Re: missing leap second patches in stable.

From: Dave Jones
Date: Sun Jun 17 2012 - 16:09:32 EST


On Sat, Jun 16, 2012 at 07:50:09AM +0200, Richard Cochran wrote:
> On Fri, Jun 15, 2012 at 03:09:59PM -0400, Dave Jones wrote:
> > On Fri, Jun 15, 2012 at 11:48:34AM -0700, John Stultz wrote:
> > > On 06/15/2012 08:20 AM, Dave Jones wrote:
> > > > Should these be in -stable ? Looks like all the other recent changes
> > > > in that area are present. With the leap second just two weeks away,
> > > > it seems like they should be.
> > > >
> > > > Looks like 6b43ae8a619d17c4935c3320d2ef9e92bdeed05d is in 3.4-stable,
> > > > (haven't checked earlier -stable trees).
> > >
> > > So the second patch has been sent out for stable review as of yesterday.
> > > So it should be on its way, but you're right that I forgot to CC stable
> > > on the first TAI offset fix.
> > >
> > > I'll generate the patch and send it to Greg. Thanks for the close
> > > review here!
> >
> > fwiw, I did a test on 3.5rc2 yesterday where I forced a fake leap second at midnight.
> > Nothing untoward happened, unlike the previous ones :-)
>
> Out of curiosity, how do you test that? Do you have any programs
> specifically for testing the leap second issue?

no, I just patched the kernel to do this..

diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 70b33ab..5f4a1f0 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -396,6 +396,13 @@ int second_overflow(unsigned long secs)

spin_lock_irqsave(&ntp_lock, flags);

+ if (time_state == TIME_OK) {
+ if (secs % 86400 == 0) {
+ printk("Faking leap second.\n");
+ time_state = TIME_INS;
+ }
+ }
+
/*
* Leap second processing. If in leap-insert state at the end of the
* day, the system clock is set back one second; if in leap-delete


and then waited until midnight UTC, and then..

[68242.572516] Faking leap second.
[68242.573379] Clock: inserting leap second 23:59:60 UTC

Dave

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/