IPoIB: Fix kernel unaligned access on ia64

Fix misaligned access faults on ia64: never cast a misaligned
neighbour->ha + 4 pointer to union ib_gid type; pass a void * pointer
instead.  The memcpy was being optimized to use full word accesses
because the compiler thought that union ib_gid is always aligned.

The cast in IPOIB_GID_ARG is safe, since it is fixed to access each
byte separately.

Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

3 files changed, 39 insertions, 34 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib.h b/drivers/infiniband/ulp/ipoib/ipoib.h
index 12a1e0572ef2..491d2afaf5b4 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib.h
+++ b/drivers/infiniband/ulp/ipoib/ipoib.h
@@ -272,8 +272,7 @@ int ipoib_dev_init(struct net_device *dev, struct ib_device *ca, int port);
 void ipoib_dev_cleanup(struct net_device *dev);
 
 void ipoib_mcast_join_task(void *dev_ptr);
-void ipoib_mcast_send(struct net_device *dev, union ib_gid *mgid,
-                      struct sk_buff *skb);
+void ipoib_mcast_send(struct net_device *dev, void *mgid, struct sk_buff *skb);
 
 void ipoib_mcast_restart_task(void *dev_ptr);
 int ipoib_mcast_start_thread(struct net_device *dev);
@@ -369,15 +368,26 @@ extern int ipoib_debug_level;
 #endif /* CONFIG_INFINIBAND_IPOIB_DEBUG_DATA */
 
 
-#define IPOIB_GID_FMT           "%x:%x:%x:%x:%x:%x:%x:%x"
-
-#define IPOIB_GID_ARG(gid)      be16_to_cpup((__be16 *) ((gid).raw +  0)), \
-                                be16_to_cpup((__be16 *) ((gid).raw +  2)), \
-                                be16_to_cpup((__be16 *) ((gid).raw +  4)), \
-                                be16_to_cpup((__be16 *) ((gid).raw +  6)), \
-                                be16_to_cpup((__be16 *) ((gid).raw +  8)), \
-                                be16_to_cpup((__be16 *) ((gid).raw + 10)), \
-                                be16_to_cpup((__be16 *) ((gid).raw + 12)), \
-                                be16_to_cpup((__be16 *) ((gid).raw + 14))
+#define IPOIB_GID_FMT           "%2.2x%2.2x:%2.2x%2.2x:%2.2x%2.2x:%2.2x%2.2x:" \
+                                "%2.2x%2.2x:%2.2x%2.2x:%2.2x%2.2x:%2.2x%2.2x"
+
+#define IPOIB_GID_RAW_ARG(gid)  ((u8 *)(gid))[0], \
+                                ((u8 *)(gid))[1], \
+                                ((u8 *)(gid))[2], \
+                                ((u8 *)(gid))[3], \
+                                ((u8 *)(gid))[4], \
+                                ((u8 *)(gid))[5], \
+                                ((u8 *)(gid))[6], \
+                                ((u8 *)(gid))[7], \
+                                ((u8 *)(gid))[8], \
+                                ((u8 *)(gid))[9], \
+                                ((u8 *)(gid))[10],\
+                                ((u8 *)(gid))[11],\
+                                ((u8 *)(gid))[12],\
+                                ((u8 *)(gid))[13],\
+                                ((u8 *)(gid))[14],\
+                                ((u8 *)(gid))[15]
+
+#define IPOIB_GID_ARG(gid)      IPOIB_GID_RAW_ARG((gid).raw)
 
 #endif /* _IPOIB_H */
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index cb078a7d0bf5..1c6ea1c682a5 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -185,8 +185,7 @@ static int ipoib_change_mtu(struct net_device *dev, int new_mtu)
         return 0;
 }
 
