1 /*
2  * lib/locking-selftest.c
3  *
4  * Testsuite for various locking APIs: spinlocks, rwlocks,
5  * mutexes and rw-semaphores.
6  *
7  * It is checking both false positives and false negatives.
8  *
9  * Started by Ingo Molnar:
10  *
11  *  Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
12  */
13 #include <linux/rwsem.h>
14 #include <linux/mutex.h>
15 #include <linux/sched.h>
16 #include <linux/delay.h>
17 #include <linux/lockdep.h>
18 #include <linux/spinlock.h>
19 #include <linux/kallsyms.h>
20 #include <linux/interrupt.h>
21 #include <linux/debug_locks.h>
22 #include <linux/irqflags.h>
23 
24 /*
25  * Change this to 1 if you want to see the failure printouts:
26  */
27 static unsigned int debug_locks_verbose;
28 
setup_debug_locks_verbose(char * str)29 static int __init setup_debug_locks_verbose(char *str)
30 {
31 	get_option(&str, &debug_locks_verbose);
32 
33 	return 1;
34 }
35 
36 __setup("debug_locks_verbose=", setup_debug_locks_verbose);
37 
38 #define FAILURE		0
39 #define SUCCESS		1
40 
41 #define LOCKTYPE_SPIN	0x1
42 #define LOCKTYPE_RWLOCK	0x2
43 #define LOCKTYPE_MUTEX	0x4
44 #define LOCKTYPE_RWSEM	0x8
45 
46 /*
47  * Normal standalone locks, for the circular and irq-context
48  * dependency tests:
49  */
50 static DEFINE_SPINLOCK(lock_A);
51 static DEFINE_SPINLOCK(lock_B);
52 static DEFINE_SPINLOCK(lock_C);
53 static DEFINE_SPINLOCK(lock_D);
54 
55 static DEFINE_RWLOCK(rwlock_A);
56 static DEFINE_RWLOCK(rwlock_B);
57 static DEFINE_RWLOCK(rwlock_C);
58 static DEFINE_RWLOCK(rwlock_D);
59 
60 static DEFINE_MUTEX(mutex_A);
61 static DEFINE_MUTEX(mutex_B);
62 static DEFINE_MUTEX(mutex_C);
63 static DEFINE_MUTEX(mutex_D);
64 
65 static DECLARE_RWSEM(rwsem_A);
66 static DECLARE_RWSEM(rwsem_B);
67 static DECLARE_RWSEM(rwsem_C);
68 static DECLARE_RWSEM(rwsem_D);
69 
70 /*
71  * Locks that we initialize dynamically as well so that
72  * e.g. X1 and X2 becomes two instances of the same class,
73  * but X* and Y* are different classes. We do this so that
74  * we do not trigger a real lockup:
75  */
76 static DEFINE_SPINLOCK(lock_X1);
77 static DEFINE_SPINLOCK(lock_X2);
78 static DEFINE_SPINLOCK(lock_Y1);
79 static DEFINE_SPINLOCK(lock_Y2);
80 static DEFINE_SPINLOCK(lock_Z1);
81 static DEFINE_SPINLOCK(lock_Z2);
82 
83 static DEFINE_RWLOCK(rwlock_X1);
84 static DEFINE_RWLOCK(rwlock_X2);
85 static DEFINE_RWLOCK(rwlock_Y1);
86 static DEFINE_RWLOCK(rwlock_Y2);
87 static DEFINE_RWLOCK(rwlock_Z1);
88 static DEFINE_RWLOCK(rwlock_Z2);
89 
90 static DEFINE_MUTEX(mutex_X1);
91 static DEFINE_MUTEX(mutex_X2);
92 static DEFINE_MUTEX(mutex_Y1);
93 static DEFINE_MUTEX(mutex_Y2);
94 static DEFINE_MUTEX(mutex_Z1);
95 static DEFINE_MUTEX(mutex_Z2);
96 
97 static DECLARE_RWSEM(rwsem_X1);
98 static DECLARE_RWSEM(rwsem_X2);
99 static DECLARE_RWSEM(rwsem_Y1);
100 static DECLARE_RWSEM(rwsem_Y2);
101 static DECLARE_RWSEM(rwsem_Z1);
102 static DECLARE_RWSEM(rwsem_Z2);
103 
104 /*
105  * non-inlined runtime initializers, to let separate locks share
106  * the same lock-class:
107  */
108 #define INIT_CLASS_FUNC(class) 				\
109 static noinline void					\
110 init_class_##class(spinlock_t *lock, rwlock_t *rwlock, struct mutex *mutex, \
111 		 struct rw_semaphore *rwsem)		\
112 {							\
113 	spin_lock_init(lock);				\
114 	rwlock_init(rwlock);				\
115 	mutex_init(mutex);				\
116 	init_rwsem(rwsem);				\
117 }
118 
119 INIT_CLASS_FUNC(X)
INIT_CLASS_FUNC(Y)120 INIT_CLASS_FUNC(Y)
121 INIT_CLASS_FUNC(Z)
122 
123 static void init_shared_classes(void)
124 {
125 	init_class_X(&lock_X1, &rwlock_X1, &mutex_X1, &rwsem_X1);
126 	init_class_X(&lock_X2, &rwlock_X2, &mutex_X2, &rwsem_X2);
127 
128 	init_class_Y(&lock_Y1, &rwlock_Y1, &mutex_Y1, &rwsem_Y1);
129 	init_class_Y(&lock_Y2, &rwlock_Y2, &mutex_Y2, &rwsem_Y2);
130 
131 	init_class_Z(&lock_Z1, &rwlock_Z1, &mutex_Z1, &rwsem_Z1);
132 	init_class_Z(&lock_Z2, &rwlock_Z2, &mutex_Z2, &rwsem_Z2);
133 }
134 
135 /*
136  * For spinlocks and rwlocks we also do hardirq-safe / softirq-safe tests.
