Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751481AbaKYT3a (ORCPT ); Tue, 25 Nov 2014 14:29:30 -0500 Received: from cantor2.suse.de ([195.135.220.15]:51620 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750784AbaKYT33 (ORCPT ); Tue, 25 Nov 2014 14:29:29 -0500 Date: Tue, 25 Nov 2014 20:29:31 +0100 (CET) From: Jiri Kosina To: Steven Rostedt cc: Petr Mladek , Masami Hiramatsu , Seth Jennings , Josh Poimboeuf , Vojtech Pavlik , Miroslav Benes , Christoph Hellwig , Greg KH , Andy Lutomirski , live-patching@vger.kernel.org, x86@kernel.org, kpatch@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCHv3 2/3] kernel: add support for live patching In-Reply-To: <20141125121606.547031b4@gandalf.local.home> Message-ID: References: <1416522580-5593-1-git-send-email-sjenning@redhat.com> <1416522580-5593-3-git-send-email-sjenning@redhat.com> <546EA5DC.6000207@hitachi.com> <20141125163942.GD22487@pathway.suse.cz> <20141125115210.4d7cfca3@gandalf.local.home> <20141125170431.GE22487@pathway.suse.cz> <20141125121606.547031b4@gandalf.local.home> User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 25 Nov 2014, Steven Rostedt wrote: > It is not guaranteed from ftrace's stand point. What happens if we have > a kprobe handler that modifies it for someplace else? Changing the ip > address may not be a kpatch/kGraft privilege only. This brings me back to the RFC patch I sent back then in october ... what we really want to do is to at least warn about situations when we are going to redirect code flow (through IPMODIFY) for function that has a kprobe installed anywhere inside it. Otherwise the probe will silently vanish (there is no way how to migrate it to the new function automatically), which might be very confusing for uses (cosider systemtap, for example). I'll resurect my patch if noone beats me doing it. It should go in together with the live patching framework I believe. Thanks, -- Jiri Kosina SUSE Labs -- 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/