diff options
| -rw-r--r-- | include/linux/context_tracking.h | 28 | ||||
| -rw-r--r-- | kernel/context_tracking.c | 16 |
2 files changed, 29 insertions, 15 deletions
diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h index e24339c..b28d161 100644 --- a/include/linux/context_tracking.h +++ b/include/linux/context_tracking.h @@ -3,12 +3,40 @@ #ifdef CONFIG_CONTEXT_TRACKING #include <linux/sched.h> +#include <linux/percpu.h> + +struct context_tracking { + /* + * When active is false, probes are unset in order + * to minimize overhead: TIF flags are cleared + * and calls to user_enter/exit are ignored. This + * may be further optimized using static keys. + */ + bool active; + enum { + IN_KERNEL = 0, + IN_USER, + } state; +}; + +DECLARE_PER_CPU(struct context_tracking, context_tracking); + +static inline bool context_tracking_in_user(void) +{ + return __this_cpu_read(context_tracking.state) == IN_USER; +} + +static inline bool context_tracking_active(void) +{ + return __this_cpu_read(context_tracking.active); +} extern void user_enter(void); extern void user_exit(void); extern void context_tracking_task_switch(struct task_struct *prev, struct task_struct *next); #else +static inline bool context_tracking_in_user(void) { return false; } static inline void user_enter(void) { } static inline void user_exit(void) { } static inline void context_tracking_task_switch(struct task_struct *prev, diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c index e0e07fd..54f471e 100644 --- a/kernel/context_tracking.c +++ b/kernel/context_tracking.c @@ -1,24 +1,10 @@ #include <linux/context_tracking.h> #include <linux/rcupdate.h> #include <linux/sched.h> -#include <linux/percpu.h> #include <linux/hardirq.h> -struct context_tracking { - /* - * When active is false, hooks are not set to - * minimize overhead: TIF flags are cleared - * and calls to user_enter/exit are ignored. This - * may be further optimized using static keys. - */ - bool active; - enum { - IN_KERNEL = 0, - IN_USER, - } state; -}; -static DEFINE_PER_CPU(struct context_tracking, context_tracking) = { +DEFINE_PER_CPU(struct context_tracking, context_tracking) = { #ifdef CONFIG_CONTEXT_TRACKING_FORCE .active = true, #endif |
