First, you can use some generic debug tools, such as GDB/KGDB. Please refer to the following Application Note:
http://www.nxp.com/assets/documents/data/en/application-notes/AN4553.pdf
Then, please just search the internet, there are many open source monitoring/debugging tools for Linux. For example, look here:
http://www.tecmint.com/command-line-tools-to-monitor-linux-performance/
Have a great day,
Artur
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