x86: cdev lock_kernel() pushdown

Push the cdev lock_kernel() call down into the x86 msr and cpuid drivers.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

diff --git a/arch/x86/kernel/cpuid.c b/arch/x86/kernel/cpuid.c
index daff52a6224857f79985d20c96b0661922c88504..71f1c2654bec27096042a66d2e5f1dfe7729a4b5 100644 (file)
--- 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/msr.c b/arch/x86/kernel/msr.c
index 1f3abe048e93ea3dd0aaa06225deb8a577904fc6..a153b3905f60591cb6fb627cad9dcc6e529e25cb 100644 (file)
--- 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;
 }