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>

2 files changed, 17 insertions, 8 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);
diff --git a/drivers/infiniband/hw/ipath/ipath_sysfs.c b/drivers/infiniband/hw/ipath/ipath_sysfs.c
index b48ebf62e5dd..182de34f9f47 100644
--- a/drivers/infiniband/hw/ipath/ipath_sysfs.c
+++ b/drivers/infiniband/hw/ipath/ipath_sysfs.c
@@ -257,7 +257,7 @@ static ssize_t store_guid(struct device *dev,
         struct ipath_devdata *dd = dev_get_drvdata(dev);
         ssize_t ret;
         unsigned short guid[8];
-        __be64 nguid;
+        __be64 new_guid;
         u8 *ng;
         int i;
 
@@ -266,7 +266,7 @@ static ssize_t store_guid(struct device *dev,
                    &guid[4], &guid[5], &guid[6], &guid[7]) != 8)
                 goto invalid;
 
-        ng = (u8 *) &nguid;
+        ng = (u8 *) &new_guid;
 
         for (i = 0; i < 8; i++) {
                 if (guid[i] > 0xff)
@@ -274,7 +274,10 @@ static ssize_t store_guid(struct device *dev,
                 ng[i] = guid[i];
         }
 
-        dd->ipath_guid = nguid;
+        if (new_guid == 0)
+                goto invalid;
+
+        dd->ipath_guid = new_guid;
         dd->ipath_nguid = 1;
 
         ret = strlen(buf);