How to get correct filename in probe.execve

[Arkady]

Hello,

I am doing the following

stap -e 'probe syscall.execve { { printf("exec %s\n", filename) } }'

My platform is

Linux ubuntu 4.4.0-59-generic #80-Ubuntu SMP Fri Jan 6 17:47:47 UTC
2017 x86_64 x86_64 x86_64 GNU/Linux

I am running a Python script called echo.py which contains two lines:

import os
os.system("ls /tmp")

I am doing something like python ./echo.py

In the exec probe output I am getting

exec "/usr/bin/python"
exec 00007fce05d05177

Where does 00007fce05d05177 come from?

Thanks