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>

1 files changed, 25 insertions, 25 deletions

diff --git a/drivers/net/stmmac/stmmac_main.c b/drivers/net/stmmac/stmmac_main.c
index 20f803df868..34a0af3837f 100644
--- 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;
 }