45 lines
1.1 KiB
C
45 lines
1.1 KiB
C
#ifndef _LINUX_CONTEXT_TRACKING_STATE_H
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#define _LINUX_CONTEXT_TRACKING_STATE_H
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#include <linux/percpu.h>
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#include <linux/static_key.h>
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struct context_tracking {
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/*
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* When active is false, probes are unset in order
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* to minimize overhead: TIF flags are cleared
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* and calls to user_enter/exit are ignored. This
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* may be further optimized using static keys.
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*/
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bool active;
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enum ctx_state {
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IN_KERNEL = 0,
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IN_USER,
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} state;
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};
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#ifdef CONFIG_CONTEXT_TRACKING
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extern struct static_key context_tracking_enabled;
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DECLARE_PER_CPU(struct context_tracking, context_tracking);
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static inline bool context_tracking_is_enabled(void)
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{
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return static_key_false(&context_tracking_enabled);
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}
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static inline bool context_tracking_cpu_is_enabled(void)
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{
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return __this_cpu_read(context_tracking.active);
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}
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static inline bool context_tracking_in_user(void)
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{
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return __this_cpu_read(context_tracking.state) == IN_USER;
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}
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#else
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static inline bool context_tracking_in_user(void) { return false; }
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static inline bool context_tracking_active(void) { return false; }
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#endif /* CONFIG_CONTEXT_TRACKING */
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#endif
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