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Commit afdc08b9 authored by Michael Chan's avatar Michael Chan Committed by David S. Miller
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[BNX2]: Fix rtnl deadlock in bnx2_close 



This fixes an rtnl deadlock problem when flush_scheduled_work() is
called from bnx2_close(). In rare cases, linkwatch_event() may be on
the workqueue from a previous close of a different device and it will
try to get the rtnl lock which is already held by dev_close().

The fix is to set a flag if we are in the reset task which is run
from the workqueue. bnx2_close() will loop until the flag is cleared.
As suggested by Jeff Garzik, the loop is changed to call msleep(1)
instead of yield() in the original patch.

flush_scheduled_work() is also moved to bnx2_remove_one() before the
netdev is freed.

Signed-off-by: default avatarMichael Chan <mchan@broadcom.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2373ce1c

drivers/net/bnx2.c

+14 −1
Original line number Diff line number Diff line
@@ -3975,12 +3975,17 @@ bnx2_reset_task(void *data) 
{

	struct bnx2 *bp = data;



	if (!netif_running(bp->dev))

		return;



	bp->in_reset_task = 1;

	bnx2_netif_stop(bp);



	bnx2_init_nic(bp);



	atomic_set(&bp->intr_sem, 1);

	bnx2_netif_start(bp);

	bp->in_reset_task = 0;

}



static void
@@ -4172,7 +4177,13 @@ bnx2_close(struct net_device *dev) 
	struct bnx2 *bp = dev->priv;

	u32 reset_code;



	flush_scheduled_work();

	/* Calling flush_scheduled_work() may deadlock because

	 * linkwatch_event() may be on the workqueue and it will try to get

	 * the rtnl_lock which we are holding.

	 */

	while (bp->in_reset_task)

		msleep(1);



	bnx2_netif_stop(bp);

	del_timer_sync(&bp->timer);

	if (bp->wol)
@@ -5453,6 +5464,8 @@ bnx2_remove_one(struct pci_dev *pdev) 
	struct net_device *dev = pci_get_drvdata(pdev);

	struct bnx2 *bp = dev->priv;



	flush_scheduled_work();



	unregister_netdev(dev);



	if (bp->regview)

drivers/net/bnx2.h

+1 −0
Original line number Diff line number Diff line
@@ -3874,6 +3874,7 @@ struct bnx2 { 
	int			timer_interval;

	struct			timer_list timer;

	struct work_struct	reset_task;

	int			in_reset_task;



	/* Used to synchronize phy accesses. */

	spinlock_t		phy_lock;