From: zhong jiang <zhongjiang@huawei.com>
To: <sashal@kernel.org>, <gregkh@linuxfoundation.org>,
<stable@vger.kernel.org>, <willy@infradead.org>
Cc: <linux-mm@kvack.org>, <yangyingliang@huawei.com>
Subject: [PATCH 4.19] memfd: Use radix_tree_deref_slot_protected to avoid the warning.
Date: Mon, 18 Nov 2019 11:26:08 +0800 [thread overview]
Message-ID: <20191118032610.182862-2-zhongjiang@huawei.com> (raw)
In-Reply-To: <20191118032610.182862-1-zhongjiang@huawei.com>
The commit 99b45e7a1ba1 ("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: 99b45e7a1ba1 ("memfd: Fix locking when tagging pins")
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
---
mm/memfd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/memfd.c b/mm/memfd.c
index 5859705dafe1..9e68a4320a0e 100644
--- a/mm/memfd.c
+++ b/mm/memfd.c
@@ -41,7 +41,7 @@ static void memfd_tag_pins(struct address_space *mapping)
xa_lock_irq(&mapping->i_pages);
radix_tree_for_each_slot(slot, &mapping->i_pages, &iter, start) {
- page = radix_tree_deref_slot(slot);
+ page = radix_tree_deref_slot_protected(slot, &mapping->i_pages.xa_lock);
if (!page || radix_tree_exception(page)) {
if (radix_tree_deref_retry(page)) {
slot = radix_tree_iter_retry(&iter);
--
2.20.1
next prev parent reply other threads:[~2019-11-18 3:27 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-18 3:26 [PATCH 4.14] memfd: Use radix_tree_deref_slot_protected to avoid the warning zhong jiang
2019-11-18 3:26 ` zhong jiang [this message]
2019-11-18 12:25 ` [PATCH 4.19] " Matthew Wilcox
2019-11-19 5:00 ` Patch "memfd: Use radix_tree_deref_slot_protected to avoid the warning." has been added to the 4.19-stable tree gregkh
2019-11-18 3:26 ` [PATCH 4.4] memfd: Use radix_tree_deref_slot_protected to avoid the warning zhong jiang
2019-11-18 12:25 ` Matthew Wilcox
2019-11-19 4:59 ` Patch "memfd: Use radix_tree_deref_slot_protected to avoid the warning." has been added to the 4.4-stable tree gregkh
2019-11-18 3:26 ` [PATCH 4.9] memfd: Use radix_tree_deref_slot_protected to avoid the warning zhong jiang
2019-11-18 12:25 ` Matthew Wilcox
2019-11-19 4:59 ` Patch "memfd: Use radix_tree_deref_slot_protected to avoid the warning." has been added to the 4.9-stable tree gregkh
2019-11-18 12:24 ` [PATCH 4.14] memfd: Use radix_tree_deref_slot_protected to avoid the warning Matthew Wilcox
2019-11-19 4:59 ` Patch "memfd: Use radix_tree_deref_slot_protected to avoid the warning." has been added to the 4.14-stable tree gregkh
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