Re: [PATCH net 2/3] net: tls: Cancel RX async resync request on rdc_delta overflow

[Sabrina Dubroca <sd@queasysnail.net>]

2025-09-10, 09:47:40 +0300, Tariq Toukan wrote:
> From: Shahar Shitrit <shshitrit@nvidia.com>
> 
> When a netdev issues an RX async resync request, the TLS module
> increments rcd_delta for each new record that arrives. This tracks
> how far the current record is from the point where synchronization
> was lost.
> 
> When rcd_delta reaches its threshold, it indicates that the device
> response is either excessively delayed or unlikely to arrive at all
> (at that point, tcp_sn may have wrapped around, so a match would no
> longer be valid anyway).
> 
> Previous patch introduced tls_offload_rx_resync_async_request_cancel()
> to explicitly cancel resync requests when a device response failure
> is detected.
> 
> This patch adds a final safeguard: cancel the async resync request when
> rcd_delta crosses its threshold, as reaching this point implies that
> earlier cancellation did not occur.
> 
> Signed-off-by: Shahar Shitrit <shshitrit@nvidia.com>
> Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
> ---
>  net/tls/tls_device.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
> index f672a62a9a52..56c14f1647a4 100644
> --- a/net/tls/tls_device.c
> +++ b/net/tls/tls_device.c
> @@ -721,8 +721,11 @@ tls_device_rx_resync_async(struct tls_offload_resync_async *resync_async,
>  		/* shouldn't get to wraparound:
>  		 * too long in async stage, something bad happened
>  		 */
> -		if (WARN_ON_ONCE(resync_async->rcd_delta == USHRT_MAX))
> +		if (WARN_ON_ONCE(resync_async->rcd_delta == USHRT_MAX)) {

Do we still need to WARN here? It's a condition that can actually
happen (even if it's rare), and that the stack can handle, so maybe
not?

> +			/* cancel resync request */
> +			atomic64_set(&resync_async->req, 0);
>  			return false;
> +		}
>  
>  		/* asynchronous stage: log all headers seq such that
>  		 * req_seq <= seq <= end_seq, and wait for real resync request
> -- 
> 2.31.1
> 

-- 
Sabrina