[dpdk-dev] [PATCH] net/virtio: fix build with gcc optimization on

Ferruh Yigit ferruh.yigit at intel.com
Wed Jul 4 11:52:18 CEST 2018


On 7/4/2018 11:56 AM, Marvin Liu wrote:
> build error on gcc version 8.1.1 20180502 (Red Hat 8.1.1-1),
> with optimization level >= O2
> 
> .../drivers/net/virtio/virtio_rxtx.c:
>    In function ‘virtio_xmit_cleanup_inorder’:
> .../drivers/net/virtio/virtio_rxtx.c:195:24:
>    error: ‘desc_idx’ may be used uninitialized in this function
>    [-Werror=maybe-uninitialized]
>   uint16_t i, used_idx, desc_idx, last_idx;
>                         ^~~~~~~~
> Optimization option fcode-hoisting will cause error on gcc 8.x.x.
> Initialize desc_idx before using can fix build error.
> 
> Fixes: e3851816e63c ("net/virtio: support in-order Rx and Tx")
> 
> Reported-by: Ferruh Yigit <ferruh.yigit at intel.com>
> Signed-off-by: Marvin Liu <yong.liu at intel.com>

Hi Marvin,

Sorry if this was not clear, I already did the update while merging the patch in
next-net [1]. Can you please check the latest code in next-net?

[1]
...
     193 virtio_xmit_cleanup_inorder(struct virtqueue *vq, uint16_t num)
     194 {
     195         uint16_t i, used_idx, desc_idx = 0, last_idx;
...

> 
> diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
> index 6394071b8..19beb4bf4 100644
> --- a/drivers/net/virtio/virtio_rxtx.c
> +++ b/drivers/net/virtio/virtio_rxtx.c
> @@ -192,7 +192,8 @@ virtio_xmit_cleanup(struct virtqueue *vq, uint16_t num)
>  static void
>  virtio_xmit_cleanup_inorder(struct virtqueue *vq, uint16_t num)
>  {
> -	uint16_t i, used_idx, desc_idx, last_idx;
> +	uint16_t i, used_idx, last_idx;
> +	uint16_t desc_idx = 0;
>  	int16_t free_cnt = 0;
>  	struct vq_desc_extra *dxp = NULL;
>  
> 



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