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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 2019-2022 Red Hat, Inc. Daniel Bristot de Oliveira <bristot@kernel.org>
4 *
5 * Deterministic automata (DA) monitor functions, to be used together
6 * with automata models in C generated by the dot2k tool.
7 *
8 * The dot2k tool is available at tools/verification/dot2k/
9 *
10 * For further information, see:
11 * Documentation/trace/rv/da_monitor_synthesis.rst
12 */
13
14#include <rv/automata.h>
15#include <linux/rv.h>
16#include <linux/bug.h>
17
18#ifdef CONFIG_RV_REACTORS
19
20#define DECLARE_RV_REACTING_HELPERS(name, type) \
21static char REACT_MSG_##name[1024]; \
22 \
23static inline char *format_react_msg_##name(type curr_state, type event) \
24{ \
25 snprintf(REACT_MSG_##name, 1024, \
26 "rv: monitor %s does not allow event %s on state %s\n", \
27 #name, \
28 model_get_event_name_##name(event), \
29 model_get_state_name_##name(curr_state)); \
30 return REACT_MSG_##name; \
31} \
32 \
33static void cond_react_##name(char *msg) \
34{ \
35 if (rv_##name.react) \
36 rv_##name.react(msg); \
37} \
38 \
39static bool rv_reacting_on_##name(void) \
40{ \
41 return rv_reacting_on(); \
42}
43
44#else /* CONFIG_RV_REACTOR */
45
46#define DECLARE_RV_REACTING_HELPERS(name, type) \
47static inline char *format_react_msg_##name(type curr_state, type event) \
48{ \
49 return NULL; \
50} \
51 \
52static void cond_react_##name(char *msg) \
53{ \
54 return; \
55} \
56 \
57static bool rv_reacting_on_##name(void) \
58{ \
59 return 0; \
60}
61#endif
62
63/*
64 * Generic helpers for all types of deterministic automata monitors.
65 */
66#define DECLARE_DA_MON_GENERIC_HELPERS(name, type) \
67 \
68DECLARE_RV_REACTING_HELPERS(name, type) \
69 \
70/* \
71 * da_monitor_reset_##name - reset a monitor and setting it to init state \
72 */ \
73static inline void da_monitor_reset_##name(struct da_monitor *da_mon) \
74{ \
75 da_mon->monitoring = 0; \
76 da_mon->curr_state = model_get_initial_state_##name(); \
77} \
78 \
79/* \
80 * da_monitor_curr_state_##name - return the current state \
81 */ \
82static inline type da_monitor_curr_state_##name(struct da_monitor *da_mon) \
83{ \
84 return da_mon->curr_state; \
85} \
86 \
87/* \
88 * da_monitor_set_state_##name - set the new current state \
89 */ \
90static inline void \
91da_monitor_set_state_##name(struct da_monitor *da_mon, enum states_##name state) \
92{ \
93 da_mon->curr_state = state; \
94} \
95 \
96/* \
97 * da_monitor_start_##name - start monitoring \
98 * \
99 * The monitor will ignore all events until monitoring is set to true. This \
100 * function needs to be called to tell the monitor to start monitoring. \
101 */ \
102static inline void da_monitor_start_##name(struct da_monitor *da_mon) \
103{ \
104 da_mon->curr_state = model_get_initial_state_##name(); \
105 da_mon->monitoring = 1; \
106} \
107 \
108/* \
109 * da_monitoring_##name - returns true if the monitor is processing events \
110 */ \
111static inline bool da_monitoring_##name(struct da_monitor *da_mon) \
112{ \
113 return da_mon->monitoring; \
114} \
115 \
116/* \
117 * da_monitor_enabled_##name - checks if the monitor is enabled \
118 */ \
119static inline bool da_monitor_enabled_##name(void) \
120{ \
121 /* global switch */ \
122 if (unlikely(!rv_monitoring_on())) \
123 return 0; \
124 \
125 /* monitor enabled */ \
126 if (unlikely(!rv_##name.enabled)) \
127 return 0; \
128 \
129 return 1; \
130} \
131 \
132/* \
133 * da_monitor_handling_event_##name - checks if the monitor is ready to handle events \
134 */ \
135static inline bool da_monitor_handling_event_##name(struct da_monitor *da_mon) \
136{ \
137 \
138 if (!da_monitor_enabled_##name()) \
139 return 0; \
140 \
141 /* monitor is actually monitoring */ \
142 if (unlikely(!da_monitoring_##name(da_mon))) \
143 return 0; \
144 \
145 return 1; \
146}
147
148/*
149 * Event handler for implicit monitors. Implicit monitor is the one which the
150 * handler does not need to specify which da_monitor to manipulate. Examples
151 * of implicit monitor are the per_cpu or the global ones.
