return callee_fp;
  public static VM_Address unwindNativeStackFrame(VM_Address currfp) throws VM_PragmaUninterruptible {    VM_Address ip, callee_fp;    VM_Address fp = VM_Magic.getCallerFramePointer(currfp);    do {      callee_fp = fp;      ip = VM_Magic.getReturnAddress(fp);      fp = VM_Magic.getCallerFramePointer(fp);    } while ( !MM_Interface.refInVM(ip) && fp.NE(STACKFRAME_SENTINEL_FP)) ;	//-#if RVM_FOR_POWERPC && RVM_FOR_LINUX	// for SVR4 convention, a Java-to-C frame has two mini frames,	// stop before the mini frame 1 whose ip is in VM (out of line machine	// code), in the case of sentinel fp, it has to return the callee's fp	// because GC ScanThread uses it to get return address and so on.	if (MM_Interface.refInVM(ip)) {      return fp;	} else {	  return callee_fp;	}	//-#else	return callee_fp;	//-#endif  }