+ maple_tree-fix-get-wrong-data_end-in-mtree_lookup_walk.patch added to mm-unstable branch

+ maple_tree-fix-get-wrong-data_end-in-mtree_lookup_walk.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: maple_tree: fix get wrong data_end in mtree_lookup_walk()
has been added to the -mm mm-unstable branch.  Its filename is
     maple_tree-fix-get-wrong-data_end-in-mtree_lookup_walk.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-fix-get-wrong-data_end-in-mtree_lookup_walk.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Peng Zhang <zhangpeng.00@bytedance.com>
Subject: maple_tree: fix get wrong data_end in mtree_lookup_walk()
Date: Tue, 14 Mar 2023 20:42:01 +0800

Patch series "Some fixes and cleanup for maple tree", v2.

Some fixes and clean up for maple tree.


This patch (of 3):

if (likely(offset > end))
	max = pivots[offset];

The above code should be changed to if (likely(offset < end)), which is
correct.  This affects the correctness of ma_data_end().  Now it seems
that the final result will not be wrong, but it is best to change it. 
This patch does not change the code as above, because it simplifies the
code by the way.

Link: https://lkml.kernel.org/r/20230314124203.91572-1-zhangpeng.00@bytedance.com
Link: https://lkml.kernel.org/r/20230314124203.91572-2-zhangpeng.00@bytedance.com
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/maple_tree.c |   15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

--- a/lib/maple_tree.c~maple_tree-fix-get-wrong-data_end-in-mtree_lookup_walk
+++ a/lib/maple_tree.c
@@ -3941,18 +3941,13 @@ static inline void *mtree_lookup_walk(st
 		end = ma_data_end(node, type, pivots, max);
 		if (unlikely(ma_dead_node(node)))
 			goto dead_node;
-
-		if (pivots[offset] >= mas->index)
-			goto next;
-
 		do {
-			offset++;
-		} while ((offset < end) && (pivots[offset] < mas->index));
-
-		if (likely(offset > end))
-			max = pivots[offset];
+			if (pivots[offset] >= mas->index) {
+				max = pivots[offset];
+				break;
+			}
+		} while (++offset < end);
 
-next:
 		slots = ma_slots(node, type);
 		next = mt_slot(mas->tree, slots, offset);
 		if (unlikely(ma_dead_node(node)))
_

Patches currently in -mm which might be from zhangpeng.00@bytedance.com are

mm-kfence-improve-the-performance-of-__kfence_alloc-and-__kfence_free.patch
maple_tree-fix-get-wrong-data_end-in-mtree_lookup_walk.patch
maple_tree-simplify-mas_wr_node_walk.patch
maple_tree-fix-a-potential-concurrency-bug-in-rcu-mode.patch