137  * The following functions use a lock from a simulated hardirq/softirq
138  * context, causing the locks to be marked as hardirq-safe/softirq-safe:
139  */
140 
141 #define HARDIRQ_DISABLE		local_irq_disable
142 #define HARDIRQ_ENABLE		local_irq_enable
143 
144 #define HARDIRQ_ENTER()				\
145 	local_irq_disable();			\
146 	__irq_enter();				\
147 	WARN_ON(!in_irq());
148 
149 #define HARDIRQ_EXIT()				\
150 	__irq_exit();				\
151 	local_irq_enable();
152 
153 #define SOFTIRQ_DISABLE		local_bh_disable
154 #define SOFTIRQ_ENABLE		local_bh_enable
155 
156 #define SOFTIRQ_ENTER()				\
157 		local_bh_disable();		\
158 		local_irq_disable();		\
159 		lockdep_softirq_enter();	\
160 		WARN_ON(!in_softirq());
161 
162 #define SOFTIRQ_EXIT()				\
163 		lockdep_softirq_exit();		\
164 		local_irq_enable();		\
165 		local_bh_enable();
166 
167 /*
168  * Shortcuts for lock/unlock API variants, to keep
169  * the testcases compact:
170  */
171 #define L(x)			spin_lock(&lock_##x)
172 #define U(x)			spin_unlock(&lock_##x)
173 #define LU(x)			L(x); U(x)
174 #define SI(x)			spin_lock_init(&lock_##x)
175 
176 #define WL(x)			write_lock(&rwlock_##x)
177 #define WU(x)			write_unlock(&rwlock_##x)
178 #define WLU(x)			WL(x); WU(x)
179 
180 #define RL(x)			read_lock(&rwlock_##x)
181 #define RU(x)			read_unlock(&rwlock_##x)
182 #define RLU(x)			RL(x); RU(x)
183 #define RWI(x)			rwlock_init(&rwlock_##x)
184 
185 #define ML(x)			mutex_lock(&mutex_##x)
186 #define MU(x)			mutex_unlock(&mutex_##x)
187 #define MI(x)			mutex_init(&mutex_##x)
188 
189 #define WSL(x)			down_write(&rwsem_##x)
190 #define WSU(x)			up_write(&rwsem_##x)
191 
192 #define RSL(x)			down_read(&rwsem_##x)
193 #define RSU(x)			up_read(&rwsem_##x)
194 #define RWSI(x)			init_rwsem(&rwsem_##x)
195 
196 #define LOCK_UNLOCK_2(x,y)	LOCK(x); LOCK(y); UNLOCK(y); UNLOCK(x)
197 
198 /*
199  * Generate different permutations of the same testcase, using
200  * the same basic lock-dependency/state events:
201  */
202 
203 #define GENERATE_TESTCASE(name)			\
204 						\
205 static void name(void) { E(); }
206 
207 #define GENERATE_PERMUTATIONS_2_EVENTS(name)	\
208 						\
209 static void name##_12(void) { E1(); E2(); }	\
210 static void name##_21(void) { E2(); E1(); }
211 
212 #define GENERATE_PERMUTATIONS_3_EVENTS(name)		\
213 							\
214 static void name##_123(void) { E1(); E2(); E3(); }	\
215 static void name##_132(void) { E1(); E3(); E2(); }	\
216 static void name##_213(void) { E2(); E1(); E3(); }	\
217 static void name##_231(void) { E2(); E3(); E1(); }	\
218 static void name##_312(void) { E3(); E1(); E2(); }	\
219 static void name##_321(void) { E3(); E2(); E1(); }
220 
221 /*
222  * AA deadlock:
223  */
224 
225 #define E()					\
226 						\
227 	LOCK(X1);				\
228 	LOCK(X2); /* this one should fail */
229 
230 /*
231  * 6 testcases:
232  */
233 #include "locking-selftest-spin.h"
234 GENERATE_TESTCASE(AA_spin)
235 #include "locking-selftest-wlock.h"
GENERATE_TESTCASE(AA_wlock)236 GENERATE_TESTCASE(AA_wlock)
237 #include "locking-selftest-rlock.h"
238 GENERATE_TESTCASE(AA_rlock)
239 #include "locking-selftest-mutex.h"
240 GENERATE_TESTCASE(AA_mutex)
241 #include "locking-selftest-wsem.h"
242 GENERATE_TESTCASE(AA_wsem)
243 #include "locking-selftest-rsem.h"
244 GENERATE_TESTCASE(AA_rsem)
245 
246 #undef E
247 
248 /*
249  * Special-case for read-locking, they are
250  * allowed to recurse on the same lock class:
251  */
252 static void rlock_AA1(void)
253 {
254 	RL(X1);
255 	RL(X1); // this one should NOT fail
256 }
257 
rlock_AA1B(void)258 static void rlock_AA1B(void)
259 {
260 	RL(X1);
261 	RL(X2); // this one should NOT fail
262 }
263 
rsem_AA1(void)264 static void rsem_AA1(void)
265 {
266 	RSL(X1);
267 	RSL(X1); // this one should fail
268 }
269 
rsem_AA1B(void)270 static void rsem_AA1B(void)
271 {
272 	RSL(X1);
273 	RSL(X2); // this one should fail
274 }
275 /*
276  * The mixing of read and write locks is not allowed:
277  */
rlock_AA2(void)278 static void rlock_AA2(void)
279 {
280 	RL(X1);
281 	WL(X2); // this one should fail
282 }
283 
rsem_AA2(void)284 static void rsem_AA2(void)
285 {
286 	RSL(X1);
287 	WSL(X2); // this one should fail
288 }
289 
rlock_AA3(void)290 static void rlock_AA3(void)
291 {
292 	WL(X1);
293 	RL(X2); // this one should fail
294 }
295 
rsem_AA3(void)296 static void rsem_AA3(void)
297 {
298 	WSL(X1);
299 	RSL(X2); // this one should fail
300 }
301 
302 /*
303  * ABBA deadlock:
304  */
305 
306 #define E()					\
307 						\
308 	LOCK_UNLOCK_2(A, B);			\
309 	LOCK_UNLOCK_2(B, A); /* fail */
310 
311 /*
312  * 6 testcases:
313  */
