usb: usbip: Fix possible deadlocks reported by lockdep
authorAndrew Goodbody <andrew.goodbody@cambrionix.com>
Tue, 2 Feb 2016 17:36:39 +0000 (17:36 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 3 Feb 2016 21:52:10 +0000 (13:52 -0800)
Change spin_lock calls to spin_lock_irqsave to prevent
attmpted recursive lock taking in interrupt context.

This patch fixes Bug 109351
  https://bugzilla.kernel.org/show_bug.cgi?id=109351

Signed-off-by: Andrew Goodbody <andrew.goodbody@cambrionix.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/usbip/usbip_event.c
drivers/usb/usbip/vhci_hcd.c
drivers/usb/usbip/vhci_rx.c
drivers/usb/usbip/vhci_sysfs.c
drivers/usb/usbip/vhci_tx.c

index 64933b993d7a5f0a8ff64a82979ed20bb9890534..2580a32bcdfff088d4e5f86af1e09f93b13c20ce 100644 (file)
@@ -117,11 +117,12 @@ EXPORT_SYMBOL_GPL(usbip_event_add);
 int usbip_event_happened(struct usbip_device *ud)
 {
        int happened = 0;
+       unsigned long flags;
 
-       spin_lock(&ud->lock);
+       spin_lock_irqsave(&ud->lock, flags);
        if (ud->event != 0)
                happened = 1;
-       spin_unlock(&ud->lock);
+       spin_unlock_irqrestore(&ud->lock, flags);
 
        return happened;
 }
index 7fbe19d5279e5c11159f141fdd20b6a3ac7ff568..fca51105974eabdd09094b7cd1e80bb945275129 100644 (file)
@@ -121,9 +121,11 @@ static void dump_port_status_diff(u32 prev_status, u32 new_status)
 
 void rh_port_connect(int rhport, enum usb_device_speed speed)
 {
+       unsigned long   flags;
+
        usbip_dbg_vhci_rh("rh_port_connect %d\n", rhport);
 
-       spin_lock(&the_controller->lock);
+       spin_lock_irqsave(&the_controller->lock, flags);
 
        the_controller->port_status[rhport] |= USB_PORT_STAT_CONNECTION
                | (1 << USB_PORT_FEAT_C_CONNECTION);
@@ -139,22 +141,24 @@ void rh_port_connect(int rhport, enum usb_device_speed speed)
                break;
        }
 
-       spin_unlock(&the_controller->lock);
+       spin_unlock_irqrestore(&the_controller->lock, flags);
 
        usb_hcd_poll_rh_status(vhci_to_hcd(the_controller));
 }
 
 static void rh_port_disconnect(int rhport)
 {
+       unsigned long   flags;
+
        usbip_dbg_vhci_rh("rh_port_disconnect %d\n", rhport);
 
-       spin_lock(&the_controller->lock);
+       spin_lock_irqsave(&the_controller->lock, flags);
 
        the_controller->port_status[rhport] &= ~USB_PORT_STAT_CONNECTION;
        the_controller->port_status[rhport] |=
                                        (1 << USB_PORT_FEAT_C_CONNECTION);
 
-       spin_unlock(&the_controller->lock);
+       spin_unlock_irqrestore(&the_controller->lock, flags);
        usb_hcd_poll_rh_status(vhci_to_hcd(the_controller));
 }
 
@@ -182,13 +186,14 @@ static int vhci_hub_status(struct usb_hcd *hcd, char *buf)
        int             retval;
        int             rhport;
        int             changed = 0;
+       unsigned long   flags;
 
        retval = DIV_ROUND_UP(VHCI_NPORTS + 1, 8);
        memset(buf, 0, retval);
 
        vhci = hcd_to_vhci(hcd);
 
