maple_tree: add RCU lock checking to rcu callback functions

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commit 790e1fa86b upstream.

Dereferencing RCU objects within the RCU callback without the RCU check
has caused lockdep to complain.  Fix the RCU dereferencing by using the
RCU callback lock to ensure the operation is safe.

Also stop creating a new lock to use for dereferencing during destruction
of the tree or subtree.  Instead, pass through a pointer to the tree that
has the lock that is held for RCU dereferencing checking.  It also does
not make sense to use the maple state in the freeing scenario as the tree
walk is a special case where the tree no longer has the normal encodings
and parent pointers.

Link: https://lkml.kernel.org/r/20230227173632.3292573-8-surenb@google.com
Fixes: 54a611b605 ("Maple Tree: add new data structure")
Cc: stable@vger.kernel.org
Reported-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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Liam R. Howlett 2023-04-11 11:10:54 -04:00 • committed by Greg Kroah-Hartman

parent a29025a1b6

commit 9b6627bc36

1 changed files with 96 additions and 92 deletions

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lib/maple_tree.c

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