[Mesa-dev] [PATCH] android: fix segfault within swap_buffers

[Eric Engestrom]

On Monday, 2017-03-06 14:27:05 +0200, Tapani Pälli wrote:
> Function droid_swap_buffers may get called without dri2_surf->buffer set,
> in these cases we don't have a back buffer set either. Patch fixes segfault
> seen with 3DMark that uses android.opengl.GLSurfaceView for rendering it's UI.
> 
> backtrace:
>     #00 pc 00013f88  /system/lib/egl/libGLES_mesa.so (droid_swap_buffers+104)
>     #01 pc 000117b2  /system/lib/egl/libGLES_mesa.so (dri2_swap_buffers+50)
>     #02 pc 000058b2  /system/lib/egl/libGLES_mesa.so (eglSwapBuffers+386)
>     #03 pc 00011329  /system/lib/libEGL.so (eglSwapBuffersWithDamageKHR+553)
>     #04 pc 000118e7  /system/lib/libEGL.so (eglSwapBuffers+55)
>     #05 pc 000754dc  /system/lib/libandroid_runtime.so
> 
> Fixes: 2acc69d ("EGL/Android: Add EGL_EXT_buffer_age extension")
> Signed-off-by: Tapani Pälli <tapani.palli at intel.com>

Reviewed-by: Eric Engestrom <eric.engestrom at imgtec.com>

> ---
>  src/egl/drivers/dri2/platform_android.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/src/egl/drivers/dri2/platform_android.c b/src/egl/drivers/dri2/platform_android.c
> index 14e13b8..d2769b8 100644
> --- a/src/egl/drivers/dri2/platform_android.c
> +++ b/src/egl/drivers/dri2/platform_android.c
> @@ -634,7 +634,9 @@ droid_swap_buffers(_EGLDriver *drv, _EGLDisplay *disp, _EGLSurface *draw)
>        if (dri2_surf->color_buffers[i].age > 0)
>           dri2_surf->color_buffers[i].age++;
>     }
> -   dri2_surf->back->age = 1;
> +
> +   if (dri2_surf->back)
> +      dri2_surf->back->age = 1;
>  
>     dri2_flush_drawable_for_swapbuffers(disp, draw);
>  
> -- 
> 2.9.3
>