fix-ipoib-add-missing-lock.patch

   1 From fa16ebed31f336e41970f3f0ea9e8279f6be2d27 Mon Sep 17 00:00:00 2001
   2 From: Shlomo Pongratz <shlomop@mellanox.com>
   3 Date: Mon, 13 Aug 2012 14:39:49 +0000
   4 Subject: IB/ipoib: Add missing locking when CM object is deleted
   5
   6 Commit b63b70d87741 ("IPoIB: Use a private hash table for path lookup
   7 in xmit path") introduced a bug where in ipoib_cm_destroy_tx() a CM
   8 object is moved between lists without any supported locking.  Under a
   9 stress test, this eventually leads to list corruption and a crash.
  10
  11 Previously when this routine was called, callers were taking the
  12 device priv lock.  Currently this function is called from the RCU
  13 callback associated with neighbour deletion.  Fix the race by taking
  14 the same lock we used to before.
  15
  16 Signed-off-by: Shlomo Pongratz <shlomop@mellanox.com>
  17 Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
  18 Signed-off-by: Roland Dreier <roland@purestorage.com>
  19 ---
  20 diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
  21 index 95ecf4e..24683fd 100644
  22 --- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c
  23 +++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
  24 @@ -1271,12 +1271,15 @@ struct ipoib_cm_tx *ipoib_cm_create_tx(struct net_device *dev, struct ipoib_path
  25  void ipoib_cm_destroy_tx(struct ipoib_cm_tx *tx)
  26  {
  27         struct ipoib_dev_priv *priv = netdev_priv(tx->dev);
  28 +       unsigned long flags;
  29         if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) {
  30 +               spin_lock_irqsave(&priv->lock, flags);
  31                 list_move(&tx->list, &priv->cm.reap_list);
  32                 queue_work(ipoib_workqueue, &priv->cm.reap_task);
  33                 ipoib_dbg(priv, "Reap connection for gid %pI6\n",
  34                           tx->neigh->daddr + 4);
  35                 tx->neigh = NULL;
  36 +               spin_unlock_irqrestore(&priv->lock, flags);
  37         }
  38  }
  39
  40 --
  41 cgit v0.9.1