[fpc-devel] Segmentation fault for Firebird exception insidethread

[Ludo Brands]

> 
> What happens if you comipile with -gl and  run the program 
> under GDB ? 
> can you post a backtrace ?
> Note that you may need to add a {$linklib pthread} to the 
> program source, 
> otherwise gdb may complain about missing threads support.
> 
> The backtrace will show us exactly where the error occurs (or 
> it should).
> 
> Michael.
> 

Was able to reproduce with fb 2.5 on ubuntu 11.10 64 bit. The crash happens
in the thread clean up code. Backtrace shows:
#0  0x00007ffff66b5b00 in ?? ()
#1  0x00007ffff7bc6ce3 in __nptl_deallocate_tsd ()
   from /lib/x86_64-linux-gnu/libpthread.so.0
#2  0x00007ffff7bc6f0a in start_thread ()
   from /lib/x86_64-linux-gnu/libpthread.so.0
#3  0x00007ffff76fd89d in clone () from /lib/x86_64-linux-gnu/libc.so.6
#4  0x0000000000000000 in ?? ()

Traced into __pthread_exit and the sigsegv happens in __pthread_unwind
calling _Unwind_ForcedUnwind. This is an indication of c++ exception being
not dealt with correctly and the exception (re?)raised by
_Unwind_ForcedUnwind isn't caught.

Ludo