4.4-stable patches

added patches:
	memfd-use-radix_tree_deref_slot_protected-to-avoid-the-warning.patch

diff --git a/queue-4.4/memfd-use-radix_tree_deref_slot_protected-to-avoid-the-warning.patch b/queue-4.4/memfd-use-radix_tree_deref_slot_protected-to-avoid-the-warning.patch
new file mode 100644 (file)
index 0000000..3607132
--- /dev/null
+++ b/queue-4.4/memfd-use-radix_tree_deref_slot_protected-to-avoid-the-warning.patch
@@ -0,0 +1,38 @@
+From zhongjiang@huawei.com  Tue Nov 19 05:57:26 2019
+From: zhong jiang <zhongjiang@huawei.com>
+Date: Mon, 18 Nov 2019 11:26:09 +0800
+Subject: memfd: Use radix_tree_deref_slot_protected to avoid the warning.
+To: <sashal@kernel.org>, <gregkh@linuxfoundation.org>, <stable@vger.kernel.org>, <willy@infradead.org>
+Cc: <linux-mm@kvack.org>, <yangyingliang@huawei.com>
+Message-ID: <20191118032610.182862-3-zhongjiang@huawei.com>
+
+From: zhong jiang <zhongjiang@huawei.com>
+
+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>
+---
+ mm/shmem.c |    2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/mm/shmem.c
++++ b/mm/shmem.c
+@@ -1862,7 +1862,7 @@ static void shmem_tag_pins(struct addres
+       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;

diff --git a/queue-4.4/series b/queue-4.4/series
index 4344fd55faab10bee4b823e129ff8e6918279f44..5d7764d36eb40a1d8765b2b5a6997a376e3e43b8 100644 (file)
--- a/queue-4.4/series
+++ b/queue-4.4/series
@@ -96,3 +96,4 @@ arm64-dts-amd-fix-spi-bus-warnings.patch
 fuse-use-read_once-on-congestion_threshold-and-max_b.patch
 bluetooth-hci_ldisc-fix-null-pointer-derefence-in-case-of-early-data.patch
 bluetooth-hci_ldisc-postpone-hci_uart_proto_ready-bit-set-in-hci_uart_set_proto.patch
+memfd-use-radix_tree_deref_slot_protected-to-avoid-the-warning.patch