Merge tag 'v3.12-rc4' into devel

Linux 3.12-rc4

1 files changed, 12 insertions, 0 deletions

diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index 247091bf0587..859c8dfd78a1 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -51,6 +51,15 @@ void context_tracking_user_enter(void)
         unsigned long flags;
 
         /*
+         * Repeat the user_enter() check here because some archs may be calling
+         * this from asm and if no CPU needs context tracking, they shouldn't
+         * go further. Repeat the check here until they support the static key
+         * check.
+         */
+        if (!static_key_false(&context_tracking_enabled))
+                return;
+
+        /*
          * Some contexts may involve an exception occuring in an irq,
          * leading to that nesting:
          * rcu_irq_enter() rcu_user_exit() rcu_user_exit() rcu_irq_exit()
@@ -151,6 +160,9 @@ void context_tracking_user_exit(void)
 {
         unsigned long flags;
 
+        if (!static_key_false(&context_tracking_enabled))
+                return;
+
         if (in_interrupt())
                 return;