diff options
| -rw-r--r-- | include/linux/context_tracking.h | 27 | ||||
| -rw-r--r-- | kernel/context_tracking.c | 12 |
2 files changed, 28 insertions, 11 deletions
diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h index c138c24..38ab60b 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 839d377..6e89e09 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; |
