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  1. 10 9月, 2015 2 次提交
  3. 09 9月, 2015 3 次提交
    • B
      dm9000: fix a typo · 7b901873
      由 Barry Song 提交于 
      Signed-off-by: NBarry Song <Baohua.Song@csr.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7b901873
    • F
      net: dsa: bcm_sf2: Fix ageing conditions and operation · 39797a27
      由 Florian Fainelli 提交于 
      The comparison check between cur_hw_state and hw_state is currently
invalid because cur_hw_state is right shifted by G_MISTP_SHIFT, while
hw_state is not, so we end-up comparing bits 2:0 with bits 7:5, which is
going to cause an additional aging to occur. Fix this by not shifting
cur_hw_state while reading it, but instead, mask the value with the
appropriately shitfted bitmask.

The other problem with the fast-ageing process is that we did not set
the EN_AGE_DYNAMIC bit to request the ageing to occur for dynamically
learned MAC addresses. Finally, write back 0 to the FAST_AGE_CTRL
register to avoid leaving spurious bits sets from one operation to the
other.

Fixes: 12f460f2 ("net: dsa: bcm_sf2: add HW bridging support")
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      39797a27
    • E
      usbnet: Fix a race between usbnet_stop() and the BH · fcb0bb6a
      由 Eugene Shatokhin 提交于 
      The race may happen when a device (e.g. YOTA 4G LTE Modem) is
unplugged while the system is downloading a large file from the Net.

Hardware breakpoints and Kprobes with delays were used to confirm that
the race does actually happen.

The race is on skb_queue ('next' pointer) between usbnet_stop()
and rx_complete(), which, in turn, calls usbnet_bh().

Here is a part of the call stack with the code where the changes to the
queue happen. The line numbers are for the kernel 4.1.0:

*0 __skb_unlink (skbuff.h:1517)
    prev->next = next;
*1 defer_bh (usbnet.c:430)
    spin_lock_irqsave(&list->lock, flags);
    old_state = entry->state;
    entry->state = state;
    __skb_unlink(skb, list);
    spin_unlock(&list->lock);
    spin_lock(&dev->done.lock);
    __skb_queue_tail(&dev->done, skb);
    if (dev->done.qlen == 1)
        tasklet_schedule(&dev->bh);
    spin_unlock_irqrestore(&dev->done.lock, flags);
*2 rx_complete (usbnet.c:640)
    state = defer_bh(dev, skb, &dev->rxq, state);

At the same time, the following code repeatedly checks if the queue is
empty and reads these values concurrently with the above changes:

*0  usbnet_terminate_urbs (usbnet.c:765)
    /* maybe wait for deletions to finish. */
    while (!skb_queue_empty(&dev->rxq)
        && !skb_queue_empty(&dev->txq)
        && !skb_queue_empty(&dev->done)) {
            schedule_timeout(msecs_to_jiffies(UNLINK_TIMEOUT_MS));
            set_current_state(TASK_UNINTERRUPTIBLE);
            netif_dbg(dev, ifdown, dev->net,
                  "waited for %d urb completions\n", temp);
    }
*1  usbnet_stop (usbnet.c:806)
    if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
        usbnet_terminate_urbs(dev);

As a result, it is possible, for example, that the skb is removed from
dev->rxq by __skb_unlink() before the check
"!skb_queue_empty(&dev->rxq)" in usbnet_terminate_urbs() is made. It is
also possible in this case that the skb is added to dev->done queue
after "!skb_queue_empty(&dev->done)" is checked. So
usbnet_terminate_urbs() may stop waiting and return while dev->done
queue still has an item.

Locking in defer_bh() and usbnet_terminate_urbs() was revisited to avoid
this race.
Signed-off-by: NEugene Shatokhin <eugene.shatokhin@rosalab.ru>
Reviewed-by: NBjørn Mork <bjorn@mork.no>
Acked-by: NOliver Neukum <oneukum@suse.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      fcb0bb6a
  5. 07 9月, 2015 6 次提交
  7. 06 9月, 2015 3 次提交
  9. 04 9月, 2015 1 次提交
  11. 03 9月, 2015 3 次提交
  13. 02 9月, 2015 22 次提交