linux-kernel - Re: [PATCH V8 02/13] ntp: add ADJ

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: <1294865717.7696.17.camel@work-vm>
Date:	Wed, 12 Jan 2011 12:55:17 -0800
From:	john stultz <johnstul@...ibm.com>
To:	"Kuwahara,T." <6vvetjsrt26xsrzlh1z0zn4d2grdah@...il.com>
Cc:	Richard Cochran <richardcochran@...il.com>,
	linux-kernel@...r.kernel.org, linux-api@...r.kernel.org,
	netdev@...r.kernel.org, Alan Cox <alan@...rguk.ukuu.org.uk>,
	Arnd Bergmann <arnd@...db.de>,
	Christoph Lameter <cl@...ux.com>,
	David Miller <davem@...emloft.net>,
	Krzysztof Halasa <khc@...waw.pl>,
	Peter Zijlstra <peterz@...radead.org>,
	Rodolfo Giometti <giometti@...ux.it>,
	Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH V8 02/13] ntp: add ADJ_SETOFFSET mode bit

On Thu, 2011-01-13 at 05:39 +0900, Kuwahara,T. wrote:
> On Wed, Jan 12, 2011 at 5:55 AM, john stultz <johnstul@...ibm.com> wrote:
> > So the kernel handles leap second insertion via a timer. Thus at the end
> > of 23:59:59, it will inject a leapsecond by setting the time back by one
> > second (back to 23:59:59) and setting the TIME_OOP flag.
> >
> > This timer is an absolute timer, so if someone moves the clock forward
> > across the 23:59:59 boundary, the adjustment will still be made.
> >
> > The patch is not broken, nor useless.
> 
> It takes into account only one upcoming leap second, but ignores all
> the others.  That's not sufficient for arbitrary adjustments.

If an application wants to manage the full historical table of
leapseconds and compensate appropriately, then that's fine. The
interface proposed still functions in a reasonable manner.

Again, I agree that leapseconds are annoying to deal with. It would be
great if time() was defined as TAI time instead of UTC. I'm actually
hoping to provide a CLOCK_TAI clockid someday.

thanks
-john


--
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/