Merge branch 'context_tracking/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into sched/urgent

Pull context tracking ARM fix from Frederic Weisbecker.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 16 insertions, 4 deletions

diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index de23a9beed13..39f89fbd5111 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -329,10 +329,10 @@
 #ifdef CONFIG_CONTEXT_TRACKING
         .if     \save
         stmdb   sp!, {r0-r3, ip, lr}
-        bl      user_exit
+        bl      context_tracking_user_exit
         ldmia   sp!, {r0-r3, ip, lr}
         .else
-        bl      user_exit
+        bl      context_tracking_user_exit
         .endif
 #endif
         .endm
@@ -341,10 +341,10 @@
 #ifdef CONFIG_CONTEXT_TRACKING
         .if     \save
         stmdb   sp!, {r0-r3, ip, lr}
-        bl      user_enter
+        bl      context_tracking_user_enter
         ldmia   sp!, {r0-r3, ip, lr}
         .else
-        bl      user_enter
+        bl      context_tracking_user_enter
         .endif
 #endif
         .endm
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;