Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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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 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
94static inline void user_enter(void) { }
95static inline void user_exit(void) { }
96static inline void user_enter_irqoff(void) { }
97static inline void user_exit_irqoff(void) { }
98static inline int exception_enter(void) { return 0; }
99static inline void exception_exit(enum ctx_state prev_ctx) { }
100static inline int ct_state(void) { return -1; }
101static inline int __ct_state(void) { return -1; }
102static __always_inline bool context_tracking_guest_enter(void) { return false; }
103static __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
108extern void context_tracking_init(void);
109#else
110static inline void context_tracking_init(void) { }
111#endif /* CONFIG_CONTEXT_TRACKING_USER_FORCE */
112
113#ifdef CONFIG_CONTEXT_TRACKING_IDLE
114extern void ct_idle_enter(void);
115extern 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 */
122static __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 */
131static __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
136static __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
153static __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
161static inline void ct_idle_enter(void) { }
162static inline void ct_idle_exit(void) { }
163
164static __always_inline bool warn_rcu_enter(void) { return false; }
165static __always_inline void warn_rcu_exit(bool rcu) { }
166#endif /* !CONFIG_CONTEXT_TRACKING_IDLE */
167
168#endif