314 #include "locking-selftest-spin.h"
315 GENERATE_TESTCASE(ABBA_spin)
316 #include "locking-selftest-wlock.h"
GENERATE_TESTCASE(ABBA_wlock)317 GENERATE_TESTCASE(ABBA_wlock)
318 #include "locking-selftest-rlock.h"
319 GENERATE_TESTCASE(ABBA_rlock)
320 #include "locking-selftest-mutex.h"
321 GENERATE_TESTCASE(ABBA_mutex)
322 #include "locking-selftest-wsem.h"
323 GENERATE_TESTCASE(ABBA_wsem)
324 #include "locking-selftest-rsem.h"
325 GENERATE_TESTCASE(ABBA_rsem)
326 
327 #undef E
328 
329 /*
330  * AB BC CA deadlock:
331  */
332 
333 #define E()					\
334 						\
335 	LOCK_UNLOCK_2(A, B);			\
336 	LOCK_UNLOCK_2(B, C);			\
337 	LOCK_UNLOCK_2(C, A); /* fail */
338 
339 /*
340  * 6 testcases:
341  */
342 #include "locking-selftest-spin.h"
343 GENERATE_TESTCASE(ABBCCA_spin)
344 #include "locking-selftest-wlock.h"
345 GENERATE_TESTCASE(ABBCCA_wlock)
346 #include "locking-selftest-rlock.h"
347 GENERATE_TESTCASE(ABBCCA_rlock)
348 #include "locking-selftest-mutex.h"
349 GENERATE_TESTCASE(ABBCCA_mutex)
350 #include "locking-selftest-wsem.h"
351 GENERATE_TESTCASE(ABBCCA_wsem)
352 #include "locking-selftest-rsem.h"
353 GENERATE_TESTCASE(ABBCCA_rsem)
354 
355 #undef E
356 
357 /*
358  * AB CA BC deadlock:
359  */
360 
361 #define E()					\
362 						\
363 	LOCK_UNLOCK_2(A, B);			\
364 	LOCK_UNLOCK_2(C, A);			\
365 	LOCK_UNLOCK_2(B, C); /* fail */
366 
367 /*
368  * 6 testcases:
369  */
370 #include "locking-selftest-spin.h"
371 GENERATE_TESTCASE(ABCABC_spin)
372 #include "locking-selftest-wlock.h"
373 GENERATE_TESTCASE(ABCABC_wlock)
374 #include "locking-selftest-rlock.h"
375 GENERATE_TESTCASE(ABCABC_rlock)
376 #include "locking-selftest-mutex.h"
377 GENERATE_TESTCASE(ABCABC_mutex)
378 #include "locking-selftest-wsem.h"
379 GENERATE_TESTCASE(ABCABC_wsem)
380 #include "locking-selftest-rsem.h"
381 GENERATE_TESTCASE(ABCABC_rsem)
382 
383 #undef E
384 
385 /*
386  * AB BC CD DA deadlock:
387  */
388 
389 #define E()					\
390 						\
391 	LOCK_UNLOCK_2(A, B);			\
392 	LOCK_UNLOCK_2(B, C);			\
393 	LOCK_UNLOCK_2(C, D);			\
394 	LOCK_UNLOCK_2(D, A); /* fail */
395 
396 /*
397  * 6 testcases:
398  */
399 #include "locking-selftest-spin.h"
400 GENERATE_TESTCASE(ABBCCDDA_spin)
401 #include "locking-selftest-wlock.h"
402 GENERATE_TESTCASE(ABBCCDDA_wlock)
403 #include "locking-selftest-rlock.h"
404 GENERATE_TESTCASE(ABBCCDDA_rlock)
405 #include "locking-selftest-mutex.h"
406 GENERATE_TESTCASE(ABBCCDDA_mutex)
407 #include "locking-selftest-wsem.h"
408 GENERATE_TESTCASE(ABBCCDDA_wsem)
409 #include "locking-selftest-rsem.h"
410 GENERATE_TESTCASE(ABBCCDDA_rsem)
411 
412 #undef E
413 
414 /*
415  * AB CD BD DA deadlock:
416  */
417 #define E()					\
418 						\
419 	LOCK_UNLOCK_2(A, B);			\
420 	LOCK_UNLOCK_2(C, D);			\
421 	LOCK_UNLOCK_2(B, D);			\
422 	LOCK_UNLOCK_2(D, A); /* fail */
423 
424 /*
425  * 6 testcases:
426  */
427 #include "locking-selftest-spin.h"
428 GENERATE_TESTCASE(ABCDBDDA_spin)
429 #include "locking-selftest-wlock.h"
430 GENERATE_TESTCASE(ABCDBDDA_wlock)
431 #include "locking-selftest-rlock.h"
432 GENERATE_TESTCASE(ABCDBDDA_rlock)
433 #include "locking-selftest-mutex.h"
434 GENERATE_TESTCASE(ABCDBDDA_mutex)
435 #include "locking-selftest-wsem.h"
436 GENERATE_TESTCASE(ABCDBDDA_wsem)
437 #include "locking-selftest-rsem.h"
438 GENERATE_TESTCASE(ABCDBDDA_rsem)
439 
440 #undef E
441 
442 /*
443  * AB CD BC DA deadlock:
444  */
445 #define E()					\
446 						\
447 	LOCK_UNLOCK_2(A, B);			\
448 	LOCK_UNLOCK_2(C, D);			\
449 	LOCK_UNLOCK_2(B, C);			\
450 	LOCK_UNLOCK_2(D, A); /* fail */
451 
452 /*
453  * 6 testcases:
454  */
455 #include "locking-selftest-spin.h"
456 GENERATE_TESTCASE(ABCDBCDA_spin)
457 #include "locking-selftest-wlock.h"
458 GENERATE_TESTCASE(ABCDBCDA_wlock)
459 #include "locking-selftest-rlock.h"
460 GENERATE_TESTCASE(ABCDBCDA_rlock)
461 #include "locking-selftest-mutex.h"
462 GENERATE_TESTCASE(ABCDBCDA_mutex)
463 #include "locking-selftest-wsem.h"
464 GENERATE_TESTCASE(ABCDBCDA_wsem)
465 #include "locking-selftest-rsem.h"
466 GENERATE_TESTCASE(ABCDBCDA_rsem)
467 
468 #undef E
469 
470 /*
471  * Double unlock:
472  */
473 #define E()					\
474 						\
475 	LOCK(A);				\
476 	UNLOCK(A);				\
477 	UNLOCK(A); /* fail */
478 
479 /*
480  * 6 testcases:
481  */
482 #include "locking-selftest-spin.h"
483 GENERATE_TESTCASE(double_unlock_spin)
484 #include "locking-selftest-wlock.h"
485 GENERATE_TESTCASE(double_unlock_wlock)
486 #include "locking-selftest-rlock.h"
487 GENERATE_TESTCASE(double_unlock_rlock)
488 #include "locking-selftest-mutex.h"
489 GENERATE_TESTCASE(double_unlock_mutex)
490 #include "locking-selftest-wsem.h"
