linux-kernel - Re: [PATCH] NTP: remove clock_was

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: <1183492590.3291.39.camel@chaos>
Date:	Tue, 03 Jul 2007 21:56:30 +0200
From:	Thomas Gleixner <tglx@...utronix.de>
To:	Linus Torvalds <torvalds@...l.org>
Cc:	LKML <linux-kernel@...r.kernel.org>, Dave Jones <davej@...hat.com>,
	Andrew Morton <akpm@...l.org>,
	john stultz <johnstul@...ibm.com>, Ingo Molnar <mingo@...e.hu>,
	Stable Team <stable@...nel.org>,
	"Fortier,Vincent [Montreal]" <Vincent.Fortier1@...GC.CA>
Subject: Re: [PATCH] NTP: remove clock_was_set() call to prevent deadlock

On Tue, 2007-07-03 at 20:05 +0200, Thomas Gleixner wrote:
> The clock_was_set() call in seconds_overflow() which happens only when
> leap seconds are inserted / deleted is wrong in two aspects:
> 
> 1. it results in a call to on_each_cpu() with interrupts disabled
> 2. it is potential deadlock source vs. call_lock in smp_call_function()
> 
> The only possible side effect of the removal might be, that an absolute
> CLOCK_REALTIME timer fires 1 second too late, in the rare case of leap
> second deletion and an absolute CLOCK_REALTIME timer which expires in
> the affected time frame. It will never fire too early.
> 
> This was probably observed by the reporter of a June 30th -> July 1st
> hang: http://lkml.org/lkml/2007/7/3/

Ooops, missed the full reference:

http://lkml.org/lkml/2007/7/3/103

	tglx


-
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/