Rap’s provocateur-in-chief strikes back after a troubled five-year break, with his knack for writing songs that cut like a scalpel unblunted by drug struggles or the passage of time. Eminem’s still capable of daring ideas (rapping from the perspective of a serial killer on “3Am”) and acid-tongued humor (spitting one-liners over the circus-esque beat of “We Made You”). He’s most striking confronting his personal problems, exploring parallels with his mother’s drug use on “My Mom” and grappling with depression on “Beautiful.”