Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 83c34fd0 authored by John Greene's avatar John Greene Committed by David S. Miller
Browse files

8139cp: Prevent dev_close/cp_interrupt race on MTU change 



commit:  cb64edb6 upstream

Above commit may introduce a race between cp_interrupt and dev_close
/ change MTU / dev_open up state. Changes cp_interrupt to tolerate
this.  Change spin_locking in cp_interrupt to avoid possible
but unobserved race.

Reported-by: default avatar"Francois Romieu" <romieu@fr.zoreil.com>

Tested on virtual hardware, Tx MTU size up to 4096, max tx payload
    was ping -s 4068 for MTU of 4096. No real hardware, need test
    assist.

Signed-off-by: default avatar"John Greene" <jogreene@redhat.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: "David Woodhouse" <David.Woodhouse@intel.com>
Tested-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f8b84034

drivers/net/ethernet/realtek/8139cp.c

+11 −7
Original line number Diff line number Diff line
@@ -577,28 +577,30 @@ static irqreturn_t cp_interrupt (int irq, void *dev_instance) 
{

	struct net_device *dev = dev_instance;

	struct cp_private *cp;

	int handled = 0;

	u16 status;



	if (unlikely(dev == NULL))

		return IRQ_NONE;

	cp = netdev_priv(dev);



	spin_lock(&cp->lock);



	status = cpr16(IntrStatus);

	if (!status || (status == 0xFFFF))

		return IRQ_NONE;

		goto out_unlock;



	handled = 1;



	netif_dbg(cp, intr, dev, "intr, status %04x cmd %02x cpcmd %04x\n",

		  status, cpr8(Cmd), cpr16(CpCmd));



	cpw16(IntrStatus, status & ~cp_rx_intr_mask);



	spin_lock(&cp->lock);



	/* close possible race's with dev_close */

	if (unlikely(!netif_running(dev))) {

		cpw16(IntrMask, 0);

		spin_unlock(&cp->lock);

		return IRQ_HANDLED;

		goto out_unlock;

	}



	if (status & (RxOK | RxErr | RxEmpty | RxFIFOOvr))
@@ -612,7 +614,6 @@ static irqreturn_t cp_interrupt (int irq, void *dev_instance) 
	if (status & LinkChg)

		mii_check_media(&cp->mii_if, netif_msg_link(cp), false);



	spin_unlock(&cp->lock);



	if (status & PciErr) {

		u16 pci_status;
@@ -625,7 +626,10 @@ static irqreturn_t cp_interrupt (int irq, void *dev_instance) 
		/* TODO: reset hardware */

	}



	return IRQ_HANDLED;

out_unlock:

	spin_unlock(&cp->lock);



	return IRQ_RETVAL(handled);

}



#ifdef CONFIG_NET_POLL_CONTROLLER