Merge tag 'v5.3.15' into dev-5.3dev-5.3

This is the 5.3.15 stable release

Signed-off-by: Joel Stanley <joel@jms.id.au>

1 files changed, 7 insertions, 7 deletions

diff --git a/mm/ksm.c b/mm/ksm.c
index 3dc4346411e4..4d5998ca31ae 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -885,13 +885,13 @@ static int remove_stable_node(struct stable_node *stable_node)
 		return 0;
 	}
 
-	if (WARN_ON_ONCE(page_mapped(page))) {
-		/*
-		 * This should not happen: but if it does, just refuse to let
-		 * merge_across_nodes be switched - there is no need to panic.
-		 */
-		err = -EBUSY;
-	} else {
+	/*
+	 * Page could be still mapped if this races with __mmput() running in
+	 * between ksm_exit() and exit_mmap(). Just refuse to let
+	 * merge_across_nodes/max_page_sharing be switched.
+	 */
+	err = -EBUSY;
+	if (!page_mapped(page)) {
 		/*
 		 * The stable node did not yet appear stale to get_ksm_page(),
 		 * since that allows for an unmapped ksm page to be recognized