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Troubleshooting Grinder logging failure

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Stephen Fewer edited this page Feb 28, 2014 · 5 revisions

A Grinder Node may fail to log a testcase for several reasons.

  • Hooking the JavaScript side into grinder_logger.dll fail's because public symbols aren't available, so resolving the location for the JavaScript StrToDbl function cant work as expected. The is sometimes an issue for Internet Explorer after patch Tuesday as the IE public symbols may take a few weeks to be published. You would see an error in the console if this happens.

  • Solution: Either wait for the public symbols to be made available or manually edit the hooking code in .\node\browser\BROWSER.rb to hardcode the location of JavaScript StrToDbl.

  • The grinder_logger.dll failed to inject into the browser process. This is unlikely and there will be an error in the console.

  • Solution: Ensure grinder_logger.dll is present on your system. The error message will provide details as to where the dll should be placed. Disable any Antivirus or HIPS which may prevent a dll being injected.

  • The HTML/JS fuzzer which is generating the test-cases and logging them isn't using the LOGGER class correctly. You have to call "logger.starting();" and "logger.finished();" for everything to work smoothly (See .\node\fuzzer\SimpleExample.html).

  • Solution: See SimpleExample.html for how to use LOGGER correctly and do this in your own fuzzer.

  • For browsers like Chrome or IE which have a broker process and child processes, if the crash happens in the broker process, no log file can be generated because this process isn't the one which is logging the testcase.

  • Solution: None.

  • The directory where the logger tries to write the log files must have suitable permissions so the process where grinder_logger.dll is working can actually create and write files. Specified in the config file, the $logger_dir location can normally be left to its default ('C:\Users\%USERNAME%\AppData\Local\Temp\Low\').

  • Solution: Either use the default directory specified above or modify the directory permissions so the browser process (which may be running with Low or Untrusted integrity) can write to this directory.

  • When a browser gets updated, the hooking stubs may need to be updated in order to correctly read out the StrToDbl parameter so that it can be passed back up to grinder_logger.dll (each browser has a class in .\node\browser\ which does the hooking). The browser will crash every time it is run and the crash will be in an allocation around the location described in the console message "Hooked JavaScript parseFloat() to grinder_logger.dll via proxy @ 0xNNNNNNNN"

  • Solution: Open an Issue so the hooking stub can be modified to work on the new browser.

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