Microsoft Technology Licensing, LLC

Robert McNeill Norton-wright

David Thomas Chisnall

Nathaniel Wesley Filardo

Hongyan Xia

A hardware revocation engine for invalidating a pointer, that refers to a deallocated object, from memory in a memory constrained system. The hardware revocation engine has a revocation pipeline coupled to a pipeline of a main processor of the memory constrained system. The revocation pipeline shares access to memory with the main pipeline, the revocation pipeline comprising at least a first stage and a subsequent second stage. In a first cycle of the revocation pipeline, the first stage of the revocation pipeline loads a first pointer-sized value from the memory. In a second cycle: the second stage checks whether the first loaded pointer-sized value is a pointer referring to deallocated memory. In a third cycle: in response to the outcome of the check indicating that the first loaded pointer-sized value is a pointer referring to deallocated memory, the first stage invalidates the first pointer-sized value.

Hardware revocation engine for temporal memory safety

In examples there is a computing device comprising a processor, the processor having a memory management unit. The computing device also has a memory that stores instructions that, when executed by the processor, cause the memory management unit to receive a memory access instruction comprising a virtual memory address; translate the virtual memory address to a physical memory address of the memory, and obtain permission information associated with the physical memory address. Responsive to the permission information indicating that metadata is permitted to be associated with the physical memory address, a check is made of a metadata summary table stored in the physical memory to check whether metadata is compatible with the physical memory address. Responsive to the check being unsuccessful, a trap is sent to system software of the computing device in order to trigger dynamic allocation of physical memory for storing metadata associated with the physical memory address.

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Cambridge, United Kingdom

Robert McNeill Norton-wright