1 files changed, 253 insertions, 189 deletions

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index f045cc50832d..34e5eac81424 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -65,14 +65,14 @@ struct timekeeper {
          * used instead.
          */
         struct timespec         wall_to_monotonic;
-        /* time spent in suspend */
-        struct timespec         total_sleep_time;
-        /* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
-        struct timespec         raw_time;
         /* Offset clock monotonic -> clock realtime */
         ktime_t                 offs_real;
+        /* time spent in suspend */
+        struct timespec         total_sleep_time;
         /* Offset clock monotonic -> clock boottime */
         ktime_t                 offs_boot;
+        /* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
+        struct timespec         raw_time;
         /* Seqlock for all timekeeper values */
         seqlock_t               lock;
 };
@@ -108,13 +108,39 @@ static struct timespec tk_xtime(struct timekeeper *tk)
 static void tk_set_xtime(struct timekeeper *tk, const struct timespec *ts)
 {
         tk->xtime_sec = ts->tv_sec;
-        tk->xtime_nsec = ts->tv_nsec << tk->shift;
+        tk->xtime_nsec = (u64)ts->tv_nsec << tk->shift;
 }
 
 static void tk_xtime_add(struct timekeeper *tk, const struct timespec *ts)
 {
         tk->xtime_sec += ts->tv_sec;
-        tk->xtime_nsec += ts->tv_nsec << tk->shift;
+        tk->xtime_nsec += (u64)ts->tv_nsec << tk->shift;
+        tk_normalize_xtime(tk);
+}
+
+static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec wtm)
+{
+        struct timespec tmp;
+
+        /*
+         * Verify consistency of: offset_real = -wall_to_monotonic
+         * before modifying anything
+         */
+        set_normalized_timespec(&tmp, -tk->wall_to_monotonic.tv_sec,
+                                        -tk->wall_to_monotonic.tv_nsec);
+        WARN_ON_ONCE(tk->offs_real.tv64 != timespec_to_ktime(tmp).tv64);
+        tk->wall_to_monotonic = wtm;
+        set_normalized_timespec(&tmp, -wtm.tv_sec, -wtm.tv_nsec);
+        tk->offs_real = timespec_to_ktime(tmp);
+}
+
+static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t)
+{
+        /* Verify consistency before modifying */
+        WARN_ON_ONCE(tk->offs_boot.tv64 != timespec_to_ktime(tk->total_sleep_time).tv64);
+
+        tk->total_sleep_time    = t;
+        tk->offs_boot           = timespec_to_ktime(t);
 }
 
 /**
@@ -217,14 +243,6 @@ static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
         return nsec + arch_gettimeoffset();
 }
 
-static void update_rt_offset(struct timekeeper *tk)
-{
-        struct timespec tmp, *wtm = &tk->wall_to_monotonic;
-
-        set_normalized_timespec(&tmp, -wtm->tv_sec, -wtm->tv_nsec);
-        tk->offs_real = timespec_to_ktime(tmp);
-}
-
 /* must hold write on timekeeper.lock */
 static void timekeeping_update(struct timekeeper *tk, bool clearntp)
 {
@@ -234,12 +252,10 @@ static void timekeeping_update(struct timekeeper *tk, bool clearntp)
                 tk->ntp_error = 0;
                 ntp_clear();
         }
-        update_rt_offset(tk);
         xt = tk_xtime(tk);
         update_vsyscall(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult);
 }
 
-
 /**
  * timekeeping_forward_now - update clock to the current time
  *
@@ -261,7 +277,7 @@ static void timekeeping_forward_now(struct timekeeper *tk)
         tk->xtime_nsec += cycle_delta * tk->mult;
 
         /* If arch requires, add in gettimeoffset() */
-        tk->xtime_nsec += arch_gettimeoffset() << tk->shift;
+        tk->xtime_nsec += (u64)arch_gettimeoffset() << tk->shift;
 
         tk_normalize_xtime(tk);
 
@@ -277,18 +293,19 @@ static void timekeeping_forward_now(struct timekeeper *tk)
  */
 void getnstimeofday(struct timespec *ts)
 {
+        struct timekeeper *tk = &timekeeper;
         unsigned long seq;
         s64 nsecs = 0;
 
         WARN_ON(timekeeping_suspended);
 
         do {
-                seq = read_seqbegin(&timekeeper.lock);
+                seq = read_seqbegin(&tk->lock);
 
-                ts->tv_sec = timekeeper.xtime_sec;
-                ts->tv_nsec = timekeeping_get_ns(&timekeeper);
+                ts->tv_sec = tk->xtime_sec;
+                ts->tv_nsec = timekeeping_get_ns(tk);
 
