5 files changed, 39 insertions, 12 deletions

diff --git a/arch/x86/kernel/apm_32.c b/arch/x86/kernel/apm_32.c
index bf9290e..8222236 100644
--- a/arch/x86/kernel/apm_32.c
+++ b/arch/x86/kernel/apm_32.c
@@ -204,6 +204,7 @@
 #include <linux/module.h>
 
 #include <linux/poll.h>
+#include <linux/smp_lock.h>
 #include <linux/types.h>
 #include <linux/stddef.h>
 #include <linux/timer.h>
@@ -1544,10 +1545,12 @@ static int do_open(struct inode *inode, struct file *filp)
 {
 	struct apm_user *as;
 
+	lock_kernel();
 	as = kmalloc(sizeof(*as), GFP_KERNEL);
 	if (as == NULL) {
 		printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
 		       sizeof(*as));
+		       unlock_kernel();
 		return -ENOMEM;
 	}
 	as->magic = APM_BIOS_MAGIC;
@@ -1569,6 +1572,7 @@ static int do_open(struct inode *inode, struct file *filp)
 	user_list = as;
 	spin_unlock(&user_list_lock);
 	filp->private_data = as;
+	unlock_kernel();
 	return 0;
 }
 
diff --git a/arch/x86/kernel/cpu/mcheck/mce_64.c b/arch/x86/kernel/cpu/mcheck/mce_64.c
index e07e8c0..4ef1516 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_64.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_64.c
@@ -9,6 +9,7 @@
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
+#include <linux/smp_lock.h>
 #include <linux/string.h>
 #include <linux/rcupdate.h>
 #include <linux/kallsyms.h>
@@ -527,10 +528,12 @@ static int open_exclu;	/* already open exclusive? */
 
 static int mce_open(struct inode *inode, struct file *file)
 {
+	lock_kernel();
 	spin_lock(&mce_state_lock);
 
 	if (open_exclu || (open_count && (file->f_flags & O_EXCL))) {
 		spin_unlock(&mce_state_lock);
+		unlock_kernel();
 		return -EBUSY;
 	}
 
@@ -539,6 +542,7 @@ static int mce_open(struct inode *inode, struct file *file)
 	open_count++;
 
 	spin_unlock(&mce_state_lock);
+	unlock_kernel();
 
 	return nonseekable_open(inode, file);
 }
diff --git a/arch/x86/kernel/cpuid.c b/arch/x86/kernel/cpuid.c
index daff52a..71f1c26 100644
--- a/arch/x86/kernel/cpuid.c
+++ b/arch/x86/kernel/cpuid.c
@@ -33,6 +33,7 @@
 #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>
@@ -107,15 +108,23 @@ static ssize_t cpuid_read(struct file *file, char __user *buf,
 
 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;
 }
 
 /*
diff --git a/arch/x86/kernel/microcode.c b/arch/x86/kernel/microcode.c
index 69729e3..9f0a994 100644
--- a/arch/x86/kernel/microcode.c
+++ b/arch/x86/kernel/microcode.c
@@ -75,6 +75,7 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/sched.h>
+#include <linux/smp_lock.h>
 #include <linux/cpumask.h>
 #include <linux/module.h>
 #include <linux/slab.h>
@@ -422,6 +423,7 @@ out:
 
 static int microcode_open (struct inode *unused1, struct file *unused2)
 {
+	cycle_kernel_lock();
 	return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
 }
 
diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c
index 1f3abe0..a153b39 100644
--- a/arch/x86/kernel/msr.c
+++ b/arch/x86/kernel/msr.c
@@ -117,12 +117,20 @@ 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;
 
-	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;
 }