1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _LINUX_CONTEXT_TRACKING_H
  3#define _LINUX_CONTEXT_TRACKING_H
  4
  5#include <linux/sched.h>
  6#include <linux/vtime.h>
  7#include <linux/context_tracking_state.h>
  8#include <linux/instrumentation.h>
  9
 10#include <asm/ptrace.h>
 11
 12
 13#ifdef CONFIG_CONTEXT_TRACKING
 14extern void context_tracking_cpu_set(int cpu);
 15
 16/* Called with interrupts disabled.  */
 17extern void __context_tracking_enter(enum ctx_state state);
 18extern void __context_tracking_exit(enum ctx_state state);
 19
 20extern void context_tracking_enter(enum ctx_state state);
 21extern void context_tracking_exit(enum ctx_state state);
 22extern void context_tracking_user_enter(void);
 23extern void context_tracking_user_exit(void);
 24
 25static inline void user_enter(void)
 26{
 27	if (context_tracking_enabled())
 28		context_tracking_enter(CONTEXT_USER);
 29
 30}
 31static inline void user_exit(void)
 32{
 33	if (context_tracking_enabled())
 34		context_tracking_exit(CONTEXT_USER);
 35}
 36
 37/* Called with interrupts disabled.  */
 38static __always_inline void user_enter_irqoff(void)
 39{
 40	if (context_tracking_enabled())
 41		__context_tracking_enter(CONTEXT_USER);
 42
 43}
 44static __always_inline void user_exit_irqoff(void)
 45{
 46	if (context_tracking_enabled())
 47		__context_tracking_exit(CONTEXT_USER);
 48}
 49
 50static inline enum ctx_state exception_enter(void)
 51{
 52	enum ctx_state prev_ctx;
 53
 54	if (IS_ENABLED(CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK) ||
 55	    !context_tracking_enabled())
 56		return 0;
 57
 58	prev_ctx = this_cpu_read(context_tracking.state);
 59	if (prev_ctx != CONTEXT_KERNEL)
 60		context_tracking_exit(prev_ctx);
 61
 62	return prev_ctx;
 63}
 64
 65static inline void exception_exit(enum ctx_state prev_ctx)
 66{
 67	if (!IS_ENABLED(CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK) &&
 68	    context_tracking_enabled()) {
 69		if (prev_ctx != CONTEXT_KERNEL)
 70			context_tracking_enter(prev_ctx);
 71	}
 72}
 73
 74static __always_inline bool context_tracking_guest_enter(void)
 75{
 76	if (context_tracking_enabled())
 77		__context_tracking_enter(CONTEXT_GUEST);
 78
 79	return context_tracking_enabled_this_cpu();
 80}
 81
 82static __always_inline void context_tracking_guest_exit(void)
 83{
 84	if (context_tracking_enabled())
 85		__context_tracking_exit(CONTEXT_GUEST);
 86}
 87
 88/**
 89 * ct_state() - return the current context tracking state if known
 90 *
 91 * Returns the current cpu's context tracking state if context tracking
 92 * is enabled.  If context tracking is disabled, returns
 93 * CONTEXT_DISABLED.  This should be used primarily for debugging.
 94 */
 95static __always_inline enum ctx_state ct_state(void)
 96{
 97	return context_tracking_enabled() ?
 98		this_cpu_read(context_tracking.state) : CONTEXT_DISABLED;
 99}
100#else
101static inline void user_enter(void) { }
102static inline void user_exit(void) { }
103static inline void user_enter_irqoff(void) { }
104static inline void user_exit_irqoff(void) { }
105static inline enum ctx_state exception_enter(void) { return 0; }
106static inline void exception_exit(enum ctx_state prev_ctx) { }
107static inline enum ctx_state ct_state(void) { return CONTEXT_DISABLED; }
108static inline bool context_tracking_guest_enter(void) { return false; }
109static inline void context_tracking_guest_exit(void) { }
110
111#endif /* !CONFIG_CONTEXT_TRACKING */
112
113#define CT_WARN_ON(cond) WARN_ON(context_tracking_enabled() && (cond))
114
115#ifdef CONFIG_CONTEXT_TRACKING_FORCE
116extern void context_tracking_init(void);
117#else
118static inline void context_tracking_init(void) { }
119#endif /* CONFIG_CONTEXT_TRACKING_FORCE */
120
121#endif