-        } while (read_seqretry(&timekeeper.lock, seq));
+        } while (read_seqretry(&tk->lock, seq));
 
         timespec_add_ns(ts, nsecs);
 }
@@ -296,19 +313,18 @@ EXPORT_SYMBOL(getnstimeofday);
 
 ktime_t ktime_get(void)
 {
+        struct timekeeper *tk = &timekeeper;
         unsigned int seq;
         s64 secs, nsecs;
 
         WARN_ON(timekeeping_suspended);
 
         do {
-                seq = read_seqbegin(&timekeeper.lock);
-                secs = timekeeper.xtime_sec +
-                                timekeeper.wall_to_monotonic.tv_sec;
-                nsecs = timekeeping_get_ns(&timekeeper) +
-                                timekeeper.wall_to_monotonic.tv_nsec;
+                seq = read_seqbegin(&tk->lock);
+                secs = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
+                nsecs = timekeeping_get_ns(tk) + tk->wall_to_monotonic.tv_nsec;
 
-        } while (read_seqretry(&timekeeper.lock, seq));
+        } while (read_seqretry(&tk->lock, seq));
         /*
          * Use ktime_set/ktime_add_ns to create a proper ktime on
          * 32-bit architectures without CONFIG_KTIME_SCALAR.
@@ -327,18 +343,19 @@ EXPORT_SYMBOL_GPL(ktime_get);
  */
 void ktime_get_ts(struct timespec *ts)
 {
+        struct timekeeper *tk = &timekeeper;
         struct timespec tomono;
         unsigned int seq;
 
         WARN_ON(timekeeping_suspended);
 
         do {
-                seq = read_seqbegin(&timekeeper.lock);
-                ts->tv_sec = timekeeper.xtime_sec;
-                ts->tv_nsec = timekeeping_get_ns(&timekeeper);
-                tomono = timekeeper.wall_to_monotonic;
+                seq = read_seqbegin(&tk->lock);
+                ts->tv_sec = tk->xtime_sec;
+                ts->tv_nsec = timekeeping_get_ns(tk);
+                tomono = tk->wall_to_monotonic;
 
-        } while (read_seqretry(&timekeeper.lock, seq));
+        } while (read_seqretry(&tk->lock, seq));
 
         set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
                                 ts->tv_nsec + tomono.tv_nsec);
@@ -358,22 +375,23 @@ EXPORT_SYMBOL_GPL(ktime_get_ts);
  */
 void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
 {
+        struct timekeeper *tk = &timekeeper;
         unsigned long seq;
         s64 nsecs_raw, nsecs_real;
 
         WARN_ON_ONCE(timekeeping_suspended);
 
         do {
-                seq = read_seqbegin(&timekeeper.lock);
+                seq = read_seqbegin(&tk->lock);
 
-                *ts_raw = timekeeper.raw_time;
-                ts_real->tv_sec = timekeeper.xtime_sec;
+                *ts_raw = tk->raw_time;
+                ts_real->tv_sec = tk->xtime_sec;
                 ts_real->tv_nsec = 0;
 
-                nsecs_raw = timekeeping_get_ns_raw(&timekeeper);
-                nsecs_real = timekeeping_get_ns(&timekeeper);
+                nsecs_raw = timekeeping_get_ns_raw(tk);
+                nsecs_real = timekeeping_get_ns(tk);
 
-        } while (read_seqretry(&timekeeper.lock, seq));
+        } while (read_seqretry(&tk->lock, seq));
 
         timespec_add_ns(ts_raw, nsecs_raw);
         timespec_add_ns(ts_real, nsecs_real);
@@ -406,28 +424,28 @@ EXPORT_SYMBOL(do_gettimeofday);
  */
 int do_settimeofday(const struct timespec *tv)
 {
+        struct timekeeper *tk = &timekeeper;
         struct timespec ts_delta, xt;
         unsigned long flags;
 
-        if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
+        if (!timespec_valid_strict(tv))
                 return -EINVAL;
 
-        write_seqlock_irqsave(&timekeeper.lock, flags);
+        write_seqlock_irqsave(&tk->lock, flags);
 
-        timekeeping_forward_now(&timekeeper);
+        timekeeping_forward_now(tk);
 
-        xt = tk_xtime(&timekeeper);
+        xt = tk_xtime(tk);
         ts_delta.tv_sec = tv->tv_sec - xt.tv_sec;
         ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec;
 
-        timekeeper.wall_to_monotonic =
-                        timespec_sub(timekeeper.wall_to_monotonic, ts_delta);
+        tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, ts_delta));
 
