US Patent 11182507 Domain crossing in executing instructions in computer processors

Systems, apparatuses, and methods related to securing domain crossing using domain access tables are described. For example, a computer processor can have registers configured to store locations of domain access tables respectively for predefined, non-hierarchical domains. Each respective domain access table can be pre-associated with a respective domain and can have entries configured to identify entry points of the respective domain. The processor is configured to enforce domain crossing in instruction execution using the domain access tables and to prevent arbitrary and/or unauthorized domain crossing.