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

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

diff --git a/mm/page_owner.c b/mm/page_owner.c
index 792b56d..c6cda3e 100644 (file)
--- a/mm/page_owner.c
+++ b/mm/page_owner.c
@@ -55,6 +55,8 @@ void __reset_page_owner(struct page *page, unsigned int order)
 
        for (i = 0; i < (1 << order); i++) {
                page_ext = lookup_page_ext(page + i);
+               if (unlikely(!page_ext))
+                       continue;
                __clear_bit(PAGE_EXT_OWNER, &page_ext->flags);
        }
 }
@@ -62,6 +64,7 @@ void __reset_page_owner(struct page *page, unsigned int order)
 void __set_page_owner(struct page *page, unsigned int order, gfp_t gfp_mask)
 {
        struct page_ext *page_ext = lookup_page_ext(page);
+
        struct stack_trace trace = {
                .nr_entries = 0,
                .max_entries = ARRAY_SIZE(page_ext->trace_entries),
@@ -69,6 +72,9 @@ void __set_page_owner(struct page *page, unsigned int order, gfp_t gfp_mask)
                .skip = 3,
        };
 
+       if (unlikely(!page_ext))
+               return;
+
        save_stack_trace(&trace);
 
        page_ext->order = order;
@@ -82,6 +88,8 @@ void __set_page_owner(struct page *page, unsigned int order, gfp_t gfp_mask)
 void __set_page_owner_migrate_reason(struct page *page, int reason)
 {
        struct page_ext *page_ext = lookup_page_ext(page);
+       if (unlikely(!page_ext))
+               return;
 
        page_ext->last_migrate_reason = reason;
 }
@@ -89,6 +97,12 @@ void __set_page_owner_migrate_reason(struct page *page, int reason)
 gfp_t __get_page_owner_gfp(struct page *page)
 {
        struct page_ext *page_ext = lookup_page_ext(page);
+       if (unlikely(!page_ext))
+               /*
+                * The caller just returns 0 if no valid gfp
+                * So return 0 here too.
+                */
+               return 0;
 
        return page_ext->gfp_mask;
 }
@@ -99,6 +113,9 @@ void __copy_page_owner(struct page *oldpage, struct page *newpage)
        struct page_ext *new_ext = lookup_page_ext(newpage);
        int i;
 
+       if (unlikely(!old_ext || !new_ext))
+               return;
+
        new_ext->order = old_ext->order;
        new_ext->gfp_mask = old_ext->gfp_mask;
        new_ext->nr_entries = old_ext->nr_entries;
@@ -193,6 +210,11 @@ void __dump_page_owner(struct page *page)
        gfp_t gfp_mask = page_ext->gfp_mask;
        int mt = gfpflags_to_migratetype(gfp_mask);
 
+       if (unlikely(!page_ext)) {
+               pr_alert("There is not page extension available.\n");
+               return;
+       }
+
        if (!test_bit(PAGE_EXT_OWNER, &page_ext->flags)) {
                pr_alert("page_owner info is not active (free page?)\n");
                return;
@@ -251,6 +273,8 @@ read_page_owner(struct file *file, char __user *buf, size_t count, loff_t *ppos)
                }
 
                page_ext = lookup_page_ext(page);
+               if (unlikely(!page_ext))
+                       continue;
 
                /*
                 * Some pages could be missed by concurrent allocation or free,
@@ -317,6 +341,8 @@ static void init_pages_in_zone(pg_data_t *pgdat, struct zone *zone)
                                continue;
 
                        page_ext = lookup_page_ext(page);
+                       if (unlikely(!page_ext))
+                               continue;
 
                        /* Maybe overraping zone */
                        if (test_bit(PAGE_EXT_OWNER, &page_ext->flags))