From 3d2e83a2a6a0657c1cf145fa6ba23620715d6c36 Mon Sep 17 00:00:00 2001
From: Frederic Weisbecker <frederic@kernel.org>
Date: Fri, 17 Jul 2020 16:05:41 +0200
Subject: [PATCH] timers: Preserve higher bits of expiration on index
 calculation
Git-commit: 3d2e83a2a6a0657c1cf145fa6ba23620715d6c36
Patch-mainline: v5.9-rc1
References: bsc#1179365

The higher bits of the timer expiration are cropped while calling
calc_index() due to the implicit cast from unsigned long to unsigned int.

This loss shouldn't have consequences on the current code since all the
computation to calculate the index is done on the lower 32 bits.

However to prepare for returning the actual bucket expiration from
calc_index() in order to properly fix base->next_expiry updates, the higher
bits need to be preserved.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200717140551.29076-3-frederic@kernel.org
Signed-off-by: Frederic Weisbecker <fweisbecker@suse.com>
---
 kernel/time/timer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index df1ff803acc4..bcdc3045138d 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -487,7 +487,7 @@ static inline void timer_set_idx(struct timer_list *timer, unsigned int idx)
  * Helper function to calculate the array index for a given expiry
  * time.
  */
-static inline unsigned calc_index(unsigned expires, unsigned lvl)
+static inline unsigned calc_index(unsigned long expires, unsigned lvl)
 {
 	expires = (expires + LVL_GRAN(lvl)) >> LVL_SHIFT(lvl);
 	return LVL_OFFS(lvl) + (expires & LVL_MASK);
-- 
2.25.1