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Message-Id: <1559196547-17917-1-git-send-email-ioana.ciornei@nxp.com>
Date: Thu, 30 May 2019 09:09:07 +0300
From: Ioana Ciornei <ioana.ciornei@....com>
To: linux@...linux.org.uk, f.fainelli@...il.com, andrew@...n.ch,
hkallweit1@...il.com, maxime.chevallier@...tlin.com,
olteanv@...il.com, thomas.petazzoni@...tlin.com,
davem@...emloft.net, vivien.didelot@...il.com
Cc: netdev@...r.kernel.org, Ioana Ciornei <ioana.ciornei@....com>
Subject: [PATCH v2 net-next] 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 <ioana.ciornei@....com>
Reported-by: kernel test robot <rong.a.chen@...el.com>
---
Sorry for sending this again but the first time I mistyped the netdev list
address.
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;
}
--
2.21.0
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