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 <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
---
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
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 <[email protected]>
AuthorDate: Thu, 30 Jan 2020 21:08:51 +08:00
Committer: Thomas Gleixner <[email protected]>
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 <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
---
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);