* [PATCH] hrtimer: fix an explicit cast in __ktime_divns()
@ 2020-01-30 13:08 Wen Yang
2020-03-04 9:20 ` [tip: timers/core] hrtimer: Cast explicitely to u32t " tip-bot2 for Wen Yang
0 siblings, 1 reply; 2+ messages in thread
From: Wen Yang @ 2020-01-30 13:08 UTC (permalink / raw)
To: Thomas Gleixner; +Cc: Wen Yang, linux-kernel
do_div() does a 64-by-32 division, while the divisor 'div' is
explicitly casted to unsigned long, thus 64-bit on 64-bit platforms.
In addition, the above lines also ensures that the divisor is less
than 2^32. Hence the proper cast type is u32.
Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
---
kernel/time/hrtimer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index d8b62f93fc8d..57e543860660 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -311,7 +311,7 @@ s64 __ktime_divns(const ktime_t kt, s64 div)
div >>= 1;
}
tmp >>= sft;
- do_div(tmp, (unsigned long) div);
+ do_div(tmp, (u32) div);
return dclc < 0 ? -tmp : tmp;
}
EXPORT_SYMBOL_GPL(__ktime_divns);
--
2.23.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [tip: timers/core] hrtimer: Cast explicitely to u32t in __ktime_divns()
2020-01-30 13:08 [PATCH] hrtimer: fix an explicit cast in __ktime_divns() Wen Yang
@ 2020-03-04 9:20 ` tip-bot2 for Wen Yang
0 siblings, 0 replies; 2+ messages in thread
From: tip-bot2 for Wen Yang @ 2020-03-04 9:20 UTC (permalink / raw)
To: linux-tip-commits; +Cc: Wen Yang, Thomas Gleixner, x86, LKML
The following commit has been merged into the timers/core branch of tip:
Commit-ID: 38f7b0b1316d435f38ec3f2bb078897b7a1cfdea
Gitweb: https://git.kernel.org/tip/38f7b0b1316d435f38ec3f2bb078897b7a1cfdea
Author: Wen Yang <wenyang@linux.alibaba.com>
AuthorDate: Thu, 30 Jan 2020 21:08:51 +08:00
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Wed, 04 Mar 2020 10:17:51 +01:00
hrtimer: Cast explicitely to u32t in __ktime_divns()
do_div() does a 64-by-32 division at least on 32bit platforms, while the
divisor 'div' is explicitly casted to unsigned long, thus 64-bit on 64-bit
platforms.
The code already ensures that the divisor is less than 2^32. Hence the
proper cast type is u32.
Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200130130851.29204-1-wenyang@linux.alibaba.com
---
kernel/time/hrtimer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 3a609e7..d74fdcd 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -311,7 +311,7 @@ s64 __ktime_divns(const ktime_t kt, s64 div)
div >>= 1;
}
tmp >>= sft;
- do_div(tmp, (unsigned long) div);
+ do_div(tmp, (u32) div);
return dclc < 0 ? -tmp : tmp;
}
EXPORT_SYMBOL_GPL(__ktime_divns);
^ permalink raw reply related [flat|nested] 2+ messages in thread
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