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ntp: Fix RTC synchronization on 32-bit platforms

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Due to an integer overflow, RTC synchronization now happens every 2s
instead of the intended 11 minutes.  Fix this by forcing 64-bit
arithmetic for the sync period calculation.

Annotate the other place which multiplies seconds for consistency as well.

Fixes: c9e6189fb0 ("ntp: Make the RTC synchronization more reliable")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210111103956.290378-1-geert+renesas@glider.be
This commit is contained in:
Geert Uytterhoeven 2021-01-11 11:39:56 +01:00 committed by Thomas Gleixner
parent aba428a0c6
commit e3fab2f3de
1 changed files with 2 additions and 2 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

4
kernel/time/ntp.c
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@ -498,7 +498,7 @@ int second_overflow(time64_t secs)
static void sync_hw_clock(struct work_struct *work); static void sync_hw_clock(struct work_struct *work);
static DECLARE_WORK(sync_work, sync_hw_clock); static DECLARE_WORK(sync_work, sync_hw_clock);
static struct hrtimer sync_hrtimer; static struct hrtimer sync_hrtimer;
#define SYNC_PERIOD_NS (11UL * 60 * NSEC_PER_SEC) #define SYNC_PERIOD_NS (11ULL * 60 * NSEC_PER_SEC)
static enum hrtimer_restart sync_timer_callback(struct hrtimer *timer) static enum hrtimer_restart sync_timer_callback(struct hrtimer *timer)
{ {
@ -512,7 +512,7 @@ static void sched_sync_hw_clock(unsigned long offset_nsec, bool retry)
ktime_t exp = ktime_set(ktime_get_real_seconds(), 0); ktime_t exp = ktime_set(ktime_get_real_seconds(), 0);
if (retry) if (retry)
exp = ktime_add_ns(exp, 2 * NSEC_PER_SEC - offset_nsec); exp = ktime_add_ns(exp, 2ULL * NSEC_PER_SEC - offset_nsec);
else else
exp = ktime_add_ns(exp, SYNC_PERIOD_NS - offset_nsec); exp = ktime_add_ns(exp, SYNC_PERIOD_NS - offset_nsec);