1 files changed, 9 insertions, 14 deletions

diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c
index 6a3cefc7dda1..4bd93c9b2b27 100644
--- a/arch/x86/kernel/msr.c
+++ b/arch/x86/kernel/msr.c
@@ -172,23 +172,18 @@ static long msr_ioctl(struct file *file, unsigned int ioc, unsigned long arg)
 
 static int msr_open(struct inode *inode, struct file *file)
 {
-        unsigned int cpu = iminor(file->f_path.dentry->d_inode);
-        struct cpuinfo_x86 *c = &cpu_data(cpu);
-        int ret = 0;
+        unsigned int cpu;
+        struct cpuinfo_x86 *c;
 
-        lock_kernel();
         cpu = iminor(file->f_path.dentry->d_inode);
+        if (cpu >= nr_cpu_ids || !cpu_online(cpu))
+                return -ENXIO;  /* No such CPU */
 
-        if (cpu >= nr_cpu_ids || !cpu_online(cpu)) {
-                ret = -ENXIO;   /* No such CPU */
-                goto out;
-        }
         c = &cpu_data(cpu);
         if (!cpu_has(c, X86_FEATURE_MSR))
-                ret = -EIO;     /* MSR not supported */
-out:
-        unlock_kernel();
-        return ret;
+                return -EIO;    /* MSR not supported */
+
+        return 0;
 }
 
 /*
@@ -251,7 +246,7 @@ static int __init msr_init(void)
         int i, err = 0;
         i = 0;
 
-        if (register_chrdev(MSR_MAJOR, "cpu/msr", &msr_fops)) {
+        if (__register_chrdev(MSR_MAJOR, 0, NR_CPUS, "cpu/msr", &msr_fops)) {
                 printk(KERN_ERR "msr: unable to get major %d for msr\n",
                        MSR_MAJOR);
                 err = -EBUSY;
@@ -279,7 +274,7 @@ out_class:
                 msr_device_destroy(i);
         class_destroy(msr_class);
 out_chrdev:
-        unregister_chrdev(MSR_MAJOR, "cpu/msr");
+        __unregister_chrdev(MSR_MAJOR, 0, NR_CPUS, "cpu/msr");
 out:
         return err;
 }