Cregit: context_tracking

Contributors: 4
Author	Tokens	Token Proportion	Commits	Commit Proportion
Frédéric Weisbecker	132	79.04%	5	50.00%
Rik Van Riel	26	15.57%	2	20.00%
Andrew Lutomirski	8	4.79%	2	20.00%
Greg Kroah-Hartman	1	0.60%	1	10.00%
Total	167		10

/* SPDX-License-Identifier: GPL-2.0 */
#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;
	int recursion;
	enum ctx_state {
		CONTEXT_DISABLED = -1,	/* returned by ct_state() if unknown */
		CONTEXT_KERNEL = 0,
		CONTEXT_USER,
		CONTEXT_GUEST,
	} state;
};

#ifdef CONFIG_CONTEXT_TRACKING
extern struct static_key_false context_tracking_enabled;
DECLARE_PER_CPU(struct context_tracking, context_tracking);

static inline bool context_tracking_is_enabled(void)
{
	return static_branch_unlikely(&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) == CONTEXT_USER;
}
#else
static inline bool context_tracking_in_user(void) { return false; }
static inline bool context_tracking_active(void) { return false; }
static inline bool context_tracking_is_enabled(void) { return false; }
static inline bool context_tracking_cpu_is_enabled(void) { return false; }
#endif /* CONFIG_CONTEXT_TRACKING */

#endif

context_tracking_state.h