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_DISABLED = -1, /* returned by ct_state() if unknown */ 18 CONTEXT_KERNEL = 0, 19 CONTEXT_USER, 20 CONTEXT_GUEST, 21 } state; 22 }; 23 24 #ifdef CONFIG_CONTEXT_TRACKING 25 extern struct static_key context_tracking_enabled; 26 DECLARE_PER_CPU(struct context_tracking, context_tracking); 27 context_tracking_is_enabled(void)28static inline bool context_tracking_is_enabled(void) 29 { 30 return static_key_false(&context_tracking_enabled); 31 } 32 context_tracking_cpu_is_enabled(void)33static inline bool context_tracking_cpu_is_enabled(void) 34 { 35 return __this_cpu_read(context_tracking.active); 36 } 37 context_tracking_in_user(void)38static inline bool context_tracking_in_user(void) 39 { 40 return __this_cpu_read(context_tracking.state) == CONTEXT_USER; 41 } 42 #else context_tracking_in_user(void)43static inline bool context_tracking_in_user(void) { return false; } context_tracking_active(void)44static inline bool context_tracking_active(void) { return false; } context_tracking_is_enabled(void)45static inline bool context_tracking_is_enabled(void) { return false; } context_tracking_cpu_is_enabled(void)46static inline bool context_tracking_cpu_is_enabled(void) { return false; } 47 #endif /* CONFIG_CONTEXT_TRACKING */ 48 49 #endif 50