Predicting program phases and defending against side-channel attacks using hardware performance counters

Sharing of functional units inside a processor by two applications can lead to to information leaks and micro-architectural side-channel attacks. Meanwhile, processors now commonly come with hardware performance counters which can count a variety of micro-architectural events, ranging from cache behavior to floating point unit usage. In this paper we propose that the hardware performance counters can be leveraged by the operating system's scheduler to predict the upcoming program phases of the applications running on the system. By detecting and predicting program phases, the scheduler can make sure that programs in the same program phase, i.e. using same type of functional unit, are not scheduled on the same processor core, thus helping to mitigate potential side-channel attacks.