diff --git a/include/linux/mm.h b/include/linux/mm.h
index 679300c050f5720f07597d5ee4ac3ec3e564f19f..ff83798e1c27913876cf47f00c619c0f79a1cfd3 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -402,16 +402,23 @@ static inline void init_page_count(struct page *page)
 /*
  * PageBuddy() indicate that the page is free and in the buddy system
  * (see mm/page_alloc.c).
+ *
+ * PAGE_BUDDY_MAPCOUNT_VALUE must be <= -2 but better not too close to
+ * -2 so that an underflow of the page_mapcount() won't be mistaken
+ * for a genuine PAGE_BUDDY_MAPCOUNT_VALUE. -128 can be created very
+ * efficiently by most CPU architectures.
  */
+#define PAGE_BUDDY_MAPCOUNT_VALUE (-128)
+
 static inline int PageBuddy(struct page *page)
 {
-	return atomic_read(&page->_mapcount) == -2;
+	return atomic_read(&page->_mapcount) == PAGE_BUDDY_MAPCOUNT_VALUE;
 }
 
 static inline void __SetPageBuddy(struct page *page)
 {
 	VM_BUG_ON(atomic_read(&page->_mapcount) != -1);
-	atomic_set(&page->_mapcount, -2);
+	atomic_set(&page->_mapcount, PAGE_BUDDY_MAPCOUNT_VALUE);
 }
 
 static inline void __ClearPageBuddy(struct page *page)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index bd7625676a645c2bfe6d7aacd4197a0cfc5b23fd..7945247b1e534541ffa9cc145353191064ad6b2f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -286,7 +286,7 @@ static void bad_page(struct page *page)
 
 	/* Don't complain about poisoned pages */
 	if (PageHWPoison(page)) {
-		__ClearPageBuddy(page);
+		reset_page_mapcount(page); /* remove PageBuddy */
 		return;
 	}
 
@@ -317,7 +317,7 @@ static void bad_page(struct page *page)
 	dump_stack();
 out:
 	/* Leave bad fields for debug, except PageBuddy could make trouble */
-	__ClearPageBuddy(page);
+	reset_page_mapcount(page); /* remove PageBuddy */
 	add_taint(TAINT_BAD_PAGE);
 }