linux-kernel - Re: [PATCH 1/5] ftrace: Synchronize variable setting with breakpoints

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

Message-ID: <1338486029.28384.93.camel@twins>
Date:	Thu, 31 May 2012 19:40:29 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	Steven Rostedt <rostedt@...dmis.org>
Cc:	linux-kernel@...r.kernel.org, Ingo Molnar <mingo@...e.hu>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>,
	"H. Peter Anvin" <hpa@...or.com>, Dave Jones <davej@...hat.com>,
	Andi Kleen <ak@...ux.intel.com>
Subject: Re: [PATCH 1/5] ftrace: Synchronize variable setting with
 breakpoints

On Thu, 2012-05-31 at 10:08 -0400, Steven Rostedt wrote:
> > Also, why does this stuff live in ftrace? I always thought you were
> > going to replace text_poke() so everybody that uses cross-modifying code
> > could profit?
> 
> I discussed this with Masami at Collaboration Summit. The two are
> similar but also very different. But we want to start merging the two
> together where it makes sense. 

Argh,. I so disagree. You're doing it backwards.

First you merge whatever is there, regardless of who came first.

Then, when everybody doing text modification is using the same
interface, do a second implementation using a Kconfig knob. If the scary
new one breaks, no sweat, flip the config. If its proven stable, kill
off the old one.

I really don't see why ftrace would be special here.. if you have all
text_poke() users use the magic new way you'll have more coverage and
better chances of hitting any snags if there are any.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/