-        tk_set_xtime(&timekeeper, tv);
+        tk_set_xtime(tk, tv);
 
-        timekeeping_update(&timekeeper, true);
+        timekeeping_update(tk, true);
 
-        write_sequnlock_irqrestore(&timekeeper.lock, flags);
+        write_sequnlock_irqrestore(&tk->lock, flags);
 
         /* signal hrtimers about time change */
         clock_was_set();
@@ -436,7 +454,6 @@ int do_settimeofday(const struct timespec *tv)
 }
 EXPORT_SYMBOL(do_settimeofday);
 
-
 /**
  * timekeeping_inject_offset - Adds or subtracts from the current time.
  * @tv:         pointer to the timespec variable containing the offset
@@ -445,28 +462,37 @@ EXPORT_SYMBOL(do_settimeofday);
  */
 int timekeeping_inject_offset(struct timespec *ts)
 {
+        struct timekeeper *tk = &timekeeper;
         unsigned long flags;
+        struct timespec tmp;
+        int ret = 0;
 
         if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
                 return -EINVAL;
 
-        write_seqlock_irqsave(&timekeeper.lock, flags);
+        write_seqlock_irqsave(&tk->lock, flags);
 
-        timekeeping_forward_now(&timekeeper);
+        timekeeping_forward_now(tk);
 
+        /* Make sure the proposed value is valid */
+        tmp = timespec_add(tk_xtime(tk),  *ts);
+        if (!timespec_valid_strict(&tmp)) {
+                ret = -EINVAL;
+                goto error;
+        }
 
-        tk_xtime_add(&timekeeper, ts);
-        timekeeper.wall_to_monotonic =
-                                timespec_sub(timekeeper.wall_to_monotonic, *ts);
+        tk_xtime_add(tk, ts);
+        tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *ts));
 
-        timekeeping_update(&timekeeper, true);
+error: /* even if we error out, we forwarded the time, so call update */
+        timekeeping_update(tk, true);
 
-        write_sequnlock_irqrestore(&timekeeper.lock, flags);
+        write_sequnlock_irqrestore(&tk->lock, flags);
 
         /* signal hrtimers about time change */
         clock_was_set();
 
-        return 0;
+        return ret;
 }
 EXPORT_SYMBOL(timekeeping_inject_offset);
 
@@ -477,23 +503,24 @@ EXPORT_SYMBOL(timekeeping_inject_offset);
  */
 static int change_clocksource(void *data)
 {
+        struct timekeeper *tk = &timekeeper;
         struct clocksource *new, *old;
         unsigned long flags;
 
         new = (struct clocksource *) data;
 
-        write_seqlock_irqsave(&timekeeper.lock, flags);
+        write_seqlock_irqsave(&tk->lock, flags);
 
-        timekeeping_forward_now(&timekeeper);
+        timekeeping_forward_now(tk);
         if (!new->enable || new->enable(new) == 0) {
-                old = timekeeper.clock;
-                tk_setup_internals(&timekeeper, new);
+                old = tk->clock;
+                tk_setup_internals(tk, new);
                 if (old->disable)
                         old->disable(old);
         }
-        timekeeping_update(&timekeeper, true);
+        timekeeping_update(tk, true);
 
-        write_sequnlock_irqrestore(&timekeeper.lock, flags);
+        write_sequnlock_irqrestore(&tk->lock, flags);
 
         return 0;
 }
@@ -507,7 +534,9 @@ static int change_clocksource(void *data)
  */
 void timekeeping_notify(struct clocksource *clock)
 {
-        if (timekeeper.clock == clock)
+        struct timekeeper *tk = &timekeeper;
+
+        if (tk->clock == clock)
                 return;
         stop_machine(change_clocksource, clock, NULL);
         tick_clock_notify();
@@ -536,35 +565,36 @@ EXPORT_SYMBOL_GPL(ktime_get_real);
  */
 void getrawmonotonic(struct timespec *ts)
 {
+        struct timekeeper *tk = &timekeeper;
         unsigned long seq;
         s64 nsecs;
 
         do {
-                seq = read_seqbegin(&timekeeper.lock);
-                nsecs = timekeeping_get_ns_raw(&timekeeper);
-                *ts = timekeeper.raw_time;
+                seq = read_seqbegin(&tk->lock);
+                nsecs = timekeeping_get_ns_raw(tk);
+                *ts = tk->raw_time;
 