-static struct ipoib_path *__path_find(struct net_device *dev,
-                                      union ib_gid *gid)
+static struct ipoib_path *__path_find(struct net_device *dev, void *gid)
 {
         struct ipoib_dev_priv *priv = netdev_priv(dev);
         struct rb_node *n = priv->path_tree.rb_node;
@@ -196,7 +195,7 @@ static struct ipoib_path *__path_find(struct net_device *dev,
         while (n) {
                 path = rb_entry(n, struct ipoib_path, rb_node);
 
-                ret = memcmp(gid->raw, path->pathrec.dgid.raw,
+                ret = memcmp(gid, path->pathrec.dgid.raw,
                              sizeof (union ib_gid));
 
                 if (ret < 0)
@@ -424,8 +423,7 @@ static void path_rec_completion(int status,
         }
 }
 
-static struct ipoib_path *path_rec_create(struct net_device *dev,
-                                          union ib_gid *gid)
+static struct ipoib_path *path_rec_create(struct net_device *dev, void *gid)
 {
         struct ipoib_dev_priv *priv = netdev_priv(dev);
         struct ipoib_path *path;
@@ -440,7 +438,7 @@ static struct ipoib_path *path_rec_create(struct net_device *dev,
 
         INIT_LIST_HEAD(&path->neigh_list);
 
-        memcpy(path->pathrec.dgid.raw, gid->raw, sizeof (union ib_gid));
+        memcpy(path->pathrec.dgid.raw, gid, sizeof (union ib_gid));
         path->pathrec.sgid      = priv->local_gid;
         path->pathrec.pkey      = cpu_to_be16(priv->pkey);
         path->pathrec.numb_path = 1;
@@ -498,10 +496,9 @@ static void neigh_add_path(struct sk_buff *skb, struct net_device *dev)
          */
         spin_lock(&priv->lock);
 
-        path = __path_find(dev, (union ib_gid *) (skb->dst->neighbour->ha + 4));
+        path = __path_find(dev, skb->dst->neighbour->ha + 4);
         if (!path) {
-                path = path_rec_create(dev,
-                                       (union ib_gid *) (skb->dst->neighbour->ha + 4));
+                path = path_rec_create(dev, skb->dst->neighbour->ha + 4);
                 if (!path)
                         goto err_path;
 
@@ -551,7 +548,7 @@ static void ipoib_path_lookup(struct sk_buff *skb, struct net_device *dev)
         /* Add in the P_Key for multicasts */
         skb->dst->neighbour->ha[8] = (priv->pkey >> 8) & 0xff;
         skb->dst->neighbour->ha[9] = priv->pkey & 0xff;
-        ipoib_mcast_send(dev, (union ib_gid *) (skb->dst->neighbour->ha + 4), skb);
+        ipoib_mcast_send(dev, skb->dst->neighbour->ha + 4, skb);
 }
 
 static void unicast_arp_send(struct sk_buff *skb, struct net_device *dev,
@@ -566,10 +563,9 @@ static void unicast_arp_send(struct sk_buff *skb, struct net_device *dev,
          */
         spin_lock(&priv->lock);
 
-        path = __path_find(dev, (union ib_gid *) (phdr->hwaddr + 4));
+        path = __path_find(dev, phdr->hwaddr + 4);
         if (!path) {
-                path = path_rec_create(dev,
-                                       (union ib_gid *) (phdr->hwaddr + 4));
+                path = path_rec_create(dev, phdr->hwaddr + 4);
                 if (path) {
                         /* put pseudoheader back on for next time */
                         skb_push(skb, sizeof *phdr);
@@ -660,7 +656,7 @@ static int ipoib_start_xmit(struct sk_buff *skb, struct net_device *dev)
                         phdr->hwaddr[8] = (priv->pkey >> 8) & 0xff;
                         phdr->hwaddr[9] = priv->pkey & 0xff;
 
-                        ipoib_mcast_send(dev, (union ib_gid *) (phdr->hwaddr + 4), skb);
+                        ipoib_mcast_send(dev, phdr->hwaddr + 4, skb);
                 } else {
                         /* unicast GID -- should be ARP or RARP reply */
 
