diff options
Diffstat (limited to 'include/linux/page_ref.h')
| -rw-r--r-- | include/linux/page_ref.h | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/include/linux/page_ref.h b/include/linux/page_ref.h index 490d0ad6e56d..8c236c651d1d 100644 --- a/include/linux/page_ref.h +++ b/include/linux/page_ref.h @@ -230,7 +230,13 @@ static inline int folio_ref_dec_return(struct folio *folio) static inline bool page_ref_add_unless(struct page *page, int nr, int u) { - bool ret = atomic_add_unless(&page->_refcount, nr, u); + bool ret = false; + + rcu_read_lock(); + /* avoid writing to the vmemmap area being remapped */ + if (!page_is_fake_head(page) && page_ref_count(page) != u) + ret = atomic_add_unless(&page->_refcount, nr, u); + rcu_read_unlock(); if (page_ref_tracepoint_active(page_ref_mod_unless)) __page_ref_mod_unless(page, nr, ret); |