x86/mce: Improve mcheck_init_device() error handling

Check return code of every function called by mcheck_init_device().

Signed-off-by: Mathieu Souchaud <mattieu.souchaud@free.fr>
Link: http://lkml.kernel.org/r/1399151031-19905-1-git-send-email-mattieu.souchaud@free.fr
Signed-off-by: Borislav Petkov <bp@suse.de>

diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 68317c80de7f65723c3f909762c6204629ef562d..0078761219a2418a691dd96db5780cbe7742ef86 100644 (file)
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -2437,32 +2437,65 @@ static __init int mcheck_init_device(void)
        int err;
        int i = 0;
 
-       if (!mce_available(&boot_cpu_data))
-               return -EIO;
+       if (!mce_available(&boot_cpu_data)) {
+               err = -EIO;
+               goto err_out;
+       }
 
-       zalloc_cpumask_var(&mce_device_initialized, GFP_KERNEL);
+       if (!zalloc_cpumask_var(&mce_device_initialized, GFP_KERNEL)) {
+               err = -ENOMEM;
+               goto err_out;
+       }
 
        mce_init_banks();
 
        err = subsys_system_register(&mce_subsys, NULL);
        if (err)
-               return err;
+               goto err_out_mem;
 
        cpu_notifier_register_begin();
        for_each_online_cpu(i) {
                err = mce_device_create(i);
                if (err) {
                        cpu_notifier_register_done();
-                       return err;
+                       goto err_device_create;
                }
        }
 
-       register_syscore_ops(&mce_syscore_ops);
        __register_hotcpu_notifier(&mce_cpu_notifier);
        cpu_notifier_register_done();
 
+       register_syscore_ops(&mce_syscore_ops);
+
        /* register character device /dev/mcelog */
-       misc_register(&mce_chrdev_device);
+       err = misc_register(&mce_chrdev_device);
+       if (err)
+               goto err_register;
+
+       return 0;
+
+err_register:
+       unregister_syscore_ops(&mce_syscore_ops);
+
+       cpu_notifier_register_begin();
+       __unregister_hotcpu_notifier(&mce_cpu_notifier);
+       cpu_notifier_register_done();
+
+err_device_create:
+       /*
+        * We didn't keep track of which devices were created above, but
+        * even if we had, the set of online cpus might have changed.
+        * Play safe and remove for every possible cpu, since
+        * mce_device_remove() will do the right thing.
+        */
+       for_each_possible_cpu(i)
+               mce_device_remove(i);
+
+err_out_mem:
+       free_cpumask_var(mce_device_initialized);
+
+err_out:
+       pr_err("Unable to init device /dev/mcelog (rc: %d)\n", err);
 
        return err;
 }