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#ifndef _LINUX_CONTEXT_TRACKING_STATE_H
#define _LINUX_CONTEXT_TRACKING_STATE_H
#include <linux/percpu.h>
#include <linux/static_key.h>
struct context_tracking {
/*
* When active is false, probes are unset in order
* to minimize overhead: TIF flags are cleared
* and calls to user_enter/exit are ignored. This
* may be further optimized using static keys.
*/
bool active;
enum ctx_state {
IN_KERNEL = 0,
IN_USER,
} state;
};
#ifdef CONFIG_CONTEXT_TRACKING
extern struct static_key context_tracking_enabled;
DECLARE_PER_CPU(struct context_tracking, context_tracking);
static inline bool context_tracking_is_enabled(void)
{
return static_key_false(&context_tracking_enabled);
}
static inline bool context_tracking_cpu_is_enabled(void)
{
return __this_cpu_read(context_tracking.active);
}
static inline bool context_tracking_in_user(void)
{
return __this_cpu_read(context_tracking.state) == IN_USER;
}
#else
static inline bool context_tracking_in_user(void) { return false; }
static inline bool context_tracking_active(void) { return false; }
#endif /* CONFIG_CONTEXT_TRACKING */
#endif
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