diff mbox series

[net,4/4] phy: phy_ethtool_ksettings_set: Lock the PHY while changing settings

Message ID 20211024194805.2762333-5-andrew@lunn.ch (mailing list archive)
State Accepted
Delegated to: Netdev Maintainers
Headers show
Series ksettings_{get|set} lock fixes | expand

Checks

Context Check Description
netdev/cover_letter success Series has a cover letter
netdev/fixes_present success Fixes tag present in non-next series
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for net
netdev/subject_prefix success Link
netdev/cc_maintainers warning 1 maintainers not CCed: linux@armlinux.org.uk
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Fixes tag looks correct
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 17 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/header_inline success No static functions without inline keyword in header files

Commit Message

Andrew Lunn Oct. 24, 2021, 7:48 p.m. UTC
There is a race condition where the PHY state machine can change
members of the phydev structure at the same time userspace requests a
change via ethtool. To prevent this, have phy_ethtool_ksettings_set
take the PHY lock.

Fixes: 2d55173e71b0 ("phy: add generic function to support ksetting support")
Reported-by: Walter Stoll <Walter.Stoll@duagon.com>
Suggested-by: Walter Stoll <Walter.Stoll@duagon.com>
Tested-by: Walter Stoll <Walter.Stoll@duagon.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
---
 drivers/net/phy/phy.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index d845afab1af7..a3bfb156c83d 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -798,6 +798,7 @@  int phy_ethtool_ksettings_set(struct phy_device *phydev,
 	      duplex != DUPLEX_FULL)))
 		return -EINVAL;
 
+	mutex_lock(&phydev->lock);
 	phydev->autoneg = autoneg;
 
 	if (autoneg == AUTONEG_DISABLE) {
@@ -814,8 +815,9 @@  int phy_ethtool_ksettings_set(struct phy_device *phydev,
 	phydev->mdix_ctrl = cmd->base.eth_tp_mdix_ctrl;
 
 	/* Restart the PHY */
-	phy_start_aneg(phydev);
+	_phy_start_aneg(phydev);
 
+	mutex_unlock(&phydev->lock);
 	return 0;
 }
 EXPORT_SYMBOL(phy_ethtool_ksettings_set);