diff options
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 17 |
1 files changed, 12 insertions, 5 deletions
diff --git a/mm/memory.c b/mm/memory.c index 9bdfce15e98f..9f5f829a1b1f 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -825,7 +825,8 @@ copy_nonpresent_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm, */ get_page(page); rss[mm_counter(page)]++; - page_dup_rmap(page, false); + /* Cannot fail as these pages cannot get pinned. */ + BUG_ON(page_try_dup_anon_rmap(page, false, src_vma)); /* * We do not preserve soft-dirty information, because so @@ -921,18 +922,24 @@ copy_present_pte(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma, struct page *page; page = vm_normal_page(src_vma, addr, pte); - if (page && unlikely(page_needs_cow_for_dma(src_vma, page))) { + if (page && PageAnon(page)) { /* * If this page may have been pinned by the parent process, * copy the page immediately for the child so that we'll always * guarantee the pinned page won't be randomly replaced in the * future. */ - return copy_present_page(dst_vma, src_vma, dst_pte, src_pte, - addr, rss, prealloc, page); + get_page(page); + if (unlikely(page_try_dup_anon_rmap(page, false, src_vma))) { + /* Page maybe pinned, we have to copy. */ + put_page(page); + return copy_present_page(dst_vma, src_vma, dst_pte, src_pte, + addr, rss, prealloc, page); + } + rss[mm_counter(page)]++; } else if (page) { get_page(page); - page_dup_rmap(page, false); + page_dup_file_rmap(page, false); rss[mm_counter(page)]++; } |