| /* 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 |