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 | 16 ++++++++++++++--
drivers/net/ethernet/broadcom/genet/bcmgenet.h | 4 +++-
.../net/ethernet/broadcom/genet/bcmgenet_wol.c | 8 +++++++-
drivers/net/ethernet/broadcom/genet/bcmmii.c | 6 +++++-
4 files changed, 29 insertions(+), 5 deletions(-)
--
Changes in v2:
Corrected [PATCH] to [PATCH net] and email address of
[email protected]
2.34.1
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: [email protected]
Signed-off-by: Doug Berger <[email protected]>
---
drivers/net/ethernet/broadcom/genet/bcmmii.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c
index 9ada89355747..86a4aa72b3d4 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmmii.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c
@@ -2,7 +2,7 @@
/*
* Broadcom GENET MDIO routines
*
- * Copyright (c) 2014-2017 Broadcom
+ * Copyright (c) 2014-2024 Broadcom
*/
#include <linux/acpi.h>
@@ -275,6 +275,7 @@ int bcmgenet_mii_config(struct net_device *dev, bool init)
* block for the interface to work, unconditionally clear the
* Out-of-band disable since we do not need it.
*/
+ mutex_lock(&phydev->lock);
reg = bcmgenet_ext_readl(priv, EXT_RGMII_OOB_CTRL);
reg &= ~OOB_DISABLE;
if (priv->ext_phy) {
@@ -286,6 +287,7 @@ int bcmgenet_mii_config(struct net_device *dev, bool init)
reg |= RGMII_MODE_EN;
}
bcmgenet_ext_writel(priv, reg, EXT_RGMII_OOB_CTRL);
+ mutex_unlock(&phydev->lock);
if (init)
dev_info(kdev, "configuring instance for %s\n", phy_name);
--
2.34.1
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: [email protected]
Signed-off-by: Doug Berger <[email protected]>
---
drivers/net/ethernet/broadcom/genet/bcmgenet.c | 12 +++++++++++-
drivers/net/ethernet/broadcom/genet/bcmgenet.h | 4 +++-
drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c | 8 +++++++-
drivers/net/ethernet/broadcom/genet/bcmmii.c | 2 ++
4 files changed, 23 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index 5452b7dc6e6a..c7e7dac057a3 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -2467,14 +2467,18 @@ 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
@@ -2490,8 +2494,10 @@ 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)
@@ -3597,16 +3603,19 @@ 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 */
@@ -4005,6 +4014,7 @@ static int bcmgenet_probe(struct platform_device *pdev)
goto err;
}
+ spin_lock_init(&priv->reg_lock);
spin_lock_init(&priv->lock);
/* Set default pause parameters */
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.h b/drivers/net/ethernet/broadcom/genet/bcmgenet.h
index 7523b60b3c1c..43b923c48b14 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.h
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.h
@@ -1,6 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/*
- * Copyright (c) 2014-2020 Broadcom
+ * Copyright (c) 2014-2024 Broadcom
*/
#ifndef __BCMGENET_H__
@@ -573,6 +573,8 @@ struct bcmgenet_rxnfc_rule {
/* 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 7a41cad5788f..1248792d7fd4 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet_wol.c
@@ -2,7 +2,7 @@
/*
* Broadcom GENET (Gigabit Ethernet) Wake-on-LAN support
*
- * Copyright (c) 2014-2020 Broadcom
+ * Copyright (c) 2014-2024 Broadcom
*/
#define pr_fmt(fmt) "bcmgenet_wol: " fmt
@@ -151,6 +151,7 @@ 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;
@@ -158,6 +159,7 @@ 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);
if (priv->wolopts & (WAKE_MAGIC | WAKE_MAGICSECURE)) {
@@ -203,6 +205,7 @@ int bcmgenet_wol_power_down_cfg(struct bcmgenet_priv *priv,
}
/* 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;
@@ -210,6 +213,7 @@ 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);
reg = UMAC_IRQ_MPD_R;
if (hfb_enable)
@@ -256,7 +260,9 @@ void bcmgenet_wol_power_up_cfg(struct bcmgenet_priv *priv,
}
/* 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);
}
diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c
index 86a4aa72b3d4..c4a3698cef66 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmmii.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c
