- unsigned int cpu = iminor(file->f_path.dentry->d_inode);
- struct cpuinfo_x86 *c = &cpu_data(cpu);
-
- if (cpu >= NR_CPUS || !cpu_online(cpu))
- return -ENXIO; /* No such CPU */
+ unsigned int cpu;
+ struct cpuinfo_x86 *c;
+ int ret = 0;
+
+ 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);