491 GENERATE_TESTCASE(double_unlock_wsem)
492 #include "locking-selftest-rsem.h"
493 GENERATE_TESTCASE(double_unlock_rsem)
494 
495 #undef E
496 
497 /*
498  * Bad unlock ordering:
499  */
500 #define E()					\
501 						\
502 	LOCK(A);				\
503 	LOCK(B);				\
504 	UNLOCK(A); /* fail */			\
505 	UNLOCK(B);
506 
507 /*
508  * 6 testcases:
509  */
510 #include "locking-selftest-spin.h"
511 GENERATE_TESTCASE(bad_unlock_order_spin)
512 #include "locking-selftest-wlock.h"
513 GENERATE_TESTCASE(bad_unlock_order_wlock)
514 #include "locking-selftest-rlock.h"
515 GENERATE_TESTCASE(bad_unlock_order_rlock)
516 #include "locking-selftest-mutex.h"
517 GENERATE_TESTCASE(bad_unlock_order_mutex)
518 #include "locking-selftest-wsem.h"
519 GENERATE_TESTCASE(bad_unlock_order_wsem)
520 #include "locking-selftest-rsem.h"
521 GENERATE_TESTCASE(bad_unlock_order_rsem)
522 
523 #undef E
524 
525 /*
526  * initializing a held lock:
527  */
528 #define E()					\
529 						\
530 	LOCK(A);				\
531 	INIT(A); /* fail */
532 
533 /*
534  * 6 testcases:
535  */
536 #include "locking-selftest-spin.h"
537 GENERATE_TESTCASE(init_held_spin)
538 #include "locking-selftest-wlock.h"
539 GENERATE_TESTCASE(init_held_wlock)
540 #include "locking-selftest-rlock.h"
541 GENERATE_TESTCASE(init_held_rlock)
542 #include "locking-selftest-mutex.h"
543 GENERATE_TESTCASE(init_held_mutex)
544 #include "locking-selftest-wsem.h"
545 GENERATE_TESTCASE(init_held_wsem)
546 #include "locking-selftest-rsem.h"
547 GENERATE_TESTCASE(init_held_rsem)
548 
549 #undef E
550 
551 /*
552  * locking an irq-safe lock with irqs enabled:
553  */
554 #define E1()				\
555 					\
556 	IRQ_ENTER();			\
557 	LOCK(A);			\
558 	UNLOCK(A);			\
559 	IRQ_EXIT();
560 
561 #define E2()				\
562 					\
563 	LOCK(A);			\
564 	UNLOCK(A);
565 
566 /*
567  * Generate 24 testcases:
568  */
569 #include "locking-selftest-spin-hardirq.h"
570 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_spin)
571 
572 #include "locking-selftest-rlock-hardirq.h"
573 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_rlock)
574 
575 #include "locking-selftest-wlock-hardirq.h"
576 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_hard_wlock)
577 
578 #include "locking-selftest-spin-softirq.h"
579 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_spin)
580 
581 #include "locking-selftest-rlock-softirq.h"
582 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_rlock)
583 
584 #include "locking-selftest-wlock-softirq.h"
585 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe1_soft_wlock)
586 
587 #undef E1
588 #undef E2
589 
590 /*
591  * Enabling hardirqs with a softirq-safe lock held:
592  */
593 #define E1()				\
594 					\
595 	SOFTIRQ_ENTER();		\
596 	LOCK(A);			\
597 	UNLOCK(A);			\
598 	SOFTIRQ_EXIT();
599 
600 #define E2()				\
601 					\
602 	HARDIRQ_DISABLE();		\
603 	LOCK(A);			\
604 	HARDIRQ_ENABLE();		\
605 	UNLOCK(A);
606 
607 /*
608  * Generate 12 testcases:
609  */
610 #include "locking-selftest-spin.h"
611 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2A_spin)
612 
613 #include "locking-selftest-wlock.h"
614 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2A_wlock)
615 
616 #include "locking-selftest-rlock.h"
617 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2A_rlock)
618 
619 #undef E1
620 #undef E2
621 
622 /*
623  * Enabling irqs with an irq-safe lock held:
624  */
625 #define E1()				\
626 					\
627 	IRQ_ENTER();			\
628 	LOCK(A);			\
629 	UNLOCK(A);			\
630 	IRQ_EXIT();
631 
632 #define E2()				\
633 					\
634 	IRQ_DISABLE();			\
635 	LOCK(A);			\
636 	IRQ_ENABLE();			\
637 	UNLOCK(A);
638 
639 /*
640  * Generate 24 testcases:
641  */
642 #include "locking-selftest-spin-hardirq.h"
643 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_spin)
644 
645 #include "locking-selftest-rlock-hardirq.h"
646 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_rlock)
647 
648 #include "locking-selftest-wlock-hardirq.h"
649 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_hard_wlock)
650 
651 #include "locking-selftest-spin-softirq.h"
652 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_spin)
653 
654 #include "locking-selftest-rlock-softirq.h"
655 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_rlock)
656 
657 #include "locking-selftest-wlock-softirq.h"
658 GENERATE_PERMUTATIONS_2_EVENTS(irqsafe2B_soft_wlock)
659 
660 #undef E1
661 #undef E2
662 
663 /*
664  * Acquiring a irq-unsafe lock while holding an irq-safe-lock:
665  */
666 #define E1()				\
667 					\
668 	LOCK(A);			\
669 	LOCK(B);			\
670 	UNLOCK(B);			\
671 	UNLOCK(A);			\
