8139cp: Prevent dev_close/cp_interrupt race on MTU change
commit: cb64edb6b89491edfdbae52ba7db9a8b8391d339 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>
diff --git a/drivers/net/ethernet/realtek/8139cp.c b/drivers/net/ethernet/realtek/8139cp.c
index cb6fc5a..5ac9332 100644
--- a/drivers/net/ethernet/realtek/8139cp.c
+++ b/drivers/net/ethernet/realtek/8139cp.c
@@ -577,28 +577,30 @@
{
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 @@
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 @@
/* TODO: reset hardware */
}
- return IRQ_HANDLED;
+out_unlock:
+ spin_unlock(&cp->lock);
+
+ return IRQ_RETVAL(handled);
}
#ifdef CONFIG_NET_POLL_CONTROLLER