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
14 extern void ct_cpu_track_user(int cpu);
15 
16 /* Called with interrupts disabled.  */
17 extern void __ct_user_enter(enum ctx_state state);
18 extern void __ct_user_exit(enum ctx_state state);
19 
20 extern void ct_user_enter(enum ctx_state state);
21 extern void ct_user_exit(enum ctx_state state);
22 
23 extern void user_enter_callable(void);
24 extern void user_exit_callable(void);
25 
26 static inline void user_enter(void)
27 {
28 	if (context_tracking_enabled())
29 		ct_user_enter(CONTEXT_USER);
30 
31 }
32 static inline void user_exit(void)
33 {
34 	if (context_tracking_enabled())
35 		ct_user_exit(CONTEXT_USER);
36 }
37 
38 /* Called with interrupts disabled.  */
39 static __always_inline void user_enter_irqoff(void)
40 {
41 	if (context_tracking_enabled())
42 		__ct_user_enter(CONTEXT_USER);
43 
44 }
45 static __always_inline void user_exit_irqoff(void)
46 {
47 	if (context_tracking_enabled())
48 		__ct_user_exit(CONTEXT_USER);
49 }
50 
51 static inline enum ctx_state exception_enter(void)
52 {
53 	enum ctx_state prev_ctx;
54 
55 	if (IS_ENABLED(CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK) ||
56 	    !context_tracking_enabled())
57 		return 0;
58 
59 	prev_ctx = this_cpu_read(context_tracking.state);
60 	if (prev_ctx != CONTEXT_KERNEL)
61 		ct_user_exit(prev_ctx);
62 
63 	return prev_ctx;
64 }
65 
66 static inline void exception_exit(enum ctx_state prev_ctx)
67 {
68 	if (!IS_ENABLED(CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK) &&
69 	    context_tracking_enabled()) {
70 		if (prev_ctx != CONTEXT_KERNEL)
71 			ct_user_enter(prev_ctx);
72 	}
73 }
74 
75 static __always_inline bool context_tracking_guest_enter(void)
76 {
77 	if (context_tracking_enabled())
78 		__ct_user_enter(CONTEXT_GUEST);
79 
80 	return context_tracking_enabled_this_cpu();
81 }
82 
83 static __always_inline void context_tracking_guest_exit(void)
84 {
85 	if (context_tracking_enabled())
86 		__ct_user_exit(CONTEXT_GUEST);
87 }
88 
89 /**
90  * ct_state() - return the current context tracking state if known
91  *
92  * Returns the current cpu's context tracking state if context tracking
93  * is enabled.  If context tracking is disabled, returns
94  * CONTEXT_DISABLED.  This should be used primarily for debugging.
95  */
96 static __always_inline enum ctx_state ct_state(void)
97 {
98 	return context_tracking_enabled() ?
99 		this_cpu_read(context_tracking.state) : CONTEXT_DISABLED;
100 }
101 #else
102 static inline void user_enter(void) { }
103 static inline void user_exit(void) { }
104 static inline void user_enter_irqoff(void) { }
105 static inline void user_exit_irqoff(void) { }
106 static inline enum ctx_state exception_enter(void) { return 0; }
107 static inline void exception_exit(enum ctx_state prev_ctx) { }
108 static inline enum ctx_state ct_state(void) { return CONTEXT_DISABLED; }
109 static __always_inline bool context_tracking_guest_enter(void) { return false; }
110 static inline void context_tracking_guest_exit(void) { }
111 
112 #endif /* !CONFIG_CONTEXT_TRACKING */
113 
114 #define CT_WARN_ON(cond) WARN_ON(context_tracking_enabled() && (cond))
115 
116 #ifdef CONFIG_CONTEXT_TRACKING_FORCE
117 extern void context_tracking_init(void);
118 #else
119 static inline void context_tracking_init(void) { }
120 #endif /* CONFIG_CONTEXT_TRACKING_FORCE */
121 
122 #endif
123