Merge branch 'topic/core-fixes' into for-linus

1 files changed, 7 insertions, 7 deletions

diff --git a/mm/memory.c b/mm/memory.c
index 30991f83d0bf..635451abc8f7 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1591,10 +1591,15 @@ int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 	 * than insert_pfn).  If a zero_pfn were inserted into a VM_MIXEDMAP
 	 * without pte special, it would there be refcounted as a normal page.
 	 */
-	if (!HAVE_PTE_SPECIAL && pfn_t_valid(pfn)) {
+	if (!HAVE_PTE_SPECIAL && !pfn_t_devmap(pfn) && pfn_t_valid(pfn)) {
 		struct page *page;
 
-		page = pfn_t_to_page(pfn);
+		/*
+		 * At this point we are committed to insert_page()
+		 * regardless of whether the caller specified flags that
+		 * result in pfn_t_has_page() == false.
+		 */
+		page = pfn_to_page(pfn_t_to_pfn(pfn));
 		return insert_page(vma, addr, page, vma->vm_page_prot);
 	}
 	return insert_pfn(vma, addr, pfn, vma->vm_page_prot);
@@ -2232,11 +2237,6 @@ static int wp_page_shared(struct mm_struct *mm, struct vm_area_struct *vma,
 
 	page_cache_get(old_page);
 
-	/*
-	 * Only catch write-faults on shared writable pages,
-	 * read-only shared pages can get COWed by
-	 * get_user_pages(.write=1, .force=1).
-	 */
 	if (vma->vm_ops && vma->vm_ops->page_mkwrite) {
 		int tmp;