giedrius@giedrius-laptop:~$ sudo gdb /usr/bin/Xorg
[sudo] password for giedrius:
GNU gdb 6.7.1-debian
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This GDB was configured as "i486-linux-gnu"...
Using host libthread_db library "/lib/tls/i686/cmov/libthread_db.so.1".
(gdb) attach 6284
Attaching to program: /usr/bin/Xorg, process 6284
Reading symbols from /lib/tls/i686/cmov/libdl.so.2...done.
Loaded symbols for /lib/tls/i686/cmov/libdl.so.2
Reading symbols from /usr/lib/libXfont.so.1...done.
Loaded symbols for /usr/lib/libXfont.so.1
Reading symbols from /usr/lib/libXau.so.6...done.
Loaded symbols for /usr/lib/libXau.so.6
Reading symbols from /usr/lib/libfontenc.so.1...done.
Loaded symbols for /usr/lib/libfontenc.so.1
Reading symbols from /usr/lib/libpixman-1.so.0...done.
Loaded symbols for /usr/lib/libpixman-1.so.0
Reading symbols from /usr/lib/libhal.so.1...done.
Loaded symbols for /usr/lib/libhal.so.1
Reading symbols from /usr/lib/libdbus-1.so.3...done.
Loaded symbols for /usr/lib/libdbus-1.so.3
Reading symbols from /usr/lib/libXdmcp.so.6...done.
Loaded symbols for /usr/lib/libXdmcp.so.6
Reading symbols from /lib/tls/i686/cmov/libm.so.6...done.
Loaded symbols for /lib/tls/i686/cmov/libm.so.6
Reading symbols from /lib/tls/i686/cmov/librt.so.1...done.
Loaded symbols for /lib/tls/i686/cmov/librt.so.1
Reading symbols from /lib/libgcc_s.so.1...done.
Loaded symbols for /lib/libgcc_s.so.1
Reading symbols from /lib/tls/i686/cmov/libc.so.6...done.
Loaded symbols for /lib/tls/i686/cmov/libc.so.6
Reading symbols from /lib/ld-linux.so.2...done.
Loaded symbols for /lib/ld-linux.so.2
Reading symbols from /usr/lib/libfreetype.so.6...done.
Loaded symbols for /usr/lib/libfreetype.so.6
Reading symbols from /usr/lib/libz.so.1...done.
Loaded symbols for /usr/lib/libz.so.1
Reading symbols from /lib/tls/i686/cmov/libpthread.so.0...done.
[Thread debugging using libthread_db enabled]
[New Thread 0xb7c6aa30 (LWP 6284)]
Loaded symbols for /lib/tls/i686/cmov/libpthread.so.0
Reading symbols from /usr/lib/xorg/modules/libpcidata.so...Reading symbols from /usr/lib/debug/usr/lib/xorg/modules/libpcidata.so...done.
done.
Loaded symbols for /usr/lib/xorg/modules//libpcidata.so
Reading symbols from /usr/lib/xorg/modules/extensions/libextmod.so...Reading symbols from /usr/lib/debug/usr/lib/xorg/modules/extensions/libextmod.so...done.
done.
Loaded symbols for /usr/lib/xorg/modules/extensions//libextmod.so
Reading symbols from /usr/lib/xorg/modules/extensions/libdbe.so...Reading symbols from /usr/lib/debug/usr/lib/xorg/modules/extensions/libdbe.so...done.
done.
Loaded symbols for /usr/lib/xorg/modules/extensions//libdbe.so
Reading symbols from /usr/lib/xorg/modules/extensions/libglx.so...Reading symbols from /usr/lib/debug/usr/lib/xorg/modules/extensions/libglx.so...done.
done.
Loaded symbols for /usr/lib/xorg/modules/extensions//libglx.so
Reading symbols from /usr/lib/xorg/modules/fonts/libfreetype.so...Reading symbols from /usr/lib/debug/usr/lib/xorg/modules/fonts/libfreetype.so...done.
done.
Loaded symbols for /usr/lib/xorg/modules//fonts/libfreetype.so
Reading symbols from /usr/lib/xorg/modules/extensions/librecord.so...Reading symbols from /usr/lib/debug/usr/lib/xorg/modules/extensions/librecord.so...done.
done.
Loaded symbols for /usr/lib/xorg/modules/extensions//librecord.so
Reading symbols from /usr/lib/xorg/modules/extensions/libdri.so...Reading symbols from /usr/lib/debug/usr/lib/xorg/modules/extensions/libdri.so...done.
done.
Loaded symbols for /usr/lib/xorg/modules/extensions//libdri.so
Reading symbols from /usr/lib/libdrm.so.2...done.
