+ maple_tree-fix-mas_validate_child_slot-to-check-last-missed-slot.patch added to mm-unstable branch

+ maple_tree-fix-mas_validate_child_slot-to-check-last-missed-slot.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: maple_tree: fix mas_validate_child_slot() to check last missed slot
has been added to the -mm mm-unstable branch.  Its filename is
     maple_tree-fix-mas_validate_child_slot-to-check-last-missed-slot.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-mas_validate_child_slot-to-check-last-missed-slot.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 mas_validate_child_slot() to check last missed slot
Date: Tue, 11 Jul 2023 11:54:40 +0800

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

Link: https://lkml.kernel.org/r/20230711035444.526-5-zhangpeng.00@bytedance.com
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/maple_tree.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

--- a/lib/maple_tree.c~maple_tree-fix-mas_validate_child_slot-to-check-last-missed-slot
+++ a/lib/maple_tree.c
@@ -7093,11 +7093,12 @@ static void mas_validate_child_slot(stru
 
 	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",
@@ -7112,6 +7113,9 @@ static void mas_validate_child_slot(stru
 			       mte_to_node(mas->node));
 			MT_BUG_ON(mas->tree, 1);
 		}
+
+		if (i < mt_pivots[type] && pivots[i] == mas->max)
+			break;
 	}
 }
 
_

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

maple_tree-set-the-node-limit-when-creating-a-new-root-node.patch
maple_tree-add-test-for-mas_wr_modify-fast-path.patch
maple_tree-add-test-for-expanding-range-in-rcu-mode.patch
maple_tree-optimize-mas_wr_append-also-improve-duplicating-vmas.patch
maple_tree-add-a-fast-path-case-in-mas_wr_slot_store.patch
maple_tree-dont-use-maple_arange64_meta_max-to-indicate-no-gap.patch
maple_tree-make-mas_validate_gaps-to-check-metadata.patch
maple_tree-fix-mas_validate_child_slot-to-check-last-missed-slot.patch
maple_tree-make-mas_validate_limits-check-root-node-and-node-limit.patch
maple_tree-update-mt_validate.patch
maple_tree-replace-mas_logical_pivot-with-mas_safe_pivot.patch
maple_tree-drop-mas_first_entry.patch