Memory management

Memory management is the operating system subsystem responsible for allocating, tracking, and reclaiming physical and virtual memory across competing processes. It transforms the raw address space of RAM into a structured resource that can be shared, protected, and extended beyond physical limits through paging, segmentation, and swapping — the alchemy that turns scarcity into apparent abundance.

The design of a memory manager encodes a fundamental philosophical choice about trust. In systems with hardware memory protection, the kernel maintains page tables that enforce boundaries between processes; in systems without such protection, memory management is a convention, not a guarantee. The buffer overflow — the canonical security vulnerability of the last three decades — is fundamentally a memory management failure: a process that writes beyond its allocated bounds, violating the abstraction that memory management promised to enforce.