From 220d4d6f63177feaf70009dc02bfc0c872fa9a2a Mon Sep 17 00:00:00 2001
From: Akinobu Mita <akinobu.mita@gmail.com>
Date: Mon, 31 Oct 2011 17:08:38 -0700
Subject: [PATCH] --- yaml --- r: 272143 b: refs/heads/master c:
 64212ec569bfdd094f7a23d9b09862209a983559 h: refs/heads/master i:   272141:
 6cc782cf0888915b2344354c629d23427bc14ed0   272139:
 ee5885b05e9754dbd4c7c9d886e77579d534d226   272135:
 b1ac3aecc151f983b0cfb2952955638eb3eea867   272127:
 f5e194b0facdc46d800f8713f3cb63f092187ca7 v: v3

---
 [refs]                     |  2 +-
 trunk/mm/debug-pagealloc.c | 44 +++++++++-----------------------------
 2 files changed, 11 insertions(+), 35 deletions(-)

diff --git a/[refs] b/[refs]
index 2bfe4ce82f13..d41b86f5b6fb 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 3ee9a4f086716d792219c021e8509f91165a4128
+refs/heads/master: 64212ec569bfdd094f7a23d9b09862209a983559
diff --git a/trunk/mm/debug-pagealloc.c b/trunk/mm/debug-pagealloc.c
index 2618933efdb3..7cea557407f4 100644
--- a/trunk/mm/debug-pagealloc.c
+++ b/trunk/mm/debug-pagealloc.c
@@ -1,6 +1,7 @@
 #include <linux/kernel.h>
 #include <linux/string.h>
 #include <linux/mm.h>
+#include <linux/highmem.h>
 #include <linux/page-debug-flags.h>
 #include <linux/poison.h>
 #include <linux/ratelimit.h>
@@ -20,28 +21,13 @@ static inline bool page_poison(struct page *page)
 	return test_bit(PAGE_DEBUG_FLAG_POISON, &page->debug_flags);
 }
 
-static void poison_highpage(struct page *page)
-{
-	/*
-	 * Page poisoning for highmem pages is not implemented.
-	 *
-	 * This can be called from interrupt contexts.
-	 * So we need to create a new kmap_atomic slot for this
-	 * application and it will need interrupt protection.
-	 */
-}
-
 static void poison_page(struct page *page)
 {
-	void *addr;
+	void *addr = kmap_atomic(page);
 
-	if (PageHighMem(page)) {
-		poison_highpage(page);
-		return;
-	}
 	set_page_poison(page);
-	addr = page_address(page);
 	memset(addr, PAGE_POISON, PAGE_SIZE);
+	kunmap_atomic(addr);
 }
 
 static void poison_pages(struct page *page, int n)
@@ -86,27 +72,17 @@ static void check_poison_mem(unsigned char *mem, size_t bytes)
 	dump_stack();
 }
 
-static void unpoison_highpage(struct page *page)
-{
-	/*
-	 * See comment in poison_highpage().
-	 * Highmem pages should not be poisoned for now
-	 */
-	BUG_ON(page_poison(page));
-}
-
 static void unpoison_page(struct page *page)
 {
-	if (PageHighMem(page)) {
-		unpoison_highpage(page);
+	void *addr;
+
+	if (!page_poison(page))
 		return;
-	}
-	if (page_poison(page)) {
-		void *addr = page_address(page);
 
-		check_poison_mem(addr, PAGE_SIZE);
-		clear_page_poison(page);
-	}
+	addr = kmap_atomic(page);
+	check_poison_mem(addr, PAGE_SIZE);
+	clear_page_poison(page);
+	kunmap_atomic(addr);
 }
 
 static void unpoison_pages(struct page *page, int n)