amd-xgbe: Add PCI device support

Hello Lendacky, Thomas,

The patch 47f164deab22: "amd-xgbe: Add PCI device support" from Nov 10, 2016, leads to the following static checker warning:

drivers/net/ethernet/amd/xgbe/xgbe-debugfs.c:360 xprop_reg_value_write()
error: uninitialized symbol 'value'.

drivers/net/ethernet/amd/xgbe/xgbe-debugfs.c
348 static ssize_t xprop_reg_value_write(struct file *filp,
349 const char __user *buffer,
350 size_t count, loff_t *ppos)
351 {

   352          struct xgbe_prv_data *pdata = filp->private_data;
   353          unsigned int value;
   354          ssize_t len;

355
356 len = xgbe_common_write(buffer, count, ppos, &value);

Assume "ppos" is non-zero then we are using uninitialized data. I suspect that xgbe_common_write() is buggy.

   357          if (len < 0)
   358                  return len;
   359  
   360          XP_IOWRITE(pdata, pdata->debugfs_xprop_reg, value);
   361  
   362          return len;
   363  }

regards,
dan carpenter

Yes, looks like this has been present for a while. I'll submit a patch to update both xgbe_common_read()/write() to return an error when *ppos != 0.

Thanks,
Tom