of_mdio_find_bus() leaks a struct device refcount, caused by using
class_find_device() and not realising that the device reference has
its refcount incremented:
* Note, you will need to drop the reference with put_device() after use.
...
while ((dev = class_dev_iter_next(&iter))) {
if (match(dev, data)) {
get_device(dev);
break;
}
Update the comment, and arrange for the phy code to drop this refcount
when disposing of a reference to it.
Signed-off-by: Russell King <rmk+ker...@arm.linux.org.uk>
---
drivers/net/phy/mdio-mux.c | 19 +++++++++++++------
drivers/net/phy/mdio_bus.c | 4 +++-
2 files changed, 16 insertions(+), 7 deletions(-)
diff --git a/drivers/net/phy/mdio-mux.c b/drivers/net/phy/mdio-mux.c
index 4d4d25efc1e1..280c7c311f72 100644
--- a/drivers/net/phy/mdio-mux.c
+++ b/drivers/net/phy/mdio-mux.c
@@ -113,18 +113,18 @@ int mdio_mux_init(struct device *dev,
if (!parent_bus_node)
return -ENODEV;
- parent_bus = of_mdio_find_bus(parent_bus_node);
- if (parent_bus == NULL) {
- ret_val = -EPROBE_DEFER;
- goto err_parent_bus;
- }
-
pb = devm_kzalloc(dev, sizeof(*pb), GFP_KERNEL);
if (pb == NULL) {
ret_val = -ENOMEM;
goto err_parent_bus;
}
+ parent_bus = of_mdio_find_bus(parent_bus_node);
+ if (parent_bus == NULL) {
+ ret_val = -EPROBE_DEFER;
+ goto err_parent_bus;
+ }
+
pb->switch_data = data;
pb->switch_fn = switch_fn;
pb->current_child = -1;
@@ -173,6 +173,10 @@ int mdio_mux_init(struct device *dev,
dev_info(dev, "Version " DRV_VERSION "\n");
return 0;
}
+
+ /* balance the reference of_mdio_find_bus() took */
+ put_device(&pb->mii_bus->dev);
+
err_parent_bus:
of_node_put(parent_bus_node);
return ret_val;
@@ -189,6 +193,9 @@ void mdio_mux_uninit(void *mux_handle)
mdiobus_free(cb->mii_bus);
cb = cb->next;
}
+
+ /* balance the reference of_mdio_find_bus() in mdio_mux_init() took */
+ put_device(&pb->mii_bus->dev);
}
EXPORT_SYMBOL_GPL(mdio_mux_uninit);
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 02a4615b65f8..67553e13bd36 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -167,7 +167,9 @@ static int of_mdio_bus_match(struct device *dev, const void
*mdio_bus_np)
* of_mdio_find_bus - Given an mii_bus node, find the mii_bus.
* @mdio_bus_np: Pointer to the mii_bus.
*
- * Returns a pointer to the mii_bus, or NULL if none found.
+ * Returns a reference to the mii_bus, or NULL if none found. The
+ * embedded struct device will have its reference count incremented,
+ * and this must be put once the bus is finished with.
*
* Because the association of a device_node and mii_bus is made via
* of_mdiobus_register(), the mii_bus cannot be found before it is
--
2.1.0
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