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ravb: Fix races between ravb_tx_timeout_work() and net related ops

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[ Upstream commit 9870257a0a338cd8d6c1cddab74e703f490f6779 ]

Fix races between ravb_tx_timeout_work() and functions of net_device_ops
and ethtool_ops by using rtnl_trylock() and rtnl_unlock(). Note that
since ravb_close() is under the rtnl lock and calls cancel_work_sync(),
ravb_tx_timeout_work() should calls rtnl_trylock(). Otherwise, a deadlock
may happen in ravb_tx_timeout_work() like below:

CPU0			CPU1
			ravb_tx_timeout()
			schedule_work()
...
__dev_close_many()
// Under rtnl lock
ravb_close()
cancel_work_sync()
// Waiting
			ravb_tx_timeout_work()
			rtnl_lock()
			// This is possible to cause a deadlock

If rtnl_trylock() fails, rescheduling the work with sleep for 1 msec.

Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Link: https://lore.kernel.org/r/20231127122420.3706751-1-yoshihiro.shimoda.uh@renesas.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Yoshihiro Shimoda 2023-11-27 21:24:20 +09:00 committed by Greg Kroah-Hartman
parent d37609b529
commit 05aa8f3e3b
1 changed files with 10 additions and 1 deletions
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11
drivers/net/ethernet/renesas/ravb_main.c
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@ -1435,6 +1435,12 @@ static void ravb_tx_timeout_work(struct work_struct *work)
struct net_device *ndev = priv->ndev;
int error;
if (!rtnl_trylock()) {
usleep_range(1000, 2000);
schedule_work(&priv->work);
return;
}
netif_tx_stop_all_queues(ndev);
/* Stop PTP Clock driver */
@ -1467,7 +1473,7 @@ static void ravb_tx_timeout_work(struct work_struct *work)
*/
netdev_err(ndev, "%s: ravb_dmac_init() failed, error %d\n",
__func__, error);
return;
goto out_unlock;
}
ravb_emac_init(ndev);
@ -1477,6 +1483,9 @@ out:
ravb_ptp_init(ndev, priv->pdev);
netif_tx_start_all_queues(ndev);
out_unlock:
rtnl_unlock();
}
/* Packet transmit function for Ethernet AVB */