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