Protections

Regions can be created with a set of access rights or protections.

The virtual pages that constitute a memory region can be protected against certain types of accesses. Protection modes are machine-dependent, but most architectures provide at least read-write and read-only. Any attempt to violate the protections triggers a page fault. The application can provide its own page fault handler.

Protections can be set independently for sub-regions inside a source region. In this case, the source region is split into several new regions. Similarly, when two contiguous regions get the same protections, they are merged into one region. The programmer is warned that abusing this module could result in consuming too many of the microkernel resources associated with regions.