[dpdk-dev] [PATCH v2] ethdev: fix check of rx configure

[wangyunjian <wangyunjian@huawei.com>]

From: Yunjian Wang <wangyunjian@huawei.com>

Coverity flags that 'rx_conf' variable is used before
it's checked for NULL. This patch fixes this issue.

Coverity issue: 363570
Fixes: 4ff702b5dfa9 ("ethdev: introduce Rx buffer split")

Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
---
v2:
    fix code styles suggested by Ferruh Yigit
---
 lib/librte_ethdev/rte_ethdev.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
index b12bb3854d..1ac59a39e3 100644
--- a/lib/librte_ethdev/rte_ethdev.c
+++ b/lib/librte_ethdev/rte_ethdev.c
@@ -1978,9 +1978,8 @@ rte_eth_rx_queue_setup(uint16_t port_id, uint16_t rx_queue_id,
 			return -EINVAL;
 		}
 	} else {
-		const struct rte_eth_rxseg_split *rx_seg =
-			(const struct rte_eth_rxseg_split *)rx_conf->rx_seg;
-		uint16_t n_seg = rx_conf->rx_nseg;
+		const struct rte_eth_rxseg_split *rx_seg;
+		uint16_t n_seg;
 
 		/* Extended multi-segment configuration check. */
 		if (rx_conf == NULL || rx_conf->rx_seg == NULL || rx_conf->rx_nseg == 0) {
@@ -1988,6 +1987,10 @@ rte_eth_rx_queue_setup(uint16_t port_id, uint16_t rx_queue_id,
 				       "Memory pool is null and no extended configuration provided\n");
 			return -EINVAL;
 		}
+
+		rx_seg = (const struct rte_eth_rxseg_split *)rx_conf->rx_seg;
+		n_seg = rx_conf->rx_nseg;
+
 		if (rx_conf->offloads & RTE_ETH_RX_OFFLOAD_BUFFER_SPLIT) {
 			ret = rte_eth_rx_queue_check_split(rx_seg, n_seg,
 							   &mbp_buf_size,
-- 
2.18.1