From e70c7aad7a95f4f9fd3f00caef1a1ceb57a4b5a4 Mon Sep 17 00:00:00 2001 From: Ioana Ciornei Date: Thu, 30 May 2019 09:09:07 +0300 Subject: [PATCH] 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: Ioana Ciornei Reported-by: kernel test robot Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller --- net/dsa/dsa2.c | 89 +++++++++++++++++++++++++++++++++++++------------- 1 file changed, 66 insertions(+), 23 deletions(-) diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c index 3b5f434cad3f..b70befe8a3c8 100644 --- a/net/dsa/dsa2.c +++ b/net/dsa/dsa2.c @@ -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; } -- 2.30.2