We present Linear Controller Verifier (LCV), a tool to verify that a controller implementation code correctly implements a linear controller model. The use of unverified code generator/transformer in the controller development may result in introducing unintended bugs in the controller implementation. Given a Simulink block diagram model and a C code implementation, LCV verifies an input-output equivalence between them. A real-world case study with the controller of a quadrotor system is demonstrated.