Loaded symbols for /usr/lib/libdrm.so.2
Reading symbols from /usr/lib/xorg/modules/drivers/intel_drv.so...done.
Loaded symbols for /usr/lib/xorg/modules/drivers//intel_drv.so
Reading symbols from /usr/lib/xorg/modules/input/mouse_drv.so...done.
Loaded symbols for /usr/lib/xorg/modules/input//mouse_drv.so
Reading symbols from /usr/lib/xorg/modules/input/kbd_drv.so...done.
Loaded symbols for /usr/lib/xorg/modules/input//kbd_drv.so
Reading symbols from /usr/lib/xorg/modules/libint10.so...Reading symbols from /usr/lib/debug/usr/lib/xorg/modules/libint10.so...done.
done.
Loaded symbols for /usr/lib/xorg/modules//libint10.so
Reading symbols from /usr/lib/xorg/modules/libvbe.so...Reading symbols from /usr/lib/debug/usr/lib/xorg/modules/libvbe.so...done.
done.
Loaded symbols for /usr/lib/xorg/modules//libvbe.so
Reading symbols from /usr/lib/xorg/modules/libvgahw.so...Reading symbols from /usr/lib/debug/usr/lib/xorg/modules/libvgahw.so...done.
done.
Loaded symbols for /usr/lib/xorg/modules//libvgahw.so
Reading symbols from /usr/lib/xorg/modules/libfb.so...Reading symbols from /usr/lib/debug/usr/lib/xorg/modules/libfb.so...done.
done.
Loaded symbols for /usr/lib/xorg/modules//libfb.so
Reading symbols from /usr/lib/xorg/modules/libexa.so...Reading symbols from /usr/lib/debug/usr/lib/xorg/modules/libexa.so...done.
done.
Loaded symbols for /usr/lib/xorg/modules//libexa.so
Reading symbols from /usr/lib/dri/i915_dri.so...done.
Loaded symbols for /usr/lib/dri/i915_dri.so
Reading symbols from /usr/lib/libexpat.so.1...done.
Loaded symbols for /usr/lib/libexpat.so.1
0xb7f8e410 in __kernel_vsyscall ()
(gdb) cont
Continuing.

Program received signal SIGINT, Interrupt.
[Switching to Thread 0xb7c6aa30 (LWP 6284)]
0xb7f8e410 in __kernel_vsyscall ()
(gdb) backtrace full
#0  0xb7f8e410 in __kernel_vsyscall ()
No symbol table info available.
#1  0xb7dd7d89 in ioctl () from /lib/tls/i686/cmov/libc.so.6
No symbol table info available.
#2  0xb7b71a8b in drmCommandWrite () from /usr/lib/libdrm.so.2
No symbol table info available.
#3  0xa76e7af8 in intelWaitIrq () from /usr/lib/dri/i915_dri.so
No symbol table info available.
#4  0xa76e8a05 in intelWaitForIdle () from /usr/lib/dri/i915_dri.so
No symbol table info available.
#5  0xa76e8a4a in intelFinish () from /usr/lib/dri/i915_dri.so
No symbol table info available.
#6  0xa7710198 in _mesa_Finish () from /usr/lib/dri/i915_dri.so
No symbol table info available.
#7  0xb7bbb7fa in __glXDisp_Finish (cl=0x834ee80, pc=0x89359c0 "\217l\002")
    at ../../../GL/glx/single2.c:238
        cx = (__GLXcontext *) 0x83623a0
        client = <value optimized out>
        error = <value optimized out>
#8  0xb7b9b9a6 in __glXDispatch (client=0x863dea0)
    at ../../../GL/glx/glxext.c:561
        stuff = (xGLXSingleReq *) 0x89359c0
        opcode = 108 'l'
---Type <return> to continue, or q <return> to quit---
        proc = (__GLXdispatchSingleProcPtr) 0xb7bbb7b0 <__glXDisp_Finish>
        cl = (__GLXclientState *) 0x834ee80
        retval = 1
#9  0x081506fe in XaceCatchExtProc (client=0x863dea0) at ../../Xext/xace.c:299
        major = 143
        ext = <value optimized out>
#10 0x0808d8df in Dispatch () at ../../dix/dispatch.c:502
        result = <value optimized out>
        client = (ClientPtr) 0x863dea0
        nready = 0
        start_tick = 1760
#11 0x0807471b in main (argc=10, argv=0xbfa56734, envp=Cannot access memory at address 0x4004644d
)
    at ../../dix/main.c:452
        pScreen = <value optimized out>
        i = 1
        error = 136163204
        xauthfile = <value optimized out>
        alwaysCheckForInput = {0, 1}
(gdb)