Linux kernel mirror (for testing)
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linux
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
14extern void ct_cpu_track_user(int cpu);
15
16/* Called with interrupts disabled. */
17extern void __ct_user_enter(enum ctx_state state);
18extern void __ct_user_exit(enum ctx_state state);
19
20extern void ct_user_enter(enum ctx_state state);
21extern void ct_user_exit(enum ctx_state state);
22
23extern void user_enter_callable(void);
24extern void user_exit_callable(void);
25
26static inline void user_enter(void)
27{
28 if (context_tracking_enabled())
29 ct_user_enter(CONTEXT_USER);
30
31}
32static inline void user_exit(void)
33{
34 if (context_tracking_enabled())
35 ct_user_exit(CONTEXT_USER);
36}
37
38/* Called with interrupts disabled. */
39static __always_inline void user_enter_irqoff(void)
40{
41 if (context_tracking_enabled())
42 __ct_user_enter(CONTEXT_USER);
43
44}
45static __always_inline void user_exit_irqoff(void)
46{
47 if (context_tracking_enabled())
48 __ct_user_exit(CONTEXT_USER);
49}
50
51static 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
66static 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
75static __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
83static __always_inline void context_tracking_guest_exit(void)
84{
85 if (context_tracking_enabled())
86 __ct_user_exit(CONTEXT_GUEST);
87}
88
89#define CT_WARN_ON(cond) WARN_ON(context_tracking_enabled() && (cond))
90
91#else
92static inline void user_enter(void) { }
93static inline void user_exit(void) { }
94static inline void user_enter_irqoff(void) { }
95static inline void user_exit_irqoff(void) { }
96static inline int exception_enter(void) { return 0; }
97static inline void exception_exit(enum ctx_state prev_ctx) { }
98static inline int ct_state(void) { return -1; }
99static __always_inline bool context_tracking_guest_enter(void) { return false; }
100static inline void context_tracking_guest_exit(void) { }
101#define CT_WARN_ON(cond) do { } while (0)
102#endif /* !CONFIG_CONTEXT_TRACKING_USER */
103
104#ifdef CONFIG_CONTEXT_TRACKING_USER_FORCE
105extern void context_tracking_init(void);
106#else
107static inline void context_tracking_init(void) { }
108#endif /* CONFIG_CONTEXT_TRACKING_USER_FORCE */
109
110#ifdef CONFIG_CONTEXT_TRACKING_IDLE
111extern void ct_idle_enter(void);
112extern void ct_idle_exit(void);
113
114/*
115 * Is the current CPU in an extended quiescent state?
116 *
117 * No ordering, as we are sampling CPU-local information.
118 */
119static __always_inline bool rcu_dynticks_curr_cpu_in_eqs(void)
120{
121 return !(arch_atomic_read(this_cpu_ptr(&context_tracking.state)) & RCU_DYNTICKS_IDX);
122}
123
124/*
125 * Increment the current CPU's context_tracking structure's ->state field
126 * with ordering. Return the new value.
127 */
128static __always_inline unsigned long ct_state_inc(int incby)
129{
130 return arch_atomic_add_return(incby, this_cpu_ptr(&context_tracking.state));
131}
132
133static __always_inline bool warn_rcu_enter(void)
134{
135 bool ret = false;
136
137 /*
138 * Horrible hack to shut up recursive RCU isn't watching fail since
139 * lots of the actual reporting also relies on RCU.
140 */
141 preempt_disable_notrace();
142 if (rcu_dynticks_curr_cpu_in_eqs()) {
143 ret = true;
144 ct_state_inc(RCU_DYNTICKS_IDX);
145 }
146
147 return ret;
148}
149
150static __always_inline void warn_rcu_exit(bool rcu)
151{
152 if (rcu)
153 ct_state_inc(RCU_DYNTICKS_IDX);
154 preempt_enable_notrace();
155}
156
157#else
158static inline void ct_idle_enter(void) { }
159static inline void ct_idle_exit(void) { }
160
161static __always_inline bool warn_rcu_enter(void) { return false; }
162static __always_inline void warn_rcu_exit(bool rcu) { }
163#endif /* !CONFIG_CONTEXT_TRACKING_IDLE */
164
165#endif