[Intel-gfx] [PATCH v2 1/2] drm/i915/huc: Avoid attempting to authenticate non-existent fw

[Michal Wajdeczko]

On Fri, Jan 20, 2017 at 04:28:23PM +0100, Michał Winiarski wrote:
> HuC authentication is called even if HuC firmware is not present in the
> system, leading to NULL ptr dereference on not allocated gem_object.
> Let's avoid trying to authenticate HuC if its firmware is not loaded
> successfully.
> 
> Fixes: dac84a388528 ("drm/i915/huc: Support HuC authentication")
> 
> v2: Check inside the auth function, split the assert (Michał)
> 
> Cc: Anusha Srivatsa <anusha.srivatsa at intel.com>
> Cc: Arkadiusz Hiler <arkadiusz.hiler at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Signed-off-by: Michał Winiarski <michal.winiarski at intel.com>

Reviewed-by: Michal Wajdeczko <michal.wajdeczko.intel.com>

> ---
>  drivers/gpu/drm/i915/intel_huc.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_huc.c b/drivers/gpu/drm/i915/intel_huc.c
> index 897ef31..d1e65fa 100644
> --- a/drivers/gpu/drm/i915/intel_huc.c
> +++ b/drivers/gpu/drm/i915/intel_huc.c
> @@ -299,6 +299,9 @@ void intel_guc_auth_huc(struct drm_i915_private *dev_priv)
>  	int ret;
>  	u32 data[2];
>  
> +	if (huc_fw->load_status != INTEL_UC_FIRMWARE_SUCCESS)
> +		return;
> +
>  	vma = i915_gem_object_ggtt_pin(huc->fw.obj, NULL, 0, 0,
>  				PIN_OFFSET_BIAS | GUC_WOPCM_TOP);
>  	if (IS_ERR(vma)) {
> -- 
> 2.9.3
>