Hello Dimitris Michailidis,
The patch ee6373ddf3a9: "net/funeth: probing and netdev ops" from Feb
24, 2022, leads to the following Smatch static checker warning:
drivers/net/ethernet/fungible/funeth/funeth_main.c:477 fun_free_rings()
warn: 'rxqs' was already freed.
drivers/net/ethernet/fungible/funeth/funeth_main.c
443 static void fun_free_rings(struct net_device *netdev, struct fun_qset *qset)
444 {
445 struct funeth_priv *fp = netdev_priv(netdev);
446 struct funeth_txq **xdpqs = qset->xdpqs;
447 struct funeth_rxq **rxqs = qset->rxqs;
448
449 /* qset may not specify any queues to operate on. In that case the
450 * currently installed queues are implied.
451 */
452 if (!rxqs) {
453 rxqs = rtnl_dereference(fp->rxqs);
454 xdpqs = rtnl_dereference(fp->xdpqs);
455 qset->txqs = fp->txqs;
456 qset->nrxqs = netdev->real_num_rx_queues;
457 qset->ntxqs = netdev->real_num_tx_queues;
458 qset->nxdpqs = fp->num_xdpqs;
459 }
460 if (!rxqs)
461 return;
462
463 if (rxqs == rtnl_dereference(fp->rxqs)) {
464 rcu_assign_pointer(fp->rxqs, NULL);
465 rcu_assign_pointer(fp->xdpqs, NULL);
466 synchronize_net();
467 fp->txqs = NULL;
468 }
469
470 free_rxqs(rxqs, qset->nrxqs, qset->rxq_start, qset->state);
471 free_txqs(qset->txqs, qset->ntxqs, qset->txq_start, qset->state);
472 free_xdpqs(xdpqs, qset->nxdpqs, qset->xdpq_start, qset->state);
473 if (qset->state == FUN_QSTATE_DESTROYED)
474 kfree(rxqs);
^^^^^^^^^^^
Should this return or set "rxqs = NULL" or something?
475
476 /* Tell the caller which queues were operated on. */
--> 477 qset->rxqs = rxqs;
^^^^^^^^^^^^^^^^^^
Only bad things will happen with safing this freed pointer.
478 qset->xdpqs = xdpqs;
479 }
regards,
dan carpenter
