time: Prevent early expiry of hrtimers[CLOCK_REALTIME] at the leap second edge

[deliverable/linux.git] / kernel / time / timekeeping.c

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 849b93265904f8a5fb5e9d894a9b38f085c52890..5d67ffb7e3173159e29c062a911a6d4dbf95f302 100644 (file)
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -539,6 +539,17 @@ int pvclock_gtod_unregister_notifier(struct notifier_block *nb)
 }
 EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier);
 
+/*
+ * tk_update_leap_state - helper to update the next_leap_ktime
+ */
+static inline void tk_update_leap_state(struct timekeeper *tk)
+{
+       tk->next_leap_ktime = ntp_get_next_leap();
+       if (tk->next_leap_ktime.tv64 != KTIME_MAX)
+               /* Convert to monotonic time */
+               tk->next_leap_ktime = ktime_sub(tk->next_leap_ktime, tk->offs_real);
+}
+
 /*
  * Update the ktime_t based scalar nsec members of the timekeeper
  */
@@ -580,6 +591,7 @@ static void timekeeping_update(struct timekeeper *tk, unsigned int action)
                ntp_clear();
        }
 
+       tk_update_leap_state(tk);
        tk_update_ktime_data(tk);
 
        update_vsyscall(tk);
@@ -1956,15 +1968,22 @@ ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, ktime_t *offs_real,
 
                base = tk->tkr_mono.base;
                nsecs = timekeeping_get_ns(&tk->tkr_mono);
+               base = ktime_add_ns(base, nsecs);
+
                if (*cwsseq != tk->clock_was_set_seq) {
                        *cwsseq = tk->clock_was_set_seq;
                        *offs_real = tk->offs_real;
                        *offs_boot = tk->offs_boot;
                        *offs_tai = tk->offs_tai;
                }
+
+               /* Handle leapsecond insertion adjustments */
+               if (unlikely(base.tv64 >= tk->next_leap_ktime.tv64))
+                       *offs_real = ktime_sub(tk->offs_real, ktime_set(1, 0));
+
        } while (read_seqcount_retry(&tk_core.seq, seq));
 
-       return ktime_add_ns(base, nsecs);
+       return base;
 }
 
 /**
@@ -2006,6 +2025,8 @@ int do_adjtimex(struct timex *txc)
                __timekeeping_set_tai_offset(tk, tai);
                timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
        }
+       tk_update_leap_state(tk);
+
        write_seqcount_end(&tk_core.seq);
        raw_spin_unlock_irqrestore(&timekeeper_lock, flags);