timekeeping: Hold timekeepering locks in do_adjtimex and hardpps

In moving the NTP state to be protected by the timekeeping locks,
be sure to acquire the timekeeping locks prior to calling
ntp functions.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>

1 files changed, 17 insertions, 2 deletions

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index e44915c7b16c..d10bd734b151 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -787,10 +787,10 @@ void __init timekeeping_init(void)
                 boot.tv_nsec = 0;
         }
 
-        ntp_init();
-
         raw_spin_lock_irqsave(&timekeeper_lock, flags);
         write_seqcount_begin(&timekeeper_seq);
+        ntp_init();
+
         clock = clocksource_default_clock();
         if (clock->enable)
                 clock->enable(clock);
@@ -1618,6 +1618,7 @@ EXPORT_SYMBOL_GPL(ktime_get_monotonic_offset);
  */
 int do_adjtimex(struct timex *txc)
 {
+        unsigned long flags;
         struct timespec ts;
         s32 tai, orig_tai;
         int ret;
@@ -1641,8 +1642,14 @@ int do_adjtimex(struct timex *txc)
         getnstimeofday(&ts);
         orig_tai = tai = timekeeping_get_tai_offset();
 
+        raw_spin_lock_irqsave(&timekeeper_lock, flags);
+        write_seqcount_begin(&timekeeper_seq);
+
         ret = __do_adjtimex(txc, &ts, &tai);
 
+        write_seqcount_end(&timekeeper_seq);
+        raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+
         if (tai != orig_tai)
                 timekeeping_set_tai_offset(tai);
 
@@ -1655,7 +1662,15 @@ int do_adjtimex(struct timex *txc)
  */
 void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
 {
+        unsigned long flags;
+
+        raw_spin_lock_irqsave(&timekeeper_lock, flags);
+        write_seqcount_begin(&timekeeper_seq);
+
         __hardpps(phase_ts, raw_ts);
+
+        write_seqcount_end(&timekeeper_seq);
+        raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
 }
 EXPORT_SYMBOL(hardpps);
 #endif