include/linux/context_tracking.h

   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