@@ -671,7 +667,7 @@ static int ipoib_start_xmit(struct sk_buff *skb, struct net_device *dev)
                                            skb->dst ? "neigh" : "dst",
                                            be16_to_cpup((__be16 *) skb->data),
                                            be32_to_cpup((__be32 *) phdr->hwaddr),
-                                           IPOIB_GID_ARG(*(union ib_gid *) (phdr->hwaddr + 4)));
+                                           IPOIB_GID_RAW_ARG(phdr->hwaddr + 4));
                                 dev_kfree_skb_any(skb);
                                 ++priv->stats.tx_dropped;
                                 goto out;
@@ -754,7 +750,7 @@ static void ipoib_neigh_destructor(struct neighbour *n)
         ipoib_dbg(priv,
                   "neigh_destructor for %06x " IPOIB_GID_FMT "\n",
                   be32_to_cpup((__be32 *) n->ha),
-                  IPOIB_GID_ARG(*((union ib_gid *) (n->ha + 4))));
+                  IPOIB_GID_RAW_ARG(n->ha + 4));
 
         spin_lock_irqsave(&priv->lock, flags);
 
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
index 1dae4b238252..ec41c8f46c72 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
@@ -154,7 +154,7 @@ static struct ipoib_mcast *ipoib_mcast_alloc(struct net_device *dev,
         return mcast;
 }
 
-static struct ipoib_mcast *__ipoib_mcast_find(struct net_device *dev, union ib_gid *mgid)
+static struct ipoib_mcast *__ipoib_mcast_find(struct net_device *dev, void *mgid)
 {
         struct ipoib_dev_priv *priv = netdev_priv(dev);
         struct rb_node *n = priv->multicast_tree.rb_node;
@@ -165,7 +165,7 @@ static struct ipoib_mcast *__ipoib_mcast_find(struct net_device *dev, union ib_g
 
                 mcast = rb_entry(n, struct ipoib_mcast, rb_node);
 
-                ret = memcmp(mgid->raw, mcast->mcmember.mgid.raw,
+                ret = memcmp(mgid, mcast->mcmember.mgid.raw,
                              sizeof (union ib_gid));
                 if (ret < 0)
                         n = n->rb_left;
@@ -694,8 +694,7 @@ static int ipoib_mcast_leave(struct net_device *dev, struct ipoib_mcast *mcast)
         return 0;
 }
 
-void ipoib_mcast_send(struct net_device *dev, union ib_gid *mgid,
-                      struct sk_buff *skb)
+void ipoib_mcast_send(struct net_device *dev, void *mgid, struct sk_buff *skb)
 {
         struct ipoib_dev_priv *priv = netdev_priv(dev);
         struct ipoib_mcast *mcast;
@@ -718,7 +717,7 @@ void ipoib_mcast_send(struct net_device *dev, union ib_gid *mgid,
         if (!mcast) {
                 /* Let's create a new send only group now */
                 ipoib_dbg_mcast(priv, "setting up send only multicast group for "
-                                IPOIB_GID_FMT "\n", IPOIB_GID_ARG(*mgid));
+                                IPOIB_GID_FMT "\n", IPOIB_GID_RAW_ARG(mgid));
 
                 mcast = ipoib_mcast_alloc(dev, 0);
                 if (!mcast) {
@@ -730,7 +729,7 @@ void ipoib_mcast_send(struct net_device *dev, union ib_gid *mgid,
                 }
 
                 set_bit(IPOIB_MCAST_FLAG_SENDONLY, &mcast->flags);
-                mcast->mcmember.mgid = *mgid;
+                memcpy(mcast->mcmember.mgid.raw, mgid, sizeof (union ib_gid));
                 __ipoib_mcast_add(dev, mcast);
                 list_add_tail(&mcast->list, &priv->multicast_list);
         }