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Commit e70c7aad authored by Ioana Ciornei's avatar Ioana Ciornei Committed by David S. Miller
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net: dsa: Add error path handling in dsa_tree_setup() 



In case a call to dsa_tree_setup() fails, an attempt to cleanup is made
by calling dsa_tree_remove_switch(), which should take care of
removing/unregistering any resources previously allocated. This does not
happen because it is conditioned by dst->setup being true, which is set
only after _all_ setup steps were performed successfully.

This is especially interesting when the internal MDIO bus is registered
but afterwards, a port setup fails and the mdiobus_unregister() is never
called. This leads to a BUG_ON() complaining about the fact that it's
trying to free an MDIO bus that's still registered.

Add proper error handling in all functions branching from
dsa_tree_setup().

Signed-off-by: default avatarIoana Ciornei <ioana.ciornei@nxp.com>
Reported-by: default avatarkernel test robot <rong.a.chen@intel.com>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1b0b807d

net/dsa/dsa2.c

+66 −23
Original line number Diff line number Diff line
@@ -261,7 +261,7 @@ static int dsa_port_setup(struct dsa_port *dp) 
	enum devlink_port_flavour flavour;

	struct dsa_switch *ds = dp->ds;

	struct dsa_switch_tree *dst = ds->dst;

	int err;

	int err = 0;



	if (dp->type == DSA_PORT_TYPE_UNUSED)

		return 0;
@@ -299,19 +299,15 @@ static int dsa_port_setup(struct dsa_port *dp) 
		break;

	case DSA_PORT_TYPE_CPU:

		err = dsa_port_link_register_of(dp);

		if (err) {

		if (err)

			dev_err(ds->dev, "failed to setup link for port %d.%d\n",

				ds->index, dp->index);

			return err;

		}

		break;

	case DSA_PORT_TYPE_DSA:

		err = dsa_port_link_register_of(dp);

		if (err) {

		if (err)

			dev_err(ds->dev, "failed to setup link for port %d.%d\n",

				ds->index, dp->index);

			return err;

		}

		break;

	case DSA_PORT_TYPE_USER:

		err = dsa_slave_create(dp);
@@ -323,7 +319,10 @@ static int dsa_port_setup(struct dsa_port *dp) 
		break;

	}



	return 0;

	if (err)

		devlink_port_unregister(&dp->devlink_port);



	return err;

}



static void dsa_port_teardown(struct dsa_port *dp)
@@ -351,7 +350,7 @@ static void dsa_port_teardown(struct dsa_port *dp) 


static int dsa_switch_setup(struct dsa_switch *ds)

{

	int err;

	int err = 0;



	/* Initialize ds->phys_mii_mask before registering the slave MDIO bus

	 * driver and before ops->setup() has run, since the switch drivers and
@@ -369,29 +368,41 @@ static int dsa_switch_setup(struct dsa_switch *ds) 


	err = devlink_register(ds->devlink, ds->dev);

	if (err)

		return err;

		goto free_devlink;



	err = dsa_switch_register_notifier(ds);

	if (err)

		return err;

		goto unregister_devlink;



	err = ds->ops->setup(ds);

	if (err < 0)

		return err;

		goto unregister_notifier;



	if (!ds->slave_mii_bus && ds->ops->phy_read) {

		ds->slave_mii_bus = devm_mdiobus_alloc(ds->dev);

		if (!ds->slave_mii_bus)

			return -ENOMEM;

		if (!ds->slave_mii_bus) {

			err = -ENOMEM;

			goto unregister_notifier;

		}



		dsa_slave_mii_bus_init(ds);



		err = mdiobus_register(ds->slave_mii_bus);

		if (err < 0)

			return err;

			goto unregister_notifier;

	}



	return 0;



unregister_notifier:

	dsa_switch_unregister_notifier(ds);

unregister_devlink:

	devlink_unregister(ds->devlink);

free_devlink:

	devlink_free(ds->devlink);

	ds->devlink = NULL;



	return err;

}



static void dsa_switch_teardown(struct dsa_switch *ds)
@@ -413,8 +424,8 @@ static int dsa_tree_setup_switches(struct dsa_switch_tree *dst) 
{

	struct dsa_switch *ds;

	struct dsa_port *dp;

	int device, port;

	int err;

	int device, port, i;

	int err = 0;



	for (device = 0; device < DSA_MAX_SWITCHES; device++) {

		ds = dst->ds[device];
@@ -423,18 +434,41 @@ static int dsa_tree_setup_switches(struct dsa_switch_tree *dst) 


		err = dsa_switch_setup(ds);

		if (err)

			return err;

			goto switch_teardown;



		for (port = 0; port < ds->num_ports; port++) {

			dp = &ds->ports[port];



			err = dsa_port_setup(dp);

			if (err)

				return err;

				goto ports_teardown;

		}

	}



	return 0;



ports_teardown:

	for (i = 0; i < port; i++)

		dsa_port_teardown(&ds->ports[i]);



	dsa_switch_teardown(ds);



switch_teardown:

	for (i = 0; i < device; i++) {

		ds = dst->ds[i];

		if (!ds)

			continue;



		for (port = 0; port < ds->num_ports; port++) {

			dp = &ds->ports[port];



			dsa_port_teardown(dp);

		}



		dsa_switch_teardown(ds);

	}



	return err;

}



static void dsa_tree_teardown_switches(struct dsa_switch_tree *dst)
@@ -496,17 +530,24 @@ static int dsa_tree_setup(struct dsa_switch_tree *dst) 


	err = dsa_tree_setup_switches(dst);

	if (err)

		return err;

		goto teardown_default_cpu;



	err = dsa_tree_setup_master(dst);

	if (err)

		return err;

		goto teardown_switches;



	dst->setup = true;



	pr_info("DSA: tree %d setup\n", dst->index);



	return 0;



teardown_switches:

	dsa_tree_teardown_switches(dst);

teardown_default_cpu:

	dsa_tree_teardown_default_cpu(dst);



	return err;

}



static void dsa_tree_teardown(struct dsa_switch_tree *dst)
@@ -547,8 +588,10 @@ static int dsa_tree_add_switch(struct dsa_switch_tree *dst, 
	dst->ds[index] = ds;



	err = dsa_tree_setup(dst);

	if (err)

		dsa_tree_remove_switch(dst, index);

	if (err) {

		dst->ds[index] = NULL;

		dsa_tree_put(dst);

	}



	return err;

}