Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751458AbaKIUSO (ORCPT ); Sun, 9 Nov 2014 15:18:14 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:58087 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751095AbaKIUSN (ORCPT ); Sun, 9 Nov 2014 15:18:13 -0500 Date: Sun, 9 Nov 2014 12:16:41 -0800 From: Greg KH To: Seth Jennings Cc: Josh Poimboeuf , Jiri Kosina , Vojtech Pavlik , Steven Rostedt , live-patching@vger.kernel.org, kpatch@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/2] Kernel Live Patching Message-ID: <20141109201641.GA21349@kroah.com> References: <1415284748-14648-1-git-send-email-sjenning@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1415284748-14648-1-git-send-email-sjenning@redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 06, 2014 at 08:39:06AM -0600, Seth Jennings wrote: > This patchset implements an ftrace-based mechanism and kernel interface for > doing live patching of kernel and kernel module functions. It represents the > greatest common functionality set between kpatch [1] and kGraft [2] and can > accept patches built using either method. This solution was discussed in the > Live Patching Mini-conference at LPC 2014 [3]. > > The model consists of a live patching "core" that provides an interface for > other "patch" kernel modules to register patches with the core. > > Patch modules contain the new function code and create an lp_patch > structure containing the required data about what functions to patch, where the > new code for each patched function resides, and in which kernel object (vmlinux > or module) the function to be patch resides. The patch module then invokes the > lp_register_patch() function to register with the core module, then > lp_enable_patch() to have to core module redirect the execution paths using > ftrace. > > An example patch module can be found here: > https://github.com/spartacus06/livepatch/blob/master/patch/patch.c > > The live patching core creates a sysfs hierarchy for user-level access to live > patching information. The hierarchy is structured like this: > > /sys/kernel/livepatch > /sys/kernel/livepatch/ > /sys/kernel/livepatch//enabled > /sys/kernel/livepatch//