Re: howto debug libthread_db

Carmelo Amoroso
2006-09-26T14:24:04Z

Daniel Jacobowitz wrote:
> On Tue, Sep 26, 2006 at 04:06:57PM +0200, Carmelo Amoroso wrote:
>> Hi All,
>> I'm trying to debug a simple multithread application on a remote target,
>> and I like to debug the libthread_db itself... is it possible to do it?
>> is it possible to set some breakpoints and stepping through?
>> Is there anyone already played with it?
>>
>> I tried to use symbol-file to gdb client, and I successfully added a
>> breakpoint, but I cannot reach it after I connected to the target and
>> issued 'continue'.
>>
>> Any help will be appreciated
>
> Sorry, but you need to be more precise. What exactly did you do - the
> entire GDB session? What didn't work? Do you really mean
> libthread_db, or do you mean libpthread?
>
Yes, libthread_db exactly... I got a SIGSEV due to a unaligned access
just after exiting from td_ta_map_lwp2thr function, and I never return
to the caller (iterate_thread_list).
I added a lot of printf into my own libthread_db and I can track all the
flow until the end td_ta_map_lwp2thr... and then nothing

The thread_db library belongs to the uClibc-nptl port on SH.
gdbserver has been linked against uClibc-nptl port and works
fine for non multithread example

Carmelo