{
unsigned int cpu = iminor(file->f_path.dentry->d_inode);
struct cpuinfo_x86 *c = &cpu_data(cpu);
+ int ret = 0;
- if (cpu >= NR_CPUS || !cpu_online(cpu))
- return -ENXIO; /* No such CPU */
- if (!cpu_has(c, X86_FEATURE_MSR))
- return -EIO; /* MSR not supported */
+ lock_kernel();
+ cpu = iminor(file->f_path.dentry->d_inode);
+ if (cpu >= NR_CPUS || !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 0;
}