ixgbevf: Fix multiple issues in ixgbevf_get/set_ringparam

In ixgbevf_get_ringparam we could run into a NULL pointer dereference
if the rings were not allocated when we attempted the call.  To prevent
that we can just access the tx/rx_ring_count values instead of attempting
to access the rings to get the count.

This change corrects a memory leak and memory corruption in
ixgbevf_set_ringparam.

The memory leak was due to us not freeing the resources from the ring
before overwriting them.  This change corrects the memory leak by making
certain to call ixgbe_free_tx/rx_resources on the rings prior to freeing
them.

The memory corruption was because we were replacing the rings but not
updating the q_vectors.  It addresses the memory corruption by leaving the
rings in place and instead just copying the contents of the new rings into
the existing rings.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Greg Rose <gregory.v.rose@intel.com>
Tested-by: Sibai Li <sibai.li@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ixgbevf/ethtool.c

@@ -284,47 +284,40 @@ static void ixgbevf_get_ringparam(struct net_device *netdev,
 				  struct ethtool_ringparam *ring)
 {
 	struct ixgbevf_adapter *adapter = netdev_priv(netdev);
-	struct ixgbevf_ring *tx_ring = adapter->tx_ring;
-	struct ixgbevf_ring *rx_ring = adapter->rx_ring;
 
 	ring->rx_max_pending = IXGBEVF_MAX_RXD;
 	ring->tx_max_pending = IXGBEVF_MAX_TXD;
-	ring->rx_pending = rx_ring->count;
-	ring->tx_pending = tx_ring->count;
+	ring->rx_pending = adapter->rx_ring_count;
+	ring->tx_pending = adapter->tx_ring_count;
 }
 
 static int ixgbevf_set_ringparam(struct net_device *netdev,
 				 struct ethtool_ringparam *ring)
 {
 	struct ixgbevf_adapter *adapter = netdev_priv(netdev);
 	struct ixgbevf_ring *tx_ring = NULL, *rx_ring = NULL;
-	int i, err = 0;
 	u32 new_rx_count, new_tx_count;
+	int i, err = 0;
 
 	if ((ring->rx_mini_pending) || (ring->rx_jumbo_pending))
 		return -EINVAL;
 
-	new_rx_count = max(ring->rx_pending, (u32)IXGBEVF_MIN_RXD);
-	new_rx_count = min(new_rx_count, (u32)IXGBEVF_MAX_RXD);
-	new_rx_count = ALIGN(new_rx_count, IXGBE_REQ_RX_DESCRIPTOR_MULTIPLE);
-
-	new_tx_count = max(ring->tx_pending, (u32)IXGBEVF_MIN_TXD);
-	new_tx_count = min(new_tx_count, (u32)IXGBEVF_MAX_TXD);
+	new_tx_count = max_t(u32, ring->tx_pending, IXGBEVF_MIN_TXD);
+	new_tx_count = min_t(u32, new_tx_count, IXGBEVF_MAX_TXD);
 	new_tx_count = ALIGN(new_tx_count, IXGBE_REQ_TX_DESCRIPTOR_MULTIPLE);
 
-	if ((new_tx_count == adapter->tx_ring->count) &&
-	    (new_rx_count == adapter->rx_ring->count)) {
-		/* nothing to do */
+	new_rx_count = max_t(u32, ring->rx_pending, IXGBEVF_MIN_RXD);
+	new_rx_count = min_t(u32, new_rx_count, IXGBEVF_MAX_RXD);
+	new_rx_count = ALIGN(new_rx_count, IXGBE_REQ_RX_DESCRIPTOR_MULTIPLE);
+
+	/* if nothing to do return success */
+	if ((new_tx_count == adapter->tx_ring_count) &&
+	    (new_rx_count == adapter->rx_ring_count))
 		return 0;
-	}
 
 	while (test_and_set_bit(__IXGBEVF_RESETTING, &adapter->state))
-		msleep(1);
+		usleep_range(1000, 2000);
 
-	/*
-	 * If the adapter isn't up and running then just set the
-	 * new parameters and scurry for the exits.
-	 */
 	if (!netif_running(adapter->netdev)) {
 		for (i = 0; i < adapter->num_tx_queues; i++)
 			adapter->tx_ring[i].count = new_tx_count;
@@ -335,78 +328,98 @@ static int ixgbevf_set_ringparam(struct net_device *netdev,
 		goto clear_reset;
 	}
 
-	tx_ring = kcalloc(adapter->num_tx_queues,
-			  sizeof(struct ixgbevf_ring), GFP_KERNEL);
-	if (!tx_ring) {
-		err = -ENOMEM;
-		goto clear_reset;
-	}
-
-	rx_ring = kcalloc(adapter->num_rx_queues,
-			  sizeof(struct ixgbevf_ring), GFP_KERNEL);
-	if (!rx_ring) {
-		err = -ENOMEM;
-		goto err_rx_setup;
-	}
-
-	ixgbevf_down(adapter);
+	if (new_tx_count != adapter->tx_ring_count) {
+		tx_ring = vmalloc(adapter->num_tx_queues * sizeof(*tx_ring));
+		if (!tx_ring) {
+			err = -ENOMEM;
+			goto clear_reset;
+		}
 
