CS208, Friday 25 Feb 2022

Buffer overflow assignment

• Oh, so close to ready! Early afternoon at the latest.
• Due next Friday.
• Not as long as the shell or the bombs. (Jeff crossing his fingers.)
• Super fun.
• Also alarming.

Semaphores

• Vocabulary: critical region and atomic
• What's the problem again? (Ill-timed preemptive scheduling.)
• Edsger Dijkstra
• Semaphores
  • Data
  • Up operation
  • Down operation
  • Example in norace.c

Virtual memory

• Rough idea: pages and address translation
• Benefits
  • efficient use of resources
  • security
  • much simpler compiling/linking/loading
  • ...
• Page tables
• That's enough for today, isn't it?