[PATCH 2/2] ethdev: fix race condition in fast-path ops setup

[Ashok Kaladi]

If ethdev enqueue or dequeue function is called during
eth_dev_fp_ops_setup(), it may get pre-empted after setting
the function pointers, but before setting the pointer to port data.
In this case the newly registered enqueue/dequeue function will use
dummy port data and end up in seg fault.

This patch moves the updation of each data pointers before updating
corresponding function pointers.

Fixes: c87d435a4d79 ("ethdev: copy fast-path API into separate structure")
Cc: sta...@dpdk.org

Signed-off-by: Ashok Kaladi <ashok.k.kal...@intel.com>

diff --git a/lib/ethdev/ethdev_private.c b/lib/ethdev/ethdev_private.c
index 48090c879a..a0232c669f 100644
--- a/lib/ethdev/ethdev_private.c
+++ b/lib/ethdev/ethdev_private.c
@@ -270,17 +270,17 @@ void
 eth_dev_fp_ops_setup(struct rte_eth_fp_ops *fpo,
                const struct rte_eth_dev *dev)
 {
+       fpo->rxq.data = dev->data->rx_queues;
        fpo->rx_pkt_burst = dev->rx_pkt_burst;
+       fpo->txq.data = dev->data->tx_queues;
        fpo->tx_pkt_burst = dev->tx_pkt_burst;
        fpo->tx_pkt_prepare = dev->tx_pkt_prepare;
        fpo->rx_queue_count = dev->rx_queue_count;
        fpo->rx_descriptor_status = dev->rx_descriptor_status;
        fpo->tx_descriptor_status = dev->tx_descriptor_status;
 
-       fpo->rxq.data = dev->data->rx_queues;
        fpo->rxq.clbk = (void **)(uintptr_t)dev->post_rx_burst_cbs;
 
-       fpo->txq.data = dev->data->tx_queues;
        fpo->txq.clbk = (void **)(uintptr_t)dev->pre_tx_burst_cbs;
 }
 
-- 
2.25.1