-       spin_lock(&vhci->lock);
+       spin_lock_irqsave(&vhci->lock, flags);
        if (!HCD_HW_ACCESSIBLE(hcd)) {
                usbip_dbg_vhci_rh("hw accessible flag not on?\n");
                goto done;
@@ -209,7 +214,7 @@ static int vhci_hub_status(struct usb_hcd *hcd, char *buf)
                usb_hcd_resume_root_hub(hcd);
 
 done:
-       spin_unlock(&vhci->lock);
+       spin_unlock_irqrestore(&vhci->lock, flags);
        return changed ? retval : 0;
 }
 
@@ -231,6 +236,7 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
        struct vhci_hcd *dum;
        int             retval = 0;
        int             rhport;
+       unsigned long   flags;
 
        u32 prev_port_status[VHCI_NPORTS];
 
@@ -249,7 +255,7 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 
        dum = hcd_to_vhci(hcd);
 
-       spin_lock(&dum->lock);
+       spin_lock_irqsave(&dum->lock, flags);
 
        /* store old status and compare now and old later */
        if (usbip_dbg_flag_vhci_rh) {
@@ -403,7 +409,7 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
        }
        usbip_dbg_vhci_rh(" bye\n");
 
-       spin_unlock(&dum->lock);
+       spin_unlock_irqrestore(&dum->lock, flags);
 
        return retval;
 }
@@ -426,6 +432,7 @@ static void vhci_tx_urb(struct urb *urb)
 {
        struct vhci_device *vdev = get_vdev(urb->dev);
        struct vhci_priv *priv;
+       unsigned long flags;
 
        if (!vdev) {
                pr_err("could not get virtual device");
@@ -438,7 +445,7 @@ static void vhci_tx_urb(struct urb *urb)
                return;
        }
 
-       spin_lock(&vdev->priv_lock);
+       spin_lock_irqsave(&vdev->priv_lock, flags);
 
        priv->seqnum = atomic_inc_return(&the_controller->seqnum);
        if (priv->seqnum == 0xffff)
@@ -452,7 +459,7 @@ static void vhci_tx_urb(struct urb *urb)
        list_add_tail(&priv->list, &vdev->priv_tx);
 
        wake_up(&vdev->waitq_tx);
-       spin_unlock(&vdev->priv_lock);
+       spin_unlock_irqrestore(&vdev->priv_lock, flags);
 }
 
 static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
@@ -461,6 +468,7 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
        struct device *dev = &urb->dev->dev;
        int ret = 0;
        struct vhci_device *vdev;
+       unsigned long flags;
 
        usbip_dbg_vhci_hc("enter, usb_hcd %p urb %p mem_flags %d\n",
                          hcd, urb, mem_flags);
@@ -468,11 +476,11 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
        /* patch to usb_sg_init() is in 2.5.60 */
        BUG_ON(!urb->transfer_buffer && urb->transfer_buffer_length);
 
-       spin_lock(&the_controller->lock);
+       spin_lock_irqsave(&the_controller->lock, flags);
 
        if (urb->status != -EINPROGRESS) {
                dev_err(dev, "URB already unlinked!, status %d\n", urb->status);
-               spin_unlock(&the_controller->lock);
+               spin_unlock_irqrestore(&the_controller->lock, flags);
                return urb->status;
        }
 
@@ -484,7 +492,7 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
            vdev->ud.status == VDEV_ST_ERROR) {
                dev_err(dev, "enqueue for inactive port %d\n", vdev->rhport);
                spin_unlock(&vdev->ud.lock);
-               spin_unlock(&the_controller->lock);
+               spin_unlock_irqrestore(&the_controller->lock, flags);
                return -ENODEV;
        }
        spin_unlock(&vdev->ud.lock);
@@ -557,14 +565,14 @@ static int vhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb,
 
 out:
        vhci_tx_urb(urb);
-       spin_unlock(&the_controller->lock);
+       spin_unlock_irqrestore(&the_controller->lock, flags);
 
        return 0;
 
 no_need_xmit:
        usb_hcd_unlink_urb_from_ep(hcd, urb);
 no_need_unlink:
-       spin_unlock(&the_controller->lock);
+       spin_unlock_irqrestore(&the_controller->lock, flags);
        if (!ret)
                usb_hcd_giveback_urb(vhci_to_hcd(the_controller),
                                     urb, urb->status);
@@ -621,16 +629,17 @@ static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 {
        struct vhci_priv *priv;
        struct vhci_device *vdev;
+       unsigned long flags;
 
        pr_info("dequeue a urb %p\n", urb);
 
