diff options
| author | Liam R. Howlett <Liam.Howlett@Oracle.com> | 2024-08-20 19:54:17 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-09-02 02:59:01 +0200 |
| commit | f806de88d8f7f8191afd0fd9b94db4cd058e7d4f (patch) | |
| tree | f45262d730d256cd077e7ef811adbc79ed13fd80 /lib/maple_tree.c | |
| parent | kexec_file: fix elfcorehdr digest exclusion when CONFIG_CRASH_HOTPLUG=y (diff) | |
| download | linux-f806de88d8f7f8191afd0fd9b94db4cd058e7d4f.tar.xz linux-f806de88d8f7f8191afd0fd9b94db4cd058e7d4f.zip | |
maple_tree: remove rcu_read_lock() from mt_validate()
The write lock should be held when validating the tree to avoid updates
racing with checks. Holding the rcu read lock during a large tree
validation may also cause a prolonged rcu read window and "rcu_preempt
detected stalls" warnings.
Link: https://lore.kernel.org/all/0000000000001d12d4062005aea1@google.com/
Link: https://lkml.kernel.org/r/20240820175417.2782532-1-Liam.Howlett@oracle.com
Fixes: 54a611b60590 ("Maple Tree: add new data structure")
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reported-by: syzbot+036af2f0c7338a33b0cd@syzkaller.appspotmail.com
Cc: Hillf Danton <hdanton@sina.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to '')
| -rw-r--r-- | lib/maple_tree.c | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/lib/maple_tree.c b/lib/maple_tree.c index aa3a5df15b8e..6df3a8b95808 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -7566,14 +7566,14 @@ static void mt_validate_nulls(struct maple_tree *mt) * 2. The gap is correctly set in the parents */ void mt_validate(struct maple_tree *mt) + __must_hold(mas->tree->ma_lock) { unsigned char end; MA_STATE(mas, mt, 0, 0); - rcu_read_lock(); mas_start(&mas); if (!mas_is_active(&mas)) - goto done; + return; while (!mte_is_leaf(mas.node)) mas_descend(&mas); @@ -7594,9 +7594,6 @@ void mt_validate(struct maple_tree *mt) mas_dfs_postorder(&mas, ULONG_MAX); } mt_validate_nulls(mt); -done: - rcu_read_unlock(); - } EXPORT_SYMBOL_GPL(mt_validate); |