Merge tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipgrafted

Pull futex fix from Ingo Molnar:

 - Also allocate a default private futex hash on vfork() as well, to
   avoid races with (private) futex waiters (Peter Zijlstra)

* tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Also allocate private hash on vfork()

1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/md/persistent-data/dm-persistent-data-internal.h b/drivers/md/persistent-data/dm-persistent-data-internal.h
new file mode 100644
index 000000000..c482434e5
--- /dev/null
+++ b/drivers/md/persistent-data/dm-persistent-data-internal.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2011 Red Hat, Inc.
+ *
+ * This file is released under the GPL.
+ */
+
+#ifndef _DM_PERSISTENT_DATA_INTERNAL_H
+#define _DM_PERSISTENT_DATA_INTERNAL_H
+
+#include "dm-block-manager.h"
+
+static inline unsigned int dm_hash_block(dm_block_t b, unsigned int hash_mask)
+{
+	const unsigned int BIG_PRIME = 4294967291UL;
+
+	return (((unsigned int) b) * BIG_PRIME) & hash_mask;
+}
+
+#endif	/* _PERSISTENT_DATA_INTERNAL_H */