-        } while (read_seqretry(&timekeeper.lock, seq));
+        } while (read_seqretry(&tk->lock, seq));
 
         timespec_add_ns(ts, nsecs);
 }
 EXPORT_SYMBOL(getrawmonotonic);
 
-
 /**
  * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres
  */
 int timekeeping_valid_for_hres(void)
 {
+        struct timekeeper *tk = &timekeeper;
         unsigned long seq;
         int ret;
 
         do {
-                seq = read_seqbegin(&timekeeper.lock);
+                seq = read_seqbegin(&tk->lock);
 
-                ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
+                ret = tk->clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
 
-        } while (read_seqretry(&timekeeper.lock, seq));
+        } while (read_seqretry(&tk->lock, seq));
 
         return ret;
 }
@@ -574,15 +604,16 @@ int timekeeping_valid_for_hres(void)
  */
 u64 timekeeping_max_deferment(void)
 {
+        struct timekeeper *tk = &timekeeper;
         unsigned long seq;
         u64 ret;
 
         do {
-                seq = read_seqbegin(&timekeeper.lock);
+                seq = read_seqbegin(&tk->lock);
 
-                ret = timekeeper.clock->max_idle_ns;
+                ret = tk->clock->max_idle_ns;
 
-        } while (read_seqretry(&timekeeper.lock, seq));
+        } while (read_seqretry(&tk->lock, seq));
 
         return ret;
 }
@@ -622,46 +653,56 @@ void __attribute__((weak)) read_boot_clock(struct timespec *ts)
  */
 void __init timekeeping_init(void)
 {
+        struct timekeeper *tk = &timekeeper;
         struct clocksource *clock;
         unsigned long flags;
-        struct timespec now, boot;
+        struct timespec now, boot, tmp;
 
         read_persistent_clock(&now);
+        if (!timespec_valid_strict(&now)) {
+                pr_warn("WARNING: Persistent clock returned invalid value!\n"
+                        "         Check your CMOS/BIOS settings.\n");
+                now.tv_sec = 0;
+                now.tv_nsec = 0;
+        }
+
         read_boot_clock(&boot);
+        if (!timespec_valid_strict(&boot)) {
+                pr_warn("WARNING: Boot clock returned invalid value!\n"
+                        "         Check your CMOS/BIOS settings.\n");
+                boot.tv_sec = 0;
+                boot.tv_nsec = 0;
+        }
 
-        seqlock_init(&timekeeper.lock);
+        seqlock_init(&tk->lock);
 
         ntp_init();
 
-        write_seqlock_irqsave(&timekeeper.lock, flags);
+        write_seqlock_irqsave(&tk->lock, flags);
         clock = clocksource_default_clock();
         if (clock->enable)
                 clock->enable(clock);
-        tk_setup_internals(&timekeeper, clock);
+        tk_setup_internals(tk, clock);
 
-        tk_set_xtime(&timekeeper, &now);
-        timekeeper.raw_time.tv_sec = 0;
-        timekeeper.raw_time.tv_nsec = 0;
+        tk_set_xtime(tk, &now);
+        tk->raw_time.tv_sec = 0;
+        tk->raw_time.tv_nsec = 0;
         if (boot.tv_sec == 0 && boot.tv_nsec == 0)
-                boot = tk_xtime(&timekeeper);
-
-        set_normalized_timespec(&timekeeper.wall_to_monotonic,
-                                -boot.tv_sec, -boot.tv_nsec);
-        update_rt_offset(&timekeeper);
-        timekeeper.total_sleep_time.tv_sec = 0;
-        timekeeper.total_sleep_time.tv_nsec = 0;
-        write_sequnlock_irqrestore(&timekeeper.lock, flags);
+                boot = tk_xtime(tk);
+
+        set_normalized_timespec(&tmp, -boot.tv_sec, -boot.tv_nsec);
+        tk_set_wall_to_mono(tk, tmp);
+
+        tmp.tv_sec = 0;
+        tmp.tv_nsec = 0;
+        tk_set_sleep_time(tk, tmp);
+
+        write_sequnlock_irqrestore(&tk->lock, flags);
 }
 
 /* time in seconds when suspend began */
 static struct timespec timekeeping_suspend_time;
 
