Patch "cfq: explicitly use 64bit divide operation for 64bit arguments" has been added to the 3.11-stable tree

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This is a note to let you know that I've just added the patch titled

    cfq: explicitly use 64bit divide operation for 64bit arguments

to the 3.11-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     cfq-explicitly-use-64bit-divide-operation-for-64bit-arguments.patch
and it can be found in the queue-3.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.


>From f3cff25f05f2ac29b2ee355e611b0657482f6f1d Mon Sep 17 00:00:00 2001
From: Anatol Pomozov <anatol.pomozov@xxxxxxxxx>
Date: Sun, 22 Sep 2013 12:43:47 -0600
Subject: cfq: explicitly use 64bit divide operation for 64bit arguments

From: Anatol Pomozov <anatol.pomozov@xxxxxxxxx>

commit f3cff25f05f2ac29b2ee355e611b0657482f6f1d upstream.

'samples' is 64bit operant, but do_div() second parameter is 32.
do_div silently truncates high 32 bits and calculated result
is invalid.

In case if low 32bit of 'samples' are zeros then do_div() produces
kernel crash.

Signed-off-by: Anatol Pomozov <anatol.pomozov@xxxxxxxxx>
Acked-by: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Cc: Jonghwan Choi <jhbird.choi@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 block/cfq-iosched.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1803,7 +1803,7 @@ static u64 cfqg_prfill_avg_queue_size(st
 
 	if (samples) {
 		v = blkg_stat_read(&cfqg->stats.avg_queue_size_sum);
-		do_div(v, samples);
+		v = div64_u64(v, samples);
 	}
 	__blkg_prfill_u64(sf, pd, v);
 	return 0;


Patches currently in stable-queue which might be from anatol.pomozov@xxxxxxxxx are

queue-3.11/cfq-explicitly-use-64bit-divide-operation-for-64bit-arguments.patch
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