Re: linux-next: Tree for Jun 23 (objtool (2))

From: Miroslav Benes <mbenes@suse.cz>
To: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Petr Mladek <pmladek@suse.com>,
	Randy Dunlap <rdunlap@infradead.org>,
	Stephen Rothwell <sfr@canb.auug.org.au>,
	Linux Next Mailing List <linux-next@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	live-patching@vger.kernel.org, Yannick Cote <ycote@redhat.com>
Subject: Re: linux-next: Tree for Jun 23 (objtool (2))
Date: Thu, 16 Jul 2020 13:20:50 +0200 (CEST)	[thread overview]
Message-ID: <alpine.LSU.2.21.2007161315490.3958@pobox.suse.cz> (raw)
In-Reply-To: <20200715162457.mhoz2rgjbl4okx6d@treble>

On Wed, 15 Jul 2020, Josh Poimboeuf wrote:

> On Wed, Jul 15, 2020 at 03:41:55PM +0200, Petr Mladek wrote:
> > On Wed 2020-07-15 14:10:54, Petr Mladek wrote:
> > > On Wed 2020-07-15 13:11:14, Miroslav Benes wrote:
> > > > Petr, would you agree to revert -flive-patching.
> > > 
> > > Yes, I agree.
> > 
> > Or better to say that I will not block it.
> > 
> > I see that it causes maintenance burden. There are questions about
> > reliability and performance impact. I do not have a magic solution
> > in the pocket.
> > 
> > Anyway, we need a solution to know what functions need to get livepatched.
> > I do not have experience with comparing the assembly, so I do not know
> > how it is complicated and reliable.
> 
> Thanks Petr/Miroslav.  I can do the revert patch.  It doesn't have to be
> a permanent revert.  I'd certainly be willing to ACK it again in the
> future if/when it becomes more ready.

Ok.

> Yannick has agreed to start looking at the objtool function diff
> feature.  It's purely theoretical at the moment, we'll see how it works
> in practice.  We already do something similar in kpatch-build -- it
> differs from the objtool model, but it at least shows that something
> similar is possible.

Great. I'm looking forward to seeing that.

Thanks
Miroslav