Re: [PATCH 0/2] Kernel Live Patching

From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: Vojtech Pavlik <vojtech@suse.cz>,
	Seth Jennings <sjenning@redhat.com>,
	Jiri Kosina <jkosina@suse.cz>,
	Steven Rostedt <rostedt@goodmis.org>,
	live-patching@vger.kernel.org, kpatch@redhat.com,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/2] Kernel Live Patching
Date: Fri, 7 Nov 2014 07:11:53 -0600	[thread overview]
Message-ID: <20141107131153.GD4071@treble.redhat.com> (raw)
In-Reply-To: <20141107074745.GC22703@infradead.org>

On Thu, Nov 06, 2014 at 11:47:45PM -0800, Christoph Hellwig wrote:
> On Thu, Nov 06, 2014 at 09:24:23PM +0100, Vojtech Pavlik wrote:
> > One reason is that there are currently at least two generators using
> > very different methods of generation (in addition to the option of doing
> > the patch module by hand), and neither of them are currently in a state
> > where they would be ready for inclusion into the kernel (although the
> > kpatch one is clearly closer to that).
> 
> So agree on one method and get it into shape, just like we do for other
> kernel subsystems.

That's our goal (and it sounds like everybody's on board with that).

But we have two different implementations, all the way up the stack.  I
think we have to work on combining and stabilizing one thing at a time.
We want to do this in stages:

1. Define a common core module with an API that can be used by all three
   approaches (manual, kpatch generator, kGraft generator)

2. Add consistency model(s) (e.g. kpatch stop_machine, kGraft per-task
   consistency, Masami's per task ref counting)

3. Add combined patch module generation tool

-- 
Josh