1 files changed, 8 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/mcheck/mce-inject.c b/arch/x86/kernel/cpu/mcheck/mce-inject.c
index fc4beb393577..ddc72f839332 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-inject.c
+++ b/arch/x86/kernel/cpu/mcheck/mce-inject.c
@@ -78,6 +78,7 @@ static void raise_exception(struct mce *m, struct pt_regs *pregs)
 }
 
 static cpumask_var_t mce_inject_cpumask;
+static DEFINE_MUTEX(mce_inject_mutex);
 
 static int mce_raise_notify(unsigned int cmd, struct pt_regs *regs)
 {
@@ -194,7 +195,11 @@ static void raise_mce(struct mce *m)
                 put_online_cpus();
         } else
 #endif
+        {
+                preempt_disable();
                 raise_local();
+                preempt_enable();
+        }
 }
 
 /* Error injection interface */
@@ -225,7 +230,10 @@ static ssize_t mce_write(struct file *filp, const char __user *ubuf,
          * so do it a jiffie or two later everywhere.
          */
         schedule_timeout(2);
+
+        mutex_lock(&mce_inject_mutex);
         raise_mce(&m);
+        mutex_unlock(&mce_inject_mutex);
         return usize;
 }