From 4b65246b427152fc7e8e1f673d3f0dc7582a89af Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Tue, 22 Nov 2016 13:55:31 -0800 Subject: [PATCH] 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: 968ad9da7e0e ("ethtool: Implements ETHTOOL_PHY_GTUNABLE/ETHTOOL_PHY_STUNABLE") Fixes: 310d9ad57ae0 ("net: phy: Add downshift get/set support in Microsemi PHYs driver") Signed-off-by: Florian Fainelli Reviewed-by: Andrew Lunn Reviewed-by: Allan W. Nielsen Signed-off-by: David S. Miller --- drivers/net/phy/mscc.c | 16 +++++----------- net/core/ethtool.c | 4 ++++ 2 files changed, 9 insertions(+), 11 deletions(-) diff --git a/drivers/net/phy/mscc.c b/drivers/net/phy/mscc.c index 92018ba..7a3740c 100644 --- a/drivers/net/phy/mscc.c +++ b/drivers/net/phy/mscc.c @@ -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; } diff --git a/net/core/ethtool.c b/net/core/ethtool.c index e9b45567..0adb3be 100644 --- a/net/core/ethtool.c +++ b/net/core/ethtool.c @@ -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); -- 2.7.4