linux-kernel - Re: [PATCH 1/2] livepatch: Implement separate coming and going module notifiers

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20160201144810.GE22854@treble.redhat.com>
Date:	Mon, 1 Feb 2016 08:48:10 -0600
From:	Josh Poimboeuf <jpoimboe@...hat.com>
To:	Jiri Kosina <jikos@...nel.org>
Cc:	Steven Rostedt <rostedt@...dmis.org>,
	Miroslav Benes <mbenes@...e.cz>, Jessica Yu <jeyu@...hat.com>,
	Seth Jennings <sjenning@...hat.com>,
	Vojtech Pavlik <vojtech@...e.com>,
	Ingo Molnar <mingo@...hat.com>, live-patching@...r.kernel.org,
	linux-kernel@...r.kernel.org, Rusty Russell <rusty@...tcorp.com.au>
Subject: Re: [PATCH 1/2] livepatch: Implement separate coming and going
 module notifiers

On Mon, Feb 01, 2016 at 01:27:57PM +0100, Jiri Kosina wrote:
> On Fri, 29 Jan 2016, Josh Poimboeuf wrote:
> 
> > Right, as you say it's basically a nop 99.99% of the time.  But we still 
> > need to do the "are any patches loaded" check, so we still need the call 
> > into a livepatch function to do that.
> 
> We might create a static key for that (some might call it 
> over-optimization though, given it's happening on kind of a slow path 
> anyway).

I really don't think that's needed.  Nobody will notice an extra
function call in the module load path.  (And BTW it'll be slightly
faster than today since it doesn't go through the notifier first.)

-- 
Josh