Merge tag 'timers_urgent_for_v6.13_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer fix from Borislav Petkov:

 - Handle the case where clocksources with small counter width can,
   in conjunction with overly long idle sleeps, falsely trigger the
   negative motion detection of clocksources

* tag 'timers_urgent_for_v6.13_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource: Make negative motion detection more robust

1 files changed, 4 insertions, 4 deletions

diff --git a/kernel/time/timekeeping_internal.h b/kernel/time/timekeeping_internal.h
index 63e600e943a7..8c9079108ffb 100644
--- a/kernel/time/timekeeping_internal.h
+++ b/kernel/time/timekeeping_internal.h
@@ -30,15 +30,15 @@ static inline void timekeeping_inc_mg_floor_swaps(void)
 
 #endif
 
-static inline u64 clocksource_delta(u64 now, u64 last, u64 mask)
+static inline u64 clocksource_delta(u64 now, u64 last, u64 mask, u64 max_delta)
 {
 	u64 ret = (now - last) & mask;
 
 	/*
-	 * Prevent time going backwards by checking the MSB of mask in
-	 * the result. If set, return 0.
+	 * Prevent time going backwards by checking the result against
+	 * @max_delta. If greater, return 0.
 	 */
-	return ret & ~(mask >> 1) ? 0 : ret;
+	return ret > max_delta ? 0 : ret;
 }
 
 /* Semi public for serialization of non timekeeper VDSO updates. */