Segfault with gcc4 and LD_PRELOAD (was: Need help to fill bug report (gcc 4.0.1 and above))

[Mathieu Malaterre]

Hi,

	I am very sorry to insist but I would really appreciate if someone 
could shed some light on my current problem. I really don't see why my 
code is only segfaulting when using gcc4.0.1 (and above).

Description:
I am running a program that is outputing a file. The very same program 
when run with LD_PRELOAD set to libGL.so, is segfaulting.

The backtrace can be found here:
http://www.creatis.insa-lyon.fr/~malaterre/gcc/gdb.log


And I ran also strace with/ and without LD_PRELOAD set:

$ export LD_PRELOAD=/usr/X11R6/lib/libGL.so
$ strace /home/mathieu/Dashboards/MyTests/VTK-gcc4/bin/vtkParseOGLExt 
/home/mathieu/Dashboards/MyTests/VTK-gcc4/Rendering 
/home/mathieu/Dashboards/MyTests/ParaView/VTK/Utilities/ParseOGLExt/headers/glext.h 
/home/mathieu/Dashboards/MyTests/ParaView/VTK/Utilities/ParseOGLExt/headers/glxext.h 
/home/mathieu/Dashboards/MyTests/ParaView/VTK/Utilities/ParseOGLExt/headers/wglext.h 
 >& /tmp/log1

$ unset LD_PRELOAD
$ strace /home/mathieu/Dashboards/MyTests/VTK-gcc4/bin/vtkParseOGLExt 
/home/mathieu/Dashboards/MyTests/VTK-gcc4/Rendering 
/home/mathieu/Dashboards/MyTests/ParaView/VTK/Utilities/ParseOGLExt/headers/glext.h 
/home/mathieu/Dashboards/MyTests/ParaView/VTK/Utilities/ParseOGLExt/headers/glxext.h 
/home/mathieu/Dashboards/MyTests/ParaView/VTK/Utilities/ParseOGLExt/headers/wglext.h 
 >& /tmp/log2

Those logs files can be found here:
http://www.creatis.insa-lyon.fr/~malaterre/gcc/log1
and
http://www.creatis.insa-lyon.fr/~malaterre/gcc/log2

-----------------------------------------------------------------------------------

Anyone interested in reproducing the bug need a debian testing with gcc4:

(assuming gcc points to gcc 4.0.1)
$ sudo apt-get install cmake
$ cvs -d:pserver:anoncvs@vtk.org:2401/cvsroot/VTK login
$ cvs -d:pserver:anoncvs@vtk.org:2401/cvsroot/VTK co VTK
$ mkdir VTK-gcc
$ cd VTK-gcc
$ cmake ../VTK
$ make
...

Thanks for any advice on tracking down this bug,
Mathieu

Mathieu Malaterre wrote:
> Hello,
> 
>     I have currently a reproducable seg fault from an exe produced by 
> gcc 4.0.1 (*). It does not appear using gcc 2.95, 3.2, 3.3, 3.4.
> If I run it throught gdb I get:
> 
> 0x402814b1 in __gnu_cxx::__pool<true>::_M_reclaim_block () from 
> /usr/lib/libstdc++.so.6
> (gdb) bt
> #0  0x402814b1 in __gnu_cxx::__pool<true>::_M_reclaim_block () from 
> /usr/lib/libstdc++.so.6
> #1  0x08062907 in 
> __gnu_cxx::__mt_alloc<std::_Rb_tree_node<std::pair<std::string, 
> std::string> >, __gnu_cxx::__common_pool_policy<__gnu_cxx::__pool, true> 
>  >::deallocate (this=0x806d888, __p=0x8221f10, __n=1) at mt_allocator.h:746
> ...
> 
> and the structure being:
> static std::set< std::pair< std::string, std::string > > foo;
> 
> 
> 
> If I try to run through valgrind 3.0 everything is fine, and it produce 
> correct output.
> 
> Any advice on a way to narrow down a simple testcase, right now it would 
> require building VTK(**)
> 
> Thanks for any help,
> Mathieu
> (*) debian testing. but I can also reproduce with gcc 4.1.0 20050726 
> (gcc-snapshot)
> (**) http://vtk.org
>