summary refs log tree commit diff
path: root/lib
diff options
context:
space:
mode:
authorLiam R. Howlett <Liam.Howlett@oracle.com>2023-04-14 10:57:27 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-04-26 14:28:39 +0200
commit66f13a1acf0ae80bcd5cd336a6e864c2eaff851d (patch)
treee5b5d394a967761c32071d2bf08be4300b785d31 /lib
parentc51b9ef3f52161ee009af34555af7719fdcf74f1 (diff)
downloadlinux-66f13a1acf0ae80bcd5cd336a6e864c2eaff851d.tar.gz
maple_tree: fix mas_empty_area() search
commit 06e8fd999334bcd76b4d72d7b9206d4aea89764e upstream.

The internal function of mas_awalk() was incorrectly skipping the last
entry in a node, which could potentially be NULL.  This is only a problem
for the left-most node in the tree - otherwise that NULL would not exist.

Fix mas_awalk() by using the metadata to obtain the end of the node for
the loop and the logical pivot as apposed to the raw pivot value.

Link: https://lkml.kernel.org/r/20230414145728.4067069-2-Liam.Howlett@oracle.com
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/maple_tree.c20
1 files changed, 11 insertions, 9 deletions
diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 2309c4e1b58a..f026d5fb51ab 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -5059,10 +5059,10 @@ static inline bool mas_anode_descend(struct ma_state *mas, unsigned long size)
 {
 	enum maple_type type = mte_node_type(mas->node);
 	unsigned long pivot, min, gap = 0;
-	unsigned char offset;
-	unsigned long *gaps;
-	unsigned long *pivots = ma_pivots(mas_mn(mas), type);
-	void __rcu **slots = ma_slots(mas_mn(mas), type);
+	unsigned char offset, data_end;
+	unsigned long *gaps, *pivots;
+	void __rcu **slots;
+	struct maple_node *node;
 	bool found = false;
 
 	if (ma_is_dense(type)) {
@@ -5070,13 +5070,15 @@ static inline bool mas_anode_descend(struct ma_state *mas, unsigned long size)
 		return true;
 	}
 
-	gaps = ma_gaps(mte_to_node(mas->node), type);
+	node = mas_mn(mas);
+	pivots = ma_pivots(node, type);
+	slots = ma_slots(node, type);
+	gaps = ma_gaps(node, type);
 	offset = mas->offset;
 	min = mas_safe_min(mas, pivots, offset);
-	for (; offset < mt_slots[type]; offset++) {
-		pivot = mas_safe_pivot(mas, pivots, offset, type);
-		if (offset && !pivot)
-			break;
+	data_end = ma_data_end(node, type, pivots, mas->max);
+	for (; offset <= data_end; offset++) {
+		pivot = mas_logical_pivot(mas, pivots, offset, type);
 
 		/* Not within lower bounds */
 		if (mas->index > pivot)