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path: root/drivers/net/phy
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-rw-r--r--drivers/net/phy/fixed_phy.c2
-rw-r--r--drivers/net/phy/mdio-mux.c19
-rw-r--r--drivers/net/phy/mdio_bus.c24
-rw-r--r--drivers/net/phy/phy_device.c62
4 files changed, 78 insertions, 29 deletions
diff --git a/drivers/net/phy/fixed_phy.c b/drivers/net/phy/fixed_phy.c
index fb1299c6326e..e23bf5b90e17 100644
--- a/drivers/net/phy/fixed_phy.c
+++ b/drivers/net/phy/fixed_phy.c
@@ -220,7 +220,7 @@ int fixed_phy_update_state(struct phy_device *phydev,
struct fixed_mdio_bus *fmb = &platform_fmb;
struct fixed_phy *fp;
- if (!phydev || !phydev->bus)
+ if (!phydev || phydev->bus != fmb->mii_bus)
return -EINVAL;
list_for_each_entry(fp, &fmb->phys, node) {
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..c340e412b38f 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
@@ -242,7 +244,7 @@ static inline void of_mdiobus_link_phydev(struct mii_bus *mdio,
*
* Returns 0 on success or < 0 on error.
*/
-int mdiobus_register(struct mii_bus *bus)
+int __mdiobus_register(struct mii_bus *bus, struct module *owner)
{
int i, err;
@@ -253,6 +255,7 @@ int mdiobus_register(struct mii_bus *bus)
BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
bus->state != MDIOBUS_UNREGISTERED);
+ bus->owner = owner;
bus->dev.parent = bus->parent;
bus->dev.class = &mdio_bus_class;
bus->dev.groups = NULL;
@@ -288,13 +291,16 @@ int mdiobus_register(struct mii_bus *bus)
error:
while (--i >= 0) {
- if (bus->phy_map[i])
- device_unregister(&bus->phy_map[i]->dev);
+ struct phy_device *phydev = bus->phy_map[i];
+ if (phydev) {
+ phy_device_remove(phydev);
+ phy_device_free(phydev);
+ }
}
device_del(&bus->dev);
return err;
}
-EXPORT_SYMBOL(mdiobus_register);
+EXPORT_SYMBOL(__mdiobus_register);
void mdiobus_unregister(struct mii_bus *bus)
{
@@ -304,9 +310,11 @@ void mdiobus_unregister(struct mii_bus *bus)
bus->state = MDIOBUS_UNREGISTERED;
for (i = 0; i < PHY_MAX_ADDR; i++) {
- if (bus->phy_map[i])
- device_unregister(&bus->phy_map[i]->dev);
- bus->phy_map[i] = NULL;
+ struct phy_device *phydev = bus->phy_map[i];
+ if (phydev) {
+ phy_device_remove(phydev);
+ phy_device_free(phydev);
+ }
}
device_del(&bus->dev);
}
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index c0f211127274..f761288abe66 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -384,6 +384,24 @@ int phy_device_register(struct phy_device *phydev)
EXPORT_SYMBOL(phy_device_register);
/**
+ * phy_device_remove - Remove a previously registered phy device from the MDIO bus
+ * @phydev: phy_device structure to remove
+ *
+ * This doesn't free the phy_device itself, it merely reverses the effects
+ * of phy_device_register(). Use phy_device_free() to free the device
+ * after calling this function.
+ */
+void phy_device_remove(struct phy_device *phydev)
+{
+ struct mii_bus *bus = phydev->bus;
+ int addr = phydev->addr;
+
+ device_del(&phydev->dev);
+ bus->phy_map[addr] = NULL;
+}
+EXPORT_SYMBOL(phy_device_remove);
+
+/**
* phy_find_first - finds the first PHY device on the bus
* @bus: the target MII bus
*/
@@ -578,14 +596,22 @@ EXPORT_SYMBOL(phy_init_hw);
* generic driver is used. The phy_device is given a ptr to
* the attaching device, and given a callback for link status
* change. The phy_device is returned to the attaching driver.
+ * This function takes a reference on the phy device.
*/
int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
u32 flags, phy_interface_t interface)
{
+ struct mii_bus *bus = phydev->bus;
struct device *d = &phydev->dev;
- struct module *bus_module;
int err;
+ if (!try_module_get(bus->owner)) {
+ dev_err(&dev->dev, "failed to get the bus module\n");
+ return -EIO;
+ }
+
+ get_device(d);
+
/* Assume that if there is no driver, that it doesn't
* exist, and we should use the genphy driver.
*/
@@ -600,20 +626,13 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
err = device_bind_driver(d);
if (err)
- return err;
+ goto error;
}
if (phydev->attached_dev) {
dev_err(&dev->dev, "PHY already attached\n");
- return -EBUSY;
- }
-
- /* Increment the bus module reference count */
- bus_module = phydev->bus->dev.driver ?
- phydev->bus->dev.driver->owner : NULL;
- if (!try_module_get(bus_module)) {
- dev_err(&dev->dev, "failed to get the bus module\n");
- return -EIO;
+ err = -EBUSY;
+ goto error;
}
phydev->attached_dev = dev;
@@ -636,6 +655,11 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
phy_resume(phydev);
return err;
+
+error:
+ put_device(d);
+ module_put(bus->owner);
+ return err;
}
EXPORT_SYMBOL(phy_attach_direct);
@@ -677,14 +701,15 @@ EXPORT_SYMBOL(phy_attach);
/**
* phy_detach - detach a PHY device from its network device
* @phydev: target phy_device struct
+ *
+ * This detaches the phy device from its network device and the phy
+ * driver, and drops the reference count taken in phy_attach_direct().
*/
void phy_detach(struct phy_device *phydev)
{
+ struct mii_bus *bus;
int i;
- if (phydev->bus->dev.driver)
- module_put(phydev->bus->dev.driver->owner);
-
phydev->attached_dev->phydev = NULL;
phydev->attached_dev = NULL;
phy_suspend(phydev);
@@ -700,6 +725,15 @@ void phy_detach(struct phy_device *phydev)
break;
}
}
+
+ /*
+ * The phydev might go away on the put_device() below, so avoid
+ * a use-after-free bug by reading the underlying bus first.
+ */
+ bus = phydev->bus;
+
+ put_device(&phydev->dev);
+ module_put(bus->owner);
}
EXPORT_SYMBOL(phy_detach);
generated by cgit v1.2.3 (git 2.0.4) at 2026-09-19 20:15:24 +0000