diff options
| author | John Greene <jogreene@redhat.com> | 2012-12-19 13:47:48 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-12-20 02:30:59 +0400 |
| commit | 83c34fd00d0c3989466e95808bf12af9bf87e383 (patch) | |
| tree | 477e1bde4443e5708f4c1c7885c9c552dcd7d4d6 | |
| parent | f8b840344cbf4fa7212223b436adfb7559ca0e1e (diff) | |
| download | linux-83c34fd00d0c3989466e95808bf12af9bf87e383.tar.xz | |
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>
| -rw-r--r-- | drivers/net/ethernet/realtek/8139cp.c | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/drivers/net/ethernet/realtek/8139cp.c b/drivers/net/ethernet/realtek/8139cp.c index cb6fc5a743ca..5ac93323a40c 100644 --- a/drivers/net/ethernet/realtek/8139cp.c +++ b/drivers/net/ethernet/realtek/8139cp.c @@ -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 |