From 30c426867d882a71dda794720f92495b2359072b Mon Sep 17 00:00:00 2001
From: Andrew Morton <akpm@linux-foundation.org>
Date: Wed, 20 Feb 2013 13:14:17 +1100
Subject: [PATCH] 
 memory-hotplug-common-apis-to-support-page-tables-hot-remove-fix-fix-fix-fix-fix-fix-fix

fix used-uninitialised bug

Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Jianguo Wu <wujianguo@huawei.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 arch/x86/mm/init_64.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 6bcca6563c28..ca6cd403a275 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -993,12 +993,12 @@ remove_pagetable(unsigned long start, unsigned long end, bool direct)
 	bool pgd_changed = false;
 
 	for (; start < end; start = next) {
+		next = pgd_addr_end(start, end);
+
 		pgd = pgd_offset_k(start);
 		if (!pgd_present(*pgd))
 			continue;
 
-		next = pgd_addr_end(start, end);
-
 		pud = (pud_t *)pgd_page_vaddr(*pgd);
 		remove_pud_table(pud, start, next, direct);
 		if (free_pud_table(pud, pgd))
-- 
2.39.5