-	memcpy(tx_ring, adapter->tx_ring,
-	       adapter->num_tx_queues * sizeof(struct ixgbevf_ring));
-	for (i = 0; i < adapter->num_tx_queues; i++) {
-		tx_ring[i].count = new_tx_count;
-		err = ixgbevf_setup_tx_resources(adapter, &tx_ring[i]);
-		if (err) {
+		for (i = 0; i < adapter->num_tx_queues; i++) {
+			/* clone ring and setup updated count */
+			tx_ring[i] = adapter->tx_ring[i];
+			tx_ring[i].count = new_tx_count;
+			err = ixgbevf_setup_tx_resources(adapter, &tx_ring[i]);
+			if (!err)
+				continue;
 			while (i) {
 				i--;
 				ixgbevf_free_tx_resources(adapter, &tx_ring[i]);
 			}
-			goto err_tx_ring_setup;
+
+			vfree(tx_ring);
+			tx_ring = NULL;
+
+			goto clear_reset;
 		}
 	}
 
-	memcpy(rx_ring, adapter->rx_ring,
-	       adapter->num_rx_queues * sizeof(struct ixgbevf_ring));
-	for (i = 0; i < adapter->num_rx_queues; i++) {
-		rx_ring[i].count = new_rx_count;
-		err = ixgbevf_setup_rx_resources(adapter, &rx_ring[i]);
-		if (err) {
+	if (new_rx_count != adapter->rx_ring_count) {
+		rx_ring = vmalloc(adapter->num_rx_queues * sizeof(*rx_ring));
+		if (!rx_ring) {
+			err = -ENOMEM;
+			goto clear_reset;
+		}
+
+		for (i = 0; i < adapter->num_rx_queues; i++) {
+			/* clone ring and setup updated count */
+			rx_ring[i] = adapter->rx_ring[i];
+			rx_ring[i].count = new_rx_count;
+			err = ixgbevf_setup_rx_resources(adapter, &rx_ring[i]);
+			if (!err)
+				continue;
 			while (i) {
 				i--;
 				ixgbevf_free_rx_resources(adapter, &rx_ring[i]);
 			}
-				goto err_rx_ring_setup;
+
+			vfree(rx_ring);
+			rx_ring = NULL;
+
+			goto clear_reset;
 		}
 	}
 
-	/*
-	 * Only switch to new rings if all the prior allocations
-	 * and ring setups have succeeded.
-	 */
-	kfree(adapter->tx_ring);
-	adapter->tx_ring = tx_ring;
-	adapter->tx_ring_count = new_tx_count;
-
-	kfree(adapter->rx_ring);
-	adapter->rx_ring = rx_ring;
-	adapter->rx_ring_count = new_rx_count;
+	/* bring interface down to prepare for update */
+	ixgbevf_down(adapter);
 
-	/* success! */
-	ixgbevf_up(adapter);
+	/* Tx */
+	if (tx_ring) {
+		for (i = 0; i < adapter->num_tx_queues; i++) {
+			ixgbevf_free_tx_resources(adapter,
+						  &adapter->tx_ring[i]);
+			adapter->tx_ring[i] = tx_ring[i];
+		}
+		adapter->tx_ring_count = new_tx_count;
 
-	goto clear_reset;
+		vfree(tx_ring);
+		tx_ring = NULL;
+	}
 
-err_rx_ring_setup:
-	for(i = 0; i < adapter->num_tx_queues; i++)
-		ixgbevf_free_tx_resources(adapter, &tx_ring[i]);
+	/* Rx */
+	if (rx_ring) {
+		for (i = 0; i < adapter->num_rx_queues; i++) {
+			ixgbevf_free_rx_resources(adapter,
+						  &adapter->rx_ring[i]);
+			adapter->rx_ring[i] = rx_ring[i];
+		}
+		adapter->rx_ring_count = new_rx_count;
 
-err_tx_ring_setup:
-	kfree(rx_ring);
+		vfree(rx_ring);
+		rx_ring = NULL;
+	}
 
-err_rx_setup:
-	kfree(tx_ring);
+	/* restore interface using new values */
+	ixgbevf_up(adapter);
 
 clear_reset:
+	/* free Tx resources if Rx error is encountered */
+	if (tx_ring) {
+		for (i = 0; i < adapter->num_tx_queues; i++)
+			ixgbevf_free_tx_resources(adapter, &tx_ring[i]);
+		vfree(tx_ring);
+	}
+
 	clear_bit(__IXGBEVF_RESETTING, &adapter->state);
 	return err;
 }