4 files changed, 73 insertions, 7 deletions

diff --git a/mm/Kconfig.debug b/mm/Kconfig.debug
index 1ba81c7769f7..56badfc4810a 100644
--- a/mm/Kconfig.debug
+++ b/mm/Kconfig.debug
@@ -12,6 +12,7 @@ config DEBUG_PAGEALLOC
         depends on DEBUG_KERNEL
         depends on !HIBERNATION || ARCH_SUPPORTS_DEBUG_PAGEALLOC && !PPC && !SPARC
         depends on !KMEMCHECK
+        select PAGE_EXTENSION
         select PAGE_POISONING if !ARCH_SUPPORTS_DEBUG_PAGEALLOC
         select PAGE_GUARD if ARCH_SUPPORTS_DEBUG_PAGEALLOC
         ---help---
diff --git a/mm/debug-pagealloc.c b/mm/debug-pagealloc.c
index 789ff70c8a4a..0072f2c53331 100644
--- a/mm/debug-pagealloc.c
+++ b/mm/debug-pagealloc.c
@@ -2,23 +2,49 @@
 #include <linux/string.h>
 #include <linux/mm.h>
 #include <linux/highmem.h>
-#include <linux/page-debug-flags.h>
+#include <linux/page_ext.h>
 #include <linux/poison.h>
 #include <linux/ratelimit.h>
 
+static bool page_poisoning_enabled __read_mostly;
+
+static bool need_page_poisoning(void)
+{
+        return true;
+}
+
+static void init_page_poisoning(void)
+{
+        page_poisoning_enabled = true;
+}
+
+struct page_ext_operations page_poisoning_ops = {
+        .need = need_page_poisoning,
+        .init = init_page_poisoning,
+};
+
 static inline void set_page_poison(struct page *page)
 {
-        __set_bit(PAGE_DEBUG_FLAG_POISON, &page->debug_flags);
+        struct page_ext *page_ext;
+
+        page_ext = lookup_page_ext(page);
+        __set_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags);
 }
 
 static inline void clear_page_poison(struct page *page)
 {
-        __clear_bit(PAGE_DEBUG_FLAG_POISON, &page->debug_flags);
+        struct page_ext *page_ext;
+
+        page_ext = lookup_page_ext(page);
+        __clear_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags);
 }
 
 static inline bool page_poison(struct page *page)
 {
-        return test_bit(PAGE_DEBUG_FLAG_POISON, &page->debug_flags);
+        struct page_ext *page_ext;
+
+        page_ext = lookup_page_ext(page);
+        return test_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags);
 }
 
 static void poison_page(struct page *page)
@@ -95,6 +121,9 @@ static void unpoison_pages(struct page *page, int n)
 
 void kernel_map_pages(struct page *page, int numpages, int enable)
 {
+        if (!page_poisoning_enabled)
+                return;
+
         if (enable)
                 unpoison_pages(page, numpages);
         else
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b64666cf5865..e0a39d328ca1 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -56,7 +56,7 @@
 #include <linux/prefetch.h>
 #include <linux/mm_inline.h>
 #include <linux/migrate.h>
-#include <linux/page-debug-flags.h>
+#include <linux/page_ext.h>
 #include <linux/hugetlb.h>
 #include <linux/sched/rt.h>
 
@@ -425,6 +425,22 @@ static inline void prep_zero_page(struct page *page, unsigned int order,
 
 #ifdef CONFIG_DEBUG_PAGEALLOC
 unsigned int _debug_guardpage_minorder;
+bool _debug_guardpage_enabled __read_mostly;
+
+static bool need_debug_guardpage(void)
+{
+        return true;
+}
+
+static void init_debug_guardpage(void)
+{
+        _debug_guardpage_enabled = true;
+}
+
+struct page_ext_operations debug_guardpage_ops = {
+        .need = need_debug_guardpage,
+        .init = init_debug_guardpage,
+};
 
 static int __init debug_guardpage_minorder_setup(char *buf)
 {
@@ -443,7 +459,14 @@ __setup("debug_guardpage_minorder=", debug_guardpage_minorder_setup);
 static inline void set_page_guard(struct zone *zone, struct page *page,
                                 unsigned int order, int migratetype)
 {
-        __set_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
+        struct page_ext *page_ext;
+
+        if (!debug_guardpage_enabled())
+                return;
+
+        page_ext = lookup_page_ext(page);
+        __set_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
+
         INIT_LIST_HEAD(&page->lru);
         set_page_private(page, order);
         /* Guard pages are not available for any usage */
@@ -453,12 +476,20 @@ static inline void set_page_guard(struct zone *zone, struct page *page,
 static inline void clear_page_guard(struct zone *zone, struct page *page,
                                 unsigned int order, int migratetype)
 {
-        __clear_bit(PAGE_DEBUG_FLAG_GUARD, &page->debug_flags);
+        struct page_ext *page_ext;
+
+        if (!debug_guardpage_enabled())
+                return;
+
+        page_ext = lookup_page_ext(page);
+        __clear_bit(PAGE_EXT_DEBUG_GUARD, &page_ext->flags);
+
         set_page_private(page, 0);
         if (!is_migrate_isolate(migratetype))
                 __mod_zone_freepage_state(zone, (1 << order), migratetype);
 }
 #else
+struct page_ext_operations debug_guardpage_ops = { NULL, };
 static inline void set_page_guard(struct zone *zone, struct page *page,
                                 unsigned int order, int migratetype) {}
 static inline void clear_page_guard(struct zone *zone, struct page *page,
@@ -869,6 +900,7 @@ static inline void expand(struct zone *zone, struct page *page,
                 VM_BUG_ON_PAGE(bad_range(zone, &page[size]), &page[size]);
 
                 if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) &&
+                        debug_guardpage_enabled() &&
                         high < debug_guardpage_minorder()) {
                         /*
                          * Mark as guard pages (or page), that will allow to
diff --git a/mm/page_ext.c b/mm/page_ext.c
index 514a3bccd63f..c2cd7b15f0de 100644
--- a/mm/page_ext.c
+++ b/mm/page_ext.c
@@ -51,6 +51,10 @@
  */
 
 static struct page_ext_operations *page_ext_ops[] = {
+        &debug_guardpage_ops,
+#ifdef CONFIG_PAGE_POISONING
+        &page_poisoning_ops,
+#endif
 };
 
 static unsigned long total_usage;