Skip site navigation (1)Skip section navigation (2)
Date:      Sun, 10 Jul 2011 12:42:52 -0400
From:      Kurt Lidl <lidl@pix.net>
To:        Warner Losh <imp@bsdimp.com>
Cc:        freebsd-hackers@freebsd.org, grarpamp <grarpamp@gmail.com>
Subject:   Re: Jails: Setting different times in jails
Message-ID:  <20110710164252.GA50703@pix.net>
In-Reply-To: <55627D64-E412-4D04-AA17-3D912EEE6589@bsdimp.com>
References:  <CAD2Ti2-55tQqjSmWbMr6OCXg8X5Mhbw%2Btpe87FM%2Bn%2BKzjUVyNQ@mail.gmail.com> <4E11ECE2.9050402@freebsd.org> <CAD2Ti2_GM%2ByT3HNx%2B20xHL0UdnkUbUAoFN64txxHoUkJAkLFXA@mail.gmail.com> <55627D64-E412-4D04-AA17-3D912EEE6589@bsdimp.com>

next in thread | previous in thread | raw e-mail | index | archive | help
On Sat, Jul 09, 2011 at 11:19:23PM -0600, Warner Losh wrote:
> Why on earth would you want this?

Oh, it's not hard to imagine why you want to do this.  Say
you're testing a particular date rollover event, and want
to make sure your software is up to snuff.  Doing it in a
jail would make it easy to do it.

I hacked over a unix kernel to do this for Y2K testing, along with
the company's mandatory 9/9/99 testing (and we extended it through
to 1-Mar-2000 just to be thorough).  In that case, not only did I
just start the systems with a clock value of 9/8/99, I hacked it
so the time was incremented by one second at each hardclock, rather
than 1/100 of a second.  So my applications saw every second of
every "day" between 9/8/99 and 3/1/00.  (Remember that 28-Feb-2000
went straight through to 1-Mar-2000 -- 2000 was NOT a leap year!)

Heck, maybe if this got put in, Apple would pick it up and finally
make the calandering stuff in OS X not fail every daylight savings
time.  Nah, I'm just dreaming now...

-Kurt

> On Jul 7, 2011, at 2:31 AM, grarpamp wrote:
> 
> >> possibly achievable in libc?
> > 
> > I don't know. Where else would it be done?
> > stat, utimes, gettimeofday, clock_gettime,
> > adjtime, etc and their variations.
> > 
> > I've not checked what currently happens, but I
> > don't think root in a jail should be able to set
> > any kernel time parameters, absent a syscall
> > that says it should.
> > 
> >> in any case file this idea somewhere.. :-)
> > 
> > Don't know here either. I looked at the lists and
> > hackers seemed closest. I'll bcc current. Someone
> > could maybe todo-wiki this thread as low hanging
> > fruit. Cheers.
> > _______________________________________________
> > freebsd-hackers@freebsd.org mailing list
> > http://lists.freebsd.org/mailman/listinfo/freebsd-hackers
> > To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org"
> > 
> > 
> 
> _______________________________________________
> freebsd-hackers@freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-hackers
> To unsubscribe, send any mail to "freebsd-hackers-unsubscribe@freebsd.org"



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20110710164252.GA50703>