LXR linux/include/linux/context

   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
  14extern void context_tracking_cpu_set(int cpu);
  15
  16/* Called with interrupts disabled.  */
  17extern void __context_tracking_enter(enum ctx_state state);
  18extern void __context_tracking_exit(enum ctx_state state);
  19
  20extern void context_tracking_enter(enum ctx_state state);
  21extern void context_tracking_exit(enum ctx_state state);
  22extern void context_tracking_user_enter(void);
  23extern void context_tracking_user_exit(void);
  24
  25static inline void user_enter(void)
  26{
  27        if (context_tracking_enabled())
  28                context_tracking_enter(CONTEXT_USER);
  29
  30}
  31static inline void user_exit(void)
  32{
  33        if (context_tracking_enabled())
  34                context_tracking_exit(CONTEXT_USER);
  35}
  36
  37/* Called with interrupts disabled.  */
  38static __always_inline void user_enter_irqoff(void)
  39{
  40        if (context_tracking_enabled())
  41                __context_tracking_enter(CONTEXT_USER);
  42
  43}
  44static __always_inline void user_exit_irqoff(void)
  45{
  46        if (context_tracking_enabled())
  47                __context_tracking_exit(CONTEXT_USER);
  48}
  49
  50static inline enum ctx_state exception_enter(void)
  51{
  52        enum ctx_state prev_ctx;
  53
  54        if (IS_ENABLED(CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK) ||
  55            !context_tracking_enabled())
  56                return 0;
  57
  58        prev_ctx = this_cpu_read(context_tracking.state);
  59        if (prev_ctx != CONTEXT_KERNEL)
  60                context_tracking_exit(prev_ctx);
  61
  62        return prev_ctx;
  63}
  64
  65static inline void exception_exit(enum ctx_state prev_ctx)
  66{
  67        if (!IS_ENABLED(CONFIG_HAVE_CONTEXT_TRACKING_OFFSTACK) &&
  68            context_tracking_enabled()) {
  69                if (prev_ctx != CONTEXT_KERNEL)
  70                        context_tracking_enter(prev_ctx);
  71        }
  72}
  73
  74static __always_inline bool context_tracking_guest_enter(void)
  75{
  76        if (context_tracking_enabled())
  77                __context_tracking_enter(CONTEXT_GUEST);
  78
  79        return context_tracking_enabled_this_cpu();
  80}
  81
  82static __always_inline void context_tracking_guest_exit(void)
  83{
  84        if (context_tracking_enabled())
  85                __context_tracking_exit(CONTEXT_GUEST);
  86}
  87
  88/**
  89 * ct_state() - return the current context tracking state if known
  90 *
  91 * Returns the current cpu's context tracking state if context tracking
  92 * is enabled.  If context tracking is disabled, returns
  93 * CONTEXT_DISABLED.  This should be used primarily for debugging.
  94 */
  95static __always_inline enum ctx_state ct_state(void)
  96{
  97        return context_tracking_enabled() ?
  98                this_cpu_read(context_tracking.state) : CONTEXT_DISABLED;
  99}
 100#else
 101static inline void user_enter(void) { }
 102static inline void user_exit(void) { }
 103static inline void user_enter_irqoff(void) { }
 104static inline void user_exit_irqoff(void) { }
 105static inline enum ctx_state exception_enter(void) { return 0; }
 106static inline void exception_exit(enum ctx_state prev_ctx) { }
 107static inline enum ctx_state ct_state(void) { return CONTEXT_DISABLED; }
 108static inline bool context_tracking_guest_enter(void) { return false; }
 109static inline void context_tracking_guest_exit(void) { }
 110
 111#endif /* !CONFIG_CONTEXT_TRACKING */
 112
 113#define CT_WARN_ON(cond) WARN_ON(context_tracking_enabled() && (cond))
 114
 115#ifdef CONFIG_CONTEXT_TRACKING_FORCE
 116extern void context_tracking_init(void);
 117#else
 118static inline void context_tracking_init(void) { }
 119#endif /* CONFIG_CONTEXT_TRACKING_FORCE */
 120
 121#endif
 122