672 
673 #define E2()				\
674 					\
675 	LOCK(B);			\
676 	UNLOCK(B);
677 
678 #define E3()				\
679 					\
680 	IRQ_ENTER();			\
681 	LOCK(A);			\
682 	UNLOCK(A);			\
683 	IRQ_EXIT();
684 
685 /*
686  * Generate 36 testcases:
687  */
688 #include "locking-selftest-spin-hardirq.h"
689 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_spin)
690 
691 #include "locking-selftest-rlock-hardirq.h"
692 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_rlock)
693 
694 #include "locking-selftest-wlock-hardirq.h"
695 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_hard_wlock)
696 
697 #include "locking-selftest-spin-softirq.h"
698 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_spin)
699 
700 #include "locking-selftest-rlock-softirq.h"
701 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_rlock)
702 
703 #include "locking-selftest-wlock-softirq.h"
704 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe3_soft_wlock)
705 
706 #undef E1
707 #undef E2
708 #undef E3
709 
710 /*
711  * If a lock turns into softirq-safe, but earlier it took
712  * a softirq-unsafe lock:
713  */
714 
715 #define E1()				\
716 	IRQ_DISABLE();			\
717 	LOCK(A);			\
718 	LOCK(B);			\
719 	UNLOCK(B);			\
720 	UNLOCK(A);			\
721 	IRQ_ENABLE();
722 
723 #define E2()				\
724 	LOCK(B);			\
725 	UNLOCK(B);
726 
727 #define E3()				\
728 	IRQ_ENTER();			\
729 	LOCK(A);			\
730 	UNLOCK(A);			\
731 	IRQ_EXIT();
732 
733 /*
734  * Generate 36 testcases:
735  */
736 #include "locking-selftest-spin-hardirq.h"
737 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_spin)
738 
739 #include "locking-selftest-rlock-hardirq.h"
740 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_rlock)
741 
742 #include "locking-selftest-wlock-hardirq.h"
743 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_hard_wlock)
744 
745 #include "locking-selftest-spin-softirq.h"
746 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_spin)
747 
748 #include "locking-selftest-rlock-softirq.h"
749 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_rlock)
750 
751 #include "locking-selftest-wlock-softirq.h"
752 GENERATE_PERMUTATIONS_3_EVENTS(irqsafe4_soft_wlock)
753 
754 #undef E1
755 #undef E2
756 #undef E3
757 
758 /*
759  * read-lock / write-lock irq inversion.
760  *
761  * Deadlock scenario:
762  *
763  * CPU#1 is at #1, i.e. it has write-locked A, but has not
764  * taken B yet.
765  *
766  * CPU#2 is at #2, i.e. it has locked B.
767  *
768  * Hardirq hits CPU#2 at point #2 and is trying to read-lock A.
769  *
770  * The deadlock occurs because CPU#1 will spin on B, and CPU#2
771  * will spin on A.
772  */
773 
774 #define E1()				\
775 					\
776 	IRQ_DISABLE();			\
777 	WL(A);				\
778 	LOCK(B);			\
779 	UNLOCK(B);			\
780 	WU(A);				\
781 	IRQ_ENABLE();
782 
783 #define E2()				\
784 					\
785 	LOCK(B);			\
786 	UNLOCK(B);
787 
788 #define E3()				\
789 					\
790 	IRQ_ENTER();			\
791 	RL(A);				\
792 	RU(A);				\
793 	IRQ_EXIT();
794 
795 /*
796  * Generate 36 testcases:
797  */
798 #include "locking-selftest-spin-hardirq.h"
799 GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_hard_spin)
800 
801 #include "locking-selftest-rlock-hardirq.h"
802 GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_hard_rlock)
803 
804 #include "locking-selftest-wlock-hardirq.h"
805 GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_hard_wlock)
806 
807 #include "locking-selftest-spin-softirq.h"
808 GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_soft_spin)
809 
810 #include "locking-selftest-rlock-softirq.h"
811 GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_soft_rlock)
812 
813 #include "locking-selftest-wlock-softirq.h"
814 GENERATE_PERMUTATIONS_3_EVENTS(irq_inversion_soft_wlock)
815 
816 #undef E1
817 #undef E2
818 #undef E3
819 
820 /*
821  * read-lock / write-lock recursion that is actually safe.
822  */
823 
824 #define E1()				\
825 					\
826 	IRQ_DISABLE();			\
827 	WL(A);				\
828 	WU(A);				\
829 	IRQ_ENABLE();
830 
831 #define E2()				\
832 					\
833 	RL(A);				\
834 	RU(A);				\
835 
836 #define E3()				\
837 					\
838 	IRQ_ENTER();			\
839 	RL(A);				\
840 	L(B);				\
841 	U(B);				\
842 	RU(A);				\
843 	IRQ_EXIT();
844 
845 /*
846  * Generate 12 testcases:
847  */
848 #include "locking-selftest-hardirq.h"
849 GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion_hard)
850 
851 #include "locking-selftest-softirq.h"
852 GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion_soft)
853 
854 #undef E1
855 #undef E2
856 #undef E3
857 
858 /*
859  * read-lock / write-lock recursion that is unsafe.
