The present disclosure describes an apparatus, device, method and
computer program for modifying a target application. Examples relate to apparatuses, devices, methods, and computer programs for modifying a target application. An apparatus for a computer
system includes memory circuitry,
machine-readable instructions, and processor circuitry to execute the
machine-readable instructions to: launch a target application using a
loader application; obtaining, by the
loader application, information related to a
kernel system call that has been made by the target application; and an instruction to modify, by the
loader application, the target application based on information relating to a
kernel system call that has been made by the target application, where the modified instruction is configured to trigger an operation equivalent to the
kernel system call, where the operation is equivalent to the kernel
system call while avoiding the context switching.