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+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2019-2022 Red Hat, Inc. Daniel Bristot de Oliveira <bristot@kernel.org>
+ *
+ * Deterministic automata helper functions, to be used with the automata
+ * models in C generated by the dot2k tool.
+ */
+
+/*
+ * DECLARE_AUTOMATA_HELPERS - define a set of helper functions for automata
+ *
+ * Define a set of helper functions for automata. The 'name' argument is used
+ * as suffix for the functions and data. These functions will handle automaton
+ * with data type 'type'.
+ */
+#define DECLARE_AUTOMATA_HELPERS(name, type) \
+ \
+/* \
+ * model_get_state_name_##name - return the (string) name of the given state \
+ */ \
+static char *model_get_state_name_##name(enum states_##name state) \
+{ \
+ if ((state < 0) || (state >= state_max_##name)) \
+ return "INVALID"; \
+ \
+ return automaton_##name.state_names[state]; \
+} \
+ \
+/* \
+ * model_get_event_name_##name - return the (string) name of the given event \
+ */ \
+static char *model_get_event_name_##name(enum events_##name event) \
+{ \
+ if ((event < 0) || (event >= event_max_##name)) \
+ return "INVALID"; \
+ \
+ return automaton_##name.event_names[event]; \
+} \
+ \
+/* \
+ * model_get_initial_state_##name - return the automaton's initial state \
+ */ \
+static inline type model_get_initial_state_##name(void) \
+{ \
+ return automaton_##name.initial_state; \
+} \
+ \
+/* \
+ * model_get_next_state_##name - process an automaton event occurrence \
+ * \
+ * Given the current state (curr_state) and the event (event), returns \
+ * the next state, or INVALID_STATE in case of error. \
+ */ \
+static inline type model_get_next_state_##name(enum states_##name curr_state, \
+ enum events_##name event) \
+{ \
+ if ((curr_state < 0) || (curr_state >= state_max_##name)) \
+ return INVALID_STATE; \
+ \
+ if ((event < 0) || (event >= event_max_##name)) \
+ return INVALID_STATE; \
+ \
+ return automaton_##name.function[curr_state][event]; \
+} \
+ \
+/* \
+ * model_is_final_state_##name - check if the given state is a final state \
+ */ \
+static inline bool model_is_final_state_##name(enum states_##name state) \
+{ \
+ if ((state < 0) || (state >= state_max_##name)) \
+ return 0; \
+ \
+ return automaton_##name.final_states[state]; \
+}
Formally, a deterministic automaton, denoted by G, is defined as a quintuple: G = { X, E, f, x_0, X_m } where: - X is the set of states; - E is the finite set of events; - x_0 is the initial state; - X_m (subset of X) is the set of marked states. - f : X x E -> X $ is the transition function. It defines the state transition in the occurrence of a event from E in the state X. In the special case of deterministic automata, the occurrence of the event in E in a state in X has a deterministic next state from X. An automaton can also be represented using a graphical format of vertices (nodes) and edges. The open-source tool Graphviz can produce this graphic format using the (textual) DOT language as the source code. The dot2c tool presented in this paper: De Oliveira, Daniel Bristot; Cucinotta, Tommaso; De Oliveira, Romulo Silva. Efficient formal verification for the Linux kernel. In: International Conference on Software Engineering and Formal Methods. Springer, Cham, 2019. p. 315-332. Translates a deterministic automaton in the DOT format into a C source code representation that to be used for monitoring. This header file implements helper functions to facilitate the usage of the C output from dot2c/k for monitoring. Cc: Wim Van Sebroeck <wim@linux-watchdog.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marco Elver <elver@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Gabriele Paoloni <gpaoloni@redhat.com> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Clark Williams <williams@redhat.com> Cc: Tao Zhou <tao.zhou@linux.dev> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: linux-doc@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org> --- include/rv/automata.h | 75 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 75 insertions(+) create mode 100644 include/rv/automata.h