What is the test for a motion to vacate or modify a judgment and sentence for possession of illegal drugs?

The district court denied the petition to vacate or modify the judgment and sentence on the ground that there was more than ample evidence of constructive possession to permit a finding of knowledge of illegal importation of narcotics. It also concluded that the attack upon the instructions was without merit, apart from the fact that the objection was not available under Section 2255, distinguishing United States v. Massiah, 2 Cir. 1962, 307 F.2d 62 (reversed on other grounds, 1964, 377 U.S. 201, 84 S.Ct. 1199, 12 L.Ed.2d 246), cited by the appellant.