Software Protection Mechanisms for Dependable Systems

We expect that in future commodity hardware will be used in safety critical applications. But the used commodity microprocessors will become less reliable because of decreasing feature size and reduced power supply. Thus software-implemented approaches to deal with unreliable hardware will be required. As one basic step to software- implemented hardware-fault tolerance (SIHFT) we aim at providing failure virtualization by turning arbitrary value failures caused by erroneous execution into crash failures which are easier to handle. Existing SIHFT approaches either are not broadly applicable or lack the ability to reliably deal with permanent hardware faults. In contrast, Forin [7] introduced the Vital Coded Microprocessor which reliably detects transient and permanent hardware errors but is not applicable to arbitrary programs and requires special hardware. We discuss different approaches to generalize Forin´s approach and make it applicable to modern infrastructures.