From: Prasanna S Panchamukhi <prasanna@in...> - 2005-04-04 06:21:58
> I have been trying to get dprobes working to trace some kernel functions
> with LTT.
> I am using SuSE 9.2 Professional, but it does not seem to have the LTT
> patches against the kernel. So I pulled a kernel from SLES9, and
> compiled with all the appropriate switches in the .config and changes
> dprobes requires per the README.dpcc. I can take an LTT trace with the
> default trace points. Since it uses dprobes under the hood, it is safe
> to assume dprobes is working in some fashion?
> Compiling and running with the SLES9 kernel on SuSE 9.2 seems OK, but
> when I compile something like tut14.dpc or the examples out of the
> dprobes.lang man page, I just get a segmentation violation when it reads
> the symbol table in /usr/src/linux/vmlinux.
> dprobes itself seems OK, "dprobes -q -a -x" returns "No information
> returned." as it should.
> Please advise what to check to get dprobes working with custom probes. I
> really want to do what is close to the long example 6 back in dprobes.lang.
> Is there a beginners guide to writeing and troubleshooting rpn files?
> Most of the stuff I have found is a high level overview of dprobes
> architecture, or really detailed advanced features, not much in between.
The man pages will help you a lot to understand and use dprobes.
Can you tell what command (with options)did you use to insert probe that failed.
If dprobes is used with correct options it works fine.
Prasanna S Panchamukhi
Linux Technology Center
India Software Labs, IBM Bangalore