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-rw-r--r--include/linux/context_tracking.h27
-rw-r--r--kernel/context_tracking.c12
2 files changed, 28 insertions, 11 deletions
diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index c138c24bad1a..38ab60b3f3a6 100644
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -38,23 +38,40 @@ static inline bool context_tracking_active(void)
extern void context_tracking_cpu_set(int cpu);
-extern void user_enter(void);
-extern void user_exit(void);
+extern void context_tracking_user_enter(void);
+extern void context_tracking_user_exit(void);
+
+static inline void user_enter(void)
+{
+ if (static_key_false(&context_tracking_enabled))
+ context_tracking_user_enter();
+
+}
+static inline void user_exit(void)
+{
+ if (static_key_false(&context_tracking_enabled))
+ context_tracking_user_exit();
+}
static inline enum ctx_state exception_enter(void)
{
enum ctx_state prev_ctx;
+ if (!static_key_false(&context_tracking_enabled))
+ return 0;
+
prev_ctx = this_cpu_read(context_tracking.state);
- user_exit();
+ context_tracking_user_exit();
return prev_ctx;
}
static inline void exception_exit(enum ctx_state prev_ctx)
{
- if (prev_ctx == IN_USER)
- user_enter();
+ if (static_key_false(&context_tracking_enabled)) {
+ if (prev_ctx == IN_USER)
+ context_tracking_user_enter();
+ }
}
extern void context_tracking_task_switch(struct task_struct *prev,
diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c
index 839d377d0da5..6e89e094c80e 100644
--- a/kernel/context_tracking.c
+++ b/kernel/context_tracking.c
@@ -33,15 +33,15 @@ void context_tracking_cpu_set(int cpu)
}
/**
- * user_enter - Inform the context tracking that the CPU is going to
- * enter userspace mode.
+ * context_tracking_user_enter - Inform the context tracking that the CPU is going to
+ * enter userspace mode.
*
* This function must be called right before we switch from the kernel
* to userspace, when it's guaranteed the remaining kernel instructions
* to execute won't use any RCU read side critical section because this
* function sets RCU in extended quiescent state.
*/
-void user_enter(void)
+void context_tracking_user_enter(void)
{
unsigned long flags;
@@ -131,8 +131,8 @@ EXPORT_SYMBOL_GPL(preempt_schedule_context);
#endif /* CONFIG_PREEMPT */
/**
- * user_exit - Inform the context tracking that the CPU is
- * exiting userspace mode and entering the kernel.
+ * context_tracking_user_exit - Inform the context tracking that the CPU is
+ * exiting userspace mode and entering the kernel.
*
* This function must be called after we entered the kernel from userspace
* before any use of RCU read side critical section. This potentially include
@@ -141,7 +141,7 @@ EXPORT_SYMBOL_GPL(preempt_schedule_context);
* This call supports re-entrancy. This way it can be called from any exception
* handler without needing to know if we came from userspace or not.
*/
-void user_exit(void)
+void context_tracking_user_exit(void)
{
unsigned long flags;