Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757852AbZKXDUJ (ORCPT ); Mon, 23 Nov 2009 22:20:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757792AbZKXDUJ (ORCPT ); Mon, 23 Nov 2009 22:20:09 -0500 Received: from mail-ew0-f219.google.com ([209.85.219.219]:35268 "EHLO mail-ew0-f219.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757602AbZKXDUH (ORCPT ); Mon, 23 Nov 2009 22:20:07 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=p3kihWOB4eRNB/8bEuMwCQEK2ueVnQxGV6rPU3TJn3HvuHcVNLQdQwo4EufySeJ80J tu5GvcROZlFg1GBDvmJOtBuTqO/ae5BFPY4Ot6VP5xSn7gFwo6RVo1spcWc7hBNhh2Wr 7rsDOaGVAGfFTwjPm0CR2TNU2duWlstp+tkkg= Date: Tue, 24 Nov 2009 04:20:09 +0100 From: Frederic Weisbecker To: Masami Hiramatsu Cc: Ingo Molnar , Ananth N Mavinakayanahalli , lkml , "H. Peter Anvin" , Jim Keniston , Srikar Dronamraju , Christoph Hellwig , Steven Rostedt , Anders Kaseorg , Tim Abbott , Andi Kleen , Jason Baron , Mathieu Desnoyers , systemtap , DLE Subject: Re: [PATCH -tip v5 00/10] kprobes: Kprobes jump optimization support Message-ID: <20091124032008.GD6752@nowhere> References: <20091123232115.22071.71558.stgit@dhcp-100-2-132.bos.redhat.com> <20091124020315.GA6221@nowhere> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091124020315.GA6221@nowhere> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 967 Lines: 25 On Tue, Nov 24, 2009 at 03:03:19AM +0100, Frederic Weisbecker wrote: > On Mon, Nov 23, 2009 at 06:21:16PM -0500, Masami Hiramatsu wrote: > > When the optimized-kprobe is hit before optimization, its handler > > changes IP(instruction pointer) to copied code and exits. So, the > > instructions which were copied to detour buffer are executed on the detour > > buffer. > > > > Hm, why is it playing such hybrid game there? > If I understand well, we have executed int 3, executed the > handler and we jump back to the detour buffer? > I got it, I think. We have instructions to patch. And the above turn this area into dead code, safe to patch. But still, stop_machine() seem to make it not necessary anymore. -- 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/