[v2] net/i40e: fix integer overflow

  When config i40e rx queue, the temporary variable to store max packet
length is not big enough which leads to integer overflow issue. This
patch is to fix the issue by removing the variable and using the
expression directly since the variable only used once.

Fixes: 4861cde46116 ("i40e: new poll mode driver")
Cc: stable@dpdk.org

Signed-off-by: Xiao Zhang <xiao.zhang@intel.com>
---
v2
Correct the fixline and remove temporary variable.
---
 drivers/net/i40e/i40e_rxtx.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
  

On 10/15, Xiao Zhang wrote:
>When config i40e rx queue, the temporary variable to store max packet
>length is not big enough which leads to integer overflow issue. This
>patch is to fix the issue by removing the variable and using the
>expression directly since the variable only used once.
>
>Fixes: 4861cde46116 ("i40e: new poll mode driver")
>Cc: stable@dpdk.org
>
>Signed-off-by: Xiao Zhang <xiao.zhang@intel.com>
>---
>v2
>Correct the fixline and remove temporary variable.
>---
> drivers/net/i40e/i40e_rxtx.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
>diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
>index bfe161f..ff6eb4a 100644
>--- a/drivers/net/i40e/i40e_rxtx.c
>+++ b/drivers/net/i40e/i40e_rxtx.c
>@@ -2596,7 +2596,7 @@ i40e_rx_queue_config(struct i40e_rx_queue *rxq)
> 	struct i40e_pf *pf = I40E_VSI_TO_PF(rxq->vsi);
> 	struct i40e_hw *hw = I40E_VSI_TO_HW(rxq->vsi);
> 	struct rte_eth_dev_data *data = pf->dev_data;
>-	uint16_t buf_size, len;
>+	uint16_t buf_size;
> 
> 	buf_size = (uint16_t)(rte_pktmbuf_data_room_size(rxq->mp) -
> 		RTE_PKTMBUF_HEADROOM);
>@@ -2619,8 +2619,9 @@ i40e_rx_queue_config(struct i40e_rx_queue *rxq)
> 		break;
> 	}
> 
>-	len = hw->func_caps.rx_buf_chain_len * rxq->rx_buf_len;
>-	rxq->max_pkt_len = RTE_MIN(len, data->dev_conf.rxmode.max_rx_pkt_len);
>+	rxq->max_pkt_len =
>+		RTE_MIN((uint32_t)(hw->func_caps.rx_buf_chain_len *
>+			rxq->rx_buf_len), data->dev_conf.rxmode.max_rx_pkt_len);
> 	if (data->dev_conf.rxmode.offloads & DEV_RX_OFFLOAD_JUMBO_FRAME) {
> 		if (rxq->max_pkt_len <= RTE_ETHER_MAX_LEN ||
> 			rxq->max_pkt_len > I40E_FRAME_SIZE_MAX) {
>-- 
>2.7.4
>

Acked-by: Xiaolong Ye <xiaolong.ye@intel.com>

Applied to dpdk-next-net-intel.