Messages in this thread Patch in this message |  | | From | Daniel Bristot de Oliveira <> | Subject | [PATCH V5 03/16] rv/include: Add helper functions for deterministic automata | Date | Wed, 13 Jul 2022 23:17:19 +0200 |
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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
diff --git a/include/rv/automata.h b/include/rv/automata.h new file mode 100644 index 000000000000..7125c91df607 --- /dev/null +++ b/include/rv/automata.h @@ -0,0 +1,75 @@ +/* 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_init_state_##name - return the automaton's initial state \ + */ \ +static inline type model_get_init_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]; \ +} -- 2.35.1
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