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From:   Jiasheng Jiang <jiasheng@iscas.ac.cn>
To:     willy@infradead.org, akpm@linux-foundation.org
Cc:     linux-kernel@vger.kernel.org, Jiasheng Jiang <jiasheng@iscas.ac.cn>
Subject: [PATCH] XArray: Fix xa_to_node by adding xa_is_node
Date:   Tue, 12 Oct 2021 08:42:50 +0000
Message-Id: <1634028170-1753612-1-git-send-email-jiasheng@iscas.ac.cn>
Precedence: bulk

Directly using xa_to_node may lead to the compulsory type
conversion of unknown type,which is unsafe.
So it might be better that adding xa_is_node before.

Fixes: 58d6ea3 ("xarray: Add XArray unconditional store operations")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
---
 lib/test_xarray.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/test_xarray.c b/lib/test_xarray.c
index 8b1c318..7ad3d51 100644
--- a/lib/test_xarray.c
+++ b/lib/test_xarray.c
@@ -606,8 +606,10 @@ static noinline void check_multi_store(struct xarray *xa)
 	XA_BUG_ON(xa, xa_load(xa, 1) != xa_mk_value(0));
 	XA_BUG_ON(xa, xa_load(xa, 2) != NULL);
 	rcu_read_lock();
-	XA_BUG_ON(xa, xa_to_node(xa_head(xa))->count != 2);
-	XA_BUG_ON(xa, xa_to_node(xa_head(xa))->nr_values != 2);
+	if (xa_is_node(xa_head(xa))) {
+		XA_BUG_ON(xa, xa_to_node(xa_head(xa))->count != 2);
+		XA_BUG_ON(xa, xa_to_node(xa_head(xa))->nr_values != 2);
+	}
 	rcu_read_unlock();
 
 	/* Storing adjacent to the value does not alter the value */
-- 
2.7.4