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Subject[PATCH 6/8] timekeeping: Hold timekeepering locks in do_adjtimex and hardpps
Date
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>
---
kernel/time/timekeeping.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index e44915c..d10bd73 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
--
1.7.10.4


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