8139cp: Prevent dev_close/cp_interrupt race on MTU change

commit:  cb64edb6b8 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: "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: "John Greene" <jogreene@redhat.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: "David Woodhouse" <David.Woodhouse@intel.com>
Tested-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
John Greene 2012-12-19 09:47:48 +00:00 коммит произвёл David S. Miller
Родитель f8b840344c
Коммит 83c34fd00d
1 изменённых файлов: 11 добавлений и 7 удалений

Просмотреть файл

@ -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