IB/ipath: Clean up handling of GUID 0

Respond with an error to the SM if our GUID is 0, and don't allow the
user to set our GUID to 0.

Signed-off-by: Bryan O'Sullivan <bryan.osullivan@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 11 insertions, 5 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_mad.c b/drivers/infiniband/hw/ipath/ipath_mad.c
index 72d1db89db8f..25908b02fbe5 100644
--- a/drivers/infiniband/hw/ipath/ipath_mad.c
+++ b/drivers/infiniband/hw/ipath/ipath_mad.c
@@ -87,7 +87,8 @@ static int recv_subn_get_nodeinfo(struct ib_smp *smp,
         struct ipath_devdata *dd = to_idev(ibdev)->dd;
         u32 vendor, majrev, minrev;
 
-        if (smp->attr_mod)
+        /* GUID 0 is illegal */
+        if (smp->attr_mod || (dd->ipath_guid == 0))
                 smp->status |= IB_SMP_INVALID_FIELD;
 
         nip->base_version = 1;
@@ -131,10 +132,15 @@ static int recv_subn_get_guidinfo(struct ib_smp *smp,
          * We only support one GUID for now.  If this changes, the
          * portinfo.guid_cap field needs to be updated too.
          */
-        if (startgx == 0)
-                /* The first is a copy of the read-only HW GUID. */
-                *p = to_idev(ibdev)->dd->ipath_guid;
-        else
+        if (startgx == 0) {
+                __be64 g = to_idev(ibdev)->dd->ipath_guid;
+                if (g == 0)
+                        /* GUID 0 is illegal */
+                        smp->status |= IB_SMP_INVALID_FIELD;
+                else
+                        /* The first is a copy of the read-only HW GUID. */
+                        *p = g;
+        } else
                 smp->status |= IB_SMP_INVALID_FIELD;
 
         return reply(smp);