stmmac: unwind properly in stmmac_dvr_probe()

The original code had a several problems:
*) It had potential null dereferences of "priv" and "res".
*) It released the memory region before it was aquired.
*) It didn't free "ndev" after it was allocated.
*) It didn't call unregister_netdev() after calling stmmac_probe().

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/stmmac/stmmac_main.c b/drivers/net/stmmac/stmmac_main.c
index 20f803d..34a0af3 100644 (file)
--- a/drivers/net/stmmac/stmmac_main.c
+++ b/drivers/net/stmmac/stmmac_main.c
@@ -1647,10 +1647,8 @@ static int stmmac_dvr_probe(struct platform_device *pdev)
 
        pr_info("STMMAC driver:\n\tplatform registration... ");
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-       if (!res) {
-               ret = -ENODEV;
-               goto out;
-       }
+       if (!res)
+               return -ENODEV;
        pr_info("\tdone!\n");
 
        if (!request_mem_region(res->start, resource_size(res),
@@ -1658,22 +1656,21 @@ static int stmmac_dvr_probe(struct platform_device *pdev)
                pr_err("%s: ERROR: memory allocation failed"
                       "cannot get the I/O addr 0x%x\n",
                       __func__, (unsigned int)res->start);
-               ret = -EBUSY;
-               goto out;
+               return -EBUSY;
        }
 
        addr = ioremap(res->start, resource_size(res));
        if (!addr) {
                pr_err("%s: ERROR: memory mapping failed\n", __func__);
                ret = -ENOMEM;
-               goto out;
+               goto out_release_region;
        }
 
        ndev = alloc_etherdev(sizeof(struct stmmac_priv));
        if (!ndev) {
                pr_err("%s: ERROR: allocating the device\n", __func__);
                ret = -ENOMEM;
-               goto out;
+               goto out_unmap;
        }
 
        SET_NETDEV_DEV(ndev, &pdev->dev);
@@ -1683,8 +1680,8 @@ static int stmmac_dvr_probe(struct platform_device *pdev)
        if (ndev->irq == -ENXIO) {
                pr_err("%s: ERROR: MAC IRQ configuration "
                       "information not found\n", __func__);
-               ret = -ENODEV;
-               goto out;
+               ret = -ENXIO;
+               goto out_free_ndev;
        }
 
        priv = netdev_priv(ndev);
@@ -1711,18 +1708,18 @@ static int stmmac_dvr_probe(struct platform_device *pdev)
        if (priv->plat->init) {
                ret = priv->plat->init(pdev);
                if (unlikely(ret))
-                       goto out;
+                       goto out_free_ndev;
        }
 
        /* MAC HW revice detection */
        ret = stmmac_mac_device_setup(ndev);
        if (ret < 0)
-               goto out;
+               goto out_plat_exit;
 
        /* Network Device Registration */
        ret = stmmac_probe(ndev);
        if (ret < 0)
-               goto out;
+               goto out_plat_exit;
 
        /* associate a PHY - it is provided by another platform bus */
        if (!driver_for_each_device
@@ -1730,7 +1727,7 @@ static int stmmac_dvr_probe(struct platform_device *pdev)
             stmmac_associate_phy)) {
                pr_err("No PHY device is associated with this MAC!\n");
                ret = -ENODEV;
-               goto out;
+               goto out_unregister;
        }
 
        pr_info("\t%s - (dev. name: %s - id: %d, IRQ #%d\n"
@@ -1741,19 +1738,22 @@ static int stmmac_dvr_probe(struct platform_device *pdev)
        pr_debug("\tMDIO bus (id: %d)...", priv->plat->bus_id);
        ret = stmmac_mdio_register(ndev);
        if (ret < 0)
-               goto out;
+               goto out_unregister;
        pr_debug("registered!\n");
+       return 0;
 
-out:
-       if (ret < 0) {
-               if (priv->plat->exit)
-                       priv->plat->exit(pdev);
-
-               platform_set_drvdata(pdev, NULL);
-               release_mem_region(res->start, resource_size(res));
-               if (addr != NULL)
-                       iounmap(addr);
-       }
+out_unregister:
+       unregister_netdev(ndev);
+out_plat_exit:
+       if (priv->plat->exit)
+               priv->plat->exit(pdev);
+out_free_ndev:
+       free_netdev(ndev);
+       platform_set_drvdata(pdev, NULL);
+out_unmap:
+       iounmap(addr);
+out_release_region:
+       release_mem_region(res->start, resource_size(res));
 
        return ret;
 }