This is a note to let you know that I've just added the patch titled
maple_tree: make maple state reusable after mas_empty_area_rev()
to the 6.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
maple_tree-make-maple-state-reusable-after-mas_empty_area_rev.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From fad8e4291da5e3243e086622df63cb952db444d8 Mon Sep 17 00:00:00 2001
From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
Date: Fri, 14 Apr 2023 10:57:26 -0400
Subject: maple_tree: make maple state reusable after mas_empty_area_rev()
From: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
commit fad8e4291da5e3243e086622df63cb952db444d8 upstream.
Stop using maple state min/max for the range by passing through pointers
for those values. This will allow the maple state to be reused without
resetting.
Also add some logic to fail out early on searching with invalid
arguments.
Link: https://lkml.kernel.org/r/20230414145728.4067069-1-Liam.Howlett@xxxxxxxxxx
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Reported-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
lib/maple_tree.c | 27 +++++++++++++--------------
1 file changed, 13 insertions(+), 14 deletions(-)
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -4973,7 +4973,8 @@ not_found:
* Return: True if found in a leaf, false otherwise.
*
*/
-static bool mas_rev_awalk(struct ma_state *mas, unsigned long size)
+static bool mas_rev_awalk(struct ma_state *mas, unsigned long size,
+ unsigned long *gap_min, unsigned long *gap_max)
{
enum maple_type type = mte_node_type(mas->node);
struct maple_node *node = mas_mn(mas);
@@ -5038,8 +5039,8 @@ static bool mas_rev_awalk(struct ma_stat
if (unlikely(ma_is_leaf(type))) {
mas->offset = offset;
- mas->min = min;
- mas->max = min + gap - 1;
+ *gap_min = min;
+ *gap_max = min + gap - 1;
return true;
}
@@ -5315,6 +5316,9 @@ int mas_empty_area(struct ma_state *mas,
unsigned long *pivots;
enum maple_type mt;
+ if (min >= max)
+ return -EINVAL;
+
if (mas_is_start(mas))
mas_start(mas);
else if (mas->offset >= 2)
@@ -5369,6 +5373,9 @@ int mas_empty_area_rev(struct ma_state *
{
struct maple_enode *last = mas->node;
+ if (min >= max)
+ return -EINVAL;
+
if (mas_is_start(mas)) {
mas_start(mas);
mas->offset = mas_data_end(mas);
@@ -5388,7 +5395,7 @@ int mas_empty_area_rev(struct ma_state *
mas->index = min;
mas->last = max;
- while (!mas_rev_awalk(mas, size)) {
+ while (!mas_rev_awalk(mas, size, &min, &max)) {
if (last == mas->node) {
if (!mas_rewind_node(mas))
return -EBUSY;
@@ -5403,17 +5410,9 @@ int mas_empty_area_rev(struct ma_state *
if (unlikely(mas->offset == MAPLE_NODE_SLOTS))
return -EBUSY;
- /*
- * mas_rev_awalk() has set mas->min and mas->max to the gap values. If
- * the maximum is outside the window we are searching, then use the last
- * location in the search.
- * mas->max and mas->min is the range of the gap.
- * mas->index and mas->last are currently set to the search range.
- */
-
/* Trim the upper limit to the max. */
- if (mas->max <= mas->last)
- mas->last = mas->max;
+ if (max <= mas->last)
+ mas->last = max;
mas->index = mas->last - size + 1;
return 0;
Patches currently in stable-queue which might be from Liam.Howlett@xxxxxxxxxx are
queue-6.2/maple_tree-make-maple-state-reusable-after-mas_empty_area_rev.patch
queue-6.2/maple_tree-fix-a-potential-memory-leak-oob-access-or-other-unpredictable-bug.patch
queue-6.2/maple_tree-fix-mas_empty_area-search.patch
