Security Now 237

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Security Now
Episode 237

Security Now 237: The Power Of Pointers

News & Errata

04:36 - 06:11

  • Adobe Reader has been updated to fix multiple security flaws

06:12 - 08:17

  • Google Chrome has been updated to fix multiple security flaws

08:18 - 12:10

  • Open Office has been updated to fix multiple security flaws

12:11 - 19:44

  • A Pennsylvania high school district has been spying on its students at home, using school-issued MacBooks with a webcam
  • They are being sued

Spinrite Story

19:45 - 23:56 Jared Shockley (Bellevue, Washington)

A listener tried to fix his hard drive with Spinrite but it didnt work, it did however discover a problem with the RAID controller. He later on used it to fix a different drive.

The Power Of Pointers

27:45 - 52:26

  • One approach to scan through memory would be to have successive operations load the next part of memory and read it but this would take a long time
  • Another approach is to have the program modify itself which becomes messy quickly
  • So what the original architects of these early machines decided is instead of the instruction, like said load 100, instead of that instruction specifying what to load, the instruction would have an option of specifying the location that contains the address of what to load.
  • These early computers used one more bit, that is, so there was an opcode of four bits, and then for example another bit right next to it called the "indirection bit."
  • And then the rest of the bits that were remaining specified the location.
  • That is to say that the designers of these machines took one more bit for this purpose from the instruction.
  • So what this meant was, if it was a so-called, for example,
  • an indirect load, if it said "load indirect 100," what that meant was the computer would get the contents of location 100 and treat the contents as the address to load the data.
  • In other words, that the location, the contents of location 100 was a pointer to the data that should be loaded.


Go To Meeting

Production Information

  • Edited by: Tony
  • Notes:
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