net: dcb: move getapptrust to separate function

This patch fixes a frame size warning, reported by kernel test robot.

>> net/dcb/dcbnl.c:1230:1: warning: the frame size of 1244 bytes is
>> larger than 1024 bytes [-Wframe-larger-than=]

The getapptrust part of dcbnl_ieee_fill is moved to a separate function,
and the selector array is now dynamically allocated, instead of stack
allocated.

Tested on microchip sparx5 driver.

Fixes: 6182d5875c33 ("net: dcb: add new apptrust attribute")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
Link: https://lore.kernel.org/r/20221114092950.2490451-1-daniel.machon@microchip.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
index cec0632..f9949e0 100644 (file)
--- a/net/dcb/dcbnl.c
+++ b/net/dcb/dcbnl.c
@@ -1060,11 +1060,50 @@ nla_put_failure:
        return err;
 }
 
+static int dcbnl_getapptrust(struct net_device *netdev, struct sk_buff *skb)
+{
+       const struct dcbnl_rtnl_ops *ops = netdev->dcbnl_ops;
+       enum ieee_attrs_app type;
+       struct nlattr *apptrust;
+       int nselectors, err, i;
+       u8 *selectors;
+
+       selectors = kzalloc(IEEE_8021QAZ_APP_SEL_MAX + 1, GFP_KERNEL);
+       if (!selectors)
+               return -ENOMEM;
+
+       err = ops->dcbnl_getapptrust(netdev, selectors, &nselectors);
+       if (err) {
+               err = 0;
+               goto out;
+       }
+
+       apptrust = nla_nest_start(skb, DCB_ATTR_DCB_APP_TRUST_TABLE);
+       if (!apptrust) {
+               err = -EMSGSIZE;
+               goto out;
+       }
+
+       for (i = 0; i < nselectors; i++) {
+               type = dcbnl_app_attr_type_get(selectors[i]);
+               err = nla_put_u8(skb, type, selectors[i]);
+               if (err) {
+                       nla_nest_cancel(skb, apptrust);
+                       goto out;
+               }
+       }
+       nla_nest_end(skb, apptrust);
+
+out:
+       kfree(selectors);
+       return err;
+}
+
 /* Handle IEEE 802.1Qaz/802.1Qau/802.1Qbb GET commands. */
 static int dcbnl_ieee_fill(struct sk_buff *skb, struct net_device *netdev)
 {
        const struct dcbnl_rtnl_ops *ops = netdev->dcbnl_ops;
-       struct nlattr *ieee, *app, *apptrust;
+       struct nlattr *ieee, *app;
        struct dcb_app_type *itr;
        int dcbx;
        int err;
@@ -1168,27 +1207,9 @@ static int dcbnl_ieee_fill(struct sk_buff *skb, struct net_device *netdev)
        nla_nest_end(skb, app);
 
        if (ops->dcbnl_getapptrust) {
-               u8 selectors[IEEE_8021QAZ_APP_SEL_MAX + 1] = {0};
-               int nselectors, i;
-
-               apptrust = nla_nest_start(skb, DCB_ATTR_DCB_APP_TRUST_TABLE);
-               if (!apptrust)
-                       return -EMSGSIZE;
-
-               err = ops->dcbnl_getapptrust(netdev, selectors, &nselectors);
-               if (!err) {
-                       for (i = 0; i < nselectors; i++) {
-                               enum ieee_attrs_app type =
-                                       dcbnl_app_attr_type_get(selectors[i]);
-                               err = nla_put_u8(skb, type, selectors[i]);
-                               if (err) {
-                                       nla_nest_cancel(skb, apptrust);
-                                       return err;
-                               }
-                       }
-               }
-
-               nla_nest_end(skb, apptrust);
+               err = dcbnl_getapptrust(netdev, skb);
+               if (err)
+                       return err;
        }
 
        /* get peer info if available */