Messages in this thread Patch in this message | | | From | Wen Yang <> | Subject | [PATCH] hrtimer: fix an explicit cast in __ktime_divns() | Date | Thu, 30 Jan 2020 21:08:51 +0800 |
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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
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