860  */
861 
862 #define E1()				\
863 					\
864 	IRQ_DISABLE();			\
865 	L(B);				\
866 	WL(A);				\
867 	WU(A);				\
868 	U(B);				\
869 	IRQ_ENABLE();
870 
871 #define E2()				\
872 					\
873 	RL(A);				\
874 	RU(A);				\
875 
876 #define E3()				\
877 					\
878 	IRQ_ENTER();			\
879 	L(B);				\
880 	U(B);				\
881 	IRQ_EXIT();
882 
883 /*
884  * Generate 12 testcases:
885  */
886 #include "locking-selftest-hardirq.h"
887 // GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion2_hard)
888 
889 #include "locking-selftest-softirq.h"
890 // GENERATE_PERMUTATIONS_3_EVENTS(irq_read_recursion2_soft)
891 
892 #ifdef CONFIG_DEBUG_LOCK_ALLOC
893 # define I_SPINLOCK(x)	lockdep_reset_lock(&lock_##x.dep_map)
894 # define I_RWLOCK(x)	lockdep_reset_lock(&rwlock_##x.dep_map)
895 # define I_MUTEX(x)	lockdep_reset_lock(&mutex_##x.dep_map)
896 # define I_RWSEM(x)	lockdep_reset_lock(&rwsem_##x.dep_map)
897 #else
898 # define I_SPINLOCK(x)
899 # define I_RWLOCK(x)
900 # define I_MUTEX(x)
901 # define I_RWSEM(x)
902 #endif
903 
904 #define I1(x)					\
905 	do {					\
906 		I_SPINLOCK(x);			\
907 		I_RWLOCK(x);			\
908 		I_MUTEX(x);			\
909 		I_RWSEM(x);			\
910 	} while (0)
911 
912 #define I2(x)					\
913 	do {					\
914 		spin_lock_init(&lock_##x);	\
915 		rwlock_init(&rwlock_##x);	\
916 		mutex_init(&mutex_##x);		\
917 		init_rwsem(&rwsem_##x);		\
918 	} while (0)
919 
920 static void reset_locks(void)
921 {
922 	local_irq_disable();
923 	I1(A); I1(B); I1(C); I1(D);
924 	I1(X1); I1(X2); I1(Y1); I1(Y2); I1(Z1); I1(Z2);
925 	lockdep_reset();
926 	I2(A); I2(B); I2(C); I2(D);
927 	init_shared_classes();
928 	local_irq_enable();
929 }
930 
931 #undef I
932 
933 static int testcase_total;
934 static int testcase_successes;
935 static int expected_testcase_failures;
936 static int unexpected_testcase_failures;
937 
dotest(void (* testcase_fn)(void),int expected,int lockclass_mask)938 static void dotest(void (*testcase_fn)(void), int expected, int lockclass_mask)
939 {
940 	unsigned long saved_preempt_count = preempt_count();
941 	int expected_failure = 0;
942 
943 	WARN_ON(irqs_disabled());
944 
945 	testcase_fn();
946 	/*
947 	 * Filter out expected failures:
948 	 */
949 #ifndef CONFIG_PROVE_LOCKING
950 	if ((lockclass_mask & LOCKTYPE_SPIN) && debug_locks != expected)
951 		expected_failure = 1;
952 	if ((lockclass_mask & LOCKTYPE_RWLOCK) && debug_locks != expected)
953 		expected_failure = 1;
954 	if ((lockclass_mask & LOCKTYPE_MUTEX) && debug_locks != expected)
955 		expected_failure = 1;
956 	if ((lockclass_mask & LOCKTYPE_RWSEM) && debug_locks != expected)
957 		expected_failure = 1;
958 #endif
959 	if (debug_locks != expected) {
960 		if (expected_failure) {
961 			expected_testcase_failures++;
962 			printk("failed|");
963 		} else {
964 			unexpected_testcase_failures++;
965 
966 			printk("FAILED|");
967 			dump_stack();
968 		}
969 	} else {
970 		testcase_successes++;
971 		printk("  ok  |");
972 	}
973 	testcase_total++;
974 
975 	if (debug_locks_verbose)
976 		printk(" lockclass mask: %x, debug_locks: %d, expected: %d\n",
977 			lockclass_mask, debug_locks, expected);
978 	/*
979 	 * Some tests (e.g. double-unlock) might corrupt the preemption
980 	 * count, so restore it:
981 	 */
982 	preempt_count() = saved_preempt_count;
983 #ifdef CONFIG_TRACE_IRQFLAGS
984 	if (softirq_count())
985 		current->softirqs_enabled = 0;
986 	else
987 		current->softirqs_enabled = 1;
988 #endif
989 
990 	reset_locks();
991 }
992 
print_testname(const char * testname)993 static inline void print_testname(const char *testname)
994 {
995 	printk("%33s:", testname);
996 }
997 
998 #define DO_TESTCASE_1(desc, name, nr)				\
999 	print_testname(desc"/"#nr);				\
1000 	dotest(name##_##nr, SUCCESS, LOCKTYPE_RWLOCK);		\
1001 	printk("\n");
1002 
1003 #define DO_TESTCASE_1B(desc, name, nr)				\
1004 	print_testname(desc"/"#nr);				\
1005 	dotest(name##_##nr, FAILURE, LOCKTYPE_RWLOCK);		\
1006 	printk("\n");
1007 
1008 #define DO_TESTCASE_3(desc, name, nr)				\
1009 	print_testname(desc"/"#nr);				\
1010 	dotest(name##_spin_##nr, FAILURE, LOCKTYPE_SPIN);	\
