Created attachment 32056 [details]
example

gdb output:

Program received signal SIGSEGV, Segmentation fault.
0xb78fa084 in vbo_VertexAttrib4fvARB ()
   from /usr/lib/xorg/modules/dri/libdricore.so

The test program seems to work OK here.  Which driver are you using?

intel

It works OK with the Intel driver here for me.  I don't know what to suggest.

Please provide the information requested at: http://intellinuxgraphics.org/how_to_report_bug.html  At the very least, a full backtrace from the crash and the output of glxinfo would be helpful.

video card: Intel Corporation Mobile 945GM
uname -srm: Linux 2.6.31-ARCH i686
distribution: Arch Linux
xf86-video-intel-2.9.1-1, xorg-server-1.7.3.901-1, mesa-7.6-2, libdrm-2.4.15-1
machine: Toshiba Satellite A100-36
backtrace:
#0  0xb78fa084 in vbo_VertexAttrib4fvARB ()
   from /usr/lib/xorg/modules/dri/libdricore.so
#1  0xb78ec8d1 in neutral_VertexAttrib4fvARB ()
   from /usr/lib/xorg/modules/dri/libdricore.so
#2  0x080488b7 in main (argc=1, argv=0xbffff9d4)
    at main.c:22

I have the same problem. I'm also using Arch Linux but with a Radeon R300 card.
My computer was up for 2 weeks when new versions of ati-dri(7.6.1-1), libgl(7.6.1-1), libdrm(2.4.17-2), mesa(7.6.1-1), xf86-video-ati(6.12.4-2) where uploaded in the repositories, so i installed them and rebooted but i noticed significant performance loss in every "graphic" applications.
I could not play flash video in fullscreen. An emulator that was running perfectly before was now running at 1.5fps. Glxgears was having poor results and eating 50% of my CPU.
So i decided to downgrade all those packages (i'm now using ati-dri(7.6-2), libgl(7.6-2), libdrm(2.4.16-1), mesa(7.6-2), xf86-video-ati(6.12.99.git20091014-1)),  and now, i can play flash videos again but everytime i try to launch an OpenGL application (glxgears, the emulator, or any other app, including Michael Ivko's example) the application segfault instantly with the same error.

$ glxgears
Segmentation Fault (core dumped)
$ gdb glxgears glxgears.core 
(...)
Core was generated by `glxgears'.
Program terminated with signal 11, Segmentation fault.
#0  0xb72bc084 in vbo_VertexAttrib4fvARB () from /usr/lib/xorg/modules/dri/libdricore.so
(gdb) bt full
#0  0xb72bc084 in vbo_VertexAttrib4fvARB () from /usr/lib/xorg/modules/dri/libdricore.so
No symbol table info available.
#1  0xb72ae8d1 in neutral_VertexAttrib4fvARB () from /usr/lib/xorg/modules/dri/libdricore.so
No symbol table info available.
#2  0x0804a275 in ?? ()
No symbol table info available.
#3  0x00000001 in ?? ()
No symbol table info available.
#4  0x00001300 in ?? ()
No symbol table info available.
#5  0x0804b220 in ?? ()
No symbol table info available.
#6  0xbf9aeefc in ?? ()
No symbol table info available.
#7  0xbf9aeef8 in ?? ()
No symbol table info available.
#8  0x00000000 in ?? ()
No symbol table info available.

However, when i launch the same applications as root, they work perfectly.
I am not sure if this is a really a Mesa-related bug... I posted a message on the official archlinux forum, but so far, no one answered me.

Can you find out which package provides libdricore.so?  I don't have such file on my debian system.

$ pacman -Ql | grep libdricore
libgl /usr/lib/xorg/modules/dri/libdricore.so

http://www.archlinux.org/packages/extra/i686/libgl/

I found out using strace that /dev/dri/card0 was not accessible...
I don't really understand where this problem come from since i specified "Mode 0666" in my xorg.conf's DRI section...

I don't know why the permission issue causes the segfault on Arch.  I tried to

$ chmod 000 /dev/dri/card0

and all GL applications fall back to software rasterizer (swrast_dri.so) just fine.  And when I further removed swrast_dri.so, they fall back to indirect rendering.

Maybe it is some misconfiguration or mismatched library versions in the distro that cause the fallback path to crash.  But that would require more info to confirm.

Inclusion of user into the group video, which owns /dev/dri/card0, resolves the issue.

It seems the issue has resolved.  I am closing this bug as NOTABUG.