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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - include/linux/context_tracking.h
1 #ifndef _LINUX_CONTEXT_TRACKING_H
2 #define _LINUX_CONTEXT_TRACKING_H
4 #include <linux/sched.h>
5 #include <linux/percpu.h>
6 #include <asm/ptrace.h>
8 struct context_tracking
{
10 * When active is false, probes are unset in order
11 * to minimize overhead: TIF flags are cleared
12 * and calls to user_enter/exit are ignored. This
13 * may be further optimized using static keys.
22 #ifdef CONFIG_CONTEXT_TRACKING
23 DECLARE_PER_CPU(struct context_tracking
, context_tracking
);
25 static inline bool context_tracking_in_user(void)
27 return __this_cpu_read(context_tracking
.state
) == IN_USER
;
30 static inline bool context_tracking_active(void)
32 return __this_cpu_read(context_tracking
.active
);
35 extern void user_enter(void);
36 extern void user_exit(void);
38 static inline enum ctx_state
exception_enter(void)
40 enum ctx_state prev_ctx
;
42 prev_ctx
= this_cpu_read(context_tracking
.state
);
48 static inline void exception_exit(enum ctx_state prev_ctx
)
50 if (prev_ctx
== IN_USER
)
54 extern void context_tracking_task_switch(struct task_struct
*prev
,
55 struct task_struct
*next
);
57 static inline bool context_tracking_in_user(void) { return false; }
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 */