diff --git a/sys/compat/linuxkpi/common/include/linux/mmu_notifier.h b/sys/compat/linuxkpi/common/include/linux/mmu_notifier.h
--- a/sys/compat/linuxkpi/common/include/linux/mmu_notifier.h
+++ b/sys/compat/linuxkpi/common/include/linux/mmu_notifier.h
@@ -1,5 +1,6 @@
 /*-
  * Copyright (c) 2017 Mark Johnston <markj@FreeBSD.org>
+ * Copyright (c) 2026 The FreeBSD Foundation
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -25,9 +26,68 @@
  */
 
 #ifndef _LINUXKPI_LINUX_MMU_NOTIFIER_H_
-#define        _LINUXKPI_LINUX_MMU_NOTIFIER_H_
+#define _LINUXKPI_LINUX_MMU_NOTIFIER_H_
+
+
+#include <linux/kernel.h>
+
+/*
+ * XXX: These functions are stubbed out. This is a temporary placeholder
+ * to allow compilation. Note that these functions have no implementation;
+ * using them will result in silent failure, memory corruption, or system
+ * instability. 
+*/ 
+
+struct mm_struct;
+struct mmu_notifier;
+
+struct mmu_notifier_ops {
+    void       (*release)(struct mmu_notifier *mn, struct mm_struct *mm);
+    struct     mmu_notifier *(*alloc_notifier)(struct mm_struct *mm);
+    void       (*free_notifier)(struct mmu_notifier *mn);
+    void       (*invalidate_range_start)(struct mmu_notifier *mn, const void *range);
+    void       (*invalidate_range_end)(struct mmu_notifier *mn, const void *range);
+};
 
 struct mmu_notifier {
+    const struct mmu_notifier_ops *ops;
 };
 
+
+static inline int 
+mmu_notifier_register(__unused struct mmu_notifier *mn, __unused struct mm_struct *mm) 
+{
+    pr_debug("%s TODO\n", __func__);
+    return (-EINVAL); 
+}
+
+static inline void 
+mmu_notifier_unregister(__unused struct mmu_notifier *mn, __unused struct mm_struct *mm) 
+{
+    pr_debug("%s TODO\n", __func__);
+}
+
+static inline struct mmu_notifier *
+mmu_notifier_get(const struct mmu_notifier_ops *ops, struct mm_struct *mm)
+{
+    pr_debug("%s TODO\n", __func__);
+    if (ops != NULL && ops->alloc_notifier != NULL)
+        return (ops->alloc_notifier(mm));
+    return (ERR_PTR(-EINVAL));
+}
+
+static inline void
+mmu_notifier_put(struct mmu_notifier *mn)
+{
+    pr_debug("%s TODO\n", __func__);
+    if (mn != NULL && mn->ops != NULL && mn->ops->free_notifier != NULL)
+        mn->ops->free_notifier(mn);
+}
+
+static inline void 
+mmu_notifier_synchronize(void)
+{
+    pr_debug("%s TODO\n", __func__);
+}
+
 #endif /* _LINUXKPI_LINUX_MMU_NOTIFIER_H_ */