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

[cascardo/linux.git] / mm / page_poison.c

diff --git a/mm/page_poison.c b/mm/page_poison.c
index 1eae5fa..2e647c6 100644 (file)
--- a/mm/page_poison.c
+++ b/mm/page_poison.c
@@ -54,6 +54,9 @@ static inline void set_page_poison(struct page *page)
        struct page_ext *page_ext;
 
        page_ext = lookup_page_ext(page);
+       if (unlikely(!page_ext))
+               return;
+
        __set_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags);
 }
 
@@ -62,6 +65,9 @@ static inline void clear_page_poison(struct page *page)
        struct page_ext *page_ext;
 
        page_ext = lookup_page_ext(page);
+       if (unlikely(!page_ext))
+               return;
+
        __clear_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags);
 }
 
@@ -70,7 +76,7 @@ bool page_is_poisoned(struct page *page)
        struct page_ext *page_ext;
 
        page_ext = lookup_page_ext(page);
-       if (!page_ext)
+       if (unlikely(!page_ext))
                return false;
 
        return test_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags);