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_USER
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_USER_OFFSTACK) ||
56 !context_tracking_enabled())
57 return 0;
58
59 prev_ctx = __ct_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_USER_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 bool context_tracking_guest_exit(void)
84 {
85 if (context_tracking_enabled())
86 __ct_user_exit(CONTEXT_GUEST);
87
88 return context_tracking_enabled_this_cpu();
89 }
90
91 #define CT_WARN_ON(cond) WARN_ON(context_tracking_enabled() && (cond))
92
93 #else
94 static inline void user_enter(void) { }
95 static inline void user_exit(void) { }
96 static inline void user_enter_irqoff(void) { }
97 static inline void user_exit_irqoff(void) { }
98 static inline int exception_enter(void) { return 0; }
99 static inline void exception_exit(enum ctx_state prev_ctx) { }
100 static inline int ct_state(void) { return -1; }
101 static inline int __ct_state(void) { return -1; }
102 static __always_inline bool context_tracking_guest_enter(void) { return false; }
103 static __always_inline bool context_tracking_guest_exit(void) { return false; }
104 #define CT_WARN_ON(cond) do { } while (0)
105 #endif /* !CONFIG_CONTEXT_TRACKING_USER */
106
107 #ifdef CONFIG_CONTEXT_TRACKING_USER_FORCE
108 extern void context_tracking_init(void);
109 #else
110 static inline void context_tracking_init(void) { }
111 #endif /* CONFIG_CONTEXT_TRACKING_USER_FORCE */
112
113 #ifdef CONFIG_CONTEXT_TRACKING_IDLE
114 extern void ct_idle_enter(void);
115 extern void ct_idle_exit(void);
116
117 /*
118 * Is the current CPU in an extended quiescent state?
119 *
120 * No ordering, as we are sampling CPU-local information.
121 */
122 static __always_inline bool rcu_dynticks_curr_cpu_in_eqs(void)
123 {
124 return !(raw_atomic_read(this_cpu_ptr(&context_tracking.state)) & RCU_DYNTICKS_IDX);
125 }
126
127 /*
128 * Increment the current CPU's context_tracking structure's ->state field
129 * with ordering. Return the new value.
130 */
131 static __always_inline unsigned long ct_state_inc(int incby)
132 {
133 return raw_atomic_add_return(incby, this_cpu_ptr(&context_tracking.state));
134 }
135
136 static __always_inline bool warn_rcu_enter(void)
137 {
138 bool ret = false;
139
140 /*
141 * Horrible hack to shut up recursive RCU isn't watching fail since
142 * lots of the actual reporting also relies on RCU.
143 */
144 preempt_disable_notrace();
145 if (rcu_dynticks_curr_cpu_in_eqs()) {
146 ret = true;
147 ct_state_inc(RCU_DYNTICKS_IDX);
148 }
149
150 return ret;
151 }
152
153 static __always_inline void warn_rcu_exit(bool rcu)
154 {
155 if (rcu)
156 ct_state_inc(RCU_DYNTICKS_IDX);
157 preempt_enable_notrace();
158 }
159
160 #else
161 static inline void ct_idle_enter(void) { }
162 static inline void ct_idle_exit(void) { }
163
164 static __always_inline bool warn_rcu_enter(void) { return false; }
165 static __always_inline void warn_rcu_exit(bool rcu) { }
166 #endif /* !CONFIG_CONTEXT_TRACKING_IDLE */
167
168 #endif
169
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