+#define arch_has_single_step() (1)
+extern void user_enable_single_step(struct task_struct *child);
+extern void user_disable_single_step(struct task_struct *child);
+/* common code demands this function */
+#define ptrace_disable(child) user_disable_single_step(child)
+
+/*
+ * Get the address of the live pt_regs for the specified task.
+ * These are saved onto the top kernel stack when the process
+ * is not running.
+ *
+ * Note: if a user thread is execve'd from kernel space, the
+ * kernel stack will not be empty on entry to the kernel, so
+ * ptracing these tasks will fail.
+ */
+#define task_pt_regs(task) \
+ (struct pt_regs *) \
+ ((unsigned long)task_stack_page(task) + \
+ (THREAD_SIZE - sizeof(struct pt_regs)))
+