1 #ifndef _LINUX_CONTEXT_TRACKING_STATE_H 2 #define _LINUX_CONTEXT_TRACKING_STATE_H 3 4 #include <linux/percpu.h> 5 #include <linux/static_key.h> 6 7 struct context_tracking { 8 /* 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. 13 */ 14 bool active; 15 enum ctx_state { 16 CONTEXT_KERNEL = 0, 17 CONTEXT_USER, 18 CONTEXT_GUEST, 19 } state; 20 }; 21 22 #ifdef CONFIG_CONTEXT_TRACKING 23 extern struct static_key context_tracking_enabled; 24 DECLARE_PER_CPU(struct context_tracking, context_tracking); 25 context_tracking_is_enabled(void)26static inline bool context_tracking_is_enabled(void) 27 { 28 return static_key_false(&context_tracking_enabled); 29 } 30 context_tracking_cpu_is_enabled(void)31static inline bool context_tracking_cpu_is_enabled(void) 32 { 33 return __this_cpu_read(context_tracking.active); 34 } 35 context_tracking_in_user(void)36static inline bool context_tracking_in_user(void) 37 { 38 return __this_cpu_read(context_tracking.state) == CONTEXT_USER; 39 } 40 #else context_tracking_in_user(void)41static inline bool context_tracking_in_user(void) { return false; } context_tracking_active(void)42static inline bool context_tracking_active(void) { return false; } context_tracking_is_enabled(void)43static inline bool context_tracking_is_enabled(void) { return false; } context_tracking_cpu_is_enabled(void)44static inline bool context_tracking_cpu_is_enabled(void) { return false; } 45 #endif /* CONFIG_CONTEXT_TRACKING */ 46 47 #endif 48