On 3/4/20 5:05 PM, Tencent TGW team wrote:
> When compiling with -O0,
> the compiler does not optimize two memory accesses into one.
> Leads to accessing a null pointer when calling the RX callback.
> The way to access the TX callback is correct.
It looks like the patch is not passed through check-git-log.sh.
RX -> Rx, TX -> Tx
>
> Signed-off-by: Tencent TGW team <tgw_t...@tencent.com>
If I'm not mistaken, it must be a person here, not team.
> ---
> lib/librte_ethdev/rte_ethdev.h | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/lib/librte_ethdev/rte_ethdev.h b/lib/librte_ethdev/rte_ethdev.h
> index d1a593ad1..35eb580ff 100644
> --- a/lib/librte_ethdev/rte_ethdev.h
> +++ b/lib/librte_ethdev/rte_ethdev.h
> @@ -4388,10 +4388,8 @@ rte_eth_rx_burst(uint16_t port_id, uint16_t queue_id,
> rx_pkts, nb_pkts);
>
> #ifdef RTE_ETHDEV_RXTX_CALLBACKS
> - if (unlikely(dev->post_rx_burst_cbs[queue_id] != NULL)) {
> - struct rte_eth_rxtx_callback *cb =
> - dev->post_rx_burst_cbs[queue_id];
> -
> + struct rte_eth_rxtx_callback *cb = dev->post_rx_burst_cbs[queue_id];
> + if (unlikely(cb != NULL)) {
> do {
> nb_rx = cb->fn.rx(port_id, queue_id, rx_pkts, nb_rx,
> nb_pkts, cb->param);
>
Sorry, but I don't understand. I don't see the difference in
potential NULL pointer deference above. What is the compiler? Version?
Or is it a race condition with queue post Rx burst callback
removal while traffic is running?
