available in > > a more generic form in a library. > > As far as I can see, KVM's instruction emulator is incomplete That's fine for you -- you only care about a subset of instructions anyways, don't you? > (it doesn't cover all instructions...) and aims to emulate > instructions, not to analyze (so I couldn't relay on it). You can use it to analyze, just plug in the right callbacks that do nothing. I looked at it some time ago for doing instruction length checking for some application, but that application then disappeared. The main obstacle with making it a library is that some KVM specific dependencies have crept in that would need to be abstracted again, but I don't think it would need a lot of effort, -Andi -- ak@linux.intel.com -- Speaking for myself only. -- 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/