diff options
| -rw-r--r-- | mm/rmap.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index 24dd3f9fee27..9f47f152b01e 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -950,7 +950,12 @@ void page_move_anon_rmap(struct page *page, VM_BUG_ON_PAGE(page->index != linear_page_index(vma, address), page); anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON; - page->mapping = (struct address_space *) anon_vma; + /* + * Ensure that anon_vma and the PAGE_MAPPING_ANON bit are written + * simultaneously, so a concurrent reader (eg page_referenced()'s + * PageAnon()) will not see one without the other. + */ + WRITE_ONCE(page->mapping, (struct address_space *) anon_vma); } /** |