[merged] linux-kernelh-fix-overflow-for-div_round_up_ull.patch removed from -mm tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



The patch titled
     Subject: linux/kernel.h: fix overflow for DIV_ROUND_UP_ULL
has been removed from the -mm tree.  Its filename was
     linux-kernelh-fix-overflow-for-div_round_up_ull.patch

This patch was dropped because it was merged into mainline or a subsystem tree

------------------------------------------------------
From: Vinod Koul <vkoul@xxxxxxxxxx>
Subject: linux/kernel.h: fix overflow for DIV_ROUND_UP_ULL

DIV_ROUND_UP_ULL adds the two arguments and then invokes
DIV_ROUND_DOWN_ULL.  But on a 32bit system the addition of two 32 bit
values can overflow.  DIV_ROUND_DOWN_ULL does it correctly and stashes the
addition into a unsigned long long so cast the result to unsigned long
long here to avoid the overflow condition.

Link: http://lkml.kernel.org/r/20190625100518.30753-1-vkoul@xxxxxxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 include/linux/kernel.h |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/include/linux/kernel.h~linux-kernelh-fix-overflow-for-div_round_up_ull
+++ a/include/linux/kernel.h
@@ -93,7 +93,8 @@
 #define DIV_ROUND_DOWN_ULL(ll, d) \
 	({ unsigned long long _tmp = (ll); do_div(_tmp, d); _tmp; })
 
-#define DIV_ROUND_UP_ULL(ll, d)		DIV_ROUND_DOWN_ULL((ll) + (d) - 1, (d))
+#define DIV_ROUND_UP_ULL(ll, d) \
+	({ DIV_ROUND_DOWN_ULL((unsigned long long)(ll) + (d) - 1, (d)) })
 
 #if BITS_PER_LONG == 32
 # define DIV_ROUND_UP_SECTOR_T(ll,d) DIV_ROUND_UP_ULL(ll, d)
_

Patches currently in -mm which might be from vkoul@xxxxxxxxxx are





[Index of Archives]     [Kernel Archive]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]

  Powered by Linux