[Mesa-dev] [PATCH] egl/dri2: dri2_initialize: Do not reference-count TestOnly display

[Martin Peres]

On 03/08/16 16:54, Nicolas Boichat wrote:
> In the case where dri2_initialize is called with a TestOnly display,
> the display is not actually initialized, so dri2_egl_display always
> fails, and we cannot do any reference counting.
>
> Fixes piglit spec at egl_khr_create_context@verify gl flavor (reproducible
> with LIBGL_ALWAYS_SOFTWARE=1) and spec at egl_khr_fence_sync@conformance.
>
> Fixes: 9ee683f877 (egl/dri2: Add reference count for dri2_egl_display)
> Cc: "12.0" <mesa-stable at lists.freedesktop.org>
> Reported-by: Michel Dänzer <michel at daenzer.net>
> Signed-off-by: Nicolas Boichat <drinkcat at chromium.org>
> ---
>
> Compile-tested only, please give it a spin, thanks!

Still crashes, same backtrace before and after the patch:

Program received signal SIGSEGV, Segmentation fault.
0x00007ffff3b90de9 in wl_proxy_destroy () from 
/usr/lib/libwayland-client.so.0
(gdb) bt
#0  0x00007ffff3b90de9 in wl_proxy_destroy () from 
/usr/lib/libwayland-client.so.0
#1  0x00007ffff679bc4e in wl_registry_destroy (wl_registry=<optimized 
out>) at /usr/include/wayland-client-protocol.h:1047
#2  dri2_display_release (disp=disp at entry=0x7913f0) at 
drivers/dri2/egl_dri2.c:896
#3  0x00007ffff679c031 in dri2_terminate (drv=<optimized out>, 
disp=0x7913f0) at drivers/dri2/egl_dri2.c:932
#4  0x00007ffff6790f7d in eglTerminate (dpy=0x7913f0) at main/eglapi.c:532
#5  0x00000000004016f5 in init_display (platform=12760, 
out_dpy=0x7fffffffe3a0) at 
/home/mupuf/programmation/piglit/tests/egl/spec/egl_khr_fence_sync/egl_khr_fence_sync.c:136
#6  0x000000000040285f in init_other_display 
(out_other_dpy=0x7fffffffe3d8, orig_dpy=0x617c50) at 
/home/mupuf/programmation/piglit/tests/egl/spec/egl_khr_fence_sync/egl_khr_fence_sync.c:956
#7  0x0000000000402917 in 
test_eglCreateSyncKHR_wrong_display_same_thread (test_data=0x0) at 
/home/mupuf/programmation/piglit/tests/egl/spec/egl_khr_fence_sync/egl_khr_fence_sync.c:1006
#8  0x00007ffff75e10aa in piglit_run_selected_subtests 
(all_subtests=0x404380 <fence_sync_subtests>, selected_subtests=0x0, 
num_selected_subtests=0, previous_result=PIGLIT_SKIP) at 
/home/mupuf/programmation/piglit/tests/util/piglit-util.c:756
#9  0x000000000040319d in main (argc=1, argv=0x7fffffffe578) at 
/home/mupuf/programmation/piglit/tests/egl/spec/egl_khr_fence_sync/egl_khr_fence_sync.c:1435

If you cannot reproduce, this is something I could be persuaded to look 
into.

>
>  src/egl/drivers/dri2/egl_dri2.c | 29 +++++++++--------------------
>  1 file changed, 9 insertions(+), 20 deletions(-)
>
> diff --git a/src/egl/drivers/dri2/egl_dri2.c b/src/egl/drivers/dri2/egl_dri2.c
> index a5cab68..8cdca6a 100644
> --- a/src/egl/drivers/dri2/egl_dri2.c
> +++ b/src/egl/drivers/dri2/egl_dri2.c
> @@ -788,45 +788,34 @@ dri2_initialize(_EGLDriver *drv, _EGLDisplay *disp)
>     if (disp->Options.UseFallback)
>        return EGL_FALSE;
>
> +   /* Nothing to initialize for a test only display */
> +   if (disp->Options.TestOnly)
> +      return EGL_TRUE;
> +
>     switch (disp->Platform) {
>  #ifdef HAVE_SURFACELESS_PLATFORM
>     case _EGL_PLATFORM_SURFACELESS:
> -      if (disp->Options.TestOnly)
> -         ret = EGL_TRUE;
> -      else
> -         ret = dri2_initialize_surfaceless(drv, disp);
> +      ret = dri2_initialize_surfaceless(drv, disp);
>        break;
>  #endif
>  #ifdef HAVE_X11_PLATFORM
>     case _EGL_PLATFORM_X11:
> -      if (disp->Options.TestOnly)
> -         ret = EGL_TRUE;
> -      else
> -         ret = dri2_initialize_x11(drv, disp);
> +      ret = dri2_initialize_x11(drv, disp);
>        break;
>  #endif
>  #ifdef HAVE_DRM_PLATFORM
>     case _EGL_PLATFORM_DRM:
> -      if (disp->Options.TestOnly)
> -         ret = EGL_TRUE;
> -      else
> -         ret = dri2_initialize_drm(drv, disp);
> +      ret = dri2_initialize_drm(drv, disp);
>        break;
>  #endif
>  #ifdef HAVE_WAYLAND_PLATFORM
>     case _EGL_PLATFORM_WAYLAND:
> -      if (disp->Options.TestOnly)
> -         ret = EGL_TRUE;
> -      else
> -         ret = dri2_initialize_wayland(drv, disp);
> +      ret = dri2_initialize_wayland(drv, disp);
>        break;
>  #endif
>  #ifdef HAVE_ANDROID_PLATFORM
>     case _EGL_PLATFORM_ANDROID:
> -      if (disp->Options.TestOnly)
> -         ret = EGL_TRUE;
> -      else
> -         ret = dri2_initialize_android(drv, disp);
> +      ret = dri2_initialize_android(drv, disp);
>        break;
>  #endif
>     default:
>