context_tracking_state.h 1.3 KB

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  1. #ifndef _LINUX_CONTEXT_TRACKING_STATE_H
  2. #define _LINUX_CONTEXT_TRACKING_STATE_H
  3. #include <linux/percpu.h>
  4. #include <linux/static_key.h>
  5. struct context_tracking {
  6. /*
  7. * When active is false, probes are unset in order
  8. * to minimize overhead: TIF flags are cleared
  9. * and calls to user_enter/exit are ignored. This
  10. * may be further optimized using static keys.
  11. */
  12. bool active;
  13. int recursion;
  14. enum ctx_state {
  15. CONTEXT_KERNEL = 0,
  16. CONTEXT_USER,
  17. CONTEXT_GUEST,
  18. } state;
  19. };
  20. #ifdef CONFIG_CONTEXT_TRACKING
  21. extern struct static_key context_tracking_enabled;
  22. DECLARE_PER_CPU(struct context_tracking, context_tracking);
  23. static inline bool context_tracking_is_enabled(void)
  24. {
  25. return static_key_false(&context_tracking_enabled);
  26. }
  27. static inline bool context_tracking_cpu_is_enabled(void)
  28. {
  29. return __this_cpu_read(context_tracking.active);
  30. }
  31. static inline bool context_tracking_in_user(void)
  32. {
  33. return __this_cpu_read(context_tracking.state) == CONTEXT_USER;
  34. }
  35. #else
  36. static inline bool context_tracking_in_user(void) { return false; }
  37. static inline bool context_tracking_active(void) { return false; }
  38. static inline bool context_tracking_is_enabled(void) { return false; }
  39. static inline bool context_tracking_cpu_is_enabled(void) { return false; }
  40. #endif /* CONFIG_CONTEXT_TRACKING */
  41. #endif