linux-kernel - Re: lockdep and debug objects together are broken?

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]

Date:	Wed, 21 Jan 2009 12:50:02 +0100
From:	Peter Zijlstra <a.p.zijlstra@...llo.nl>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	Nick Piggin <npiggin@...e.de>,
	Vegard Nossum <vegard.nossum@...il.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: lockdep and debug objects together are broken?

On Wed, 2009-01-21 at 12:42 +0100, Ingo Molnar wrote:

> So by the time you'd rearm, there's a lot of tasks with no proper locking 
> state built up. We might be able to re-arm via stop_machine_run perhaps.

Won't work either, kstopmachine only preempts everybody. We'd require
something stronger.

What we need is a point where there's guaranteed no locks held, for
regular tasks that would be a trip to userspace and back, but for kernel
tasks that's a bit harder -- does the freezer stuff guarantee this?

Supposing we have such a point for all tasks, what you then do is wipe
all lock state and rig a trigger to start tracking lock state once you
passed through the point.

--
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/