1 files changed, 4 insertions, 3 deletions

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 482ec3af2067..8ba27dbc107a 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -599,10 +599,10 @@ void __math_state_restore(void)
  * Careful.. There are problems with IBM-designed IRQ13 behaviour.
  * Don't touch unless you *really* know how it works.
  *
- * Must be called with kernel preemption disabled (in this case,
- * local interrupts are disabled at the call-site in entry.S).
+ * Must be called with kernel preemption disabled (eg with local
+ * local interrupts as in the case of do_device_not_available).
  */
-asmlinkage void math_state_restore(void)
+void math_state_restore(void)
 {
         struct thread_info *thread = current_thread_info();
         struct task_struct *tsk = thread->task;
@@ -631,6 +631,7 @@ EXPORT_SYMBOL_GPL(math_state_restore);
 dotraplinkage void __kprobes
 do_device_not_available(struct pt_regs *regs, long error_code)
 {
+        WARN_ON_ONCE(!user_mode_vm(regs));
 #ifdef CONFIG_MATH_EMULATION
         if (read_cr0() & X86_CR0_EM) {
                 struct math_emu_info info = { };