-static void update_sleep_time(struct timespec t)
-{
-        timekeeper.total_sleep_time = t;
-        timekeeper.offs_boot = timespec_to_ktime(t);
-}
-
 /**
  * __timekeeping_inject_sleeptime - Internal function to add sleep interval
  * @delta: pointer to a timespec delta value
@@ -672,18 +713,16 @@ static void update_sleep_time(struct timespec t)
 static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
                                                         struct timespec *delta)
 {
-        if (!timespec_valid(delta)) {
+        if (!timespec_valid_strict(delta)) {
                 printk(KERN_WARNING "__timekeeping_inject_sleeptime: Invalid "
                                         "sleep delta value!\n");
                 return;
         }
-
         tk_xtime_add(tk, delta);
-        tk->wall_to_monotonic = timespec_sub(tk->wall_to_monotonic, *delta);
-        update_sleep_time(timespec_add(tk->total_sleep_time, *delta));
+        tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *delta));
+        tk_set_sleep_time(tk, timespec_add(tk->total_sleep_time, *delta));
 }
 
-
 /**
  * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values
  * @delta: pointer to a timespec delta value
@@ -696,6 +735,7 @@ static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
  */
 void timekeeping_inject_sleeptime(struct timespec *delta)
 {
+        struct timekeeper *tk = &timekeeper;
         unsigned long flags;
         struct timespec ts;
 
@@ -704,21 +744,20 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
         if (!(ts.tv_sec == 0 && ts.tv_nsec == 0))
                 return;
 
-        write_seqlock_irqsave(&timekeeper.lock, flags);
+        write_seqlock_irqsave(&tk->lock, flags);
 
-        timekeeping_forward_now(&timekeeper);
+        timekeeping_forward_now(tk);
 
-        __timekeeping_inject_sleeptime(&timekeeper, delta);
+        __timekeeping_inject_sleeptime(tk, delta);
 
-        timekeeping_update(&timekeeper, true);
+        timekeeping_update(tk, true);
 
-        write_sequnlock_irqrestore(&timekeeper.lock, flags);
+        write_sequnlock_irqrestore(&tk->lock, flags);
 
         /* signal hrtimers about time change */
         clock_was_set();
 }
 
-
 /**
  * timekeeping_resume - Resumes the generic timekeeping subsystem.
  *
@@ -728,6 +767,7 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
  */
 static void timekeeping_resume(void)
 {
+        struct timekeeper *tk = &timekeeper;
         unsigned long flags;
         struct timespec ts;
 
@@ -735,18 +775,18 @@ static void timekeeping_resume(void)
 
         clocksource_resume();
 
-        write_seqlock_irqsave(&timekeeper.lock, flags);
+        write_seqlock_irqsave(&tk->lock, flags);
 
         if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) {
                 ts = timespec_sub(ts, timekeeping_suspend_time);
-                __timekeeping_inject_sleeptime(&timekeeper, &ts);
+                __timekeeping_inject_sleeptime(tk, &ts);
         }
         /* re-base the last cycle value */
-        timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);
-        timekeeper.ntp_error = 0;
+        tk->clock->cycle_last = tk->clock->read(tk->clock);
+        tk->ntp_error = 0;
         timekeeping_suspended = 0;
-        timekeeping_update(&timekeeper, false);
-        write_sequnlock_irqrestore(&timekeeper.lock, flags);
+        timekeeping_update(tk, false);
+        write_sequnlock_irqrestore(&tk->lock, flags);
 
         touch_softlockup_watchdog();
 
@@ -758,14 +798,15 @@ static void timekeeping_resume(void)
 
 static int timekeeping_suspend(void)
 {
+        struct timekeeper *tk = &timekeeper;
         unsigned long flags;
         struct timespec         delta, delta_delta;
         static struct timespec  old_delta;
 
         read_persistent_clock(&timekeeping_suspend_time);
 
-        write_seqlock_irqsave(&timekeeper.lock, flags);
-        timekeeping_forward_now(&timekeeper);
+        write_seqlock_irqsave(&tk->lock, flags);
+        timekeeping_forward_now(tk);
         timekeeping_suspended = 1;
 
         /*
@@ -774,7 +815,7 @@ static int timekeeping_suspend(void)
          * try to compensate so the difference in system time
          * and persistent_clock time stays close to constant.
          */
-        delta = timespec_sub(tk_xtime(&timekeeper), timekeeping_suspend_time);
+        delta = timespec_sub(tk_xtime(tk), timekeeping_suspend_time);
         delta_delta = timespec_sub(delta, old_delta);
         if (abs(delta_delta.tv_sec)  >= 2) {
                 /*
@@ -787,7 +828,7 @@ static int timekeeping_suspend(void)
                 timekeeping_suspend_time =
                         timespec_add(timekeeping_suspend_time, delta_delta);
         }
-        write_sequnlock_irqrestore(&timekeeper.lock, flags);
+        write_sequnlock_irqrestore(&tk->lock, flags);
 
         clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
         clocksource_suspend();
@@ -898,27 +939,29 @@ static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
                  * the error. This causes the likely below to be unlikely.
                  *
                  * The proper fix is to avoid rounding up by using
-                 * the high precision timekeeper.xtime_nsec instead of
+                 * the high precision tk->xtime_nsec instead of
                  * xtime.tv_nsec everywhere. Fixing this will take some
                  * time.
                  */
                 if (likely(error <= interval))
                         adj = 1;
                 else
-                        adj = timekeeping_bigadjust(tk, error, &interval,
-                                                        &offset);
-        } else if (error < -interval) {
-                /* See comment above, this is just switched for the negative */
-                error >>= 2;
-                if (likely(error >= -interval)) {
-                        adj = -1;
-                        interval = -interval;
-                        offset = -offset;
-                } else
-                        adj = timekeeping_bigadjust(tk, error, &interval,
-                                                        &offset);
-        } else
-                return;
+                        adj = timekeeping_bigadjust(tk, error, &interval, &offset);
+        } else {
+                if (error < -interval) {
+                        /* See comment above, this is just switched for the negative */
+                        error >>= 2;
+                        if (likely(error >= -interval)) {
+                                adj = -1;
+                                interval = -interval;
+                                offset = -offset;
+                        } else {
+                                adj = timekeeping_bigadjust(tk, error, &interval, &offset);
+                        }
+                } else {
+                        goto out_adjust;
+                }
+        }
 
         if (unlikely(tk->clock->maxadj &&
                 (tk->mult + adj > tk->clock->mult + tk->clock->maxadj))) {
@@ -981,6 +1024,7 @@ static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
         tk->xtime_nsec -= offset;
         tk->ntp_error -= (interval - offset) << tk->ntp_error_shift;
 
+out_adjust:
         /*
          * It may be possible that when we entered this function, xtime_nsec
          * was very small.  Further, if we're slightly speeding the clocksource
@@ -1003,7 +1047,6 @@ static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
 
 }
 
-
 /**
  * accumulate_nsecs_to_secs - Accumulates nsecs into secs
  *
@@ -1024,15 +1067,21 @@ static inline void accumulate_nsecs_to_secs(struct timekeeper *tk)
 
                 /* Figure out if its a leap sec and apply if needed */
                 leap = second_overflow(tk->xtime_sec);
-                tk->xtime_sec += leap;
-                tk->wall_to_monotonic.tv_sec -= leap;
-                if (leap)
-                        clock_was_set_delayed();
+                if (unlikely(leap)) {
+                        struct timespec ts;
+
+                        tk->xtime_sec += leap;
+
+                        ts.tv_sec = leap;
+                        ts.tv_nsec = 0;
+                        tk_set_wall_to_mono(tk,
+                                timespec_sub(tk->wall_to_monotonic, ts));
 
+                        clock_was_set_delayed();
+                }
         }
 }
 
-
 /**
  * logarithmic_accumulation - shifted accumulation of cycles
  *
@@ -1076,7 +1125,6 @@ static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
         return offset;
 }
 
-
 /**
  * update_wall_time - Uses the current clocksource to increment the wall time
  *
@@ -1084,25 +1132,30 @@ static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
 static void update_wall_time(void)
 {
         struct clocksource *clock;
+        struct timekeeper *tk = &timekeeper;
         cycle_t offset;
         int shift = 0, maxshift;
         unsigned long flags;
         s64 remainder;
 
-        write_seqlock_irqsave(&timekeeper.lock, flags);
+        write_seqlock_irqsave(&tk->lock, flags);
 
         /* Make sure we're fully resumed: */
         if (unlikely(timekeeping_suspended))
                 goto out;
 
-        clock = timekeeper.clock;
+        clock = tk->clock;
 
 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
-        offset = timekeeper.cycle_interval;
+        offset = tk->cycle_interval;
 #else
         offset = (clock->read(clock) - clock->cycle_last) & clock->mask;
 #endif
 
+        /* Check if there's really nothing to do */
+        if (offset < tk->cycle_interval)
+                goto out;
+
         /*
          * With NO_HZ we may have to accumulate many cycle_intervals
          * (think "ticks") worth of time at once. To do this efficiently,
@@ -1111,19 +1164,19 @@ static void update_wall_time(void)
          * chunk in one go, and then try to consume the next smaller
          * doubled multiple.
          */
-        shift = ilog2(offset) - ilog2(timekeeper.cycle_interval);
+        shift = ilog2(offset) - ilog2(tk->cycle_interval);
         shift = max(0, shift);
         /* Bound shift to one less than what overflows tick_length */
         maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1;
         shift = min(shift, maxshift);
-        while (offset >= timekeeper.cycle_interval) {
-                offset = logarithmic_accumulation(&timekeeper, offset, shift);
-                if(offset < timekeeper.cycle_interval<<shift)
+        while (offset >= tk->cycle_interval) {
+                offset = logarithmic_accumulation(tk, offset, shift);
+                if (offset < tk->cycle_interval<<shift)
                         shift--;
         }
 
