Implement architecture-specific user probe address retrieval

xtoskrnl/mm/amd64/pagemap.cc

@@ -755,6 +755,21 @@ MM::PageMapBasic::GetPxeVirtualAddress(IN PMMPXE PxePointer)
     return (PVOID)(((LONGLONG)PxePointer << 52) >> 16);
 }
 
+/**
+ * Retrieves the maximum valid memory address accessible to user-mode applications.
+ *
+ * @return This routine returns the user-mode probe address boundary.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+ULONG_PTR
+MM::PageMapBasic::GetUserProbeAddress(VOID)
+{
+    /* Return user probe address */
+    return MM_USER_PROBE_ADDRESS;
+}
+
 /**
  * Initializes page map information for basic paging (PML4).
  *
@@ -852,6 +867,21 @@ MM::PageMapXpa::GetPxeVirtualAddress(IN PMMPXE PxePointer)
     return (PVOID)(((LONGLONG)PxePointer << 43) >> 7);
 }
 
+/**
+ * Retrieves the maximum valid memory address accessible to user-mode applications.
+ *
+ * @return This routine returns the user-mode probe address boundary.
+ *
+ * @since XT 1.0
+ */
+XTAPI
+ULONG_PTR
+MM::PageMapXpa::GetUserProbeAddress(VOID)
+{
+    /* Return user probe address */
+    return MM_USER_PROBE_LA57_ADDRESS;
+}
+
 /**
  * Initializes page map information for XPA paging (PML5).
  *