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
7struct 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
23extern struct static_key context_tracking_enabled;
24DECLARE_PER_CPU(struct context_tracking, context_tracking);
25
26static inline bool context_tracking_is_enabled(void)
27{
28	return static_key_false(&context_tracking_enabled);
29}
30
31static inline bool context_tracking_cpu_is_enabled(void)
32{
33	return __this_cpu_read(context_tracking.active);
34}
35
36static inline bool context_tracking_in_user(void)
37{
38	return __this_cpu_read(context_tracking.state) == CONTEXT_USER;
39}
40#else
41static inline bool context_tracking_in_user(void) { return false; }
42static inline bool context_tracking_active(void) { return false; }
43static inline bool context_tracking_is_enabled(void) { return false; }
44static inline bool context_tracking_cpu_is_enabled(void) { return false; }
45#endif /* CONFIG_CONTEXT_TRACKING */
46
47#endif
48