drm/i915: Use the i915_device name for identifying our, request fences

[Chris Wilson]

Quoting Colin Ian King (2019-12-12 19:53:33)
> Hi,
> 
> Static analysis with Coverity has picked up an issue with the following
> commit:
> 
> commit 65c29dbb19b2451990c5c477fef7ada3b8218f05
> Author: Chris Wilson <chris at chris-wilson.co.uk>
> Date:   Wed Dec 11 15:02:04 2019 +0000
> 
>     drm/i915: Use the i915_device name for identifying our request fences
> 
> In source drivers/gpu/drm/i915/i915_request.c and function
> i915_fence_get_timeline_name there is the following:
> 
>         return to_request(fence)->gem_context->name ?: "[" DRIVER_NAME "]";
> 
> However name is an array: char name[TASK_COMM_LEN + 8], so it can never
> be null, so the ternary operator will always return name and will never
> reaturn "[" DRIVER_NAME "]".  Should it instead be checking if name[0]
> is '\0' instead?

It's older than that patch, we made it a char[] some time ago. There's a
patch pending to make it conditional on ce->gem_context instead.
-Chris