From: John Stultz <john.stultz@linaro.org>
Date: Tue, 17 Jul 2012 21:49:23 +0000 (-0400)
Subject: timekeeping: Fix CLOCK_MONOTONIC inconsistency during leapsecond
X-Git-Tag: v2.6.34.13~57
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=7df892974c2bf2487c3a08a959f0aab56d057822;p=karo-tx-linux.git

timekeeping: Fix CLOCK_MONOTONIC inconsistency during leapsecond

commit fad0c66c4bb836d57a5f125ecd38bed653ca863a upstream.
which resolves a bug the previous commit.

Commit 6b43ae8a61 (ntp: Fix leap-second hrtimer livelock) broke the
leapsecond update of CLOCK_MONOTONIC. The missing leapsecond update to
wall_to_monotonic causes discontinuities in CLOCK_MONOTONIC.

Adjust wall_to_monotonic when NTP inserted a leapsecond.

Reported-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Tested-by: Richard Cochran <richardcochran@gmail.com>
Link: http://lkml.kernel.org/r/1338400497-12420-1-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index df1e9397b55a..f8d4877687ff 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -759,6 +759,7 @@ static cycle_t logarithmic_accumulation(cycle_t offset, int shift)
 		xtime.tv_sec++;
 		leap = second_overflow(xtime.tv_sec);
 		xtime.tv_sec += leap;
+		wall_to_monotonic.tv_sec -= leap;
 	}
 
 	/* Accumulate into raw time */