[PATCH stable 5.4 0/3] net: bcmgenet: protect contended accesses

[PATCH stable 5.4 0/3] net: bcmgenet: protect contended accesses

[Doug Berger]

Some registers may be modified by parallel execution contexts and
require protections to prevent corruption.

A review of the driver revealed the need for these additional
protections.

Doug Berger (3):
  net: bcmgenet: synchronize EXT_RGMII_OOB_CTRL access
  net: bcmgenet: synchronize use of bcmgenet_set_rx_mode()
  net: bcmgenet: synchronize UMAC_CMD access

 drivers/net/ethernet/broadcom/genet/bcmgenet.c     | 14 +++++++++++++-
 drivers/net/ethernet/broadcom/genet/bcmgenet.h     |  2 ++
 drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c |  6 ++++++
 drivers/net/ethernet/broadcom/genet/bcmmii.c       |  4 ++++
 4 files changed, 25 insertions(+), 1 deletion(-)

-- 
These commits are dependent on the previously submitted:
[PATCH stable 5.4 0/2] net: bcmgenet: revisit MAC reset

2.34.1

[PATCH stable 5.4 1/3] net: bcmgenet: synchronize EXT_RGMII_OOB_CTRL access

[Doug Berger]

[ Upstream commit d85cf67a339685beae1d0aee27b7f61da95455be ]

The EXT_RGMII_OOB_CTRL register can be written from different
contexts. It is predominantly written from the adjust_link
handler which is synchronized by the phydev->lock, but can
also be written from a different context when configuring the
mii in bcmgenet_mii_config().

The chances of contention are quite low, but it is conceivable
that adjust_link could occur during resume when WoL is enabled
so use the phydev->lock synchronizer in bcmgenet_mii_config()
to be sure.

Fixes: afe3f907d20f ("net: bcmgenet: power on MII block for all MII modes")
Cc: stable@vger.kernel.org
Signed-off-by: Doug Berger <opendmb@gmail.com>
Acked-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/net/ethernet/broadcom/genet/bcmmii.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c
index 56fad34461f7..d0b59d1f6c73 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmmii.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c
@@ -269,6 +269,7 @@ int bcmgenet_mii_config(struct net_device *dev, bool init)
 	 * block for the interface to work
 	 */
 	if (priv->ext_phy) {
+		mutex_lock(&phydev->lock);
 		reg = bcmgenet_ext_readl(priv, EXT_RGMII_OOB_CTRL);
 		reg |= id_mode_dis;
 		if (GENET_IS_V1(priv) || GENET_IS_V2(priv) || GENET_IS_V3(priv))
@@ -276,6 +277,7 @@ int bcmgenet_mii_config(struct net_device *dev, bool init)
 		else
 			reg |= RGMII_MODE_EN;
 		bcmgenet_ext_writel(priv, reg, EXT_RGMII_OOB_CTRL);
+		mutex_unlock(&phydev->lock);
 	}
 
 	if (init)
-- 
2.34.1

[PATCH stable 5.4 2/3] net: bcmgenet: synchronize use of bcmgenet_set_rx_mode()

[Doug Berger]

[ Upstream commit 2dbe5f19368caae63b1f59f5bc2af78c7d522b3a ]

The ndo_set_rx_mode function is synchronized with the
netif_addr_lock spinlock and BHs disabled. Since this
function is also invoked directly from the driver the
same synchronization should be applied.

Fixes: 72f96347628e ("net: bcmgenet: set Rx mode before starting netif")
Cc: stable@vger.kernel.org
Signed-off-by: Doug Berger <opendmb@gmail.com>
Acked-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/net/ethernet/broadcom/genet/bcmgenet.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index bf52bd643846..e34df8da65e7 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -2874,7 +2874,9 @@ static void bcmgenet_netif_start(struct net_device *dev)
 	struct bcmgenet_priv *priv = netdev_priv(dev);
 
 	/* Start the network engine */
+	netif_addr_lock_bh(dev);
 	bcmgenet_set_rx_mode(dev);
+	netif_addr_unlock_bh(dev);
 	bcmgenet_enable_rx_napi(priv);
 
 	umac_enable_set(priv, CMD_TX_EN | CMD_RX_EN, true);
-- 
2.34.1

[PATCH stable 5.4 3/3] net: bcmgenet: synchronize UMAC_CMD access

[Doug Berger]

[ Upstream commit 0d5e2a82232605b337972fb2c7d0cbc46898aca1 ]

The UMAC_CMD register is written from different execution
contexts and has insufficient synchronization protections to
prevent possible corruption. Of particular concern are the
acceses from the phy_device delayed work context used by the
adjust_link call and the BH context that may be used by the
ndo_set_rx_mode call.

