1 #ifndef _LINUX_CONTEXT_TRACKING_STATE_H
2 #define _LINUX_CONTEXT_TRACKING_STATE_H
4 #include <linux/percpu.h>
5 #include <linux/static_key.h>
7 struct context_tracking {
9 * When active is false, probes are unset in order
10 * to minimize overhead: TIF flags are cleared
11 * and calls to user_enter/exit are ignored. This
12 * may be further optimized using static keys.
21 #ifdef CONFIG_CONTEXT_TRACKING
22 extern struct static_key context_tracking_enabled;
23 DECLARE_PER_CPU(struct context_tracking, context_tracking);
25 static inline bool context_tracking_is_enabled(void)
27 return static_key_false(&context_tracking_enabled);
30 static inline bool context_tracking_cpu_is_enabled(void)
32 return __this_cpu_read(context_tracking.active);
35 static inline bool context_tracking_in_user(void)
37 return __this_cpu_read(context_tracking.state) == CONTEXT_USER;
40 static inline bool context_tracking_in_user(void) { return false; }
41 static inline bool context_tracking_active(void) { return false; }
42 static inline bool context_tracking_is_enabled(void) { return false; }
43 static inline bool context_tracking_cpu_is_enabled(void) { return false; }
44 #endif /* CONFIG_CONTEXT_TRACKING */