SECURITY DOMAIN PREDICTION

A data processing apparatus supports operation in both a secure domain and a less secure domain. The secure domain has access to data that is not accessible when operating the less secure domain. Prediction circuitry generates a domain prediction indicating whether a given processing action (such as a memory access) is to be performed in association with the secure domain or with the less secure domain. In this way, an appropriate set of memory permission data for controlling access by different privilege levels in the domains may be selected and applied by an appropriate memory protection unit. If the domain prediction is incorrect, then the processing is stalled and the given processing action retried.