[PATCH net-next] tg3: copy only needed fields from userspace-provided EEE data

[PATCH net-next] tg3: copy only needed fields from userspace-provided EEE data

[Heiner Kallweit]

The current code overwrites fields in tp->eee with unchecked data from
edata, e.g. the bitmap with supported modes. ethtool properly returns
the received data from get_eee() call, but we have no guarantee that
other users of the ioctl set_eee() interface behave properly too.
Therefore copy only fields which are actually needed.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
 drivers/net/ethernet/broadcom/tg3.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index 51685cd29..7a07c5216 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -14200,7 +14200,9 @@ static int tg3_set_eee(struct net_device *dev, struct ethtool_keee *edata)
 		return -EINVAL;
 	}
 
-	tp->eee = *edata;
+	tp->eee.eee_enabled = edata->eee_enabled;
+	tp->eee.tx_lpi_enabled = edata->tx_lpi_enabled;
+	tp->eee.tx_lpi_timer = edata->tx_lpi_timer;
 
 	tp->phy_flags |= TG3_PHYFLG_USER_CONFIGURED;
 	tg3_warn_mgmt_link_flap(tp);
-- 
2.43.2

Re: [PATCH net-next] tg3: copy only needed fields from userspace-provided EEE data

[Andrew Lunn]

On Sun, Feb 18, 2024 at 03:49:55PM +0100, Heiner Kallweit wrote:
> The current code overwrites fields in tp->eee with unchecked data from
> edata, e.g. the bitmap with supported modes. ethtool properly returns
> the received data from get_eee() call, but we have no guarantee that
> other users of the ioctl set_eee() interface behave properly too.
> Therefore copy only fields which are actually needed.
> 
> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>

This one needed some time for me to understand. I missed that when
programming the PHY to advertise, it is hard coded what it actually
advertises. So there is no need to copy the advertise linkmode from
edata.

I suspect this driver is broken in that it does not wait for the
result of the auto-neg to enable/disable EEE in the hardware. But it
could be hiding somewhere in the code and i also missed that.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

Re: [PATCH net-next] tg3: copy only needed fields from userspace-provided EEE data

[Heiner Kallweit]

On 18.02.2024 18:04, Andrew Lunn wrote:
> On Sun, Feb 18, 2024 at 03:49:55PM +0100, Heiner Kallweit wrote:
>> The current code overwrites fields in tp->eee with unchecked data from
>> edata, e.g. the bitmap with supported modes. ethtool properly returns
>> the received data from get_eee() call, but we have no guarantee that
>> other users of the ioctl set_eee() interface behave properly too.
>> Therefore copy only fields which are actually needed.
>>
>> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
> 
> This one needed some time for me to understand. I missed that when
> programming the PHY to advertise, it is hard coded what it actually
> advertises. So there is no need to copy the advertise linkmode from
> edata.
> 
Especially as we have the following a few lines earlier:

    if (!linkmode_equal(edata->advertised, tp->eee.advertised)) {
                netdev_warn(tp->dev,
                            "Direct manipulation of EEE advertisement is not supported\n");
                return -EINVAL;
        }

> I suspect this driver is broken in that it does not wait for the
> result of the auto-neg to enable/disable EEE in the hardware. But it
> could be hiding somewhere in the code and i also missed that.
> 
> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
> 
>     Andrew

Re: [PATCH net-next] tg3: copy only needed fields from userspace-provided EEE data

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (main)
by David S. Miller <davem@davemloft.net>:

On Sun, 18 Feb 2024 15:49:55 +0100 you wrote:
> The current code overwrites fields in tp->eee with unchecked data from
> edata, e.g. the bitmap with supported modes. ethtool properly returns
> the received data from get_eee() call, but we have no guarantee that
> other users of the ioctl set_eee() interface behave properly too.
> Therefore copy only fields which are actually needed.
> 
> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
> 
> [...]

Here is the summary with links:
  - [net-next] tg3: copy only needed fields from userspace-provided EEE data
    https://git.kernel.org/netdev/net-next/c/8306ee08c0ff

You are awesome, thank you!
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