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authorSebastian Siewior <bigeasy@linutronix.de>2012-03-07 10:19:28 +0000
committerDavid S. Miller <davem@davemloft.net>2012-03-08 00:49:29 -0800
commit4231d47e6fe69f061f96c98c30eaf9fb4c14b96d (patch)
treebdb4f840384af48728128657d90402747cfd142d
parentac3f48de09d8f4b73397047e413fadff7f65cfa7 (diff)
downloadlinux-stericsson-4231d47e6fe69f061f96c98c30eaf9fb4c14b96d.tar.gz
net/usbnet: avoid recursive locking in usbnet_stop()
|kernel BUG at kernel/rtmutex.c:724! |[<c029599c>] (rt_spin_lock_slowlock+0x108/0x2bc) from [<c01c2330>] (defer_bh+0x1c/0xb4) |[<c01c2330>] (defer_bh+0x1c/0xb4) from [<c01c3afc>] (rx_complete+0x14c/0x194) |[<c01c3afc>] (rx_complete+0x14c/0x194) from [<c01cac88>] (usb_hcd_giveback_urb+0xa0/0xf0) |[<c01cac88>] (usb_hcd_giveback_urb+0xa0/0xf0) from [<c01e1ff4>] (musb_giveback+0x34/0x40) |[<c01e1ff4>] (musb_giveback+0x34/0x40) from [<c01e2b1c>] (musb_advance_schedule+0xb4/0x1c0) |[<c01e2b1c>] (musb_advance_schedule+0xb4/0x1c0) from [<c01e2ca8>] (musb_cleanup_urb.isra.9+0x80/0x8c) |[<c01e2ca8>] (musb_cleanup_urb.isra.9+0x80/0x8c) from [<c01e2ed0>] (musb_urb_dequeue+0xec/0x108) |[<c01e2ed0>] (musb_urb_dequeue+0xec/0x108) from [<c01cbb90>] (unlink1+0xbc/0xcc) |[<c01cbb90>] (unlink1+0xbc/0xcc) from [<c01cc2ec>] (usb_hcd_unlink_urb+0x54/0xa8) |[<c01cc2ec>] (usb_hcd_unlink_urb+0x54/0xa8) from [<c01c2a84>] (unlink_urbs.isra.17+0x2c/0x58) |[<c01c2a84>] (unlink_urbs.isra.17+0x2c/0x58) from [<c01c2b44>] (usbnet_terminate_urbs+0x94/0x10c) |[<c01c2b44>] (usbnet_terminate_urbs+0x94/0x10c) from [<c01c2d68>] (usbnet_stop+0x100/0x15c) |[<c01c2d68>] (usbnet_stop+0x100/0x15c) from [<c020f718>] (__dev_close_many+0x94/0xc8) defer_bh() takes the lock which is hold during unlink_urbs(). The safe walk suggest that the skb will be removed from the list and this is done by defer_bh() so it seems to be okay to drop the lock here. Cc: stable@kernel.org Reported-by: Aníbal Almeida Pinto <anibal.pinto@efacec.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: Oliver Neukum <oliver@neukum.org> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/usb/usbnet.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index fae0fbd8bc88..81b96e303757 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -589,6 +589,7 @@ static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
entry = (struct skb_data *) skb->cb;
urb = entry->urb;
+ spin_unlock_irqrestore(&q->lock, flags);
// during some PM-driven resume scenarios,
// these (async) unlinks complete immediately
retval = usb_unlink_urb (urb);
@@ -596,6 +597,7 @@ static int unlink_urbs (struct usbnet *dev, struct sk_buff_head *q)
netdev_dbg(dev->net, "unlink urb err, %d\n", retval);
else
count++;
+ spin_lock_irqsave(&q->lock, flags);
}
spin_unlock_irqrestore (&q->lock, flags);
return count;