[vbox-dev] Minimalist OpenGL program crashing

Mon Nov 21 12:59:38 UTC 2016

Hello Otacílio,

21.11.2016 12:57, Otacílio wrote:
> Yes, I located the exactly line where the seg fault is raised. I did a
> full report with a description and a stacktrace. Is reported here:
> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=214396

I'm afraid that you must have misunderstood me.  I said that it was 
quite likely that this would get fixed if you were able to understand 
(and by implication explain) the problem.  By understanding though I 
specifically did not mean just pointing out the line in the code where 
the segmentation fault occurs (I saw that too when I ran the programme 
in the debugger).  I meant finding the logical flaw in the reasoning 
behind the code of which this crash is a symptom.

Feel free to open a bug in our bugtracker for this of course, but 
someone will still have to do that analysis.  As I said in my previous 
reply, it is extremely unlikely that we will have resources for this in 
the near future.

Regards,

Michael

> After debugging gdb says that the exception is raised on line 679 of file /usr/ports/emulators/virtualbox-ose-additions/work/VirtualBox-5.1.8/src/VBox/GuestHost/OpenGL/util/hash.c
>
> void *crHashtableSearch( const CRHashTable *h, unsigned long key )
> {
>     unsigned int index = crHash( key );
>     CRHashNode *temp;
> #ifdef CHROMIUM_THREADSAFE
> BUG IS HERE  =======>  crLockMutex((CRmutex *)&h->mutex);
> #endif
>     for ( temp = h->buckets[index]; temp; temp = temp->next )
>     {
>         if ( temp->key == key )
>             break;
>     }
> #ifdef CHROMIUM_THREADSAFE
>     crUnlockMutex((CRmutex *)&h->mutex);
> #endif
>     if ( !temp )
>     {
>         return NULL;
>     }
>     return temp->data;
> }
>
>
> (gdb) backtrace
> #0  check_and_init_mutex (mutex=0x20c8, m=0x7fffffffe650) at /usr/src/lib/libthr/thread/thr_mutex.c:588
> #1  0x0000000802923506 in __pthread_mutex_lock (mutex=0x20c8) at /usr/src/lib/libthr/thread/thr_mutex.c:743
> #2  0x0000000801e531f1 in crHashtableSearch (h=0x0, key=56623106) at /usr/ports/emulators/virtualbox-ose-additions/work/VirtualBox-5.1.8/src/VBox/GuestHost/OpenGL/util/hash.c:679
> #3  0x000000080088f1cb in glXMakeCurrent (dpy=0x80481f000, drawable=56623106, ctx=0x1f4) at /usr/ports/emulators/virtualbox-ose-additions/work/VirtualBox-5.1.8/src/VBox/Additions/common/crOpenGL/glx.c:694
> #4  0x00000008010ce5be in fgSetWindow () from /usr/local/lib/libglut.so.3
> #5  0x00000008010cc44c in fgDestroyWindow () from /usr/local/lib/libglut.so.3
> #6  0x00000008010cc895 in fgDestroyStructure () from /usr/local/lib/libglut.so.3
> #7  0x00000008010c9841 in fgDeinitialize () from /usr/local/lib/libglut.so.3
> #8  0x0000000801b9add6 in __cxa_finalize (dso=<value optimized out>) at /usr/src/lib/libc/stdlib/atexit.c:237
> #9  0x0000000801b2a141 in exit (status=0) at /usr/src/lib/libc/stdlib/exit.c:72
> #10 0x0000000000400976 in _start ()
> #11 0x0000000800622000 in ?? ()
> #12 0x0000000000000000 in ?? ()
>
>
>
> But, if you prefer I can report in a vbox bugtracking also.
>
> Cheers
> -Otacílio
>
> Em 21/11/2016 08:25, Michael Thayer escreveu:
>> Hello Otacílio,
>>
>> 10.11.2016 13:07, Otacílio wrote:
>>> I'm using this minimalist program to test OpenGL. When running on a true
>>> machine (FreeBSD 11, clang 3.8.0) this program runs fine. But, when
>>> compiling and running in a Virtualbox guest with
>>> virtualbox-ose-additions-5.1.8 installed (FreeBSD 11, clang 3.8.0,
>>> OpenGL enabled)  I'm getting a core dump when the program exits. So its
>>> not clear to me if this is a FreeBSD port problem or not. So, please, I
>>> wold like ask you to compile and running in your's guest machine running
>>> Linux or FreeBSD and report to me the results.
>>
>> I can confirm that this affects Linux guests too.  Unfortunately we do
>> not have time to investigate X11 guest 3D issues for the foreseeable
>> future, so your best bet is probably to debug it yourself.  If you can
>> clearly locate the problem (as in understanding it) chances are good
>> that we will fix it.
>>
>> Regards,
>>
>> Michael
>>
>>>
>>> Program:
>>>
>>> #include <stdio.h>
>>> #include <GL/glew.h>
>>> #include <GL/gl.h>
>>> #include <GL/glu.h>
>>> #include <GL/glut.h>
>>> #include <GL/glext.h>
>>>
>>> int main(int argc, char **argv) {
>>>
>>>         glutInit(&argc, argv);
>>>         glutCreateWindow("GLUT");
>>>         glewInit();
>>>
>>>         printf("OpenGL version supported by this platform (%s): \n",
>>>         glGetString(GL_VERSION));
>>>
>>>         fprintf(stdout, "Exiting...\n");
>>>         fflush(stdout);
>>>
>>>         return 0;
>>> }
>>>
>>>
>>> Compiler command:
>>>
>>> cc -I/usr/local/include -L/usr/local/lib -o testegl testegl.c -lGL
>>> -lGLEW -lGLU   -lglut
>>>
>>>
>>> My results in a guest machine:
>>>
>>> [ota at nostromo /usr/home/ota/Desktop]$ ./testegl
>>> OpenGL version supported by this platform (2.1 Chromium 1.9):
>>> Exiting...
>>> Segmentation fault (imagem do núcleo gravada)
>>>
>>>
>>> Thanks a lot!
>>>
>>> []'s
>>>
>>> -Otacilio
>>>
>>> _______________________________________________
>>> vbox-dev mailing list
>>> vbox-dev at virtualbox.org
>>> https://www.virtualbox.org/mailman/listinfo/vbox-dev
>>
>

-- 
Michael Thayer | VirtualBox engineer
ORACLE Deutschland B.V. & Co. KG | Werkstr. 24 | D-71384 Weinstadt

ORACLE Deutschland B.V. & Co. KG
Hauptverwaltung: Riesstraße 25, D-80992 München
Registergericht: Amtsgericht München, HRA 95603

Komplementärin: ORACLE Deutschland Verwaltung B.V.
Hertogswetering 163/167, 3543 AS Utrecht, Niederlande Handelsregister 
der Handelskammer Midden-Nederland, Nr. 30143697
Geschäftsführer: Alexander van der Ven, Jan Schultheiss, Val Maher