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Diffstat (limited to 'arch/x86/kernel/cpuid.c')
-rw-r--r--arch/x86/kernel/cpuid.c25
1 files changed, 17 insertions, 8 deletions
diff --git a/arch/x86/kernel/cpuid.c b/arch/x86/kernel/cpuid.c
index daff52a62248..71f1c2654bec 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;
}
/*