diff options
author | zhong jiang <zhongjiang@huawei.com> | 2019-11-18 11:26:09 +0800 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-11-25 15:54:19 +0100 |
commit | 905bf98eb3381615bda17951fddb48076588e0b5 (patch) | |
tree | 2f581a5b56d4eca3e687b4cc170b1e9ee307c00a | |
parent | 29d9c5714096a47ed8d2a1632e382c949b089563 (diff) |
memfd: Use radix_tree_deref_slot_protected to avoid the warning.
The commit eb4058d8daf8 ("memfd: Fix locking when tagging pins")
introduces the following warning messages.
*WARNING: suspicious RCU usage in memfd_wait_for_pins*
It is because we still use radix_tree_deref_slot without read_rcu_lock.
We should use radix_tree_deref_slot_protected instead in the case.
Cc: stable@vger.kernel.org
Fixes: eb4058d8daf8 ("memfd: Fix locking when tagging pins")
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | mm/shmem.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/shmem.c b/mm/shmem.c index 62668379623b..e40239bf6dfe 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1862,7 +1862,7 @@ static void shmem_tag_pins(struct address_space *mapping) spin_lock_irq(&mapping->tree_lock); restart: radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) { - page = radix_tree_deref_slot(slot); + page = radix_tree_deref_slot_protected(slot, &mapping->tree_lock); if (!page || radix_tree_exception(page)) { if (radix_tree_deref_retry(page)) goto restart; |