1 files changed, 30 insertions, 15 deletions

diff --git a/arch/x86/kernel/cpuid.c b/arch/x86/kernel/cpuid.c
index daff52a62248..6a44d6465991 100644
--- a/arch/x86/kernel/cpuid.c
+++ b/arch/x86/kernel/cpuid.c
@@ -33,9 +33,9 @@
 #include <linux/init.h>
 #include <linux/poll.h>
 #include <linux/smp.h>
+#include <linux/smp_lock.h>
 #include <linux/major.h>
 #include <linux/fs.h>
-#include <linux/smp_lock.h>
 #include <linux/device.h>
 #include <linux/cpu.h>
 #include <linux/notifier.h>
@@ -88,6 +88,8 @@ static ssize_t cpuid_read(struct file *file, char __user *buf,
         struct cpuid_regs cmd;
         int cpu = iminor(file->f_path.dentry->d_inode);
         u64 pos = *ppos;
+        ssize_t bytes = 0;
+        int err = 0;
 
         if (count % 16)
                 return -EINVAL; /* Invalid chunk size */
@@ -95,27 +97,40 @@ static ssize_t cpuid_read(struct file *file, char __user *buf,
         for (; count; count -= 16) {
                 cmd.eax = pos;
                 cmd.ecx = pos >> 32;
-                smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1, 1);
-                if (copy_to_user(tmp, &cmd, 16))
-                        return -EFAULT;
+                err = smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1);
+                if (err)
+                        break;
+                if (copy_to_user(tmp, &cmd, 16)) {
+                        err = -EFAULT;
+                        break;
+                }
                 tmp += 16;
+                bytes += 16;
                 *ppos = ++pos;
         }
 
-        return tmp - buf;
+        return bytes ? bytes : err;
 }
 
 static int cpuid_open(struct inode *inode, struct file *file)
 {
-        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);
         if (c->cpuid_level < 0)
-                return -EIO;    /* CPUID not supported */
-
-        return 0;
+                ret = -EIO;     /* CPUID not supported */
+out:
+        unlock_kernel();
+        return ret;
 }
 
 /*
@@ -132,8 +147,8 @@ static __cpuinit int cpuid_device_create(int cpu)
 {
         struct device *dev;
 
-        dev = device_create(cpuid_class, NULL, MKDEV(CPUID_MAJOR, cpu),
-                            "cpu%d", cpu);
+        dev = device_create_drvdata(cpuid_class, NULL, MKDEV(CPUID_MAJOR, cpu),
+                                    NULL, "cpu%d", cpu);
         return IS_ERR(dev) ? PTR_ERR(dev) : 0;
 }