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, 6 insertions, 3 deletions

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);