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From: "Michael S. Tsirkin" <mst@redhat.com>
To: Jason Wang <jasowang@redhat.com>
Cc: elic@nvidia.com, linux-kernel@vger.kernel.org,
	virtualization@lists.linux-foundation.org
Subject: Re: [PATCH V2] mlx5: vdpa: fix possible uninitialized var
Date: Sun, 17 Jan 2021 05:30:01 -0500	[thread overview]
Message-ID: <20210117052810-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <20210114070904.9981-1-jasowang@redhat.com>

On Thu, Jan 14, 2021 at 03:09:04PM +0800, Jason Wang wrote:
> When compiling with -Werror=maybe-uninitialized, gcc may complains the
> possible uninitialized umem. Since the callers won't pass value other
> than 1 to 3, making 3 as default to fix the compiler warning.
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>

Of course if it's actually something else this is not DTRT ...
As long as we worry about this warning, let's have defence in depth:
  	case 3:
  		umem = &mvq->umem3;
  		break;
 +	default:
 +		umem = NULL;
 +              BUG();
 +		break;


> ---
>  drivers/vdpa/mlx5/net/mlx5_vnet.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> index f1d54814db97..07ccc61cd6f6 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> @@ -703,7 +703,7 @@ static void umem_destroy(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue
>  	case 2:
>  		umem = &mvq->umem2;
>  		break;
> -	case 3:
> +	default:
>  		umem = &mvq->umem3;
>  		break;
>  	}
> -- 
> 2.25.1

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WARNING: multiple messages have this Message-ID (diff)
From: "Michael S. Tsirkin" <mst@redhat.com>
To: Jason Wang <jasowang@redhat.com>
Cc: virtualization@lists.linux-foundation.org,
	linux-kernel@vger.kernel.org, elic@nvidia.com
Subject: Re: [PATCH V2] mlx5: vdpa: fix possible uninitialized var
Date: Sun, 17 Jan 2021 05:30:01 -0500	[thread overview]
Message-ID: <20210117052810-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <20210114070904.9981-1-jasowang@redhat.com>

On Thu, Jan 14, 2021 at 03:09:04PM +0800, Jason Wang wrote:
> When compiling with -Werror=maybe-uninitialized, gcc may complains the
> possible uninitialized umem. Since the callers won't pass value other
> than 1 to 3, making 3 as default to fix the compiler warning.
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>

Of course if it's actually something else this is not DTRT ...
As long as we worry about this warning, let's have defence in depth:
  	case 3:
  		umem = &mvq->umem3;
  		break;
 +	default:
 +		umem = NULL;
 +              BUG();
 +		break;


> ---
>  drivers/vdpa/mlx5/net/mlx5_vnet.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/vdpa/mlx5/net/mlx5_vnet.c b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> index f1d54814db97..07ccc61cd6f6 100644
> --- a/drivers/vdpa/mlx5/net/mlx5_vnet.c
> +++ b/drivers/vdpa/mlx5/net/mlx5_vnet.c
> @@ -703,7 +703,7 @@ static void umem_destroy(struct mlx5_vdpa_net *ndev, struct mlx5_vdpa_virtqueue
>  	case 2:
>  		umem = &mvq->umem2;
>  		break;
> -	case 3:
> +	default:
>  		umem = &mvq->umem3;
>  		break;
>  	}
> -- 
> 2.25.1


  parent reply	other threads:[~2021-01-17 10:30 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-14  7:09 [PATCH V2] mlx5: vdpa: fix possible uninitialized var Jason Wang
2021-01-14  7:09 ` Jason Wang
2021-01-14  7:23 ` Eli Cohen
2021-01-17 10:30 ` Michael S. Tsirkin [this message]
2021-01-17 10:30   ` Michael S. Tsirkin
2021-01-18  5:32   ` Jason Wang
2021-01-18  5:32     ` Jason Wang

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