From: Peng Zhang <zhangpeng.00@bytedance.com>
To: Liam.Howlett@oracle.com
Cc: akpm@linux-foundation.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, maple-tree@lists.infradead.org,
Peng Zhang <zhangpeng.00@bytedance.com>,
"Edgecombe, Rick P" <rick.p.edgecombe@intel.com>,
Tad <support@spotco.us>,
Michael Keyes <mgkeyes@vigovproductions.net>,
Stable@vger.kernel.org
Subject: [PATCH v2] maple_tree: Make maple state reusable after mas_empty_area()
Date: Fri, 5 May 2023 22:58:29 +0800 [thread overview]
Message-ID: <20230505145829.74574-1-zhangpeng.00@bytedance.com> (raw)
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.
Reported-by: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>
Reported-by: Tad <support@spotco.us>
Reported-by: Michael Keyes <mgkeyes@vigovproductions.net>
Link: https://lore.kernel.org/linux-mm/32f156ba80010fd97dbaf0a0cdfc84366608624d.camel@intel.com/
Link: https://lore.kernel.org/linux-mm/e6108286ac025c268964a7ead3aab9899f9bc6e9.camel@spotco.us/
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Cc: <Stable@vger.kernel.org>
Signed-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
---
lib/maple_tree.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)
diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 110a36479dced..8ebc43d4cc8c5 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -5317,15 +5317,9 @@ int mas_empty_area(struct ma_state *mas, unsigned long min,
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;
}
--
2.20.1
next reply other threads:[~2023-05-05 14:59 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-05 14:58 Peng Zhang [this message]
2023-05-05 16:00 ` [PATCH v2] maple_tree: Make maple state reusable after mas_empty_area() Liam R. Howlett
2023-05-05 17:36 ` Edgecombe, Rick P
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