acerhdf: fix resource reclaim in error path

Fix resource reclaim in below cases:

1. acerhdf_register_platform() does not properly handle
   platform_device_alloc() failure and platform_device_add() failure This
   patch adds error handing for acerhdf_register_platform().

2. acerhdf_register_platform() return err with acerhdf_dev == NULL.
   as a result, acerhdf_unregister_platform() does not do resource reclaim
   in acerhdf_init() error path.  This patch adds error handing for
   acerhdf_register_platform(), thus correct the error handing path in
   acerhdf_init().  goto out_err instead of err_unreg if
   acerhdf_register_platform() fail.

3. platform_device_del() should only used in error handling.  Current
   implementation missed a platform_device_put() in acerhdf_exit.  This
   patch fixes it by using platform_device_unregister() instead of
   platform_device_del() in acerhdf_unregister_platform.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Peter Feuerer <peter@piie.net>
Cc: Matthew Garrett <mjg@redhat.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

1 files changed, 16 insertions, 7 deletions

diff --git a/drivers/platform/x86/acerhdf.c b/drivers/platform/x86/acerhdf.c
index 4ce28d901b9a..60f9cfcac93f 100644
--- a/drivers/platform/x86/acerhdf.c
+++ b/drivers/platform/x86/acerhdf.c
@@ -615,17 +615,26 @@ static int acerhdf_register_platform(void)
                 return err;
 
         acerhdf_dev = platform_device_alloc("acerhdf", -1);
-        platform_device_add(acerhdf_dev);
+        if (!acerhdf_dev) {
+                err = -ENOMEM;
+                goto err_device_alloc;
+        }
+        err = platform_device_add(acerhdf_dev);
+        if (err)
+                goto err_device_add;
 
         return 0;
+
+err_device_add:
+        platform_device_put(acerhdf_dev);
+err_device_alloc:
+        platform_driver_unregister(&acerhdf_driver);
+        return err;
 }
 
 static void acerhdf_unregister_platform(void)
 {
-        if (!acerhdf_dev)
-                return;
-
-        platform_device_del(acerhdf_dev);
+        platform_device_unregister(acerhdf_dev);
         platform_driver_unregister(&acerhdf_driver);
 }
 
@@ -669,7 +678,7 @@ static int __init acerhdf_init(void)
 
         err = acerhdf_register_platform();
         if (err)
-                goto err_unreg;
+                goto out_err;
 
         err = acerhdf_register_thermal();
         if (err)
@@ -682,7 +691,7 @@ err_unreg:
         acerhdf_unregister_platform();
 
 out_err:
-        return -ENODEV;
+        return err;
 }
 
 static void __exit acerhdf_exit(void)