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| author | Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se> | 2024-09-03 19:15:36 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-09-04 17:01:21 -0700 |
| commit | 569bf6d481b0b823c3c9c3b8be77908fd7caf66b (patch) | |
| tree | a3c7c6f7dd11b70ea5cea9edbf6af56e0ea09d52 /drivers/net/phy | |
| parent | 8ed6e71219a3571a5583db6f839e80eebaa2853d (diff) | |
| download | linux-569bf6d481b0b823c3c9c3b8be77908fd7caf66b.tar.gz linux-569bf6d481b0b823c3c9c3b8be77908fd7caf66b.tar.bz2 linux-569bf6d481b0b823c3c9c3b8be77908fd7caf66b.zip | |
net: phy: Check for read errors in SIOCGMIIREG
When reading registers from the PHY using the SIOCGMIIREG IOCTL any
errors returned from either mdiobus_read() or mdiobus_c45_read() are
ignored, and parts of the returned error is passed as the register value
back to user-space.
For example, if mdiobus_c45_read() is used with a bus that do not
implement the read_c45() callback -EOPNOTSUPP is returned. This is
however directly stored in mii_data->val_out and returned as the
registers content. As val_out is a u16 the error code is truncated and
returned as a plausible register value.
Fix this by first checking the return value for errors before returning
it as the register content.
Before this patch,
# phytool read eth0/0:1/0
0xffa1
After this change,
$ phytool read eth0/0:1/0
error: phy_read (-95)
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20240903171536.628930-1-niklas.soderlund+renesas@ragnatech.se
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/phy')
| -rw-r--r-- | drivers/net/phy/phy.c | 17 |
1 files changed, 11 insertions, 6 deletions
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c index cba3af926429..4f3e742907cb 100644 --- a/drivers/net/phy/phy.c +++ b/drivers/net/phy/phy.c @@ -342,14 +342,19 @@ int phy_mii_ioctl(struct phy_device *phydev, struct ifreq *ifr, int cmd) if (mdio_phy_id_is_c45(mii_data->phy_id)) { prtad = mdio_phy_id_prtad(mii_data->phy_id); devad = mdio_phy_id_devad(mii_data->phy_id); - mii_data->val_out = mdiobus_c45_read( - phydev->mdio.bus, prtad, devad, - mii_data->reg_num); + ret = mdiobus_c45_read(phydev->mdio.bus, prtad, devad, + mii_data->reg_num); + } else { - mii_data->val_out = mdiobus_read( - phydev->mdio.bus, mii_data->phy_id, - mii_data->reg_num); + ret = mdiobus_read(phydev->mdio.bus, mii_data->phy_id, + mii_data->reg_num); } + + if (ret < 0) + return ret; + + mii_data->val_out = ret; + return 0; case SIOCSMIIREG: |