1011 	dotest(name##_wlock_##nr, FAILURE, LOCKTYPE_RWLOCK);	\
1012 	dotest(name##_rlock_##nr, SUCCESS, LOCKTYPE_RWLOCK);	\
1013 	printk("\n");
1014 
1015 #define DO_TESTCASE_3RW(desc, name, nr)				\
1016 	print_testname(desc"/"#nr);				\
1017 	dotest(name##_spin_##nr, FAILURE, LOCKTYPE_SPIN|LOCKTYPE_RWLOCK);\
1018 	dotest(name##_wlock_##nr, FAILURE, LOCKTYPE_RWLOCK);	\
1019 	dotest(name##_rlock_##nr, SUCCESS, LOCKTYPE_RWLOCK);	\
1020 	printk("\n");
1021 
1022 #define DO_TESTCASE_6(desc, name)				\
1023 	print_testname(desc);					\
1024 	dotest(name##_spin, FAILURE, LOCKTYPE_SPIN);		\
1025 	dotest(name##_wlock, FAILURE, LOCKTYPE_RWLOCK);		\
1026 	dotest(name##_rlock, FAILURE, LOCKTYPE_RWLOCK);		\
1027 	dotest(name##_mutex, FAILURE, LOCKTYPE_MUTEX);		\
1028 	dotest(name##_wsem, FAILURE, LOCKTYPE_RWSEM);		\
1029 	dotest(name##_rsem, FAILURE, LOCKTYPE_RWSEM);		\
1030 	printk("\n");
1031 
1032 #define DO_TESTCASE_6_SUCCESS(desc, name)			\
1033 	print_testname(desc);					\
1034 	dotest(name##_spin, SUCCESS, LOCKTYPE_SPIN);		\
1035 	dotest(name##_wlock, SUCCESS, LOCKTYPE_RWLOCK);		\
1036 	dotest(name##_rlock, SUCCESS, LOCKTYPE_RWLOCK);		\
1037 	dotest(name##_mutex, SUCCESS, LOCKTYPE_MUTEX);		\
1038 	dotest(name##_wsem, SUCCESS, LOCKTYPE_RWSEM);		\
1039 	dotest(name##_rsem, SUCCESS, LOCKTYPE_RWSEM);		\
1040 	printk("\n");
1041 
1042 /*
1043  * 'read' variant: rlocks must not trigger.
1044  */
1045 #define DO_TESTCASE_6R(desc, name)				\
1046 	print_testname(desc);					\
1047 	dotest(name##_spin, FAILURE, LOCKTYPE_SPIN);		\
1048 	dotest(name##_wlock, FAILURE, LOCKTYPE_RWLOCK);		\
1049 	dotest(name##_rlock, SUCCESS, LOCKTYPE_RWLOCK);		\
1050 	dotest(name##_mutex, FAILURE, LOCKTYPE_MUTEX);		\
1051 	dotest(name##_wsem, FAILURE, LOCKTYPE_RWSEM);		\
1052 	dotest(name##_rsem, FAILURE, LOCKTYPE_RWSEM);		\
1053 	printk("\n");
1054 
1055 #define DO_TESTCASE_2I(desc, name, nr)				\
1056 	DO_TESTCASE_1("hard-"desc, name##_hard, nr);		\
1057 	DO_TESTCASE_1("soft-"desc, name##_soft, nr);
1058 
1059 #define DO_TESTCASE_2IB(desc, name, nr)				\
1060 	DO_TESTCASE_1B("hard-"desc, name##_hard, nr);		\
1061 	DO_TESTCASE_1B("soft-"desc, name##_soft, nr);
1062 
1063 #define DO_TESTCASE_6I(desc, name, nr)				\
1064 	DO_TESTCASE_3("hard-"desc, name##_hard, nr);		\
1065 	DO_TESTCASE_3("soft-"desc, name##_soft, nr);
1066 
1067 #define DO_TESTCASE_6IRW(desc, name, nr)			\
1068 	DO_TESTCASE_3RW("hard-"desc, name##_hard, nr);		\
1069 	DO_TESTCASE_3RW("soft-"desc, name##_soft, nr);
1070 
1071 #define DO_TESTCASE_2x3(desc, name)				\
1072 	DO_TESTCASE_3(desc, name, 12);				\
1073 	DO_TESTCASE_3(desc, name, 21);
1074 
1075 #define DO_TESTCASE_2x6(desc, name)				\
1076 	DO_TESTCASE_6I(desc, name, 12);				\
1077 	DO_TESTCASE_6I(desc, name, 21);
1078 
1079 #define DO_TESTCASE_6x2(desc, name)				\
1080 	DO_TESTCASE_2I(desc, name, 123);			\
1081 	DO_TESTCASE_2I(desc, name, 132);			\
1082 	DO_TESTCASE_2I(desc, name, 213);			\
1083 	DO_TESTCASE_2I(desc, name, 231);			\
1084 	DO_TESTCASE_2I(desc, name, 312);			\
1085 	DO_TESTCASE_2I(desc, name, 321);
1086 
1087 #define DO_TESTCASE_6x2B(desc, name)				\
1088 	DO_TESTCASE_2IB(desc, name, 123);			\
1089 	DO_TESTCASE_2IB(desc, name, 132);			\
1090 	DO_TESTCASE_2IB(desc, name, 213);			\
1091 	DO_TESTCASE_2IB(desc, name, 231);			\
1092 	DO_TESTCASE_2IB(desc, name, 312);			\
1093 	DO_TESTCASE_2IB(desc, name, 321);
1094 
1095 #define DO_TESTCASE_6x6(desc, name)				\
1096 	DO_TESTCASE_6I(desc, name, 123);			\
1097 	DO_TESTCASE_6I(desc, name, 132);			\
1098 	DO_TESTCASE_6I(desc, name, 213);			\
1099 	DO_TESTCASE_6I(desc, name, 231);			\
1100 	DO_TESTCASE_6I(desc, name, 312);			\
1101 	DO_TESTCASE_6I(desc, name, 321);
1102 
1103 #define DO_TESTCASE_6x6RW(desc, name)				\
1104 	DO_TESTCASE_6IRW(desc, name, 123);			\
1105 	DO_TESTCASE_6IRW(desc, name, 132);			\
1106 	DO_TESTCASE_6IRW(desc, name, 213);			\
1107 	DO_TESTCASE_6IRW(desc, name, 231);			\
1108 	DO_TESTCASE_6IRW(desc, name, 312);			\
1109 	DO_TESTCASE_6IRW(desc, name, 321);
1110 
1111 
locking_selftest(void)1112 void locking_selftest(void)
1113 {
1114 	/*
1115 	 * Got a locking failure before the selftest ran?
