Re: Pan crashing in libgnuregex after -pthread switchover

Dag-Erling Smørgrav wrote:

>Jason Andresen <jandrese_at_mitre.org> writes:
>  
>
>>It seems to me that every libpthread.so.1 maps to a libc_r.so.5, but
>>when I actually run pan it still crashes and shows libpthread in the
>>backtrace.  Does anybody have a clue as to what is going on here?
>>    
>>
>
>gdb doesn't know about libmap.conf, so the backtrace is wrong.
>
>DES
>  
>
My understanding is that the dynamic linker fills a link_map (see 
sys/link_elf.h) structure with the mapped name, and gdb grovels for this 
in the core: it should work correctly on a corefile. Sounds more like 
libpthread and libc_r are both in-process to me.

Jason, try "i sh" from gdb to see what libraries were loaded in the 
process when it dumped.

Interestingly, from the stack trace, frame 3 shows "re_search" calling 
into the main application, not a shared library, at the "??" bit (the 
instruction pointer is in the wrong range for a shared library): It 
sounds like the application is implementing a function that should 
probably be resolved from a shared library, and the linker is binding 
the application version instead of the standard one: that might be an issue.

(I don't think the regex library ever uses callbacks, which would be the 
only other reason I can think it'd happen)

The sysutils/pstack has a good chance of finding the name of the "??" 
function if you want to run that on the corefile: it takes the dynamic 
exported functions into account as well as the debug information when 
finding function names.

HTH,
Peter.