-       spin_lock(&the_controller->lock);
+       spin_lock_irqsave(&the_controller->lock, flags);
 
        priv = urb->hcpriv;
        if (!priv) {
                /* URB was never linked! or will be soon given back by
                 * vhci_rx. */
-               spin_unlock(&the_controller->lock);
+               spin_unlock_irqrestore(&the_controller->lock, flags);
                return -EIDRM;
        }
 
@@ -639,7 +648,7 @@ static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 
                ret = usb_hcd_check_unlink_urb(hcd, urb, status);
                if (ret) {
-                       spin_unlock(&the_controller->lock);
+                       spin_unlock_irqrestore(&the_controller->lock, flags);
                        return ret;
                }
        }
@@ -667,10 +676,10 @@ static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 
                usb_hcd_unlink_urb_from_ep(hcd, 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);
-               spin_lock(&the_controller->lock);
+               spin_lock_irqsave(&the_controller->lock, flags);
 
        } else {
                /* tcp connection is alive */
@@ -682,7 +691,7 @@ static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
                unlink = kzalloc(sizeof(struct vhci_unlink), GFP_ATOMIC);
                if (!unlink) {
                        spin_unlock(&vdev->priv_lock);
-                       spin_unlock(&the_controller->lock);
+                       spin_unlock_irqrestore(&the_controller->lock, flags);
                        usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_MALLOC);
                        return -ENOMEM;
                }
@@ -703,7 +712,7 @@ static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
                spin_unlock(&vdev->priv_lock);
        }
 
-       spin_unlock(&the_controller->lock);
+       spin_unlock_irqrestore(&the_controller->lock, flags);
 
        usbip_dbg_vhci_hc("leave\n");
        return 0;
@@ -712,8 +721,9 @@ static int vhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
 static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
 {
        struct vhci_unlink *unlink, *tmp;
+       unsigned long flags;
 
-       spin_lock(&the_controller->lock);
+       spin_lock_irqsave(&the_controller->lock, flags);
        spin_lock(&vdev->priv_lock);
 
        list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
@@ -747,19 +757,19 @@ static void vhci_device_unlink_cleanup(struct vhci_device *vdev)
                list_del(&unlink->list);
 
                spin_unlock(&vdev->priv_lock);
-               spin_unlock(&the_controller->lock);
+               spin_unlock_irqrestore(&the_controller->lock, flags);
 
                usb_hcd_giveback_urb(vhci_to_hcd(the_controller), urb,
                                     urb->status);
 
-               spin_lock(&the_controller->lock);
+               spin_lock_irqsave(&the_controller->lock, flags);
                spin_lock(&vdev->priv_lock);
 
                kfree(unlink);
        }
 
        spin_unlock(&vdev->priv_lock);
-       spin_unlock(&the_controller->lock);
+       spin_unlock_irqrestore(&the_controller->lock, flags);
 }
 
 /*
@@ -826,8 +836,9 @@ static void vhci_shutdown_connection(struct usbip_device *ud)
 static void vhci_device_reset(struct usbip_device *ud)
 {
        struct vhci_device *vdev = container_of(ud, struct vhci_device, ud);
+       unsigned long flags;
 
-       spin_lock(&ud->lock);
+       spin_lock_irqsave(&ud->lock, flags);
 
        vdev->speed  = 0;
        vdev->devid  = 0;
@@ -841,14 +852,16 @@ static void vhci_device_reset(struct usbip_device *ud)
        }
        ud->status = VDEV_ST_NULL;
 