         /* correct the clock when NTP error is too big */
-        timekeeping_adjust(&timekeeper, offset);
+        timekeeping_adjust(tk, offset);
 
 
         /*
@@ -1135,21 +1188,21 @@ static void update_wall_time(void)
         * the vsyscall implementations are converted to use xtime_nsec
         * (shifted nanoseconds), this can be killed.
         */
-        remainder = timekeeper.xtime_nsec & ((1 << timekeeper.shift) - 1);
-        timekeeper.xtime_nsec -= remainder;
-        timekeeper.xtime_nsec += 1 << timekeeper.shift;
-        timekeeper.ntp_error += remainder << timekeeper.ntp_error_shift;
+        remainder = tk->xtime_nsec & ((1ULL << tk->shift) - 1);
+        tk->xtime_nsec -= remainder;
+        tk->xtime_nsec += 1ULL << tk->shift;
+        tk->ntp_error += remainder << tk->ntp_error_shift;
 
         /*
          * Finally, make sure that after the rounding
          * xtime_nsec isn't larger than NSEC_PER_SEC
          */
-        accumulate_nsecs_to_secs(&timekeeper);
+        accumulate_nsecs_to_secs(tk);
 
-        timekeeping_update(&timekeeper, false);
+        timekeeping_update(tk, false);
 
 out:
-        write_sequnlock_irqrestore(&timekeeper.lock, flags);
+        write_sequnlock_irqrestore(&tk->lock, flags);
 
 }
 
@@ -1166,18 +1219,18 @@ out:
  */
 void getboottime(struct timespec *ts)
 {
+        struct timekeeper *tk = &timekeeper;
         struct timespec boottime = {
-                .tv_sec = timekeeper.wall_to_monotonic.tv_sec +
-                                timekeeper.total_sleep_time.tv_sec,
-                .tv_nsec = timekeeper.wall_to_monotonic.tv_nsec +
-                                timekeeper.total_sleep_time.tv_nsec
+                .tv_sec = tk->wall_to_monotonic.tv_sec +
+                                tk->total_sleep_time.tv_sec,
+                .tv_nsec = tk->wall_to_monotonic.tv_nsec +
+                                tk->total_sleep_time.tv_nsec
         };
 
         set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec);
 }
 EXPORT_SYMBOL_GPL(getboottime);
 
-
 /**
  * get_monotonic_boottime - Returns monotonic time since boot
  * @ts:         pointer to the timespec to be set
@@ -1189,19 +1242,20 @@ EXPORT_SYMBOL_GPL(getboottime);
  */
 void get_monotonic_boottime(struct timespec *ts)
 {
+        struct timekeeper *tk = &timekeeper;
         struct timespec tomono, sleep;
         unsigned int seq;
 
         WARN_ON(timekeeping_suspended);
 
         do {
-                seq = read_seqbegin(&timekeeper.lock);
-                ts->tv_sec = timekeeper.xtime_sec;
-                ts->tv_nsec = timekeeping_get_ns(&timekeeper);
-                tomono = timekeeper.wall_to_monotonic;
-                sleep = timekeeper.total_sleep_time;
+                seq = read_seqbegin(&tk->lock);
+                ts->tv_sec = tk->xtime_sec;
+                ts->tv_nsec = timekeeping_get_ns(tk);
+                tomono = tk->wall_to_monotonic;
+                sleep = tk->total_sleep_time;
 
-        } while (read_seqretry(&timekeeper.lock, seq));
+        } while (read_seqretry(&tk->lock, seq));
 
         set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec + sleep.tv_sec,
                         ts->tv_nsec + tomono.tv_nsec + sleep.tv_nsec);
@@ -1231,31 +1285,38 @@ EXPORT_SYMBOL_GPL(ktime_get_boottime);
  */
 void monotonic_to_bootbased(struct timespec *ts)
 {
-        *ts = timespec_add(*ts, timekeeper.total_sleep_time);
+        struct timekeeper *tk = &timekeeper;
+
+        *ts = timespec_add(*ts, tk->total_sleep_time);
 }
 EXPORT_SYMBOL_GPL(monotonic_to_bootbased);
 
