[Mesa-dev] Mesa (master): intel: Fix segfault in glXSwapBuffers with no bound context

[Chad Versace]

Anuj, when a bugfix like this can be backported to a stable branch, please
annotate the commit message with
    Note: This is a candidate for the X.X branch
or
    Note: This is a candidate for the stable branches.

This helps the stable branch maintainer automate the backport
process.

Thanks,
Chad Versace
chad.versace at linux.intel.com

On 01/16/2012 03:13 PM, Anuj Phogat wrote:
> Module: Mesa
> Branch: master
> Commit: dd7220652e65a8a23e7739eeee687f3d6a865b80
> URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=dd7220652e65a8a23e7739eeee687f3d6a865b80
> 
> Author: Anuj Phogat <anuj.phogat at gmail.com>
> Date:   Wed Jan 11 15:26:10 2012 -0800
> 
> intel: Fix segfault in glXSwapBuffers with no bound context
> 
> Calling glXSwapBuffers with no bound context causes segmentation
> fault in function intelDRI2Flush. All the gl calls should be
> ignored after setting the current context to null. So the contents
> of framebuffer stay unchanged. But the driver should not seg fault.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=44614
> 
> Reported-by: Yi Sun <yi.sun at intel.com>
> Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
> Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>
> Tested-by: Yi Sun <yi.sun at intel.com>
> 
> ---
> 
>  src/mesa/drivers/dri/intel/intel_screen.c |   12 +++++++-----
>  1 files changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/src/mesa/drivers/dri/intel/intel_screen.c b/src/mesa/drivers/dri/intel/intel_screen.c
> index b0e800b..a08f3d1 100644
> --- a/src/mesa/drivers/dri/intel/intel_screen.c
> +++ b/src/mesa/drivers/dri/intel/intel_screen.c
> @@ -115,13 +115,15 @@ intelDRI2Flush(__DRIdrawable *drawable)
>     GET_CURRENT_CONTEXT(ctx);
>     struct intel_context *intel = intel_context(ctx);
>  
> -   if (intel->gen < 4)
> -      INTEL_FIREVERTICES(intel);
> +   if (intel != NULL) {
> +      if (intel->gen < 4)
> +	 INTEL_FIREVERTICES(intel);
>  
> -   intel->need_throttle = true;
> +      intel->need_throttle = true;
>  
> -   if (intel->batch.used)
> -      intel_batchbuffer_flush(intel);
> +      if (intel->batch.used)
> +	 intel_batchbuffer_flush(intel);
> +   }
>  }
>  
>  static const struct __DRI2flushExtensionRec intelFlushExtension = {