[PATCH v2 4/5] eventdev/crypto: fix overflow in circular buffer

[Gujjar, Abhinandan S]

> -----Original Message-----
> From: Kundapura, Ganapati <ganapati.kundapura at intel.com>
> Sent: Thursday, December 1, 2022 12:17 PM
> To: dev at dpdk.org; jerinj at marvell.com; Naga Harish K, S V
> <s.v.naga.harish.k at intel.com>; Gujjar, Abhinandan S
> <abhinandan.gujjar at intel.com>
> Cc: Jayatheerthan, Jay <jay.jayatheerthan at intel.com>
> Subject: [PATCH v2 4/5] eventdev/crypto: fix overflow in circular buffer
> 
> Crypto adapter checks CPM backpressure once in enq_run() This leads to
> buffer overflow if some ops failed to flush to cryptodev.
Adapter is agnostic to hardware, replace CPM with "crypto device"

Rephrase the commit message by adding:-
In case of crypto enqueue failures, even though backpressure flag is set to stop
further dequeue from eventdev the current logic does not stop dequeuing events
for max_nb events. This is fixed by checking backpressure just before dequeuing
events from event device.

> 
> Checked CPM backpressure for every iteration in enq_run()
> 
> Fixes: 7901eac3409a ("eventdev: add crypto adapter implementation")
> 
> Signed-off-by: Ganapati Kundapura <ganapati.kundapura at intel.com>
> ---
> v2:
> * Updated subject line in commit message
> 
> diff --git a/lib/eventdev/rte_event_crypto_adapter.c
> b/lib/eventdev/rte_event_crypto_adapter.c
> index 72deedd..1d39c5b 100644
> --- a/lib/eventdev/rte_event_crypto_adapter.c
> +++ b/lib/eventdev/rte_event_crypto_adapter.c
> @@ -573,14 +573,15 @@ eca_crypto_adapter_enq_run(struct
> event_crypto_adapter *adapter,
>  	if (adapter->mode == RTE_EVENT_CRYPTO_ADAPTER_OP_NEW)
>  		return 0;
> 
> -	if (unlikely(adapter->stop_enq_to_cryptodev)) {
> -		nb_enqueued += eca_crypto_enq_flush(adapter);
> +	for (nb_enq = 0; nb_enq < max_enq; nb_enq += n) {
> 
> -		if (unlikely(adapter->stop_enq_to_cryptodev))
> -			goto skip_event_dequeue_burst;
> -	}
> +		if (unlikely(adapter->stop_enq_to_cryptodev)) {
> +			nb_enqueued += eca_crypto_enq_flush(adapter);
> +
> +			if (unlikely(adapter->stop_enq_to_cryptodev))
> +				break;
> +		}
> 
> -	for (nb_enq = 0; nb_enq < max_enq; nb_enq += n) {
>  		stats->event_poll_count++;
>  		n = rte_event_dequeue_burst(event_dev_id,
>  					    event_port_id, ev, BATCH_SIZE, 0);
> @@ -591,8 +592,6 @@ eca_crypto_adapter_enq_run(struct
> event_crypto_adapter *adapter,
>  		nb_enqueued += eca_enq_to_cryptodev(adapter, ev, n);
>  	}
> 
> -skip_event_dequeue_burst:
> -
>  	if ((++adapter->transmit_loop_count &
>  		(CRYPTO_ENQ_FLUSH_THRESHOLD - 1)) == 0) {
>  		nb_enqueued += eca_crypto_enq_flush(adapter);
> --
> 2.6.4