1116 	 */
1117 	if (!debug_locks) {
1118 		printk("----------------------------------\n");
1119 		printk("| Locking API testsuite disabled |\n");
1120 		printk("----------------------------------\n");
1121 		return;
1122 	}
1123 
1124 	/*
1125 	 * Run the testsuite:
1126 	 */
1127 	printk("------------------------\n");
1128 	printk("| Locking API testsuite:\n");
1129 	printk("----------------------------------------------------------------------------\n");
1130 	printk("                                 | spin |wlock |rlock |mutex | wsem | rsem |\n");
1131 	printk("  --------------------------------------------------------------------------\n");
1132 
1133 	init_shared_classes();
1134 	debug_locks_silent = !debug_locks_verbose;
1135 
1136 	DO_TESTCASE_6R("A-A deadlock", AA);
1137 	DO_TESTCASE_6R("A-B-B-A deadlock", ABBA);
1138 	DO_TESTCASE_6R("A-B-B-C-C-A deadlock", ABBCCA);
1139 	DO_TESTCASE_6R("A-B-C-A-B-C deadlock", ABCABC);
1140 	DO_TESTCASE_6R("A-B-B-C-C-D-D-A deadlock", ABBCCDDA);
1141 	DO_TESTCASE_6R("A-B-C-D-B-D-D-A deadlock", ABCDBDDA);
1142 	DO_TESTCASE_6R("A-B-C-D-B-C-D-A deadlock", ABCDBCDA);
1143 	DO_TESTCASE_6("double unlock", double_unlock);
1144 	DO_TESTCASE_6("initialize held", init_held);
1145 	DO_TESTCASE_6_SUCCESS("bad unlock order", bad_unlock_order);
1146 
1147 	printk("  --------------------------------------------------------------------------\n");
1148 	print_testname("recursive read-lock");
1149 	printk("             |");
1150 	dotest(rlock_AA1, SUCCESS, LOCKTYPE_RWLOCK);
1151 	printk("             |");
1152 	dotest(rsem_AA1, FAILURE, LOCKTYPE_RWSEM);
1153 	printk("\n");
1154 
1155 	print_testname("recursive read-lock #2");
1156 	printk("             |");
1157 	dotest(rlock_AA1B, SUCCESS, LOCKTYPE_RWLOCK);
1158 	printk("             |");
1159 	dotest(rsem_AA1B, FAILURE, LOCKTYPE_RWSEM);
1160 	printk("\n");
1161 
1162 	print_testname("mixed read-write-lock");
1163 	printk("             |");
1164 	dotest(rlock_AA2, FAILURE, LOCKTYPE_RWLOCK);
1165 	printk("             |");
1166 	dotest(rsem_AA2, FAILURE, LOCKTYPE_RWSEM);
1167 	printk("\n");
1168 
1169 	print_testname("mixed write-read-lock");
1170 	printk("             |");
1171 	dotest(rlock_AA3, FAILURE, LOCKTYPE_RWLOCK);
1172 	printk("             |");
1173 	dotest(rsem_AA3, FAILURE, LOCKTYPE_RWSEM);
1174 	printk("\n");
1175 
1176 	printk("  --------------------------------------------------------------------------\n");
1177 
1178 	/*
1179 	 * irq-context testcases:
1180 	 */
1181 	DO_TESTCASE_2x6("irqs-on + irq-safe-A", irqsafe1);
1182 	DO_TESTCASE_2x3("sirq-safe-A => hirqs-on", irqsafe2A);
1183 	DO_TESTCASE_2x6("safe-A + irqs-on", irqsafe2B);
1184 	DO_TESTCASE_6x6("safe-A + unsafe-B #1", irqsafe3);
1185 	DO_TESTCASE_6x6("safe-A + unsafe-B #2", irqsafe4);
1186 	DO_TESTCASE_6x6RW("irq lock-inversion", irq_inversion);
1187 
1188 	DO_TESTCASE_6x2("irq read-recursion", irq_read_recursion);
1189 //	DO_TESTCASE_6x2B("irq read-recursion #2", irq_read_recursion2);
1190 
1191 	if (unexpected_testcase_failures) {
1192 		printk("-----------------------------------------------------------------\n");
1193 		debug_locks = 0;
1194 		printk("BUG: %3d unexpected failures (out of %3d) - debugging disabled! |\n",
1195 			unexpected_testcase_failures, testcase_total);
1196 		printk("-----------------------------------------------------------------\n");
1197 	} else if (expected_testcase_failures && testcase_successes) {
1198 		printk("--------------------------------------------------------\n");
1199 		printk("%3d out of %3d testcases failed, as expected. |\n",
1200 			expected_testcase_failures, testcase_total);
1201 		printk("----------------------------------------------------\n");
1202 		debug_locks = 1;
1203 	} else if (expected_testcase_failures && !testcase_successes) {
1204 		printk("--------------------------------------------------------\n");
1205 		printk("All %3d testcases failed, as expected. |\n",
1206 			expected_testcase_failures);
1207 		printk("----------------------------------------\n");
1208 		debug_locks = 1;
1209 	} else {
1210 		printk("-------------------------------------------------------\n");
1211 		printk("Good, all %3d testcases passed! |\n",
1212 			testcase_successes);
1213 		printk("---------------------------------\n");
1214 		debug_locks = 1;
1215 	}
1216 	debug_locks_silent = 0;
1217 }
1218