The patch titled
Subject: maple_tree: make maple state reusable after mas_empty_area()
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
maple_tree-make-maple-state-reusable-after-mas_empty_area.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-make-maple-state-reusable-after-mas_empty_area.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx>
Subject: maple_tree: make maple state reusable after mas_empty_area()
Date: Fri, 5 May 2023 22:58:29 +0800
Make mas->min and mas->max point to a node range instead of a leaf entry
range. This allows mas to still be usable after mas_empty_area() returns.
Users would get unexpected results from other operations on the maple
state after calling the affected function.
For example, x86 MAP_32BIT mmap() acts as if there is no suitable gap when
there should be one.
Link: https://lkml.kernel.org/r/20230505145829.74574-1-zhangpeng.00@xxxxxxxxxxxxx
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx>
Reported-by: "Edgecombe, Rick P" <rick.p.edgecombe@xxxxxxxxx>
Reported-by: Tad <support@xxxxxxxxx>
Reported-by: Michael Keyes <mgkeyes@xxxxxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/linux-mm/32f156ba80010fd97dbaf0a0cdfc84366608624d.camel@xxxxxxxxx/
Link: https://lore.kernel.org/linux-mm/e6108286ac025c268964a7ead3aab9899f9bc6e9.camel@xxxxxxxxx/
Reviewed-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Tested-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/maple_tree.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)
--- a/lib/maple_tree.c~maple_tree-make-maple-state-reusable-after-mas_empty_area
+++ a/lib/maple_tree.c
@@ -5317,15 +5317,9 @@ int mas_empty_area(struct ma_state *mas,
mt = mte_node_type(mas->node);
pivots = ma_pivots(mas_mn(mas), mt);
- if (offset)
- mas->min = pivots[offset - 1] + 1;
-
- if (offset < mt_pivots[mt])
- mas->max = pivots[offset];
-
- if (mas->index < mas->min)
- mas->index = mas->min;
-
+ min = mas_safe_min(mas, pivots, offset);
+ if (mas->index < min)
+ mas->index = min;
mas->last = mas->index + size - 1;
return 0;
}
_
Patches currently in -mm which might be from zhangpeng.00@xxxxxxxxxxxxx are
maple_tree-make-maple-state-reusable-after-mas_empty_area.patch
