[gentoo-user] Re: How to get a backtrace from a core dump?

[Nikos Chantziaras]

On 01/28/2010 01:22 AM, meino.cramer@×××.de wrote:
> Nikos Chantziaras<realnc@×××××.de>  [10-01-27 17:09]:
>> I need to get a backtrace from a core dump file.  I followed the
>> instructions here:
>>
>>    http://www.gentoo.org/proj/en/qa/backtraces.xml
>>
>> I added -g to CFLAGS and splitdebug to FEATURES and built the
>> application with those new setting (that would be media-sound/lmms in
>> this case.)  I then did "ulimit -c unlimited" and started the
>> application from that shell.  I reproduced the crash and a core file
>> was successfully produced.  But, when trying to get a backtrace, I get:
>>
>> --------
>> gdb --core core --batch --quiet -ex "thread apply all bt full" -ex
>> "quit"
>> [New Thread 3575]
>> [New Thread 3573]
>> [New Thread 3577]
>> Core was generated by `./lmms'.
>> Program terminated with signal 11, Segmentation fault.
>> #0  0x0000003007b79985 in ?? ()
>>
>> Thread 4 (Thread 3577):
>> #0  0x0000003000c0e07d in ?? ()
>> No symbol table info available.
>>
>> Thread 3 (Thread 3573):
>> #0  0x0000003000c0b1fc in ?? ()
>> No symbol table info available.
>>
>> Thread 2 (Thread 3575):
>> #0  0x000000306d44feac in ?? ()
>> No symbol table info available.
>>
>> Thread 1 (Thread 3571):
>> #0  0x0000003007b79985 in ?? ()
>> No symbol table info available.
>> --------
>>
>> Then I re-emerged the application, canceled the emerge and did a manual
>> "make" in /var/tmp/portage so I get the unstripped lmms executable.
>> However, same thing as above happens.  What am I missing?
>>
>
> Hi,
>
> you need to build all librarys, which are linked to that application
> as with debug option, too.

I'm only interested at where in the application the crash happens so I 
don't need details about the libs in the backtrace.