1 files changed, 8 insertions, 5 deletions

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 67db4f43309e..d366adfc61da 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -141,8 +141,7 @@ void ist_begin_non_atomic(struct pt_regs *regs)
          * will catch asm bugs and any attempt to use ist_preempt_enable
          * from double_fault.
          */
-        BUG_ON((unsigned long)(current_top_of_stack() -
-                               current_stack_pointer) >= THREAD_SIZE);
+        BUG_ON(!on_thread_stack());
 
         preempt_enable_no_resched();
 }
@@ -209,9 +208,6 @@ do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str,
                 if (fixup_exception(regs, trapnr))
                         return 0;
 
-                if (fixup_bug(regs, trapnr))
-                        return 0;
-
                 tsk->thread.error_code = error_code;
                 tsk->thread.trap_nr = trapnr;
                 die(str, regs, error_code);
@@ -292,6 +288,13 @@ static void do_error_trap(struct pt_regs *regs, long error_code, char *str,
 
         RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
 
+        /*
+         * WARN*()s end up here; fix them up before we call the
+         * notifier chain.
+         */
+        if (!user_mode(regs) && fixup_bug(regs, trapnr))
+                return;
+
         if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) !=
                         NOTIFY_STOP) {
                 cond_local_irq_enable(regs);