linux-kernel - Re: [PATCH] printk: robustify printk

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: <alpine.DEB.1.10.0808111050160.29861@gandalf.stny.rr.com>
Date:	Mon, 11 Aug 2008 10:55:42 -0400 (EDT)
From:	Steven Rostedt <rostedt@...dmis.org>
To:	Andi Kleen <andi@...stfloor.org>
cc:	Valdis.Kletnieks@...edu, Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Ingo Molnar <mingo@...e.hu>,
	Andrew Morton <akpm@...ux-foundation.org>,
	torvalds@...ux-foundation.org, tglx@...utronix.de,
	marcin.slusarz@...il.com, linux-kernel@...r.kernel.org,
	davem@...emloft.net, paulmck@...ux.vnet.ibm.com
Subject: Re: [PATCH] printk: robustify printk

On Mon, 11 Aug 2008, Andi Kleen wrote:

> $INSERT-ANY-OTHER-PRINTK-USE$
> 
> The point was that printk may have been perfectly adequate for 
> them with its existing buffer sizes and dynamic wake up frequency,
> and might not anymore with the timer wakeup change. Essentially
> it is making a widely used kernel facility more fragile.

I've measured several latencies in the kernel that would cause klogd to 
take serveral jiffies to wake up. I highly doubt that adding one jiffy 
will break anything. And if it did, then it would show a bug in their 
system. If adding one jiffy causes lost data, then the system 
administrators are relying on a utility (klogd) that can easily fail them 
without these patches.

If we are making a highly fragile setup a bit more fragile, maybe it will 
wake the IT guys up to change their setup.

-- Steve

--
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/