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- /* SPDX-License-Identifier: GPL-2.0 */
- #ifndef _LINUX_CONTEXT_TRACKING_STATE_H
- #define _LINUX_CONTEXT_TRACKING_STATE_H
- #include <linux/percpu.h>
- #include <linux/static_key.h>
- struct context_tracking {
- /*
- * When active is false, probes are unset in order
- * to minimize overhead: TIF flags are cleared
- * and calls to user_enter/exit are ignored. This
- * may be further optimized using static keys.
- */
- bool active;
- int recursion;
- enum ctx_state {
- CONTEXT_DISABLED = -1, /* returned by ct_state() if unknown */
- CONTEXT_KERNEL = 0,
- CONTEXT_USER,
- CONTEXT_GUEST,
- } state;
- };
- #ifdef CONFIG_CONTEXT_TRACKING
- extern struct static_key_false context_tracking_key;
- DECLARE_PER_CPU(struct context_tracking, context_tracking);
- static __always_inline bool context_tracking_enabled(void)
- {
- return static_branch_unlikely(&context_tracking_key);
- }
- static __always_inline bool context_tracking_enabled_cpu(int cpu)
- {
- return context_tracking_enabled() && per_cpu(context_tracking.active, cpu);
- }
- static inline bool context_tracking_enabled_this_cpu(void)
- {
- return context_tracking_enabled() && __this_cpu_read(context_tracking.active);
- }
- static __always_inline bool context_tracking_in_user(void)
- {
- return __this_cpu_read(context_tracking.state) == CONTEXT_USER;
- }
- #else
- static inline bool context_tracking_in_user(void) { return false; }
- static inline bool context_tracking_enabled(void) { return false; }
- static inline bool context_tracking_enabled_cpu(int cpu) { return false; }
- static inline bool context_tracking_enabled_this_cpu(void) { return false; }
- #endif /* CONFIG_CONTEXT_TRACKING */
- #endif
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