[PATCH 4.17 197/324] sh_eth: fix invalid context bug while calling auto-negotiation by ethtool

Greg Kroah-Hartman
2018-08-23T09:00:09Z

From: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>

[ Upstream commit 53a710b5044d8475faa6813000b6dd659400ef7b ]

Since commit 35b5f6b1a82b ("PHYLIB: Locking fixes for PHY I/O
potentially sleeping") phy_start_aneg() function utilizes a mutex
to serialize changes to phy state, however the helper function is
called in atomic context.

The bug can be reproduced by running "ethtool -r" command, the bug
is reported if CONFIG_DEBUG_ATOMIC_SLEEP build option is enabled.

Fixes: dc19e4e5e02f ("sh: sh_eth: Add support ethtool")
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Reviewed-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/renesas/sh_eth.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)

--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -2193,18 +2193,10 @@ static void sh_eth_get_regs(struct net_d

static int sh_eth_nway_reset(struct net_device *ndev)
{
- struct sh_eth_private *mdp = netdev_priv(ndev);
- unsigned long flags;
- int ret;
-
if (!ndev->phydev)
return -ENODEV;

- spin_lock_irqsave(&mdp->lock, flags);
- ret = phy_start_aneg(ndev->phydev);
- spin_unlock_irqrestore(&mdp->lock, flags);
-
- return ret;
+ return phy_start_aneg(ndev->phydev);
}

static u32 sh_eth_get_msglevel(struct net_device *ndev)