Advanced Operating Systems   COMP9242 2002/S2

UNSW

Printer-Friendly Version Administration                - Notices - Course Intro - Consultations # On-line Survey (closed) - Survey Results   Work - Lectures - Milestone 0 - Project Admin - Project Spec - Project FAQ - Exam   Documentation - ASysT Lab - L4 source browser - Sulima ISA Simulator - R4x00 ISA Summary  - MIPS R4700 Reference - MIPS R4000 User Manual  - Network Driver - GT64111   Related Info - Aurema OS Prize - OS Hall of Fame   History - 2000 - 1999 - 1998   Staff - Gernot Heiser (LiC)

Hot Topics -- Cool Systems Cool System: EROS[SSF99] Idea: fast, secure, reliable OS Features: segregated capabilities, single-level store, persistence (via checkpointing), fast, mandatory access control, formal proof of confinement[SW00]. EROS is a re-design of KeyKOS[BFF$^+$92]. EROS memory and access management Clists form page table EROS access rights management Limit propagation and support revocation of rights by: ``weak capabilities'': reading/writing any cap via a weak cap makes it R/O and weak can obtain transitive read-only access indirection: Reference monitor (similar to L4 chief mediates cap transfer inserts forwarding objects to capabilities implements security policy on change of policy can revoke caps by revoking forwarding object EROS performance Note: No data on cost of indirection for MAC.