@@ -668,14 +668,12 @@ EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
// precondition: never called in_interrupt
static void usbnet_terminate_urbs(struct usbnet *dev)
{
- DECLARE_WAIT_QUEUE_HEAD_ONSTACK(unlink_wakeup);
DECLARE_WAITQUEUE(wait, current);
int temp;
/* ensure there are no more active urbs */
- add_wait_queue(&unlink_wakeup, &wait);
+ add_wait_queue(&dev->wait, &wait);
set_current_state(TASK_UNINTERRUPTIBLE);
- dev->wait = &unlink_wakeup;
temp = unlink_urbs(dev, &dev->txq) +
unlink_urbs(dev, &dev->rxq);
@@ -689,15 +687,14 @@ static void usbnet_terminate_urbs(struct usbnet *dev)
"waited for %d urb completions\n", temp);
}
set_current_state(TASK_RUNNING);
- dev->wait = NULL;
- remove_wait_queue(&unlink_wakeup, &wait);
+ remove_wait_queue(&dev->wait, &wait);
}
int usbnet_stop (struct net_device *net)
{
struct usbnet *dev = netdev_priv(net);
struct driver_info *info = dev->driver_info;
- int retval;
+ int retval, pm;
clear_bit(EVENT_DEV_OPEN, &dev->flags);
netif_stop_queue (net);
@@ -707,6 +704,8 @@ int usbnet_stop (struct net_device *net)
net->stats.rx_packets, net->stats.tx_packets,
net->stats.rx_errors, net->stats.tx_errors);
+ /* to not race resume */
+ pm = usb_autopm_get_interface(dev->intf);
/* allow minidriver to stop correctly (wireless devices to turn off
* radio etc) */
if (info->stop) {
@@ -733,6 +732,9 @@ int usbnet_stop (struct net_device *net)
dev->flags = 0;
del_timer_sync (&dev->delay);
tasklet_kill (&dev->bh);
+ if (!pm)
+ usb_autopm_put_interface(dev->intf);
+
if (info->manage_power &&
!test_and_clear_bit(EVENT_NO_RUNTIME_PM, &dev->flags))
info->manage_power(dev, 0);
@@ -1274,11 +1276,12 @@ static void usbnet_bh (unsigned long param)
/* restart RX again after disabling due to high error rate */
clear_bit(EVENT_RX_KILL, &dev->flags);
- // waiting for all pending urbs to complete?
- if (dev->wait) {
- if ((dev->txq.qlen + dev->rxq.qlen + dev->done.qlen) == 0) {
- wake_up (dev->wait);
- }
+ /* waiting for all pending urbs to complete?
+ * only then can we forgo submitting anew
+ */
+ if (waitqueue_active(&dev->wait)) {
+ if (dev->txq.qlen + dev->rxq.qlen + dev->done.qlen == 0)
+ wake_up_all(&dev->wait);
// or are we maybe short a few urbs?
} else if (netif_running (dev->net) &&
@@ -1415,6 +1418,7 @@ usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
dev->driver_name = name;
dev->msg_enable = netif_msg_init (msg_level, NETIF_MSG_DRV
| NETIF_MSG_PROBE | NETIF_MSG_LINK);
+ init_waitqueue_head(&dev->wait);
skb_queue_head_init (&dev->rxq);
skb_queue_head_init (&dev->txq);
skb_queue_head_init (&dev->done);
@@ -1606,9 +1610,10 @@ int usbnet_resume (struct usb_interface *intf)
spin_unlock_irq(&dev->txq.lock);
if (test_bit(EVENT_DEV_OPEN, &dev->flags)) {
- /* handle remote wakeup ASAP */
- if (!dev->wait &&
- netif_device_present(dev->net) &&
+ /* handle remote wakeup ASAP
+ * we cannot race against stop
+ */
+ if (netif_device_present(dev->net) &&
!timer_pending(&dev->delay) &&
!test_bit(EVENT_RX_HALT, &dev->flags))
rx_alloc_submit(dev, GFP_NOIO);
@@ -30,7 +30,7 @@ struct usbnet {
struct driver_info *driver_info;
const char *driver_name;
void *driver_priv;
- wait_queue_head_t *wait;
+ wait_queue_head_t wait;
struct mutex phy_mutex;
unsigned char suspend_count;
unsigned char pkt_cnt, pkt_err;
This is a note to let you know that I have just added a patch titled usbnet: include wait queue head in device structure to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue This patch is scheduled to be released in version 3.8.13.22. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.8.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From e723f0ecb73a2f7f0f74737af3651f208aee9828 Mon Sep 17 00:00:00 2001 From: Oliver Neukum <oneukum@suse.de> Date: Wed, 26 Mar 2014 14:32:51 +0100 Subject: usbnet: include wait queue head in device structure [ Upstream commit 14a0d635d18d0fb552dcc979d6d25106e6541f2e ] This fixes a race which happens by freeing an object on the stack. Quoting Julius: > The issue is > that it calls usbnet_terminate_urbs() before that, which temporarily > installs a waitqueue in dev->wait in order to be able to wait on the > tasklet to run and finish up some queues. The waiting itself looks > okay, but the access to 'dev->wait' is totally unprotected and can > race arbitrarily. I think in this case usbnet_bh() managed to succeed > it's dev->wait check just before usbnet_terminate_urbs() sets it back > to NULL. The latter then finishes and the waitqueue_t structure on its > stack gets overwritten by other functions halfway through the > wake_up() call in usbnet_bh(). The fix is to just not allocate the data structure on the stack. As dev->wait is abused as a flag it also takes a runtime PM change to fix this bug. Signed-off-by: Oliver Neukum <oneukum@suse.de> Reported-by: Grant Grundler <grundler@google.com> Tested-by: Grant Grundler <grundler@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/net/usb/usbnet.c | 33 +++++++++++++++++++-------------- include/linux/usb/usbnet.h | 2 +- 2 files changed, 20 insertions(+), 15 deletions(-) -- 1.8.3.2