@@ -76,6 +76,7 @@ static void bcmgenet_mac_config(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 |
@@ -88,6 +89,7 @@ static void bcmgenet_mac_config(struct net_device *dev)
reg |= CMD_TX_EN | CMD_RX_EN;
}
bcmgenet_umac_writel(priv, reg, UMAC_CMD);
+ spin_unlock_bh(&priv->reg_lock);
active = phy_init_eee(phydev, 0) >= 0;
bcmgenet_eee_enable_set(dev,
--
2.34.1
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: [email protected]
Signed-off-by: Doug Berger <[email protected]>
---
drivers/net/ethernet/broadcom/genet/bcmgenet.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
index b1f84b37032a..5452b7dc6e6a 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c
@@ -2,7 +2,7 @@
/*
* Broadcom GENET (Gigabit Ethernet) controller driver
*
- * Copyright (c) 2014-2020 Broadcom
+ * Copyright (c) 2014-2024 Broadcom
*/
#define pr_fmt(fmt) "bcmgenet: " fmt
@@ -3334,7 +3334,9 @@ 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
On 4/25/24 15:27, Doug Berger wrote:
> 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: [email protected]
> Signed-off-by: Doug Berger <[email protected]>
Acked-by: Florian Fainelli <[email protected]>
--
Florian
On 4/25/24 15:27, Doug Berger wrote:
> 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: [email protected]
> Signed-off-by: Doug Berger <[email protected]>
Acked-by: Florian Fainelli <[email protected]>
As a bug fix this is totally fine. I believe there could be an
improvement made in 'net-next' whereby we introduce an
unimac_rmw_locked() or something that essentially does:
void unimac_rmw_locked(struct bcmgenet_priv *priv, u32 offset, u32
mask_clear, u32 mask_set)
{
u32 reg;
spin_lock_bh(&priv->reg_lock);
reg = bcmgenet_umac_readl(priv, offset);
reg &= ~mask_clear;
reg |= mask_set;
bcmgenet_umac_writel(priv, reg, offset);
spin_unlock_bh(&priv->reg_lock);
}
At least a couple of callers could benefit from it. Thanks!
--
Florian
On 4/26/2024 11:19 AM, Florian Fainelli wrote:
> On 4/25/24 15:27, Doug Berger wrote:
>> 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: [email protected]
>> Signed-off-by: Doug Berger <[email protected]>
>
> Acked-by: Florian Fainelli <[email protected]>
>
> As a bug fix this is totally fine. I believe there could be an
> improvement made in 'net-next' whereby we introduce an
> unimac_rmw_locked() or something that essentially does:
>
> void unimac_rmw_locked(struct bcmgenet_priv *priv, u32 offset, u32
> mask_clear, u32 mask_set)
> {
> u32 reg;
> spin_lock_bh(&priv->reg_lock);
> reg = bcmgenet_umac_readl(priv, offset);
> reg &= ~mask_clear;
> reg |= mask_set;
> bcmgenet_umac_writel(priv, reg, offset);
> spin_unlock_bh(&priv->reg_lock);
> }
>
> At least a couple of callers could benefit from it. Thanks!
The only issue I see is enforcing the 2us delay in reset_umac(). A
scenario where a different context might attempt to modify UMAC_CMD
during that window is admittedly contrived, but the approach of this
commit provides better protection.
-Doug
On 4/26/2024 12:43 PM, Doug Berger wrote:
> At least a couple of callers could benefit from it. Thanks!
Yes, adding unimac_rmw_locked() as a helper for some cases probably does
make sense for net-next.
-Doug
On 4/25/24 15:27, Doug Berger wrote:
> 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: [email protected]
> Signed-off-by: Doug Berger <[email protected]>
Acked-by: Florian Fainelli <[email protected]>
--
Florian
Hello:
This series was applied to netdev/net.git (main)
by David S. Miller <[email protected]>:
On Thu, 25 Apr 2024 15:27:18 -0700 you 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
>
> [...]
Here is the summary with links:
- [net,v2,1/3] net: bcmgenet: synchronize EXT_RGMII_OOB_CTRL access
https://git.kernel.org/netdev/net/c/d85cf67a3396
- [net,v2,2/3] net: bcmgenet: synchronize use of bcmgenet_set_rx_mode()
https://git.kernel.org/netdev/net/c/2dbe5f19368c
- [net,v2,3/3] net: bcmgenet: synchronize UMAC_CMD access
https://git.kernel.org/netdev/net/c/0d5e2a822326
You are awesome, thank you!
--
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