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| author | Liam R. Howlett <Liam.Howlett@oracle.com> | 2023-04-14 10:57:27 -0400 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-04-18 14:22:13 -0700 |
| commit | 06e8fd999334bcd76b4d72d7b9206d4aea89764e (patch) | |
| tree | 07ea252b9f0fad088ef0c4a22de9bbd057807461 /lib/maple_tree.c | |
| parent | fad8e4291da5e3243e086622df63cb952db444d8 (diff) | |
| download | lwn-06e8fd999334bcd76b4d72d7b9206d4aea89764e.tar.gz lwn-06e8fd999334bcd76b4d72d7b9206d4aea89764e.zip | |
maple_tree: fix mas_empty_area() search
The internal function of mas_awalk() was incorrectly skipping the last
entry in a node, which could potentially be NULL. This is only a problem
for the left-most node in the tree - otherwise that NULL would not exist.
Fix mas_awalk() by using the metadata to obtain the end of the node for
the loop and the logical pivot as apposed to the raw pivot value.
Link: https://lkml.kernel.org/r/20230414145728.4067069-2-Liam.Howlett@oracle.com
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'lib/maple_tree.c')
| -rw-r--r-- | lib/maple_tree.c | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/lib/maple_tree.c b/lib/maple_tree.c index d197b49eee67..1281a40d5735 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -5056,10 +5056,10 @@ static inline bool mas_anode_descend(struct ma_state *mas, unsigned long size) { enum maple_type type = mte_node_type(mas->node); unsigned long pivot, min, gap = 0; - unsigned char offset; - unsigned long *gaps; - unsigned long *pivots = ma_pivots(mas_mn(mas), type); - void __rcu **slots = ma_slots(mas_mn(mas), type); + unsigned char offset, data_end; + unsigned long *gaps, *pivots; + void __rcu **slots; + struct maple_node *node; bool found = false; if (ma_is_dense(type)) { @@ -5067,13 +5067,15 @@ static inline bool mas_anode_descend(struct ma_state *mas, unsigned long size) return true; } - gaps = ma_gaps(mte_to_node(mas->node), type); + node = mas_mn(mas); + pivots = ma_pivots(node, type); + slots = ma_slots(node, type); + gaps = ma_gaps(node, type); offset = mas->offset; min = mas_safe_min(mas, pivots, offset); - for (; offset < mt_slots[type]; offset++) { - pivot = mas_safe_pivot(mas, pivots, offset, type); - if (offset && !pivot) - break; + data_end = ma_data_end(node, type, pivots, mas->max); + for (; offset <= data_end; offset++) { + pivot = mas_logical_pivot(mas, pivots, offset, type); /* Not within lower bounds */ if (mas->index > pivot) |