From a529bea8fa6b6dded6179c72d3385e0f7d0a4fde Mon Sep 17 00:00:00 2001
From: Stafford Horne <shorne@gmail.com>
Date: Wed, 28 Jun 2017 22:21:35 +0900
Subject: [PATCH] timekeeping: Use proper timekeeper for debug code
Git-commit: a529bea8fa6b6dded6179c72d3385e0f7d0a4fde
Patch-mainline: v4.14-rc1
References: bsc#1051510

When CONFIG_DEBUG_TIMEKEEPING is enabled the timekeeping_check_update()
function will update status like last_warning and underflow_seen on the
timekeeper.

If there are issues found this state is used to rate limit the warnings
that get printed.

This rate limiting doesn't really really work if stored in real_tk as
the shadow timekeeper is overwritten onto real_tk at the end of every
update_wall_time() call, resetting last_warning and other statuses.

Fix rate limiting by using the shadow_timekeeper for
timekeeping_check_update().

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Fixes: commit 57d05a93ada7 ("time: Rework debugging variables so they aren't global")
Signed-off-by: Stafford Horne <shorne@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 kernel/time/timekeeping.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index cedafa008de5..8f5866981883 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -2066,7 +2066,7 @@ void update_wall_time(void)
 		goto out;
 
 	/* Do some additional sanity checking */
-	timekeeping_check_update(real_tk, offset);
+	timekeeping_check_update(tk, offset);
 
 	/*
 	 * With NO_HZ we may have to accumulate many cycle_intervals
-- 
2.18.0