ntp: Add ADJ_SETOFFSET mode bit

This patch adds a new mode bit into the timex structure. When set, the bit
instructs the kernel to add the given time value to the current time.

Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Acked-by: John Stultz <johnstul@us.ibm.com>
LKML-Reference: <20110201134320.688829863@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 11 insertions, 0 deletions

diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index ed8cfdf16983..5ac593267a26 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -648,6 +648,17 @@ int do_adjtimex(struct timex *txc)
                         hrtimer_cancel(&leap_timer);
         }
 
+        if (txc->modes & ADJ_SETOFFSET) {
+                struct timespec delta;
+                if ((unsigned long)txc->time.tv_usec >= NSEC_PER_SEC)
+                        return -EINVAL;
+                delta.tv_sec  = txc->time.tv_sec;
+                delta.tv_nsec = txc->time.tv_usec;
+                if (!(txc->modes & ADJ_NANO))
+                        delta.tv_nsec *= 1000;
+                timekeeping_inject_offset(&delta);
+        }
+
         getnstimeofday(&ts);
 
         write_seqlock_irq(&xtime_lock);