A spinlock is added to the driver to protect contended register
accesses (i.e. reg_lock) and it is used to synchronize accesses
to UMAC_CMD.

Fixes: 1c1008c793fa ("net: bcmgenet: add main driver file")
Cc: stable@vger.kernel.org
Signed-off-by: Doug Berger <opendmb@gmail.com>
Acked-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 drivers/net/ethernet/broadcom/genet/bcmgenet.c     | 12 +++++++++++-
 drivers/net/ethernet/broadcom/genet/bcmgenet.h     |  2 ++
 drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c |  6 ++++++
 drivers/net/ethernet/broadcom/genet/bcmmii.c       |  2 ++
 4 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index e34df8da65e7..da9df1d3662b 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -1990,14 +1990,18 @@ static void umac_enable_set(struct bcmgenet_priv *priv, u32 mask, bool enable)
 {
 	u32 reg;
 
+	spin_lock_bh(&priv->reg_lock);
 	reg = bcmgenet_umac_readl(priv, UMAC_CMD);
-	if (reg & CMD_SW_RESET)
+	if (reg & CMD_SW_RESET) {
+		spin_unlock_bh(&priv->reg_lock);
 		return;
+	}
 	if (enable)
 		reg |= mask;
 	else
 		reg &= ~mask;
 	bcmgenet_umac_writel(priv, reg, UMAC_CMD);
+	spin_unlock_bh(&priv->reg_lock);
 
 	/* UniMAC stops on a packet boundary, wait for a full-size packet
 	 * to be processed
@@ -2013,8 +2017,10 @@ static void reset_umac(struct bcmgenet_priv *priv)
 	udelay(10);
 
 	/* issue soft reset and disable MAC while updating its registers */
+	spin_lock_bh(&priv->reg_lock);
 	bcmgenet_umac_writel(priv, CMD_SW_RESET, UMAC_CMD);
 	udelay(2);
+	spin_unlock_bh(&priv->reg_lock);
 }
 
 static void bcmgenet_intr_disable(struct bcmgenet_priv *priv)
@@ -3140,16 +3146,19 @@ static void bcmgenet_set_rx_mode(struct net_device *dev)
 	 * 3. The number of filters needed exceeds the number filters
 	 *    supported by the hardware.
 	*/
+	spin_lock(&priv->reg_lock);
 	reg = bcmgenet_umac_readl(priv, UMAC_CMD);
 	if ((dev->flags & (IFF_PROMISC | IFF_ALLMULTI)) ||
 	    (nfilter > MAX_MDF_FILTER)) {
 		reg |= CMD_PROMISC;
 		bcmgenet_umac_writel(priv, reg, UMAC_CMD);
+		spin_unlock(&priv->reg_lock);
 		bcmgenet_umac_writel(priv, 0, UMAC_MDF_CTRL);
 		return;
 	} else {
 		reg &= ~CMD_PROMISC;
 		bcmgenet_umac_writel(priv, reg, UMAC_CMD);
+		spin_unlock(&priv->reg_lock);
 	}
 
 	/* update MDF filter */
@@ -3507,6 +3516,7 @@ static int bcmgenet_probe(struct platform_device *pdev)
 		goto err;
 	}
 
+	spin_lock_init(&priv->reg_lock);
 	spin_lock_init(&priv->lock);
 
 	SET_NETDEV_DEV(dev, &pdev->dev);
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.h b/drivers/net/ethernet/broadcom/genet/bcmgenet.h
index 29bf256d13f6..9efc503a9c8b 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.h
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.h
@@ -608,6 +608,8 @@ struct bcmgenet_rx_ring {
 /* device context */
 struct bcmgenet_priv {
 	void __iomem *base;
+	/* reg_lock: lock to serialize access to shared registers */
+	spinlock_t reg_lock;
 	enum bcmgenet_version version;
 	struct net_device *dev;
 
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c b/drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c
index 8ebca6bf300e..973275d116b6 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c
@@ -133,6 +133,7 @@ int bcmgenet_wol_power_down_cfg(struct bcmgenet_priv *priv,
 	}
 