152 */
153#define DECLARE_DA_MON_MODEL_HANDLER_IMPLICIT(name, type) \
154 \
155static inline bool \
156da_event_##name(struct da_monitor *da_mon, enum events_##name event) \
157{ \
158 type curr_state = da_monitor_curr_state_##name(da_mon); \
159 type next_state = model_get_next_state_##name(curr_state, event); \
160 \
161 if (next_state != INVALID_STATE) { \
162 da_monitor_set_state_##name(da_mon, next_state); \
163 \
164 trace_event_##name(model_get_state_name_##name(curr_state), \
165 model_get_event_name_##name(event), \
166 model_get_state_name_##name(next_state), \
167 model_is_final_state_##name(next_state)); \
168 \
169 return true; \
170 } \
171 \
172 if (rv_reacting_on_##name()) \
173 cond_react_##name(format_react_msg_##name(curr_state, event)); \
174 \
175 trace_error_##name(model_get_state_name_##name(curr_state), \
176 model_get_event_name_##name(event)); \
177 \
178 return false; \
179} \
180
181/*
182 * Event handler for per_task monitors.
183 */
184#define DECLARE_DA_MON_MODEL_HANDLER_PER_TASK(name, type) \
185 \
186static inline bool da_event_##name(struct da_monitor *da_mon, struct task_struct *tsk, \
187 enum events_##name event) \
188{ \
189 type curr_state = da_monitor_curr_state_##name(da_mon); \
190 type next_state = model_get_next_state_##name(curr_state, event); \
191 \
192 if (next_state != INVALID_STATE) { \
193 da_monitor_set_state_##name(da_mon, next_state); \
194 \
195 trace_event_##name(tsk->pid, \
196 model_get_state_name_##name(curr_state), \
197 model_get_event_name_##name(event), \
198 model_get_state_name_##name(next_state), \
199 model_is_final_state_##name(next_state)); \
200 \
201 return true; \
202 } \
203 \
204 if (rv_reacting_on_##name()) \
205 cond_react_##name(format_react_msg_##name(curr_state, event)); \
206 \
207 trace_error_##name(tsk->pid, \
208 model_get_state_name_##name(curr_state), \
209 model_get_event_name_##name(event)); \
210 \
211 return false; \
212}
213
214/*
215 * Functions to define, init and get a global monitor.
216 */
217#define DECLARE_DA_MON_INIT_GLOBAL(name, type) \
218 \
219/* \
220 * global monitor (a single variable) \
221 */ \
222static struct da_monitor da_mon_##name; \
223 \
224/* \
225 * da_get_monitor_##name - return the global monitor address \
226 */ \
227static struct da_monitor *da_get_monitor_##name(void) \
228{ \
229 return &da_mon_##name; \
230} \
231 \
232/* \
233 * da_monitor_reset_all_##name - reset the single monitor \
234 */ \
235static void da_monitor_reset_all_##name(void) \
236{ \
237 da_monitor_reset_##name(da_get_monitor_##name()); \
238} \
239 \
240/* \
241 * da_monitor_init_##name - initialize a monitor \
242 */ \
243static inline int da_monitor_init_##name(void) \
244{ \
245 da_monitor_reset_all_##name(); \
246 return 0; \
247} \
248 \
249/* \
250 * da_monitor_destroy_##name - destroy the monitor \
251 */ \
252static inline void da_monitor_destroy_##name(void) \
253{ \
254 return; \
255}
256
257/*
258 * Functions to define, init and get a per-cpu monitor.
259 */
260#define DECLARE_DA_MON_INIT_PER_CPU(name, type) \
261 \
262/* \
263 * per-cpu monitor variables \
264 */ \
265static DEFINE_PER_CPU(struct da_monitor, da_mon_##name); \
266 \
267/* \
268 * da_get_monitor_##name - return current CPU monitor address \
269 */ \
270static struct da_monitor *da_get_monitor_##name(void) \
271{ \
272 return this_cpu_ptr(&da_mon_##name); \
273} \
274 \
275/* \
276 * da_monitor_reset_all_##name - reset all CPUs' monitor \
277 */ \
278static void da_monitor_reset_all_##name(void) \
279{ \
280 struct da_monitor *da_mon; \
281 int cpu; \
282 for_each_cpu(cpu, cpu_online_mask) { \
283 da_mon = per_cpu_ptr(&da_mon_##name, cpu); \
284 da_monitor_reset_##name(da_mon); \
285 } \
286} \
287 \
288/* \
289 * da_monitor_init_##name - initialize all CPUs' monitor \
290 */ \
291static inline int da_monitor_init_##name(void) \
292{ \
293 da_monitor_reset_all_##name(); \
294 return 0; \
295} \
296 \
297/* \
298 * da_monitor_destroy_##name - destroy the monitor \
299 */ \
300static inline void da_monitor_destroy_##name(void) \
301{ \
302 return; \
303}
304
305/*
306 * Functions to define, init and get a per-task monitor.
