- Main point: taint tracjing can be implemented effieciently on Android
- problems motivate: Protecting user privacy on Smartphones
How things get tainted
- sources: low-bandwidth sensors, high-banwidth sensors, informat
- Unix is a moving target
- Multics is generally considered the kitchen-sink os.
- Unix is considered the efficient OS that culled the good ideas, left out the bad ones.
- What is the unifying abstraction in Unix?
- What is the V Kernel?
- OS structured around message-based IPC for diskless workstations and large file servers.
- that diskless workstations do not suffer significant penalty for remote access
- the general
1. VMM in VAX/VMS
- VAX: Virtual Address Extension
- VMS: Virtual Memory System
- UNIX was ported to the VAX, hence VAX-UNIX became a popular research platform
- de-facto VM system for Unix as well
- four reg
1. Virtual Machine
Virtual Machine Monitors
- Type I VMM runs on the raw hardware
- Type II VMM runs hosted on another OS
- Conceived by IBM in the late 1960s, used for OS debugging, time sharing, supporting multiple OS's
- OS de
- How is transparency achieved?
- distribution and replication
- every user has at least two inboxes
- registries unit of distribution, replication
- no server contains all registries
- each registry is re
- Design vs. implementation
- Performance evaluation
* Centralized Design: simpler; consume too much memory
- a single OS module, abstraction
- communication via messages
- distributed among Cm nodes fo
- All OS services operate in kernel space
- Hard to extend for special applications
- Too heavy-weight for special applications
- Minimalist approach
- IPC, VM, thread scheduling