From: Tang Chen <tangchen@cn.fujitsu.com>
Date: Thu, 7 Feb 2013 01:26:27 +0000 (+1100)
Subject: Bug fix: Do not free direct mapping pages twice.
X-Git-Tag: next-20130218~1^2~451
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=07a3735ef8dd8976253231a18e0dac062bd3ee0b;p=karo-tx-linux.git

Bug fix: Do not free direct mapping pages twice.

Direct mapped pages were freed when they were offlined, or they were not
allocated.  So we only need to free vmemmap pages, no need to free direct
mapped pages.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index 56bedb1a8224..841816abc1b3 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -829,6 +829,10 @@ remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
 
 		if (IS_ALIGNED(addr, PAGE_SIZE) &&
 		    IS_ALIGNED(next, PAGE_SIZE)) {
+			/*
+			 * Do not free direct mapping pages since they were
+			 * freed when offlining.
+			 */
 			if (!direct)
 				free_pagetable(pte_page(*pte), 0);
 
@@ -844,10 +848,11 @@ remove_pte_table(pte_t *pte_start, unsigned long addr, unsigned long end,
 			 * remove the page when it is wholly filled with 0xFD.
 			 */
 			memset((void *)addr, PAGE_INUSE, next - addr);
-			page_addr = page_address(pte_page(*pte));
 
+			page_addr = page_address(pte_page(*pte));
 			if (!memchr_inv(page_addr, PAGE_INUSE, PAGE_SIZE)) {
-				free_pagetable(pte_page(*pte), 0);
+				if (!direct)
+					free_pagetable(pte_page(*pte), 0);
 
 				spin_lock(&init_mm.page_table_lock);
 				pte_clear(&init_mm, addr, pte);