From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752991AbcCIKNM (ORCPT ); Wed, 9 Mar 2016 05:13:12 -0500 Received: from mx2.suse.de ([195.135.220.15]:47932 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750853AbcCIKNI (ORCPT ); Wed, 9 Mar 2016 05:13:08 -0500 Date: Wed, 9 Mar 2016 11:13:05 +0100 (CET) From: Jiri Kosina X-X-Sender: jkosina@pobox.suse.cz To: Torsten Duwe cc: Petr Mladek , Balbir Singh , linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, kamalesh@linux.vnet.ibm.com, jeyu@redhat.com, live-patching@vger.kernel.org, mbenes@suse.cz Subject: Re: [PATCH][v6][RFC] livepatch/ppc: Enable livepatching on powerpc In-Reply-To: <20160309100328.GB23039@lst.de> Message-ID: References: <1457506780-19556-1-git-send-email-bsingharora@gmail.com> <20160309091904.GA23039@lst.de> <20160309094423.GH10940@pathway.suse.cz> <20160309100328.GB23039@lst.de> 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 Wed, 9 Mar 2016, Torsten Duwe wrote: > > find a solution that would work transparently. I mean that adding > > an extra hacks into selected functions in the patch might be quite > > error prone and problems hard to debug. I think that we all want this > > but I wanted to be sure :-) > > Full ACK. Again, the TOC restore needs to go _after_ the replacement function, > and the klp_return_helper works as transparently as possible, so this > was my first choice. Arguments on the stack? I thought we'll deal with them > once we get there (e.g. _really_ need to patch a varargs function or one > with a silly signature). Well, the problem is, once such need arises, it's too late already. You need to be able to patch the kernels which are already out there, running on machines potentially for ages once all of a sudden there is a CVE for >8args / varargs function. At that time, only starting to put support in the kernel for that is waaay to late :) Thanks, -- Jiri Kosina SUSE Labs