Monitoring execution of privileged instructions

The execution of privileged instructions by a processor having single-step and interruption functionality is monitored by a system in which the processor automatically generates a fault, 218, when attempting to execute an instruction requiring a higher privilege level than the processor's current privilege level. In response to the fault, state information is stored, 226, for later analysis of the fault, the privilege level is temporarily raised, 228, and hardware single-stepping is enabled, 230. The faulting instruction is then executed, 204, generating a trap, 206. A trap handler restores the lower privilege level, 210, and disables the single-stepping mode, 212.