From e3fab2f3de081e98c50b7b4ace1b040161d95310 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Mon, 11 Jan 2021 11:39:56 +0100 Subject: [PATCH] ntp: Fix RTC synchronization on 32-bit platforms 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: c9e6189fb03123a7 ("ntp: Make the RTC synchronization more reliable") Signed-off-by: Geert Uytterhoeven Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20210111103956.290378-1-geert+renesas@glider.be --- kernel/time/ntp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 7404d38..87389b9 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -498,7 +498,7 @@ out: static void sync_hw_clock(struct work_struct *work); static DECLARE_WORK(sync_work, sync_hw_clock); 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) { @@ -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); 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 exp = ktime_add_ns(exp, SYNC_PERIOD_NS - offset_nsec); -- 2.7.4