net: phy: Ensure the MDIO bus module is held (b3565f27) · Commits · 戴 / test

This commit adds proper module_{get,put} to prevent the MDIO bus module from being unloaded while the phydev is connected. By doing so, we fix a kernel panic produced when a MDIO driver is removed, but the phydev that relies on it is attached and running. Signed-off-by:

Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Reviewed-by:

Florian Fainelli <f.fainelli@gmail.com> Tested-by:

Florian Fainelli <f.fainelli@gmail.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

drivers/net/phy/phy_device.c

+13 −0

Original line number	Diff line number	Diff line
		@@ -575,6 +575,7 @@ int phy_attach_direct(struct net_device dev, struct phy_device phydev,
		u32 flags, phy_interface_t interface)
		{
		struct device *d = &phydev->dev;
		struct module *bus_module;
		int err;

		/* Assume that if there is no driver, that it doesn't
		@@ -599,6 +600,14 @@ int phy_attach_direct(struct net_device dev, struct phy_device phydev,
		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;
		}

		phydev->attached_dev = dev;
		dev->phydev = phydev;

		@@ -664,6 +673,10 @@ EXPORT_SYMBOL(phy_attach);
		void phy_detach(struct phy_device *phydev)
		{
		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);

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