mm: memcg: fix use after free in mem_cgroup_iter()

[mirror_ubuntu-bionic-kernel.git] / mm / page_ext.c

diff --git a/mm/page_ext.c b/mm/page_ext.c
index 4f0367d472c4922f7a283a9530da63c7f6d9949c..2c16216c29b629a62beba50612ba2ea0fbea0d8e 100644 (file)
--- a/mm/page_ext.c
+++ b/mm/page_ext.c
@@ -125,7 +125,6 @@ struct page_ext *lookup_page_ext(struct page *page)
        struct page_ext *base;
 
        base = NODE_DATA(page_to_nid(page))->node_page_ext;
-#if defined(CONFIG_DEBUG_VM)
        /*
         * The sanity checks the page allocator does upon freeing a
         * page can reach here before the page_ext arrays are
@@ -134,7 +133,6 @@ struct page_ext *lookup_page_ext(struct page *page)
         */
        if (unlikely(!base))
                return NULL;
-#endif
        index = pfn - round_down(node_start_pfn(page_to_nid(page)),
                                        MAX_ORDER_NR_PAGES);
        return get_entry(base, index);
@@ -199,7 +197,6 @@ struct page_ext *lookup_page_ext(struct page *page)
 {
        unsigned long pfn = page_to_pfn(page);
        struct mem_section *section = __pfn_to_section(pfn);
-#if defined(CONFIG_DEBUG_VM)
        /*
         * The sanity checks the page allocator does upon freeing a
         * page can reach here before the page_ext arrays are
@@ -208,7 +205,6 @@ struct page_ext *lookup_page_ext(struct page *page)
         */
        if (!section->page_ext)
                return NULL;
-#endif
        return get_entry(section->page_ext, pfn);
 }