diff options
Diffstat (limited to 'mm/rmap.c')
| -rw-r--r-- | mm/rmap.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/mm/rmap.c b/mm/rmap.c index 24dd3f9fee27..7af1ecb21ccb 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -625,7 +625,7 @@ pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address) pmd = pmd_offset(pud, address); /* - * Some THP functions use the sequence pmdp_clear_flush(), set_pmd_at() + * Some THP functions use the sequence pmdp_huge_clear_flush(), set_pmd_at() * without holding anon_vma lock for write. So when looking for a * genuine pmde (in which to find pte), test present and !THP together. */ @@ -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); } /** |