From: chenqiwu <chenqiwu@xxxxxxxxxx>
If we get a special mapping page like device mapping page or zero page
when copy_one_pte, it's necessary add the page refcount count.
Signed-off-by: chenqiwu <chenqiwu@xxxxxxxxxx>
---
mm/memory.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/mm/memory.c b/mm/memory.c
index f703fe8..a57975a 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -802,8 +802,9 @@ struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
get_page(page);
page_dup_rmap(page, false);
rss[mm_counter(page)]++;
- } else if (pte_devmap(pte)) {
+ } else if (pte_devmap(pte) || is_zero_pfn(pte_pfn(pte))) {
page = pte_page(pte);
+ get_page(page);
}
out_set_pte:
--
1.9.1