 unsigned long get_seconds(void)
 {
-        return timekeeper.xtime_sec;
+        struct timekeeper *tk = &timekeeper;
+
+        return tk->xtime_sec;
 }
 EXPORT_SYMBOL(get_seconds);
 
 struct timespec __current_kernel_time(void)
 {
-        return tk_xtime(&timekeeper);
+        struct timekeeper *tk = &timekeeper;
+
+        return tk_xtime(tk);
 }
 
 struct timespec current_kernel_time(void)
 {
+        struct timekeeper *tk = &timekeeper;
         struct timespec now;
         unsigned long seq;
 
         do {
-                seq = read_seqbegin(&timekeeper.lock);
+                seq = read_seqbegin(&tk->lock);
 
-                now = tk_xtime(&timekeeper);
-        } while (read_seqretry(&timekeeper.lock, seq));
+                now = tk_xtime(tk);
+        } while (read_seqretry(&tk->lock, seq));
 
         return now;
 }
@@ -1263,15 +1324,16 @@ EXPORT_SYMBOL(current_kernel_time);
 
 struct timespec get_monotonic_coarse(void)
 {
+        struct timekeeper *tk = &timekeeper;
         struct timespec now, mono;
         unsigned long seq;
 
         do {
-                seq = read_seqbegin(&timekeeper.lock);
+                seq = read_seqbegin(&tk->lock);
 
-                now = tk_xtime(&timekeeper);
-                mono = timekeeper.wall_to_monotonic;
-        } while (read_seqretry(&timekeeper.lock, seq));
+                now = tk_xtime(tk);
+                mono = tk->wall_to_monotonic;
+        } while (read_seqretry(&tk->lock, seq));
 
         set_normalized_timespec(&now, now.tv_sec + mono.tv_sec,
                                 now.tv_nsec + mono.tv_nsec);
@@ -1300,14 +1362,15 @@ void do_timer(unsigned long ticks)
 void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
                                 struct timespec *wtom, struct timespec *sleep)
 {
+        struct timekeeper *tk = &timekeeper;
         unsigned long seq;
 
         do {
-                seq = read_seqbegin(&timekeeper.lock);
-                *xtim = tk_xtime(&timekeeper);
-                *wtom = timekeeper.wall_to_monotonic;
-                *sleep = timekeeper.total_sleep_time;
-        } while (read_seqretry(&timekeeper.lock, seq));
+                seq = read_seqbegin(&tk->lock);
+                *xtim = tk_xtime(tk);
+                *wtom = tk->wall_to_monotonic;
+                *sleep = tk->total_sleep_time;
+        } while (read_seqretry(&tk->lock, seq));
 }
 
 #ifdef CONFIG_HIGH_RES_TIMERS
@@ -1321,19 +1384,20 @@ void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
  */
 ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot)
 {
+        struct timekeeper *tk = &timekeeper;
         ktime_t now;
         unsigned int seq;
         u64 secs, nsecs;
 
         do {
-                seq = read_seqbegin(&timekeeper.lock);
+                seq = read_seqbegin(&tk->lock);
 
-                secs = timekeeper.xtime_sec;
-                nsecs = timekeeping_get_ns(&timekeeper);
+                secs = tk->xtime_sec;
+                nsecs = timekeeping_get_ns(tk);
 
-                *offs_real = timekeeper.offs_real;
-                *offs_boot = timekeeper.offs_boot;
-        } while (read_seqretry(&timekeeper.lock, seq));
+                *offs_real = tk->offs_real;
+                *offs_boot = tk->offs_boot;
+        } while (read_seqretry(&tk->lock, seq));
 
         now = ktime_add_ns(ktime_set(secs, 0), nsecs);
         now = ktime_sub(now, *offs_real);
@@ -1346,19 +1410,19 @@ ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot)
  */
 ktime_t ktime_get_monotonic_offset(void)
 {
+        struct timekeeper *tk = &timekeeper;
         unsigned long seq;
         struct timespec wtom;
 
         do {
-                seq = read_seqbegin(&timekeeper.lock);
-                wtom = timekeeper.wall_to_monotonic;
-        } while (read_seqretry(&timekeeper.lock, seq));
+                seq = read_seqbegin(&tk->lock);
+                wtom = tk->wall_to_monotonic;
+        } while (read_seqretry(&tk->lock, seq));
 
         return timespec_to_ktime(wtom);
 }
 EXPORT_SYMBOL_GPL(ktime_get_monotonic_offset);
 
-
 /**
  * xtime_update() - advances the timekeeping infrastructure
  * @ticks:      number of ticks, that have elapsed since the last call.