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authorLiam R. Howlett <Liam.Howlett@oracle.com>2023-07-14 15:55:51 -0400
committerAndrew Morton <akpm@linux-foundation.org>2023-08-18 10:12:40 -0700
commit19a462f06eb5a78e0c3ebe4fd4fbdc71620b8788 (patch)
treed3de1776e5a6a170d97ebecf6aa421ff73202a23 /lib
parent02fdb25fb41c563a3afbd4a97469c527a6c5abbf (diff)
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maple_tree: Be more strict about locking
Use lockdep to check the write path in the maple tree holds the lock in write mode. Introduce mt_write_lock_is_held() to check if the lock is held for writing. Update the necessary checks for rcu_dereference_protected() to use the new write lock check. Link: https://lkml.kernel.org/r/20230714195551.894800-5-Liam.Howlett@oracle.com Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oliver Sang <oliver.sang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/maple_tree.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index b6b3973897f0..3b6f8c8dac65 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -777,6 +777,12 @@ static inline void __rcu **ma_slots(struct maple_node *mn, enum maple_type mt)
}
}
+static inline bool mt_write_locked(const struct maple_tree *mt)
+{
+ return mt_external_lock(mt) ? mt_write_lock_is_held(mt) :
+ lockdep_is_held(&mt->ma_lock);
+}
+
static inline bool mt_locked(const struct maple_tree *mt)
{
return mt_external_lock(mt) ? mt_lock_is_held(mt) :
@@ -792,7 +798,7 @@ static inline void *mt_slot(const struct maple_tree *mt,
static inline void *mt_slot_locked(struct maple_tree *mt, void __rcu **slots,
unsigned char offset)
{
- return rcu_dereference_protected(slots[offset], mt_locked(mt));
+ return rcu_dereference_protected(slots[offset], mt_write_locked(mt));
}
/*
* mas_slot_locked() - Get the slot value when holding the maple tree lock.
@@ -835,7 +841,7 @@ static inline void *mas_root(struct ma_state *mas)
static inline void *mt_root_locked(struct maple_tree *mt)
{
- return rcu_dereference_protected(mt->ma_root, mt_locked(mt));
+ return rcu_dereference_protected(mt->ma_root, mt_write_locked(mt));
}
/*