Re: GDB, pthreads, and kernel threads

John Clark
2005-05-18T16:02:39Z

Nix wrote:

>On 18 May 2005, John Clark announced authoritatively:
>
>
>>Most of my work has been in the kernel and I had not paid attention to
>>user 'threads'. However, I have at the moment to a need to debug a
>>user 'pthread' based applicaiton, that I may want to move into the kernel.
>>
>>However, I can't seem to figure out how to get GDB to debug my user
>>pthreads app. What is the correct setup to debug pthreads based applications
>>now that it seems that pthreads implementation generates processes/threads
>>in the kernel.
>>
>>
>
>Use a recent GDB (>=6.2) and things should just work. (At least, they do
>for me.)
>
>

I built the latest GDB-6.3, as well as rebuilt glibc-2.3.5, and now when
I step through the
main code line, which creates the tasks (I'm using the pthreads.c from
the GDB testsuite), I do
not getany output from:

info threads

When I set a break point on the entry point of one of the
soon-to-be-created threads,
I get a diagnostic message:

Program terminated with signal SIGTRAP, Trace/Breakpoint trap.
The program no longer exists.

On the machine being used to debug the kernel is: 2.6.5.

Is there any problems with that kernel, or should I upgrade to a more
recent vintage
version?

Thanks
John Clark