1 files changed, 166 insertions, 0 deletions
diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
new file mode 100644
index 000000000..3a7909ed5
--- /dev/null
+++ b/include/linux/context_tracking.h
@@ -0,0 +1,166 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_CONTEXT_TRACKING_H
+#define _LINUX_CONTEXT_TRACKING_H
+
+#include <linux/sched.h>
+#include <linux/vtime.h>
+#include <linux/context_tracking_state.h>
+#include <linux/instrumentation.h>
+
+#include <asm/ptrace.h>
+
+
+#ifdef CONFIG_CONTEXT_TRACKING_USER
+extern void ct_cpu_track_user(int cpu);
+
+/* Called with interrupts disabled.  */
+extern void __ct_user_enter(enum ctx_state state);
+extern void __ct_user_exit(enum ctx_state state);
+
+extern void ct_user_enter(enum ctx_state state);
+extern void ct_user_exit(enum ctx_state state);
+
+extern void user_enter_callable(void);
+extern void user_exit_callable(void);
+
+static inline void user_enter(void)
+{
+	if (context_tracking_enabled())
+		ct_user_enter(CONTEXT_USER);
+
+}
+static inline void user_exit(void)
+{
+	if (context_tracking_enabled())
+		ct_user_exit(CONTEXT_USER);
+}
+
+/* Called with interrupts disabled.  */
+static __always_inline void user_enter_irqoff(void)
+{
+	if (context_tracking_enabled())
+		__ct_user_enter(CONTEXT_USER);
+
+}
+static __always_inline void user_exit_irqoff(void)
+{
+	if (context_tracking_enabled())
+		__ct_user_exit(CONTEXT_USER);
+}
+
+static inline enum ctx_state exception_enter(void)
+{
+	enum ctx_state prev_ctx;
+
+	if (IS_ENABLED(CONFIG_HAVE_CONTEXT_TRACKING_USER_OFFSTACK) ||
+	    !context_tracking_enabled())
+		return 0;
+
+	prev_ctx = __ct_state();
+	if (prev_ctx != CONTEXT_KERNEL)
+		ct_user_exit(prev_ctx);
+
+	return prev_ctx;
+}
+
+static inline void exception_exit(enum ctx_state prev_ctx)
+{
+	if (!IS_ENABLED(CONFIG_HAVE_CONTEXT_TRACKING_USER_OFFSTACK) &&
+	    context_tracking_enabled()) {
+		if (prev_ctx != CONTEXT_KERNEL)
+			ct_user_enter(prev_ctx);
+	}
+}
+
+static __always_inline bool context_tracking_guest_enter(void)
+{
+	if (context_tracking_enabled())
+		__ct_user_enter(CONTEXT_GUEST);
+
+	return context_tracking_enabled_this_cpu();
+}
+
+static __always_inline void context_tracking_guest_exit(void)
+{
+	if (context_tracking_enabled())
+		__ct_user_exit(CONTEXT_GUEST);
+}
+
+#define CT_WARN_ON(cond) WARN_ON(context_tracking_enabled() && (cond))
+
+#else
+static inline void user_enter(void) { }
+static inline void user_exit(void) { }
+static inline void user_enter_irqoff(void) { }
+static inline void user_exit_irqoff(void) { }
+static inline int exception_enter(void) { return 0; }
+static inline void exception_exit(enum ctx_state prev_ctx) { }
+static inline int ct_state(void) { return -1; }
+static inline int __ct_state(void) { return -1; }
+static __always_inline bool context_tracking_guest_enter(void) { return false; }
+static inline void context_tracking_guest_exit(void) { }
+#define CT_WARN_ON(cond) do { } while (0)
+#endif /* !CONFIG_CONTEXT_TRACKING_USER */
+
+#ifdef CONFIG_CONTEXT_TRACKING_USER_FORCE
+extern void context_tracking_init(void);
+#else
+static inline void context_tracking_init(void) { }
+#endif /* CONFIG_CONTEXT_TRACKING_USER_FORCE */
+
+#ifdef CONFIG_CONTEXT_TRACKING_IDLE
+extern void ct_idle_enter(void);
+extern void ct_idle_exit(void);
+
+/*
+ * Is the current CPU in an extended quiescent state?
+ *
+ * No ordering, as we are sampling CPU-local information.
+ */
+static __always_inline bool rcu_dynticks_curr_cpu_in_eqs(void)
+{
+	return !(arch_atomic_read(this_cpu_ptr(&context_tracking.state)) & RCU_DYNTICKS_IDX);
+}
+
+/*
+ * Increment the current CPU's context_tracking structure's ->state field
+ * with ordering.  Return the new value.
+ */
+static __always_inline unsigned long ct_state_inc(int incby)
+{
+	return arch_atomic_add_return(incby, this_cpu_ptr(&context_tracking.state));
+}
+
+static __always_inline bool warn_rcu_enter(void)
+{
+	bool ret = false;
+
+	/*
+	 * Horrible hack to shut up recursive RCU isn't watching fail since
+	 * lots of the actual reporting also relies on RCU.
+	 */
+	preempt_disable_notrace();
+	if (rcu_dynticks_curr_cpu_in_eqs()) {
+		ret = true;
+		ct_state_inc(RCU_DYNTICKS_IDX);
+	}
+
+	return ret;
+}
+
+static __always_inline void warn_rcu_exit(bool rcu)
+{
+	if (rcu)
+		ct_state_inc(RCU_DYNTICKS_IDX);
+	preempt_enable_notrace();
+}
+
+#else
+static inline void ct_idle_enter(void) { }
+static inline void ct_idle_exit(void) { }
+
+static __always_inline bool warn_rcu_enter(void) { return false; }
+static __always_inline void warn_rcu_exit(bool rcu) { }
+#endif /* !CONFIG_CONTEXT_TRACKING_IDLE */
+
+#endif