[ 02/40] ntp: Fix STA_INS/DEL clearing bug

From: Greg Kroah-Hartman
Date: Thu Jul 26 2012 - 17:30:03 EST


From: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>

3.0-stable review patch. If anyone has any objections, please let me know.

------------------

From: John Stultz <johnstul@xxxxxxxxxx>

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@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Richard Cochran <richardcochran@xxxxxxxxx>
Cc: Prarit Bhargava <prarit@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1342156917-25092-2-git-send-email-john.stultz@xxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
kernel/time/ntp.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

--- 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;


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