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, 44 insertions, 0 deletions

diff --git a/arch/x86/lib/cache-smp.c b/arch/x86/lib/cache-smp.c
new file mode 100644
index 000000000..7d3edd6de
--- /dev/null
+++ b/arch/x86/lib/cache-smp.c
@@ -0,0 +1,44 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/smp.h>
+#include <linux/export.h>
+#include <linux/kvm_types.h>
+
+static void __wbinvd(void *dummy)
+{
+	wbinvd();
+}
+
+void wbinvd_on_cpu(int cpu)
+{
+	smp_call_function_single(cpu, __wbinvd, NULL, 1);
+}
+EXPORT_SYMBOL_FOR_KVM(wbinvd_on_cpu);
+
+void wbinvd_on_all_cpus(void)
+{
+	on_each_cpu(__wbinvd, NULL, 1);
+}
+EXPORT_SYMBOL(wbinvd_on_all_cpus);
+
+void wbinvd_on_cpus_mask(struct cpumask *cpus)
+{
+	on_each_cpu_mask(cpus, __wbinvd, NULL, 1);
+}
+EXPORT_SYMBOL_FOR_KVM(wbinvd_on_cpus_mask);
+
+static void __wbnoinvd(void *dummy)
+{
+	wbnoinvd();
+}
+
+void wbnoinvd_on_all_cpus(void)
+{
+	on_each_cpu(__wbnoinvd, NULL, 1);
+}
+EXPORT_SYMBOL_FOR_KVM(wbnoinvd_on_all_cpus);
+
+void wbnoinvd_on_cpus_mask(struct cpumask *cpus)
+{
+	on_each_cpu_mask(cpus, __wbnoinvd, NULL, 1);
+}
+EXPORT_SYMBOL_FOR_KVM(wbnoinvd_on_cpus_mask);