tree 135abfabd47d4d94c0115315c593aeed4926d768
parent 6988feec3da07e2c67a4ef8ab015fab23ea33c6e
author zhong jiang <zhongjiang@huawei.com> 1574047570 +0800
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1574671989 +0100

memfd: Use radix_tree_deref_slot_protected to avoid the warning.

The commit 3ce6b467b9b2 ("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: 3ce6b467b9b2 ("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>