If we happen to receive interrupts during hv_set_host_time() execution
our adjustments may get inaccurate. Make the whole function atomic.
Unfortunately, we can's call do_settimeofday64() with interrupts
disabled as some cross-CPU work is being done but this call happens
very rarely.
Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
---
drivers/hv/hv_util.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c
index 7e97231..4e50a42 100644
--- a/drivers/hv/hv_util.c
+++ b/drivers/hv/hv_util.c
@@ -187,6 +187,9 @@ static void hv_set_host_time(struct work_struct *work)
struct timespec64 host_ts, our_ts;
struct timex txc = {0};
int ret;
+ unsigned long flags;
+
+ local_irq_save(flags);
wrk = container_of(work, struct adj_time_work, work);
@@ -218,6 +221,7 @@ static void hv_set_host_time(struct work_struct *work)
* ordered to sync our time by the host.
*/
if (abs(delta) > MAXPHASE || wrk->flags & ICTIMESYNCFLAG_SYNC) {
+ local_irq_restore(flags);
do_settimeofday64(&host_ts);
return;
}
@@ -232,6 +236,8 @@ static void hv_set_host_time(struct work_struct *work)
ret = do_adjtimex(&txc);
if (ret)
pr_debug("Failed to adjust system time: %d\n", ret);
+
+ local_irq_restore(flags);
}
/*
--
2.9.3
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