-       spin_unlock(&ud->lock);
+       spin_unlock_irqrestore(&ud->lock, flags);
 }
 
 static void vhci_device_unusable(struct usbip_device *ud)
 {
-       spin_lock(&ud->lock);
+       unsigned long flags;
+
+       spin_lock_irqsave(&ud->lock, flags);
        ud->status = VDEV_ST_ERROR;
-       spin_unlock(&ud->lock);
+       spin_unlock_irqrestore(&ud->lock, flags);
 }
 
 static void vhci_device_init(struct vhci_device *vdev)
@@ -938,12 +951,13 @@ static int vhci_get_frame_number(struct usb_hcd *hcd)
 static int vhci_bus_suspend(struct usb_hcd *hcd)
 {
        struct vhci_hcd *vhci = hcd_to_vhci(hcd);
+       unsigned long flags;
 
        dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
 
-       spin_lock(&vhci->lock);
+       spin_lock_irqsave(&vhci->lock, flags);
        hcd->state = HC_STATE_SUSPENDED;
-       spin_unlock(&vhci->lock);
+       spin_unlock_irqrestore(&vhci->lock, flags);
 
        return 0;
 }
@@ -952,15 +966,16 @@ static int vhci_bus_resume(struct usb_hcd *hcd)
 {
        struct vhci_hcd *vhci = hcd_to_vhci(hcd);
        int rc = 0;
+       unsigned long flags;
 
        dev_dbg(&hcd->self.root_hub->dev, "%s\n", __func__);
 
-       spin_lock(&vhci->lock);
+       spin_lock_irqsave(&vhci->lock, flags);
        if (!HCD_HW_ACCESSIBLE(hcd))
                rc = -ESHUTDOWN;
        else
                hcd->state = HC_STATE_RUNNING;
-       spin_unlock(&vhci->lock);
+       spin_unlock_irqrestore(&vhci->lock, flags);
 
        return rc;
 }
@@ -1058,17 +1073,18 @@ static int vhci_hcd_suspend(struct platform_device *pdev, pm_message_t state)
        int rhport = 0;
        int connected = 0;
        int ret = 0;
+       unsigned long flags;
 
        hcd = platform_get_drvdata(pdev);
 
-       spin_lock(&the_controller->lock);
+       spin_lock_irqsave(&the_controller->lock, flags);
 
        for (rhport = 0; rhport < VHCI_NPORTS; rhport++)
                if (the_controller->port_status[rhport] &
                    USB_PORT_STAT_CONNECTION)
                        connected += 1;
 
-       spin_unlock(&the_controller->lock);
+       spin_unlock_irqrestore(&the_controller->lock, flags);
 
        if (connected > 0) {
                dev_info(&pdev->dev,
index 00e4a54308e430f283f053865853089566c823d7..d656e0edc3d50104617785da0d559943532ac1a8 100644 (file)
@@ -72,10 +72,11 @@ static void vhci_recv_ret_submit(struct vhci_device *vdev,
 {
        struct usbip_device *ud = &vdev->ud;
        struct urb *urb;
+       unsigned long flags;
 
-       spin_lock(&vdev->priv_lock);
+       spin_lock_irqsave(&vdev->priv_lock, flags);
        urb = pickup_urb_and_free_priv(vdev, pdu->base.seqnum);
-       spin_unlock(&vdev->priv_lock);
+       spin_unlock_irqrestore(&vdev->priv_lock, flags);
 
        if (!urb) {
                pr_err("cannot find a urb of seqnum %u\n", pdu->base.seqnum);
@@ -104,9 +105,9 @@ static void vhci_recv_ret_submit(struct vhci_device *vdev,
 
        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);
 
@@ -117,8 +118,9 @@ static struct vhci_unlink *dequeue_pending_unlink(struct vhci_device *vdev,
                                                  struct usbip_header *pdu)
 {
        struct vhci_unlink *unlink, *tmp;
+       unsigned long flags;
 
