sfc: detach from cb_page in efx_copy_channel()

It's a resource, not a parameter, so we can't copy it into the new
 channel's TX queues, otherwise aliasing will lead to resource-
 management bugs if the channel is subsequently torn down without
 being initialised.

Before the Fixes:-tagged commit there was a similar bug with
 tsoh_page, but I'm not sure it's worth doing another fix for such
 old kernels.

Fixes: e9117e5099 ("sfc: Firmware-Assisted TSO version 2")
Suggested-by: Derek Shute <Derek.Shute@stratus.com>
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Edward Cree 2020-03-09 18:16:24 +00:00 committed by David S. Miller
parent 661388f9b0
commit 4b1bd9db07

View File

@ -583,6 +583,7 @@ struct efx_channel *efx_copy_channel(const struct efx_channel *old_channel)
if (tx_queue->channel)
tx_queue->channel = channel;
tx_queue->buffer = NULL;
tx_queue->cb_page = NULL;
memset(&tx_queue->txd, 0, sizeof(tx_queue->txd));
}