From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Tue, 14 May 2019 17:49:12 +0000 (-0400)
Subject: maple_tree: Fix range checking on skip_node
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=79539364d5c733cb56c95e2a763b8c47f1e6f75f;p=users%2Fjedix%2Flinux-maple.git

maple_tree: Fix range checking on skip_node

When skipping a node, it is only valid to break out of the loop if slot
+ 1 is valid.

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index d75c4c2659eb..077469fc0147 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -1856,15 +1856,13 @@ static inline bool _mas_awalk(struct ma_state *mas, unsigned long size)
 	enum maple_type type;
 	unsigned long pivot, max, min;
 	unsigned char pivot_cnt, i;
-	bool leaf = false, found = false;
+	bool found = false;
 
 	min = mas->min;
 	max = mas->max;
 
 	type = mt_node_type(mas->node);
 	pivot_cnt = mt_pivots[type];
-	if (type < maple_range_16)
-		leaf = true;
 
 	switch (type) {
 	case maple_leaf_64:
@@ -1950,7 +1948,7 @@ next:
 	}
 
 
-	if (!leaf) { // descend.
+	if (type >=  maple_range_16) { //descend
 		struct maple_enode *next;
 		next = _ma_get_rcu_slot(mas->node, i, type);
 		mas->min = min;
@@ -2198,7 +2196,7 @@ static inline bool mas_skip_node(struct ma_state *mas)
 	do {
 		if (ma_is_root(mas->node)) {
 			slot = ma_get_slot(mas);
-			if (slot >= mt_slot_count(mas->node) - 1) {
+			if (slot > mt_slot_count(mas->node) - 1) {
 				mas_set_err(mas, -EBUSY);
 				return false;
 			}
@@ -2206,7 +2204,7 @@ static inline bool mas_skip_node(struct ma_state *mas)
 			slot = mt_parent_slot(mas->node);
 			ma_encoded_parent(mas);
 		}
-	} while (slot >= mt_slot_count(mas->node) - 1);
+	} while (slot > mt_slot_count(mas->node) - 1);
 
 	ma_set_slot(mas, ++slot);
 	mas_update_limits(mas, slot, mt_node_type(mas->node));