-       spin_lock(&vdev->priv_lock);
+       spin_lock_irqsave(&vdev->priv_lock, flags);
 
        list_for_each_entry_safe(unlink, tmp, &vdev->unlink_rx, list) {
                pr_info("unlink->seqnum %lu\n", unlink->seqnum);
@@ -127,12 +129,12 @@ static struct vhci_unlink *dequeue_pending_unlink(struct vhci_device *vdev,
                                          unlink->seqnum);
                        list_del(&unlink->list);
 
-                       spin_unlock(&vdev->priv_lock);
+                       spin_unlock_irqrestore(&vdev->priv_lock, flags);
                        return unlink;
                }
        }
 
-       spin_unlock(&vdev->priv_lock);
+       spin_unlock_irqrestore(&vdev->priv_lock, flags);
 
        return NULL;
 }
@@ -142,6 +144,7 @@ static void vhci_recv_ret_unlink(struct vhci_device *vdev,
 {
        struct vhci_unlink *unlink;
        struct urb *urb;
+       unsigned long flags;
 
        usbip_dump_header(pdu);
 
@@ -152,9 +155,9 @@ static void vhci_recv_ret_unlink(struct vhci_device *vdev,
                return;
        }
 
-       spin_lock(&vdev->priv_lock);
+       spin_lock_irqsave(&vdev->priv_lock, flags);
        urb = pickup_urb_and_free_priv(vdev, unlink->unlink_seqnum);
-       spin_unlock(&vdev->priv_lock);
+       spin_unlock_irqrestore(&vdev->priv_lock, flags);
 
        if (!urb) {
                /*
@@ -171,9 +174,9 @@ static void vhci_recv_ret_unlink(struct vhci_device *vdev,
                urb->status = pdu->u.ret_unlink.status;
                pr_info("urb->status %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);
@@ -185,10 +188,11 @@ static void vhci_recv_ret_unlink(struct vhci_device *vdev,
 static int vhci_priv_tx_empty(struct vhci_device *vdev)
 {
        int empty = 0;
+       unsigned long flags;
 
-       spin_lock(&vdev->priv_lock);
+       spin_lock_irqsave(&vdev->priv_lock, flags);
        empty = list_empty(&vdev->priv_rx);
-       spin_unlock(&vdev->priv_lock);
+       spin_unlock_irqrestore(&vdev->priv_lock, flags);
 
        return empty;
 }
index 211f43f67ea25f28ca46146bbadc099b2532924b..5b5462eb16657b03d30b293caac2e6facfbb2226 100644 (file)
@@ -32,10 +32,11 @@ static ssize_t status_show(struct device *dev, struct device_attribute *attr,
 {
        char *s = out;
        int i = 0;
+       unsigned long flags;
 
        BUG_ON(!the_controller || !out);
 
-       spin_lock(&the_controller->lock);
+       spin_lock_irqsave(&the_controller->lock, flags);
 
        /*
         * output example:
@@ -70,7 +71,7 @@ static ssize_t status_show(struct device *dev, struct device_attribute *attr,
                spin_unlock(&vdev->ud.lock);
        }
 
-       spin_unlock(&the_controller->lock);
+       spin_unlock_irqrestore(&the_controller->lock, flags);
 
        return out - s;
 }
@@ -80,11 +81,12 @@ static DEVICE_ATTR_RO(status);
 static int vhci_port_disconnect(__u32 rhport)
 {
        struct vhci_device *vdev;
+       unsigned long flags;
 
        usbip_dbg_vhci_sysfs("enter\n");
 
        /* lock */
-       spin_lock(&the_controller->lock);
+       spin_lock_irqsave(&the_controller->lock, flags);
 
        vdev = port_to_vdev(rhport);
 
@@ -94,14 +96,14 @@ static int vhci_port_disconnect(__u32 rhport)
 
