x86, microcode: Fix the failure path of microcode update driver init code

The microcode update driver's initialization code does not handle
failures correctly. This patch fixes this issue.

Signed-off-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20111107123530.12164.31227.stgit@srivatsabhat.in.ibm.com
Link: http://lkml.kernel.org/r/4ED8E2270200007800065120@nat28.tlf.novell.com
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>

diff --git a/arch/x86/kernel/microcode_core.c b/arch/x86/kernel/microcode_core.c
index f2d2a66..9d46f5e 100644 (file)
--- a/arch/x86/kernel/microcode_core.c
+++ b/arch/x86/kernel/microcode_core.c
@@ -256,7 +256,7 @@ static int __init microcode_dev_init(void)
        return 0;
 }
 
-static void microcode_dev_exit(void)
+static void __exit microcode_dev_exit(void)
 {
        misc_deregister(&microcode_dev);
 }
@@ -519,10 +519,8 @@ static int __init microcode_init(void)
 
        microcode_pdev = platform_device_register_simple("microcode", -1,
                                                         NULL, 0);
-       if (IS_ERR(microcode_pdev)) {
-               microcode_dev_exit();
+       if (IS_ERR(microcode_pdev))
                return PTR_ERR(microcode_pdev);
-       }
 
        get_online_cpus();
        mutex_lock(&microcode_mutex);
@@ -532,14 +530,12 @@ static int __init microcode_init(void)
        mutex_unlock(&microcode_mutex);
        put_online_cpus();
 
-       if (error) {
-               platform_device_unregister(microcode_pdev);
-               return error;
-       }
+       if (error)
+               goto out_pdev;
 
        error = microcode_dev_init();
        if (error)
-               return error;
+               goto out_sysdev_driver;
 
        register_syscore_ops(&mc_syscore_ops);
        register_hotcpu_notifier(&mc_cpu_notifier);
@@ -548,6 +544,20 @@ static int __init microcode_init(void)
                " <tigran@aivazian.fsnet.co.uk>, Peter Oruba\n");
 
        return 0;
+
+out_sysdev_driver:
+       get_online_cpus();
+       mutex_lock(&microcode_mutex);
+
+       sysdev_driver_unregister(&cpu_sysdev_class, &mc_sysdev_driver);
+
+       mutex_unlock(&microcode_mutex);
+       put_online_cpus();
+
+out_pdev:
+       platform_device_unregister(microcode_pdev);
+       return error;
+
 }
 module_init(microcode_init);