From 064d9efe947542097be669581f82d6b097e81d1a Mon Sep 17 00:00:00 2001
From: Nishanth Aravamudan <nacc@us.ibm.com>
Date: Wed, 13 Feb 2008 15:03:19 -0800
Subject: hugetlb: fix overcommit locking

proc_doulongvec_minmax() calls copy_to_user()/copy_from_user(), so we can't
hold hugetlb_lock over the call.  Use a dummy variable to store the sysctl
result, like in hugetlb_sysctl_handler(), then grab the lock to update
nr_overcommit_huge_pages.

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Reported-by: Miles Lane <miles.lane@gmail.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 kernel/sysctl.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'kernel/sysctl.c')

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 924c674b76e..8b7e9541179 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -978,8 +978,8 @@ static struct ctl_table vm_table[] = {
 	{
 		.ctl_name	= CTL_UNNUMBERED,
 		.procname	= "nr_overcommit_hugepages",
-		.data		= &nr_overcommit_huge_pages,
-		.maxlen		= sizeof(nr_overcommit_huge_pages),
+		.data		= &sysctl_overcommit_huge_pages,
+		.maxlen		= sizeof(sysctl_overcommit_huge_pages),
 		.mode		= 0644,
 		.proc_handler	= &hugetlb_overcommit_handler,
 	},
-- 
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