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, 15 insertions, 0 deletions

diff --git a/tools/perf/util/pstack.h b/tools/perf/util/pstack.h
new file mode 100644
index 000000000..712051b81
--- /dev/null
+++ b/tools/perf/util/pstack.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _PERF_PSTACK_
+#define _PERF_PSTACK_
+
+#include <stdbool.h>
+
+struct pstack;
+struct pstack *pstack__new(unsigned short max_nr_entries);
+void pstack__delete(struct pstack *pstack);
+bool pstack__empty(const struct pstack *pstack);
+void pstack__remove(struct pstack *pstack, void *key);
+void pstack__push(struct pstack *pstack, void *key);
+void *pstack__peek(struct pstack *pstack);
+
+#endif /* _PERF_PSTACK_ */