307 */
308#define DECLARE_DA_MON_INIT_PER_TASK(name, type) \
309 \
310/* \
311 * The per-task monitor is stored a vector in the task struct. This variable \
312 * stores the position on the vector reserved for this monitor. \
313 */ \
314static int task_mon_slot_##name = RV_PER_TASK_MONITOR_INIT; \
315 \
316/* \
317 * da_get_monitor_##name - return the monitor in the allocated slot for tsk \
318 */ \
319static inline struct da_monitor *da_get_monitor_##name(struct task_struct *tsk) \
320{ \
321 return &tsk->rv[task_mon_slot_##name].da_mon; \
322} \
323 \
324static void da_monitor_reset_all_##name(void) \
325{ \
326 struct task_struct *g, *p; \
327 \
328 read_lock(&tasklist_lock); \
329 for_each_process_thread(g, p) \
330 da_monitor_reset_##name(da_get_monitor_##name(p)); \
331 read_unlock(&tasklist_lock); \
332} \
333 \
334/* \
335 * da_monitor_init_##name - initialize the per-task monitor \
336 * \
337 * Try to allocate a slot in the task's vector of monitors. If there \
338 * is an available slot, use it and reset all task's monitor. \
339 */ \
340static int da_monitor_init_##name(void) \
341{ \
342 int slot; \
343 \
344 slot = rv_get_task_monitor_slot(); \
345 if (slot < 0 || slot >= RV_PER_TASK_MONITOR_INIT) \
346 return slot; \
347 \
348 task_mon_slot_##name = slot; \
349 \
350 da_monitor_reset_all_##name(); \
351 return 0; \
352} \
353 \
354/* \
355 * da_monitor_destroy_##name - return the allocated slot \
356 */ \
357static inline void da_monitor_destroy_##name(void) \
358{ \
359 if (task_mon_slot_##name == RV_PER_TASK_MONITOR_INIT) { \
360 WARN_ONCE(1, "Disabling a disabled monitor: " #name); \
361 return; \
362 } \
363 rv_put_task_monitor_slot(task_mon_slot_##name); \
364 task_mon_slot_##name = RV_PER_TASK_MONITOR_INIT; \
365 return; \
366}
367
368/*
369 * Handle event for implicit monitor: da_get_monitor_##name() will figure out
370 * the monitor.
371 */
372#define DECLARE_DA_MON_MONITOR_HANDLER_IMPLICIT(name, type) \
373 \
374static inline void __da_handle_event_##name(struct da_monitor *da_mon, \
375 enum events_##name event) \
376{ \
377 bool retval; \
378 \
379 retval = da_event_##name(da_mon, event); \
380 if (!retval) \
381 da_monitor_reset_##name(da_mon); \
382} \
383 \
384/* \
385 * da_handle_event_##name - handle an event \
386 */ \
387static inline void da_handle_event_##name(enum events_##name event) \
388{ \
389 struct da_monitor *da_mon = da_get_monitor_##name(); \
390 bool retval; \
391 \
392 retval = da_monitor_handling_event_##name(da_mon); \
393 if (!retval) \
394 return; \
395 \
396 __da_handle_event_##name(da_mon, event); \
397} \
398 \
399/* \
400 * da_handle_start_event_##name - start monitoring or handle event \
401 * \
402 * This function is used to notify the monitor that the system is returning \
403 * to the initial state, so the monitor can start monitoring in the next event. \
404 * Thus: \
405 * \
406 * If the monitor already started, handle the event. \
407 * If the monitor did not start yet, start the monitor but skip the event. \
408 */ \
409static inline bool da_handle_start_event_##name(enum events_##name event) \
410{ \
411 struct da_monitor *da_mon; \
412 \
413 if (!da_monitor_enabled_##name()) \
414 return 0; \
415 \
416 da_mon = da_get_monitor_##name(); \
417 \
418 if (unlikely(!da_monitoring_##name(da_mon))) { \
419 da_monitor_start_##name(da_mon); \
420 return 0; \
421 } \
422 \
423 __da_handle_event_##name(da_mon, event); \
424 \
425 return 1; \
426} \
427 \
428/* \
429 * da_handle_start_run_event_##name - start monitoring and handle event \
430 * \
431 * This function is used to notify the monitor that the system is in the \
432 * initial state, so the monitor can start monitoring and handling event. \
433 */ \
434static inline bool da_handle_start_run_event_##name(enum events_##name event) \
435{ \
436 struct da_monitor *da_mon; \
437 \
438 if (!da_monitor_enabled_##name()) \
439 return 0; \
440 \
441 da_mon = da_get_monitor_##name(); \
442 \
443 if (unlikely(!da_monitoring_##name(da_mon))) \
444 da_monitor_start_##name(da_mon); \
445 \
446 __da_handle_event_##name(da_mon, event); \
447 \
448 return 1; \
449}
450
451/*
452 * Handle event for per task.
