Hello everyone I am working on using systemtap for probing user space applications running on some remote machine. For achieving this task I am performing the following steps:
1. In my development machine, I have the linux kernel version same as the kernel version of the deployed remote machine. 2. I am generating the module file from the script which is having the probing details as well as the handlers for those probe points ( for the user space process running on the remote machine) on the development machine using the stap -k -p4 -r /lib/modules/kernel-version/build/ process.stp -c process_name. 3. Then on the remote machine I copied the uprobes.ko as well as the stap_xxxx.ko file generated having the details of the probe point. 4. First I am inserting the uprobes.ko module on remote machine. 5. Then,I am running the staprun -v -v -u stap_xxxx.ko -c process_name. Everything is working very fine, except the probing result output is not coming to the standard output. Even the module is itself removed by the staprun program when the program gets over. I looked into the staprun and stapio code, what I get is that it is using the debugfs and relayfs concepts for transferring the data from the kernel space to user space.Can somebody please help me out. I think the problem is in this transfer of data only from the kernel space to userspace. Can I transfer the probing output to the dmesg log?
