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 int recursion; 16 enum ctx_state { 17 CONTEXT_KERNEL = 0, 18 CONTEXT_USER, 19 CONTEXT_GUEST, 20 } state; 21 }; 22 23 #ifdef CONFIG_CONTEXT_TRACKING 24 extern struct static_key context_tracking_enabled; 25 DECLARE_PER_CPU(struct context_tracking, context_tracking); 26 27 static inline bool context_tracking_is_enabled(void) 28 { 29 return static_key_false(&context_tracking_enabled); 30 } 31 32 static inline bool context_tracking_cpu_is_enabled(void) 33 { 34 return __this_cpu_read(context_tracking.active); 35 } 36 37 static inline bool context_tracking_in_user(void) 38 { 39 return __this_cpu_read(context_tracking.state) == CONTEXT_USER; 40 } 41 #else 42 static inline bool context_tracking_in_user(void) { return false; } 43 static inline bool context_tracking_active(void) { return false; } 44 static inline bool context_tracking_is_enabled(void) { return false; } 45 static inline bool context_tracking_cpu_is_enabled(void) { return false; } 46 #endif /* CONFIG_CONTEXT_TRACKING */ 47 48 #endif 49