                /* unlock */
                spin_unlock(&vdev->ud.lock);
-               spin_unlock(&the_controller->lock);
+               spin_unlock_irqrestore(&the_controller->lock, flags);
 
                return -EINVAL;
        }
 
        /* unlock */
        spin_unlock(&vdev->ud.lock);
-       spin_unlock(&the_controller->lock);
+       spin_unlock_irqrestore(&the_controller->lock, flags);
 
        usbip_event_add(&vdev->ud, VDEV_EVENT_DOWN);
 
@@ -177,6 +179,7 @@ static ssize_t store_attach(struct device *dev, struct device_attribute *attr,
        int sockfd = 0;
        __u32 rhport = 0, devid = 0, speed = 0;
        int err;
+       unsigned long flags;
 
        /*
         * @rhport: port number of vhci_hcd
@@ -202,14 +205,14 @@ static ssize_t store_attach(struct device *dev, struct device_attribute *attr,
        /* now need lock until setting vdev status as used */
 
        /* begin a lock */
-       spin_lock(&the_controller->lock);
+       spin_lock_irqsave(&the_controller->lock, flags);
        vdev = port_to_vdev(rhport);
        spin_lock(&vdev->ud.lock);
 
        if (vdev->ud.status != VDEV_ST_NULL) {
                /* end of the lock */
                spin_unlock(&vdev->ud.lock);
-               spin_unlock(&the_controller->lock);
+               spin_unlock_irqrestore(&the_controller->lock, flags);
 
                sockfd_put(socket);
 
@@ -227,7 +230,7 @@ static ssize_t store_attach(struct device *dev, struct device_attribute *attr,
        vdev->ud.status     = VDEV_ST_NOTASSIGNED;
 
        spin_unlock(&vdev->ud.lock);
-       spin_unlock(&the_controller->lock);
+       spin_unlock_irqrestore(&the_controller->lock, flags);
        /* end the lock */
 
        vdev->ud.tcp_rx = kthread_get_run(vhci_rx_loop, &vdev->ud, "vhci_rx");
index 409fd99f3257f94bb7489b0d7aa7d971bf5e303b..3e7878fe2fd463f5051b228b364a8ca4be6f4761 100644 (file)
@@ -47,16 +47,17 @@ static void setup_cmd_submit_pdu(struct usbip_header *pdup,  struct urb *urb)
 static struct vhci_priv *dequeue_from_priv_tx(struct vhci_device *vdev)
 {
        struct vhci_priv *priv, *tmp;
+       unsigned long flags;
 
-       spin_lock(&vdev->priv_lock);
+       spin_lock_irqsave(&vdev->priv_lock, flags);
 
        list_for_each_entry_safe(priv, tmp, &vdev->priv_tx, list) {
                list_move_tail(&priv->list, &vdev->priv_rx);
-               spin_unlock(&vdev->priv_lock);
+               spin_unlock_irqrestore(&vdev->priv_lock, flags);
                return priv;
        }
 
-       spin_unlock(&vdev->priv_lock);
+       spin_unlock_irqrestore(&vdev->priv_lock, flags);
 
        return NULL;
 }
@@ -136,16 +137,17 @@ static int vhci_send_cmd_submit(struct vhci_device *vdev)
 static struct vhci_unlink *dequeue_from_unlink_tx(struct vhci_device *vdev)
 {
        struct vhci_unlink *unlink, *tmp;
+       unsigned long flags;
 
-       spin_lock(&vdev->priv_lock);
+       spin_lock_irqsave(&vdev->priv_lock, flags);
 
        list_for_each_entry_safe(unlink, tmp, &vdev->unlink_tx, list) {
                list_move_tail(&unlink->list, &vdev->unlink_rx);
-               spin_unlock(&vdev->priv_lock);
+               spin_unlock_irqrestore(&vdev->priv_lock, flags);
                return unlink;
        }
 
-       spin_unlock(&vdev->priv_lock);
+       spin_unlock_irqrestore(&vdev->priv_lock, flags);
 
        return NULL;
 }