mm, fs: move randomize_stack_top from fs to mm

[linux.git] / mm / page_owner.c

diff --git a/mm/page_owner.c b/mm/page_owner.c
index 4a48e018dbdf9603f46592e5aa631bd67ff85dc5..dee931184788399c920646cef75e29e8fd347186 100644 (file)
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -24,6 +24,9 @@ struct page_owner {
        short last_migrate_reason;
        gfp_t gfp_mask;
        depot_stack_handle_t handle;
+#ifdef CONFIG_DEBUG_PAGEALLOC
+       depot_stack_handle_t free_handle;
+#endif
 };
 
 static bool page_owner_disabled = true;
@@ -102,19 +105,6 @@ static inline struct page_owner *get_page_owner(struct page_ext *page_ext)
        return (void *)page_ext + page_owner_ops.offset;
 }
 
-void __reset_page_owner(struct page *page, unsigned int order)
-{
-       int i;
-       struct page_ext *page_ext;
-
-       for (i = 0; i < (1 << order); i++) {
-               page_ext = lookup_page_ext(page + i);
-               if (unlikely(!page_ext))
-                       continue;
-               __clear_bit(PAGE_EXT_OWNER_ACTIVE, &page_ext->flags);
-       }
-}
-
 static inline bool check_recursive_alloc(unsigned long *entries,
                                         unsigned int nr_entries,
                                         unsigned long ip)
@@ -154,6 +144,32 @@ static noinline depot_stack_handle_t save_stack(gfp_t flags)
        return handle;
 }
 
+void __reset_page_owner(struct page *page, unsigned int order)
+{
+       int i;
+       struct page_ext *page_ext;
+#ifdef CONFIG_DEBUG_PAGEALLOC
+       depot_stack_handle_t handle = 0;
+       struct page_owner *page_owner;
+
+       if (debug_pagealloc_enabled())
+               handle = save_stack(GFP_NOWAIT | __GFP_NOWARN);
+#endif
+
+       for (i = 0; i < (1 << order); i++) {
+               page_ext = lookup_page_ext(page + i);
+               if (unlikely(!page_ext))
+                       continue;
+               __clear_bit(PAGE_EXT_OWNER_ACTIVE, &page_ext->flags);
+#ifdef CONFIG_DEBUG_PAGEALLOC
+               if (debug_pagealloc_enabled()) {
+                       page_owner = get_page_owner(page_ext);
+                       page_owner->free_handle = handle;
+               }
+#endif
+       }
+}
+
 static inline void __set_page_owner_handle(struct page *page,
        struct page_ext *page_ext, depot_stack_handle_t handle,
        unsigned int order, gfp_t gfp_mask)
@@ -435,6 +451,17 @@ void __dump_page_owner(struct page *page)
                stack_trace_print(entries, nr_entries, 0);
        }
 
+#ifdef CONFIG_DEBUG_PAGEALLOC
+       handle = READ_ONCE(page_owner->free_handle);
+       if (!handle) {
+               pr_alert("page_owner free stack trace missing\n");
+       } else {
+               nr_entries = stack_depot_fetch(handle, &entries);
+               pr_alert("page last free stack trace:\n");
+               stack_trace_print(entries, nr_entries, 0);
+       }
+#endif
+
        if (page_owner->last_migrate_reason != -1)
                pr_alert("page has been migrated, last migrate reason: %s\n",
                        migrate_reason_names[page_owner->last_migrate_reason]);