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From:   Geert Uytterhoeven <geert+renesas@glider.be>
To:     John Stultz <john.stultz@linaro.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc:     Stephen Boyd <sboyd@kernel.org>, linux-kernel@vger.kernel.org,
        Geert Uytterhoeven <geert+renesas@glider.be>
Subject: [PATCH] ntp: Fix RTC synchronization on 32-bit platforms
Date:   Mon, 11 Jan 2021 11:39:56 +0100
Message-Id: <20210111103956.290378-1-geert+renesas@glider.be>
MIME-Version: 1.0
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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.

Fixes: c9e6189fb03123a7 ("ntp: Make the RTC synchronization more reliable")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 kernel/time/ntp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 7404d38315276a96..54d52fab201d283e 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -498,7 +498,7 @@ int second_overflow(time64_t secs)
 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)
 {
-- 
2.25.1