ntp: Fix STA_INS/DEL clearing bug

BugLink: http://bugs.launchpad.net/bugs/1031926

commit 6b1859dba01c7d512b72d77e3fd7da8354235189 upstream.

In commit 6b43ae8a619d17c4935c3320d2ef9e92bdeed05d, I
introduced a bug that kept the STA_INS or STA_DEL bit
from being cleared from time_status via adjtimex()
without forcing STA_PLL first.

Usually once the STA_INS is set, it isn't cleared
until the leap second is applied, so its unlikely this
affected anyone. However during testing I noticed it
took some effort to cancel a leap second once STA_INS
was set.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Link: http://lkml.kernel.org/r/1342156917-25092-2-git-send-email-john.stultz@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index f1eb182b5fe..61fc450643b 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -375,7 +375,9 @@ int second_overflow(unsigned long secs)
                         time_state = TIME_DEL;
                 break;
         case TIME_INS:
-                if (secs % 86400 == 0) {
+                if (!(time_status & STA_INS))
+                        time_state = TIME_OK;
+                else if (secs % 86400 == 0) {
                         leap = -1;
                         time_state = TIME_OOP;
                         time_tai++;
@@ -384,7 +386,9 @@ int second_overflow(unsigned long secs)
                 }
                 break;
         case TIME_DEL:
-                if ((secs + 1) % 86400 == 0) {
+                if (!(time_status & STA_DEL))
+                        time_state = TIME_OK;
+                else if ((secs + 1) % 86400 == 0) {
                         leap = 1;
                         time_tai--;
                         time_state = TIME_WAIT;