[PATCH] drm/amdgpu: : Fix the null pointer dereference for amdgpu_device_switch_gang

[Christian König]

Am 03.07.24 um 11:01 schrieb Bob Zhou:
> To avoid null pointer dereference reported by Coverity,
> so add null pointer check for the return of amdgpu_device_get_gang().

NAK, that's complete nonsense in the first place.

The pointer is guaranteed to be never NULL or otherwise the logic would 
have crashed long before.

Regards,
Christian.

>
> Signed-off-by: Bob Zhou <bob.zhou at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index bcacf2e35eba..c1d82c346daa 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -6569,7 +6569,7 @@ struct dma_fence *amdgpu_device_switch_gang(struct amdgpu_device *adev,
>   		if (old == gang)
>   			break;
>   
> -		if (!dma_fence_is_signaled(old))
> +		if (!old || !dma_fence_is_signaled(old))
>   			return old;
>   
>   	} while (cmpxchg((struct dma_fence __force **)&adev->gang_submit,