mm: check the return value of lookup_page_ext for all call sites

[cascardo/linux.git] / include / linux / page_idle.h

diff --git a/include/linux/page_idle.h b/include/linux/page_idle.h
index bf268fa..fec4027 100644 (file)
--- a/include/linux/page_idle.h
+++ b/include/linux/page_idle.h
@@ -46,33 +46,62 @@ extern struct page_ext_operations page_idle_ops;
 
 static inline bool page_is_young(struct page *page)
 {
-       return test_bit(PAGE_EXT_YOUNG, &lookup_page_ext(page)->flags);
+       struct page_ext *page_ext = lookup_page_ext(page);
+
+       if (unlikely(!page_ext))
+               return false;
+
+       return test_bit(PAGE_EXT_YOUNG, &page_ext->flags);
 }
 
 static inline void set_page_young(struct page *page)
 {
-       set_bit(PAGE_EXT_YOUNG, &lookup_page_ext(page)->flags);
+       struct page_ext *page_ext = lookup_page_ext(page);
+
+       if (unlikely(!page_ext))
+               return;
+
+       set_bit(PAGE_EXT_YOUNG, &page_ext->flags);
 }
 
 static inline bool test_and_clear_page_young(struct page *page)
 {
-       return test_and_clear_bit(PAGE_EXT_YOUNG,
-                                 &lookup_page_ext(page)->flags);
+       struct page_ext *page_ext = lookup_page_ext(page);
+
+       if (unlikely(!page_ext))
+               return false;
+
+       return test_and_clear_bit(PAGE_EXT_YOUNG, &page_ext->flags);
 }
 
 static inline bool page_is_idle(struct page *page)
 {
-       return test_bit(PAGE_EXT_IDLE, &lookup_page_ext(page)->flags);
+       struct page_ext *page_ext = lookup_page_ext(page);
+
+       if (unlikely(!page_ext))
+               return false;
+
+       return test_bit(PAGE_EXT_IDLE, &page_ext->flags);
 }
 
 static inline void set_page_idle(struct page *page)
 {
-       set_bit(PAGE_EXT_IDLE, &lookup_page_ext(page)->flags);
+       struct page_ext *page_ext = lookup_page_ext(page);
+
+       if (unlikely(!page_ext))
+               return;
+
+       set_bit(PAGE_EXT_IDLE, &page_ext->flags);
 }
 
 static inline void clear_page_idle(struct page *page)
 {
-       clear_bit(PAGE_EXT_IDLE, &lookup_page_ext(page)->flags);
+       struct page_ext *page_ext = lookup_page_ext(page);
+
+       if (unlikely(!page_ext))
+               return;
+
+       clear_bit(PAGE_EXT_IDLE, &page_ext->flags);
 }
 #endif /* CONFIG_64BIT */