[12/27] staging: usbip: bugfix for deadlock
From: Greg KH <gregkh@suse.de>
Date: 2011-12-07 17:03:05
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2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Bart Westgeest <redacted> commit 438957f8d4a84daa7fa5be6978ad5897a2e9e5e5 upstream. Interrupts must be disabled prior to calling usb_hcd_unlink_urb_from_ep. If interrupts are not disabled, it can potentially lead to a deadlock. The deadlock is readily reproduceable on a slower (ARM based) device such as the TI Pandaboard. Signed-off-by: Bart Westgeest <redacted> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- drivers/staging/usbip/vhci_rx.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
--- a/drivers/staging/usbip/vhci_rx.c
+++ b/drivers/staging/usbip/vhci_rx.c@@ -67,6 +67,7 @@ static void vhci_recv_ret_submit(struct { struct usbip_device *ud = &vdev->ud; struct urb *urb; + unsigned long flags; spin_lock(&vdev->priv_lock);
@@ -107,9 +108,9 @@ static void vhci_recv_ret_submit(struct usbip_dbg_vhci_rx("now giveback urb %p\n", urb); - spin_lock(&the_controller->lock); + spin_lock_irqsave(&the_controller->lock, flags); usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb); - spin_unlock(&the_controller->lock); + spin_unlock_irqrestore(&the_controller->lock, flags); usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);
@@ -150,6 +151,7 @@ static void vhci_recv_ret_unlink(struct { struct vhci_unlink *unlink; struct urb *urb; + unsigned long flags; usbip_dump_header(pdu);
@@ -181,9 +183,9 @@ static void vhci_recv_ret_unlink(struct urb->status = pdu->u.ret_unlink.status; usbip_uinfo("%d\n", urb->status); - spin_lock(&the_controller->lock); + spin_lock_irqsave(&the_controller->lock, flags); usb_hcd_unlink_urb_from_ep(vhci_to_hcd(the_controller), urb); - spin_unlock(&the_controller->lock); + spin_unlock_irqrestore(&the_controller->lock, flags); usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb, urb->status);