Robust and High Performance Instructions for System Call

Robust system call and system return instructions are executed by a processor to transfer control between a requester and an operating system kernel. The processor includes execution circuitry and registers that store pointers to data structures in memory. The execution circuitry receives a system call instruction from a requester to transfer control from a first privilege level of the requester to a second privilege level of an operating system kernel. In response, the execution circuitry swaps the data structures that are pointed to by the registers between the requester and the operating system kernel in one atomic transition.