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

[Michal Wajdeczko]

On Fri, Jan 20, 2017 at 03:54:30PM +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
> succesfully.
> 
> While I'm here let's also assert that HuC vma is placed in GuC
> accessible range for consistency.
> 
> Fixes: dac84a388528 ("drm/i915/huc: Support HuC authentication")
> 
> 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>
> ---
>  drivers/gpu/drm/i915/intel_guc_loader.c | 4 +++-
>  drivers/gpu/drm/i915/intel_huc.c        | 2 +-
>  2 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_guc_loader.c b/drivers/gpu/drm/i915/intel_guc_loader.c
> index 2f1cf9a..777c0e0 100644
> --- a/drivers/gpu/drm/i915/intel_guc_loader.c
> +++ b/drivers/gpu/drm/i915/intel_guc_loader.c
> @@ -443,6 +443,7 @@ static int guc_hw_reset(struct drm_i915_private *dev_priv)
>  int intel_guc_setup(struct drm_i915_private *dev_priv)
>  {
>  	struct intel_uc_fw *guc_fw = &dev_priv->guc.fw;
> +	struct intel_uc_fw *huc_fw = &dev_priv->huc.fw;
>  	const char *fw_path = guc_fw->path;
>  	int retries, ret, err;
>  
> @@ -524,7 +525,8 @@ int intel_guc_setup(struct drm_i915_private *dev_priv)
>  		intel_uc_fw_status_repr(guc_fw->fetch_status),
>  		intel_uc_fw_status_repr(guc_fw->load_status));
>  
> -	intel_guc_auth_huc(dev_priv);
> +	if (huc_fw->load_status == INTEL_UC_FIRMWARE_SUCCESS)

Can we move this check into intel_guc_huc_auth() function?
Note that similar check inside is done in intel_huc_load().


> +		intel_guc_auth_huc(dev_priv);
>  
>  	if (i915.enable_guc_submission) {
>  		if (i915.guc_log_level >= 0)
> diff --git a/drivers/gpu/drm/i915/intel_huc.c b/drivers/gpu/drm/i915/intel_huc.c
> index 897ef31..ba53ea6 100644
> --- a/drivers/gpu/drm/i915/intel_huc.c
> +++ b/drivers/gpu/drm/i915/intel_huc.c
> @@ -309,7 +309,7 @@ void intel_guc_auth_huc(struct drm_i915_private *dev_priv)
>  
>  	/* Specify auth action and where public signature is. */
>  	data[0] = INTEL_GUC_ACTION_AUTHENTICATE_HUC;
> -	data[1] = i915_ggtt_offset(vma) + huc->fw.rsa_offset;
> +	data[1] = guc_ggtt_offset(vma) + huc->fw.rsa_offset;

While this is correct, I guess separate patch would be better.

Thanks,
Michal

>  
>  	ret = intel_guc_send(guc, data, ARRAY_SIZE(data));
>  	if (ret) {
> -- 
> 2.9.3
>