Segmentation Fault in glGetString() with Dual-Video Cards

upskuhr · 10-09-07, 07:44 AM

Hello,

I use two Video Cards (and 3 Monitors connected) in Xinerama mode. When I try to run compiz-fusion, I always get a Segmentation Fault in glGetString
0x00002aaaac073ce9 in glGetString () from //usr/lib64/opengl/nvidia/lib/libGL.so.1

AFAIK glGetString should _never_ Segfault. So even if there might be a problem with compiz or X.org there _must_ be one with the nvidia-drivers.

Edit: I tried with nvidia-drivers 100.14.19 and 100.14.09 both had the same result.

upskuhr · 11-13-07, 02:27 AM

*bump*

stuartlevy · 11-13-07, 05:38 PM

glGetString() might segfault in good faith if there were no active GLX context, say.

For example, before the window was created, or (depending on toolkit) if you call it outside of the display-callback or similar. Could that be the problem?
You might try calling glXGetCurrentContext() and see what it returns -- or whether it seg-faults too.

upskuhr · 11-14-07, 02:27 AM

You're right. The current context _is_ null.
But anyway instead of Segfaulting glGetString should raise an error and return false.

**Thunderbird** · 11-14-07, 02:37 AM

No it should really crash it is the case for all GL calls. (Or perhaps the specs have the behavior undefined)

11-13-07, 02:27 AM	#2
upskuhr Registered User Join Date: Oct 2007 Posts: 3	Re: Segmentation Fault in glGetString() with Dual-Video Cards bump

11-13-07, 05:38 PM	#3
stuartlevy Registered User Join Date: May 2003 Location: flat, steamy Champaign, IL Posts: 36	Re: Segmentation Fault in glGetString() with Dual-Video Cards glGetString() might segfault in good faith if there were no active GLX context, say. For example, before the window was created, or (depending on toolkit) if you call it outside of the display-callback or similar. Could that be the problem? You might try calling glXGetCurrentContext() and see what it returns -- or whether it seg-faults too.

11-14-07, 02:27 AM	#4
upskuhr Registered User Join Date: Oct 2007 Posts: 3	Re: Segmentation Fault in glGetString() with Dual-Video Cards You're right. The current context _is_ null. But anyway instead of Segfaulting glGetString should raise an error and return false.

11-14-07, 02:37 AM	#5
Thunderbird Join Date: Jul 2002 Location: Netherlands, Europe Posts: 2,105	Re: Segmentation Fault in glGetString() with Dual-Video Cards No it should really crash it is the case for all GL calls. (Or perhaps the specs have the behavior undefined)

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