[Mesa-stable] [PATCH 1/4] i965/sync: Fix uninitalized usage and leak of mutex

[Chad Versace]

On Thu 06 Oct 2016, Emil Velikov wrote:
> Hi Chad,
> 
> On 4 October 2016 at 23:37, Chad Versace <chadversary at chromium.org> wrote:
> > We locked an unitialized mutex in the callstack
> >     glClientWaitSync
> >     intel_gl_client_wait_sync
> >     brw_fence_client_wait_sync
> > because we forgot to initialize it in intel_gl_fence_sync.
> > (The EGLSync codepath didn't have this bug. It initialized the mutex in
> > intel_dri_create_sync).
> >
> > We also forgot to tear down (mtx_destroy) the mutex when destroying
> > the sync object.
> >
> > Cc: mesa-stable at lists.freedesktop.org

> Do you have a few minutes to roll an similar fix for i915 ? It should
> be identical (barring naming fixes) to this.

I would do it if i915's sync object already included a mutex. But it
doesn't.

    struct intel_sync_object {                      
       struct gl_sync_object Base;                  
                                                    
       /** Batch associated with this sync object */
       drm_intel_bo *bo;                            
    };                                              

I hesitate to make non-obvious changes (like adding a mutex) to a driver
that I'm unable to test.