Error is assigned to the trial court’s allowing the State to cross-examine defendant about previous convictions. It is asserted that the North Carolina law allowing the State to cross-examine a defendant concerning prior criminal convictions should be reconsidered. Our Supreme Court has refused to change the rule as it is hereinafter stated, and this Court will not reconsider the rule as stated in State v. McKenna, 289 N.C. 668, 224 S.E. 2d 537, vacated and remanded on other grounds sub nom McKenna v. North Carolina, --- U.S. --- , 50 L.Ed. 2d 278, 97 S.Ct. 301 (1976); State v. Foster, 284 N.C. 259, 200 S.E. 2d 782 (1973).

The rule is that where the accused testifies in his own behalf he surrenders the privilege against self-incrimination, and he is subject to impeachment by questions concerning specific criminal acts and degrading conduct. Cross-examination for impeachment *100purposes is not limited to criminal convictions but includes any conduct by defendant which tends to impeach his character. State v. McKenna, supra; State v. Poole, 289 N.C. 47, 220 S.E. 2d 320 (1975); State v. Williams, 279 N.C. 663, 185 S.E. 2d 174 (1971); State v. Clark, 28 N.C. App. 585, 221 S.E. 2d 841 (1976). The reasoning for the rule is that the State should be able “to sift the witness and impeach, if it can, the credibility of a defendant’s self-serving testimony.” State v. Foster, supra at 275, 200 S.E. 2d at 794.

Defendant further complains that even if the cross-examination concerning the commission of other crimes was proper, the trial court nevertheless erred in allowing the district attorney to cross-examine him about illegal drugs purportedly in his possession as of 3 January 1975. He contends that the district attorney was allowed to cross-examine him about drugs which were found in his home on 3 January 1975 pursuant to an illegal search.

According to the record defendant was asked whether on the 3rd day of January 1975, “you did not have in your possession in your house in your room a zip-locked bag containing . . . cocaine?” Defendant answered in the negative. There follow several pages of transcript wherein defendant indicated that he was not there when any contraband was found on that date; that if any were found it did not belong to him; and finally defendant concluded that he had “found out that something was found in my house. I didn’t find out where it was.” Defendant then went on to testify that he had been prosecuted in District Court, and that “the search was held to be unlawful.”

The questions asked of defendant related to matters within defendant’s own knowledge, and not to accusations, arrests or indictments. Cross-examination of a defendant is not limited to inquiry concerning previous convictions, but may include matters within the knowledge of defendant (State v. Poole, supra; State v. Williams, supra) and may encompass any act of defendant which tends to impeach his character. State v. McKenna, supra.

Defendant’s further contention that by permitting the cross-examination the State was allowed to profit from its unlawful act in violation of Federal and State constitutional due process is also rejected. Obviously, evidence obtained by a search and seizure *101which violates the Fourth Amendment will not be admissible, Mapp v. Ohio, 367 U.S. 643, 6 L.Ed. 2d 1081, 81 S.Ct. 1684 (1961). The record shows that defense counsel remained silent as to why the District Court may have disallowed the evidence, and there is no indication from the record that the district attorney’s questions were asked in bad faith. There was no attempt by the State to make affirmative use of such evidence against defendant, and the State was not prohibited from cross-examining defendant about having the contraband in January 1975 in order to discredit defendant’s voluntary testimony.

Defendant’s remaining contentions have been reviewed and there is found no prejudicial error which would require a new trial.

No error.