diff options
Diffstat (limited to 'arch/x86/kernel/cpuid.c')
| -rw-r--r-- | arch/x86/kernel/cpuid.c | 25 |
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; } /* |