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, 47 insertions, 0 deletions

diff --git a/drivers/perf/arm_brbe.h b/drivers/perf/arm_brbe.h
new file mode 100644
index 000000000..b7c7d8796
--- /dev/null
+++ b/drivers/perf/arm_brbe.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Branch Record Buffer Extension Helpers.
+ *
+ * Copyright (C) 2022-2025 ARM Limited
+ *
+ * Author: Anshuman Khandual <anshuman.khandual@arm.com>
+ */
+
+struct arm_pmu;
+struct perf_branch_stack;
+struct perf_event;
+
+#ifdef CONFIG_ARM64_BRBE
+void brbe_probe(struct arm_pmu *arm_pmu);
+unsigned int brbe_num_branch_records(const struct arm_pmu *armpmu);
+void brbe_invalidate(void);
+
+void brbe_enable(const struct arm_pmu *arm_pmu);
+void brbe_disable(void);
+
+bool brbe_branch_attr_valid(struct perf_event *event);
+void brbe_read_filtered_entries(struct perf_branch_stack *branch_stack,
+				const struct perf_event *event);
+#else
+static inline void brbe_probe(struct arm_pmu *arm_pmu) { }
+static inline unsigned int brbe_num_branch_records(const struct arm_pmu *armpmu)
+{
+	return 0;
+}
+
+static inline void brbe_invalidate(void) { }
+
+static inline void brbe_enable(const struct arm_pmu *arm_pmu) { };
+static inline void brbe_disable(void) { };
+
+static inline bool brbe_branch_attr_valid(struct perf_event *event)
+{
+	WARN_ON_ONCE(!has_branch_stack(event));
+	return false;
+}
+
+static void brbe_read_filtered_entries(struct perf_branch_stack *branch_stack,
+				       const struct perf_event *event)
+{
+}
+#endif