Category Archives: length restrictions

Static DTrace probes for the linuxulator updated

I got a little bit of time to update my 3 year old work of adding static DTrace probes to the linuxulator.

The changes are not in HEAD, but in my linuxulator-dtrace branch. The revision to have a look at is r230910. Included are some DTrace scripts:

  • script to check internal locks
  • script to trace futexes
  • script to generate stats for DTracified linuxulator parts
  • script to check for errors:
    • emulation errors (unsupported stuff, unknown stuff, …)
    • kernel errors (resource shortage, …)
    • programming errors (errors which can happen if someone made a mistake, but should not happen)

The programming-error checks give hints about userland programming errors respectively a hint about the reason of error return values due to resource shortage or maybe a wrong combination of parameters. An example error message for this case is “Application %s issued a sysctl which failed the length restrictions.nThe length passed is %d, the min length supported is 1 and the max length supported is %d.n