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* [PATCH 4.14] memfd: Use radix_tree_deref_slot_protected to avoid the warning.
@ 2019-11-18  3:26 zhong jiang
  2019-11-18  3:26 ` [PATCH 4.19] " zhong jiang
                   ` (4 more replies)
  0 siblings, 5 replies; 12+ messages in thread
From: zhong jiang @ 2019-11-18  3:26 UTC (permalink / raw)
  To: sashal, gregkh, stable, willy; +Cc: linux-mm, yangyingliang

The commit 391d4ee568b5 ("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: 391d4ee568b5 ("memfd: Fix locking when tagging pins")
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
---
 mm/shmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/shmem.c b/mm/shmem.c
index 5b2cc9f9b1f1..e55aa460a2c0 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2664,7 +2664,7 @@ static void shmem_tag_pins(struct address_space *mapping)
 
 	spin_lock_irq(&mapping->tree_lock);
 	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)) {
 				slot = radix_tree_iter_retry(&iter);
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 12+ messages in thread

end of thread, other threads:[~2019-11-19  5:00 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
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 ` [PATCH 4.19] " zhong jiang
2019-11-18 12:25   ` 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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