include/linux/context_tracking.h

   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 = this_cpu_read(context_tracking.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 void context_tracking_guest_exit(void)
  84 {
  85         if (context_tracking_enabled())
  86                 __ct_user_exit(CONTEXT_GUEST);
  87 }
  88
  89 /**
  90  * ct_state() - return the current context tracking state if known
  91  *
  92  * Returns the current cpu's context tracking state if context tracking
  93  * is enabled.  If context tracking is disabled, returns
  94  * CONTEXT_DISABLED.  This should be used primarily for debugging.
  95  */
  96 static __always_inline enum ctx_state ct_state(void)
  97 {
  98         return context_tracking_enabled() ?
  99                 this_cpu_read(context_tracking.state) : CONTEXT_DISABLED;
 100 }
 101 #else
 102 static inline void user_enter(void) { }
 103 static inline void user_exit(void) { }
 104 static inline void user_enter_irqoff(void) { }
 105 static inline void user_exit_irqoff(void) { }
 106 static inline enum ctx_state exception_enter(void) { return 0; }
 107 static inline void exception_exit(enum ctx_state prev_ctx) { }
 108 static inline enum ctx_state ct_state(void) { return CONTEXT_DISABLED; }
 109 static __always_inline bool context_tracking_guest_enter(void) { return false; }
 110 static inline void context_tracking_guest_exit(void) { }
 111
 112 #endif /* !CONFIG_CONTEXT_TRACKING_USER */
 113
 114 #define CT_WARN_ON(cond) WARN_ON(context_tracking_enabled() && (cond))
 115
 116 #ifdef CONFIG_CONTEXT_TRACKING_USER_FORCE
 117 extern void context_tracking_init(void);
 118 #else
 119 static inline void context_tracking_init(void) { }
 120 #endif /* CONFIG_CONTEXT_TRACKING_USER_FORCE */
 121
 122 #endif