1 #ifndef _LINUX_CONTEXT_TRACKING_H
2 #define _LINUX_CONTEXT_TRACKING_H
3 
4 #include <linux/sched.h>
5 #include <linux/vtime.h>
6 #include <linux/context_tracking_state.h>
7 #include <asm/ptrace.h>
8 
9 
10 #ifdef CONFIG_CONTEXT_TRACKING
11 extern void context_tracking_cpu_set(int cpu);
12 
13 extern void context_tracking_user_enter(void);
14 extern void context_tracking_user_exit(void);
15 extern void __context_tracking_task_switch(struct task_struct *prev,
16 					   struct task_struct *next);
17 
18 static inline void user_enter(void)
19 {
20 	if (static_key_false(&context_tracking_enabled))
21 		context_tracking_user_enter();
22 
23 }
24 static inline void user_exit(void)
25 {
26 	if (static_key_false(&context_tracking_enabled))
27 		context_tracking_user_exit();
28 }
29 
30 static inline enum ctx_state exception_enter(void)
31 {
32 	enum ctx_state prev_ctx;
33 
34 	if (!static_key_false(&context_tracking_enabled))
35 		return 0;
36 
37 	prev_ctx = this_cpu_read(context_tracking.state);
38 	context_tracking_user_exit();
39 
40 	return prev_ctx;
41 }
42 
43 static inline void exception_exit(enum ctx_state prev_ctx)
44 {
45 	if (static_key_false(&context_tracking_enabled)) {
46 		if (prev_ctx == IN_USER)
47 			context_tracking_user_enter();
48 	}
49 }
50 
51 static inline void context_tracking_task_switch(struct task_struct *prev,
52 						struct task_struct *next)
53 {
54 	if (static_key_false(&context_tracking_enabled))
55 		__context_tracking_task_switch(prev, next);
56 }
57 #else
58 static inline void user_enter(void) { }
59 static inline void user_exit(void) { }
60 static inline enum ctx_state exception_enter(void) { return 0; }
61 static inline void exception_exit(enum ctx_state prev_ctx) { }
62 static inline void context_tracking_task_switch(struct task_struct *prev,
63 						struct task_struct *next) { }
64 #endif /* !CONFIG_CONTEXT_TRACKING */
65 
66 
67 #ifdef CONFIG_CONTEXT_TRACKING_FORCE
68 extern void context_tracking_init(void);
69 #else
70 static inline void context_tracking_init(void) { }
71 #endif /* CONFIG_CONTEXT_TRACKING_FORCE */
72 
73 
74 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
75 static inline void guest_enter(void)
76 {
77 	if (vtime_accounting_enabled())
78 		vtime_guest_enter(current);
79 	else
80 		current->flags |= PF_VCPU;
81 }
82 
83 static inline void guest_exit(void)
84 {
85 	if (vtime_accounting_enabled())
86 		vtime_guest_exit(current);
87 	else
88 		current->flags &= ~PF_VCPU;
89 }
90 
91 #else
92 static inline void guest_enter(void)
93 {
94 	/*
95 	 * This is running in ioctl context so its safe
96 	 * to assume that it's the stime pending cputime
97 	 * to flush.
98 	 */
99 	vtime_account_system(current);
100 	current->flags |= PF_VCPU;
101 }
102 
103 static inline void guest_exit(void)
104 {
105 	/* Flush the guest cputime we spent on the guest */
106 	vtime_account_system(current);
107 	current->flags &= ~PF_VCPU;
108 }
109 #endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */
110 
111 #endif
112