453 */
454#define DECLARE_DA_MON_MONITOR_HANDLER_PER_TASK(name, type) \
455 \
456static inline void \
457__da_handle_event_##name(struct da_monitor *da_mon, struct task_struct *tsk, \
458 enum events_##name event) \
459{ \
460 bool retval; \
461 \
462 retval = da_event_##name(da_mon, tsk, event); \
463 if (!retval) \
464 da_monitor_reset_##name(da_mon); \
465} \
466 \
467/* \
468 * da_handle_event_##name - handle an event \
469 */ \
470static inline void \
471da_handle_event_##name(struct task_struct *tsk, enum events_##name event) \
472{ \
473 struct da_monitor *da_mon = da_get_monitor_##name(tsk); \
474 bool retval; \
475 \
476 retval = da_monitor_handling_event_##name(da_mon); \
477 if (!retval) \
478 return; \
479 \
480 __da_handle_event_##name(da_mon, tsk, event); \
481} \
482 \
483/* \
484 * da_handle_start_event_##name - start monitoring or handle event \
485 * \
486 * This function is used to notify the monitor that the system is returning \
487 * to the initial state, so the monitor can start monitoring in the next event. \
488 * Thus: \
489 * \
490 * If the monitor already started, handle the event. \
491 * If the monitor did not start yet, start the monitor but skip the event. \
492 */ \
493static inline bool \
494da_handle_start_event_##name(struct task_struct *tsk, enum events_##name event) \
495{ \
496 struct da_monitor *da_mon; \
497 \
498 if (!da_monitor_enabled_##name()) \
499 return 0; \
500 \
501 da_mon = da_get_monitor_##name(tsk); \
502 \
503 if (unlikely(!da_monitoring_##name(da_mon))) { \
504 da_monitor_start_##name(da_mon); \
505 return 0; \
506 } \
507 \
508 __da_handle_event_##name(da_mon, tsk, event); \
509 \
510 return 1; \
511}
512
513/*
514 * Entry point for the global monitor.
515 */
516#define DECLARE_DA_MON_GLOBAL(name, type) \
517 \
518DECLARE_AUTOMATA_HELPERS(name, type) \
519DECLARE_DA_MON_GENERIC_HELPERS(name, type) \
520DECLARE_DA_MON_MODEL_HANDLER_IMPLICIT(name, type) \
521DECLARE_DA_MON_INIT_GLOBAL(name, type) \
522DECLARE_DA_MON_MONITOR_HANDLER_IMPLICIT(name, type)
523
524/*
525 * Entry point for the per-cpu monitor.
526 */
527#define DECLARE_DA_MON_PER_CPU(name, type) \
528 \
529DECLARE_AUTOMATA_HELPERS(name, type) \
530DECLARE_DA_MON_GENERIC_HELPERS(name, type) \
531DECLARE_DA_MON_MODEL_HANDLER_IMPLICIT(name, type) \
532DECLARE_DA_MON_INIT_PER_CPU(name, type) \
533DECLARE_DA_MON_MONITOR_HANDLER_IMPLICIT(name, type)
534
535/*
536 * Entry point for the per-task monitor.
537 */
538#define DECLARE_DA_MON_PER_TASK(name, type) \
539 \
540DECLARE_AUTOMATA_HELPERS(name, type) \
541DECLARE_DA_MON_GENERIC_HELPERS(name, type) \
542DECLARE_DA_MON_MODEL_HANDLER_PER_TASK(name, type) \
543DECLARE_DA_MON_INIT_PER_TASK(name, type) \
544DECLARE_DA_MON_MONITOR_HANDLER_PER_TASK(name, type)
545

Warning: This file is not a C or C++ file. It does not have highlighting.

source code of linux/include/rv/da_monitor.h