context_tracking_state.h 1.4 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_DISABLED = -1, /* returned by ct_state() if unknown */
  16. CONTEXT_KERNEL = 0,
  17. CONTEXT_USER,
  18. CONTEXT_GUEST,
  19. } state;
  20. };
  21. #ifdef CONFIG_CONTEXT_TRACKING
  22. extern struct static_key_false context_tracking_enabled;
  23. DECLARE_PER_CPU(struct context_tracking, context_tracking);
  24. static inline bool context_tracking_is_enabled(void)
  25. {
  26. return static_branch_unlikely(&context_tracking_enabled);
  27. }
  28. static inline bool context_tracking_cpu_is_enabled(void)
  29. {
  30. return __this_cpu_read(context_tracking.active);
  31. }
  32. static inline bool context_tracking_in_user(void)
  33. {
  34. return __this_cpu_read(context_tracking.state) == CONTEXT_USER;
  35. }
  36. #else
  37. static inline bool context_tracking_in_user(void) { return false; }
  38. static inline bool context_tracking_active(void) { return false; }
  39. static inline bool context_tracking_is_enabled(void) { return false; }
  40. static inline bool context_tracking_cpu_is_enabled(void) { return false; }
  41. #endif /* CONFIG_CONTEXT_TRACKING */
  42. #endif