Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Peng Zhang <zhangpeng.00@bytedance.com>
To:     Liam.Howlett@oracle.com
Cc:     akpm@linux-foundation.org, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, maple-tree@lists.infradead.org,
        Peng Zhang <zhangpeng.00@bytedance.com>
Subject: [RESEND PATCH 4/8] maple_tree: fix mas_validate_child_slot() to check last missed slot
Date:   Fri,  7 Jul 2023 18:10:53 +0800
Message-Id: <20230707101057.29326-5-zhangpeng.00@bytedance.com>
In-Reply-To: <20230707101057.29326-1-zhangpeng.00@bytedance.com>
References: <20230707101057.29326-1-zhangpeng.00@bytedance.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Don't break the loop before checking the last slot. Also here check if
non-leaf nodes are missing children.

Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
---
 lib/maple_tree.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 1fe8b6a787dd..88d6373f37b0 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -7111,11 +7111,12 @@ static void mas_validate_child_slot(struct ma_state *mas)
 
 	for (i = 0; i < mt_slots[type]; i++) {
 		child = mas_slot(mas, slots, i);
-		if (!pivots[i] || pivots[i] == mas->max)
-			break;
 
-		if (!child)
-			break;
+		if (!child) {
+			pr_err("Non-leaf node lacks child at %p[%u]\n",
+			       mas_mn(mas), i);
+			MT_BUG_ON(mas->tree, 1);
+		}
 
 		if (mte_parent_slot(child) != i) {
 			pr_err("Slot error at %p[%u]: child %p has pslot %u\n",
@@ -7130,6 +7131,9 @@ static void mas_validate_child_slot(struct ma_state *mas)
 			       mte_to_node(mas->node));
 			MT_BUG_ON(mas->tree, 1);
 		}
+
+		if (i < mt_pivots[type] && pivots[i] == mas->max)
+			break;
 	}
 }
 
-- 
2.20.1