[Intel-gfx] [PATCH 1/2] drm/i915: Check new context against kernel_context after reporting an error

[Tvrtko Ursulin]

On 05/07/2017 14:18, Chris Wilson wrote:
> Avoid any pointer dereference in inspecting a potential PTR_ERR by
> checking for the error pointer before checking for an invalid context.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> ---
>   drivers/gpu/drm/i915/i915_gem_context.c | 5 ++---
>   1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
> index 2eb5d8203999..98d2ce98f467 100644
> --- a/drivers/gpu/drm/i915/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/i915_gem_context.c
> @@ -571,14 +571,13 @@ int i915_gem_context_open(struct drm_i915_private *i915,
>   	mutex_lock(&i915->drm.struct_mutex);
>   	ctx = i915_gem_create_context(i915, file_priv);
>   	mutex_unlock(&i915->drm.struct_mutex);
> -
> -	GEM_BUG_ON(i915_gem_context_is_kernel(ctx));
> -
>   	if (IS_ERR(ctx)) {
>   		idr_destroy(&file_priv->context_idr);
>   		return PTR_ERR(ctx);
>   	}
>   
> +	GEM_BUG_ON(i915_gem_context_is_kernel(ctx));
> +
>   	return 0;
>   }
>   
> 

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Regards,

Tvrtko