+/*
+ * noinline attribute so that gcc doesnt use too much stack in dev_ethtool()
+ */
+static noinline int ethtool_get_sset_info(struct net_device *dev,
+ void __user *useraddr)
+{
+ struct ethtool_sset_info info;
+ const struct ethtool_ops *ops = dev->ethtool_ops;
+ u64 sset_mask;
+ int i, idx = 0, n_bits = 0, ret, rc;
+ u32 *info_buf = NULL;
+
+ if (!ops->get_sset_count)
+ return -EOPNOTSUPP;
+
+ if (copy_from_user(&info, useraddr, sizeof(info)))
+ return -EFAULT;
+
+ /* store copy of mask, because we zero struct later on */
+ sset_mask = info.sset_mask;
+ if (!sset_mask)
+ return 0;
+
+ /* calculate size of return buffer */
+ for (i = 0; i < 64; i++)
+ if (sset_mask & (1ULL << i))
+ n_bits++;
+
+ memset(&info, 0, sizeof(info));
+ info.cmd = ETHTOOL_GSSET_INFO;
+
+ info_buf = kzalloc(n_bits * sizeof(u32), GFP_USER);
+ if (!info_buf)
+ return -ENOMEM;
+
+ /*
+ * fill return buffer based on input bitmask and successful
+ * get_sset_count return
+ */
+ for (i = 0; i < 64; i++) {
+ if (!(sset_mask & (1ULL << i)))
+ continue;
+
+ rc = ops->get_sset_count(dev, i);
+ if (rc >= 0) {
+ info.sset_mask |= (1ULL << i);
+ info_buf[idx++] = rc;
+ }
+ }
+
+ ret = -EFAULT;
+ if (copy_to_user(useraddr, &info, sizeof(info)))
+ goto out;
+
+ useraddr += offsetof(struct ethtool_sset_info, data);
+ if (copy_to_user(useraddr, info_buf, idx * sizeof(u32)))
+ goto out;
+
+ ret = 0;
+
+out:
+ kfree(info_buf);
+ return ret;
+}
+