5 ms·

Do you have any insight for what the security implications would be (if any) for an OS like this?

• ChuckMcM 13y ago
  Security is pretty solid in terms of things like libraries where every library entry point is a call to a particular address. That eliminates a number of dynamic linking vulnerabilities. Every process can have its own memory prefix (rather than everybody thinking they are at 0) which gives better visibility to memory incursion and excursions. Kernel space is distinct address from non-kernel space etc (this got really challenging on non-64 bit machines at the end of their reign) Is it a net win? I think so, there would clearly be new ways in which it would be a challenge but you can make some useful reasoning about validity of addresses with a numerical compare that isn't nearly as efficient in a variable address OS.
  • thwarted 13y ago
    Every process can have its own memory prefix (rather than everybody thinking they are at 0) The way you describe this, it sounds like segmentation. Wouldn't the value of each processing having a memory prefix be that all its internal data would think they have an offset of zero?
    • ChuckMcM 13y ago
      I was thinking more along the lines of being able to do binary arithmetic on pointers for validation, ptr & prefixmask != prefix means its out of range. That is a pretty cheap optimization, VMS and SunOS both used that sort of check in kernel space to insure that the kernel wasn't about to dereference a pointer outside of kernel space (potentially in some random process).
• jevinskie 13y ago
  You could use something like Native Client to run multiple protected "processes" in a single address space.