 	/* Can't suspend with WoL if MAC is still in reset */
+	spin_lock_bh(&priv->reg_lock);
 	reg = bcmgenet_umac_readl(priv, UMAC_CMD);
 	if (reg & CMD_SW_RESET)
 		reg &= ~CMD_SW_RESET;
@@ -140,6 +141,7 @@ int bcmgenet_wol_power_down_cfg(struct bcmgenet_priv *priv,
 	/* disable RX */
 	reg &= ~CMD_RX_EN;
 	bcmgenet_umac_writel(priv, reg, UMAC_CMD);
+	spin_unlock_bh(&priv->reg_lock);
 	mdelay(10);
 
 	reg = bcmgenet_umac_readl(priv, UMAC_MPD_CTRL);
@@ -163,6 +165,7 @@ int bcmgenet_wol_power_down_cfg(struct bcmgenet_priv *priv,
 		  retries);
 
 	/* Enable CRC forward */
+	spin_lock_bh(&priv->reg_lock);
 	reg = bcmgenet_umac_readl(priv, UMAC_CMD);
 	priv->crc_fwd_en = 1;
 	reg |= CMD_CRC_FWD;
@@ -170,6 +173,7 @@ int bcmgenet_wol_power_down_cfg(struct bcmgenet_priv *priv,
 	/* Receiver must be enabled for WOL MP detection */
 	reg |= CMD_RX_EN;
 	bcmgenet_umac_writel(priv, reg, UMAC_CMD);
+	spin_unlock_bh(&priv->reg_lock);
 
 	return 0;
 }
@@ -191,8 +195,10 @@ void bcmgenet_wol_power_up_cfg(struct bcmgenet_priv *priv,
 	bcmgenet_umac_writel(priv, reg, UMAC_MPD_CTRL);
 
 	/* Disable CRC Forward */
+	spin_lock_bh(&priv->reg_lock);
 	reg = bcmgenet_umac_readl(priv, UMAC_CMD);
 	reg &= ~CMD_CRC_FWD;
 	bcmgenet_umac_writel(priv, reg, UMAC_CMD);
+	spin_unlock_bh(&priv->reg_lock);
 	priv->crc_fwd_en = 0;
 }
diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c
index d0b59d1f6c73..bd532e5b9f73 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmmii.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c
@@ -91,6 +91,7 @@ void bcmgenet_mii_setup(struct net_device *dev)
 		reg |= RGMII_LINK;
 		bcmgenet_ext_writel(priv, reg, EXT_RGMII_OOB_CTRL);
 
+		spin_lock_bh(&priv->reg_lock);
 		reg = bcmgenet_umac_readl(priv, UMAC_CMD);
 		reg &= ~((CMD_SPEED_MASK << CMD_SPEED_SHIFT) |
 			       CMD_HD_EN |
@@ -103,6 +104,7 @@ void bcmgenet_mii_setup(struct net_device *dev)
 			reg |= CMD_TX_EN | CMD_RX_EN;
 		}
 		bcmgenet_umac_writel(priv, reg, UMAC_CMD);
+		spin_unlock_bh(&priv->reg_lock);
 
 		priv->eee.eee_active = phy_init_eee(phydev, 0) >= 0;
 		bcmgenet_eee_enable_set(dev,
-- 
2.34.1

Re: [PATCH stable 5.4 0/3] net: bcmgenet: protect contended accesses

[Greg KH]

On Thu, May 16, 2024 at 04:01:48PM -0700, Doug Berger wrote:
> Some registers may be modified by parallel execution contexts and
> require protections to prevent corruption.
> 
> A review of the driver revealed the need for these additional
> protections.
> 
> Doug Berger (3):
>   net: bcmgenet: synchronize EXT_RGMII_OOB_CTRL access
>   net: bcmgenet: synchronize use of bcmgenet_set_rx_mode()
>   net: bcmgenet: synchronize UMAC_CMD access
> 
>  drivers/net/ethernet/broadcom/genet/bcmgenet.c     | 14 +++++++++++++-
>  drivers/net/ethernet/broadcom/genet/bcmgenet.h     |  2 ++
>  drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c |  6 ++++++
>  drivers/net/ethernet/broadcom/genet/bcmmii.c       |  4 ++++
>  4 files changed, 25 insertions(+), 1 deletion(-)
> 
> -- 
> These commits are dependent on the previously submitted:
> [PATCH stable 5.4 0/2] net: bcmgenet: revisit MAC reset
> 
> 2.34.1
> 
> 

All now queued up, thanks.

greg k-h