[dpdk-dev] [PATCH v3 1/2] i40e: fix problematic dereference

[Helin Zhang <helin.zhang@intel.com>]

It fixes the issue reported by Coverity of 'Dereference before
null check', by deleting null checks as they are not necessary
at all, or move null checks before where uses it.

Coverity ID 119267: Dereference before null check.
Coverity ID 13301: Dereference before null check.
Coverity ID 13294: Dereference before null check.
Coverity ID 13299: Dereference before null check.
Coverity ID 13298: Dereference before null check.

Fixes: 8e109464c022 ("i40e: allow vector Rx and Tx usage")
Fixes: a778a1fa2e4e ("i40e: set up and initialize flow director")
Fixes: a778a1fa2e4e ("i40e: set up and initialize flow director")
Fixes: 4861cde46116 ("i40e: new poll mode driver")

Signed-off-by: Helin Zhang <helin.zhang@intel.com>
---
 drivers/net/i40e/i40e_pf.c   |  5 +++--
 drivers/net/i40e/i40e_rxtx.c | 10 +++++++---
 2 files changed, 10 insertions(+), 5 deletions(-)

v3:
 - Split the code changes into different patches, according
   to the issue type.
 - Reworded the commit logs.

v2:
 - Combined all the patches into a single one, as suggested.
 - Remove checking rxq, as it shouldn't be NULL at any time.

diff --git a/drivers/net/i40e/i40e_pf.c b/drivers/net/i40e/i40e_pf.c
index 5afd61a..1bd599b 100644
--- a/drivers/net/i40e/i40e_pf.c
+++ b/drivers/net/i40e/i40e_pf.c
@@ -123,7 +123,7 @@ int
 i40e_pf_host_vf_reset(struct i40e_pf_vf *vf, bool do_hw_reset)
 {
 	uint32_t val, i;
-	struct i40e_hw *hw = I40E_PF_TO_HW(vf->pf);
+	struct i40e_hw *hw;
 	uint16_t vf_id, abs_vf_id, vf_msix_num;
 	int ret;
 	struct i40e_virtchnl_queue_select qsel;
@@ -131,6 +131,7 @@ i40e_pf_host_vf_reset(struct i40e_pf_vf *vf, bool do_hw_reset)
 	if (vf == NULL)
 		return -EINVAL;
 
+	hw = I40E_PF_TO_HW(vf->pf);
 	vf_id = vf->vf_idx;
 	abs_vf_id = vf_id + hw->func_caps.vf_base_id;
 
@@ -913,7 +914,7 @@ i40e_pf_host_handle_vf_msg(struct rte_eth_dev *dev,
 	/* AdminQ will pass absolute VF id, transfer to internal vf id */
 	uint16_t vf_id = abs_vf_id - hw->func_caps.vf_base_id;
 
-	if (!dev || vf_id > pf->vf_num - 1 || !pf->vfs) {
+	if (vf_id > pf->vf_num - 1 || !pf->vfs) {
 		PMD_DRV_LOG(ERR, "invalid argument");
 		return;
 	}
diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
index 4d35d83..f9e17fd 100644
--- a/drivers/net/i40e/i40e_rxtx.c
+++ b/drivers/net/i40e/i40e_rxtx.c
@@ -2598,7 +2598,7 @@ i40e_rx_queue_release_mbufs(struct i40e_rx_queue *rxq)
 		return;
 	}
 
-	if (!rxq || !rxq->sw_ring) {
+	if (!rxq->sw_ring) {
 		PMD_DRV_LOG(DEBUG, "Pointer to rxq or sw_ring is NULL");
 		return;
 	}
@@ -2981,13 +2981,15 @@ i40e_fdir_setup_tx_resources(struct i40e_pf *pf)
 	struct i40e_tx_queue *txq;
 	const struct rte_memzone *tz = NULL;
 	uint32_t ring_size;
-	struct rte_eth_dev *dev = pf->adapter->eth_dev;
+	struct rte_eth_dev *dev;
 
 	if (!pf) {
 		PMD_DRV_LOG(ERR, "PF is not available");
 		return I40E_ERR_BAD_PTR;
 	}
 
+	dev = pf->adapter->eth_dev;
+
 	/* Allocate the TX queue data structure. */
 	txq = rte_zmalloc_socket("i40e fdir tx queue",
 				  sizeof(struct i40e_tx_queue),
@@ -3035,13 +3037,15 @@ i40e_fdir_setup_rx_resources(struct i40e_pf *pf)
 	struct i40e_rx_queue *rxq;
 	const struct rte_memzone *rz = NULL;
 	uint32_t ring_size;
-	struct rte_eth_dev *dev = pf->adapter->eth_dev;
+	struct rte_eth_dev *dev;
 
 	if (!pf) {
 		PMD_DRV_LOG(ERR, "PF is not available");
 		return I40E_ERR_BAD_PTR;
 	}
 
+	dev = pf->adapter->eth_dev;
+
 	/* Allocate the RX queue data structure. */
 	rxq = rte_zmalloc_socket("i40e fdir rx queue",
 				  sizeof(struct i40e_rx_queue),
-- 
2.5.0