Abstract: Examples relate to apparatuses, devices, methods and computer programs for modifying a target application. An apparatus for a computer system comprises memory circuitry, machine-readable instructions, and processor circuitry to execute the machine-readable instructions to launch, using a loader application, a target application, obtain, by the loader application, information on a kernel system call having been made by the target application, and modify, by the loader application and based on the information on the kernel system call having been made by the target application, an instruction of the target application, wherein the modified instruction is configured to trigger an operation being equivalent to the kernel system call, with the operation being equivalent to the kernel system call while avoiding a context switch.

Abstract: One or more implementations of the present specification provide a method and apparatus for securely entering a trusted execution environment in a hyper-threading scenario. The method can include: in response to that a logical processor running on a physical processor core generates a trusted execution environment entry event through an approach provided by a virtual machine monitor, labeling the logical processor with a state of expecting to enter a trusted execution environment; and in response to determining that all logical processors corresponding to the physical processor core are labeled with the state of expecting to enter a trusted execution environment, separately controlling each one of the logical processors to enter a trusted execution environment built on the physical processor core.

Abstract: One or more implementations of the present specification provide a method and apparatus for securely entering a trusted execution environment in a hyper-threading scenario. The method can include: in response to that a logical processor running on a physical processor core generates a trusted execution environment entry event through an approach provided by a virtual machine monitor, labeling the logical processor with a state of expecting to enter a trusted execution environment; and in response to determining that all logical processors corresponding to the physical processor core are labeled with the state of expecting to enter a trusted execution environment, separately controlling each one of the logical processors to enter a trusted execution environment built on the physical processor core.