Comment 27 for bug 1492037

(In reply to Samuel Iglesias from comment #19)
> I reproduced this bug on my SNB laptop and Mesa master (HEAD 7850774). I
> found that just before crashing at brw_meta_fast_clear.c:451, it prints out
> the following error:
>
> Failed to open BO for returned DRI2 buffer (1600x900, dri2 back buffer,
> named 11).
> This is likely a bug in the X Server that will lead to a crash soon.
>
> Which is printed at intel_process_dri2_buffer() when
> drm_intel_bo_gem_create_from_name() returns a NULL pointer.

Forgot to mention that when this error message is printed out, we return from intel_process_dri2_buffer() but the miptree was free'd before by intel_miptree_release(&rb->mt) call. Later on, we try to dereference it at brw_meta_fast_clear.c:451 and segmentation fault happens.

> I added some
> traces to that function at libdrm and found that drmIoctl(bufmgr_gem->fd,
> DRM_IOCTL_GEM_OPEN, &open_arg) is returning an error, so this bug seems to
> be produced by the kernel driver.
>
> My distro is Debian Jessie with a Linux kernel 3.14.
>
> Hope this helps.