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, 51 insertions, 0 deletions

diff --git a/arch/x86/lib/cpu.c b/arch/x86/lib/cpu.c
new file mode 100644
index 000000000..d39fba72f
--- /dev/null
+++ b/arch/x86/lib/cpu.c
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/types.h>
+#include <linux/export.h>
+
+#include <asm/cpu.h>
+#include <asm/cpuid/leaf_types.h>
+
+static unsigned int __x86_family(unsigned int base_fam, unsigned int ext_fam)
+{
+	if (base_fam == 0xf)
+		base_fam += ext_fam;
+
+	return base_fam;
+}
+
+static unsigned int __x86_model(unsigned int family, unsigned int base_model,
+				unsigned int ext_model)
+{
+	if (family >= 0x6)
+		base_model |= ext_model << 4;
+
+	return base_model;
+}
+
+unsigned int x86_family(unsigned int sig)
+{
+	return __x86_family((sig >> 8) & 0xf, (sig >> 20) & 0xff);
+}
+EXPORT_SYMBOL_GPL(x86_family);
+
+unsigned int x86_model(unsigned int sig)
+{
+	return __x86_model(x86_family(sig), (sig >> 4) & 0xf, (sig >> 16) & 0xf);
+}
+EXPORT_SYMBOL_GPL(x86_model);
+
+unsigned int x86_stepping(unsigned int sig)
+{
+	return sig & 0xf;
+}
+EXPORT_SYMBOL_GPL(x86_stepping);
+
+unsigned int cpuid_family(const struct leaf_0x1_0 *l)
+{
+	return __x86_family(l->base_family_id, l->ext_family);
+}
+
+unsigned int cpuid_model(const struct leaf_0x1_0 *l)
+{
+	return __x86_model(cpuid_family(l), l->base_model, l->ext_model);
+}