Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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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_in_user(void)
26{
27 return __this_cpu_read(context_tracking.state) == IN_USER;
28}
29
30static inline bool context_tracking_active(void)
31{
32 return __this_cpu_read(context_tracking.active);
33}
34#else
35static inline bool context_tracking_in_user(void) { return false; }
36static inline bool context_tracking_active(void) { return false; }
37#endif /* CONFIG_CONTEXT_TRACKING */
38
39#endif