net/mlx4_core: Fix potential kernel Oops in res tracker during Dom0 driver unload

Currently the slave and master resources are deleted after master freed
all bitmaps. If any resources were not properly cleaned up during the
shutdown process, an Oops would result.

Fix so that delete slave (only) resources during cleanup. Master resources
are cleaned up during unload process, and need not separately be cleaned.

Note that during cleanup, we need to split the resource-tracker freeing
functionality.

Before removing all the bitmaps, we free any leftover slave resources.
However, we can only remove the resource tracker linked list after
all bitmap frees, since some of the freeing functions (e.g.,
mlx4_cleanup_eq_table) use paravirtualized FW commands which expect
the resource tracker linked list to be present.

Found-by: Aviad Yehezkel <aviadye@mellanox.com>
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 12 insertions, 5 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c b/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
index bb09ed7a1484..549abfb5a397 100644
--- a/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
+++ b/drivers/net/ethernet/mellanox/mlx4/resource_tracker.c
@@ -224,16 +224,23 @@ int mlx4_init_resource_tracker(struct mlx4_dev *dev)
 	return 0 ;
 }
 
-void mlx4_free_resource_tracker(struct mlx4_dev *dev)
+void mlx4_free_resource_tracker(struct mlx4_dev *dev,
+				enum mlx4_res_tracker_free_type type)
 {
 	struct mlx4_priv *priv = mlx4_priv(dev);
 	int i;
 
 	if (priv->mfunc.master.res_tracker.slave_list) {
-		for (i = 0 ; i < dev->num_slaves; i++)
-			mlx4_delete_all_resources_for_slave(dev, i);
-
-		kfree(priv->mfunc.master.res_tracker.slave_list);
+		if (type != RES_TR_FREE_STRUCTS_ONLY)
+			for (i = 0 ; i < dev->num_slaves; i++)
+				if (type == RES_TR_FREE_ALL ||
+				    dev->caps.function != i)
+					mlx4_delete_all_resources_for_slave(dev, i);
+
+		if (type != RES_TR_FREE_SLAVES_ONLY) {
+			kfree(priv->mfunc.master.res_tracker.slave_list);
+			priv->mfunc.master.res_tracker.slave_list = NULL;
+		}
 	}
 }