+/**
+ * Add an extended sample. Use this when the PC is not from the regs, and
+ * we cannot determine if we're in kernel mode from the regs.
+ *
+ * This function does perform a backtrace.
+ *
+ */
+void oprofile_add_ext_sample(unsigned long pc, struct pt_regs * const regs,
+ unsigned long event, int is_kernel);
+