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Commit 4b65246b authored by Florian Fainelli's avatar Florian Fainelli Committed by David S. Miller
Browse files

ethtool: Protect {get, set}_phy_tunable with PHY device mutex 



PHY drivers should be able to rely on the caller of {get,set}_tunable to
have acquired the PHY device mutex, in order to both serialize against
concurrent calls of these functions, but also against PHY state machine
changes. All ethtool PHY-level functions do this, except
{get,set}_tunable, so we make them consistent here as well.

We need to update the Microsemi PHY driver in the same commit to avoid
introducing either deadlocks, or lack of proper locking.

Fixes: 968ad9da ("ethtool: Implements ETHTOOL_PHY_GTUNABLE/ETHTOOL_PHY_STUNABLE")
Fixes: 310d9ad5 ("net: phy: Add downshift get/set support in Microsemi PHYs driver")
Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Reviewed-by: default avatarAllan W. Nielsen <allan.nielsen@microsemi.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent fab96ec8

drivers/net/phy/mscc.c

+5 −11
Original line number Diff line number Diff line
@@ -115,10 +115,9 @@ static int vsc85xx_downshift_get(struct phy_device *phydev, u8 *count) 
	int rc;

	u16 reg_val;



	mutex_lock(&phydev->lock);

	rc = vsc85xx_phy_page_set(phydev, MSCC_PHY_PAGE_EXTENDED);

	if (rc != 0)

		goto out_unlock;

		goto out;



	reg_val = phy_read(phydev, MSCC_PHY_ACTIPHY_CNTL);

	reg_val &= DOWNSHIFT_CNTL_MASK;
@@ -128,9 +127,7 @@ static int vsc85xx_downshift_get(struct phy_device *phydev, u8 *count) 
		*count = ((reg_val & ~DOWNSHIFT_EN) >> DOWNSHIFT_CNTL_POS) + 2;

	rc = vsc85xx_phy_page_set(phydev, MSCC_PHY_PAGE_STANDARD);



out_unlock:

	mutex_unlock(&phydev->lock);



out:

	return rc;

}
@@ -150,23 +147,20 @@ static int vsc85xx_downshift_set(struct phy_device *phydev, u8 count) 
		count = (((count - 2) << DOWNSHIFT_CNTL_POS) | DOWNSHIFT_EN);

	}



	mutex_lock(&phydev->lock);

	rc = vsc85xx_phy_page_set(phydev, MSCC_PHY_PAGE_EXTENDED);

	if (rc != 0)

		goto out_unlock;

		goto out;



	reg_val = phy_read(phydev, MSCC_PHY_ACTIPHY_CNTL);

	reg_val &= ~(DOWNSHIFT_CNTL_MASK);

	reg_val |= count;

	rc = phy_write(phydev, MSCC_PHY_ACTIPHY_CNTL, reg_val);

	if (rc != 0)

		goto out_unlock;

		goto out;



	rc = vsc85xx_phy_page_set(phydev, MSCC_PHY_PAGE_STANDARD);



out_unlock:

	mutex_unlock(&phydev->lock);



out:

	return rc;

}

net/core/ethtool.c

+4 −0
Original line number Diff line number Diff line
@@ -2466,7 +2466,9 @@ static int get_phy_tunable(struct net_device *dev, void __user *useraddr) 
	data = kmalloc(tuna.len, GFP_USER);

	if (!data)

		return -ENOMEM;

	mutex_lock(&phydev->lock);

	ret = phydev->drv->get_tunable(phydev, &tuna, data);

	mutex_unlock(&phydev->lock);

	if (ret)

		goto out;

	useraddr += sizeof(tuna);
@@ -2501,7 +2503,9 @@ static int set_phy_tunable(struct net_device *dev, void __user *useraddr) 
	ret = -EFAULT;

	if (copy_from_user(data, useraddr, tuna.len))

		goto out;

	mutex_lock(&phydev->lock);

	ret = phydev->drv->set_tunable(phydev, &tuna, data);

	mutex_unlock(&phydev->lock);



out:

	kfree(data);