Custom loader for STAP

Arkady arkady.miasnikov@gmail.com
Wed May 24 11:14:00 GMT 2017


Hi,

I am trying to insmod the STAP driver without the staprun. I have
figured out how to do that by writing to the .cmd file - Python script
is here https://github.com/larytet/YALAS/blob/master/generate_messages.py

The approach works fine with the modern (?) kernels. In the CentOS 6.9
folder /sys/kernel/debug/systemtap does not appear after I insmod the
module. Back to the strace and I see this in CentOS 6.9
https://github.com/larytet/YALAS/blob/master/strace.log#L314

I am looking in the staprun source code functions
init_staprun()->insert_stap_module()->insert_module()
I do not see anything special.

After I use staprun once I can insmod manually - the .cmd folder is
getting created. Next boot changes something in the debugfs and I have
to execute staprun again.

There is a "secret" ingredient, but I am missing it.

I will appreciate any tip.

Thanks



More information about the Systemtap mailing list