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semanticssystemtap

Systemtap libdwfl error on Linux

I am tying to work/setup the Systemtap tool for profiling OS procesess, on a Virtual Linux. I am using VirtualBox to run the image. Via 

rpm -q kernel

and 

cat /proc/version

The version obtained is:

Linux version 2.6.32-5-686 (Debian 2.6.32-48squeeze4)

I have correctly downloaded and installed the tool and wrote a simple program (.stp). However I keep getting the same error, which I have searched information in many places without success:

After executing:

sudo stap my_profiler.stp

I get:

semantic error: libdwfl failure (all kernel modules found): no error
Pass 3: translation failed. Try again with another '--vp 001' option.

According to https://sourceware.org/systemtap/SystemTap_Beginners_Guide/errors.html

⁠semantic error: libdwfl failure There was a problem processing the debugging information. In most cases, this error results from the installation of a kernel-debuginfo package whose version does not match the probed kernel exactly. The installed kernel-debuginfo package itself may have some consistency or correctness problems.

I have found no relevant information on the "kernel-debuginfo" package. I have also tried the verbose option without benefit. I even tried with an old Snapshot of the VM. Any ideas?

The code of the .stp program I ran:

probe timer.profile{
    printf("Process: %s\n", execname())
    printf("Process ID: %d\n", pid())
}
Solution

  • Found the problem!!!! It seemed that I was using the wrong version of the Linux Kernel. I was using the default kernel supplied by the version I wrote in the question. It seems that that version (the 2.6.32-5-686 one) has problems with the debug-info so all I did was try the same with another version (the Linux version 3.9.6 with gcc version 4.7.2 Debian 4.7.2-5) and it worked without trouble :)