xref: /netbsd-src/sys/kern/subr_lockdebug.c (revision 267197ec1eebfcb9810ea27a89625b6ddf68e3e7)
1 /*	$NetBSD: subr_lockdebug.c,v 1.26 2008/01/05 12:39:27 ad Exp $	*/
2 
3 /*-
4  * Copyright (c) 2006, 2007 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Andrew Doran.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the NetBSD
21  *	Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * Basic lock debugging code shared among lock primitives.
41  */
42 
43 #include <sys/cdefs.h>
44 __KERNEL_RCSID(0, "$NetBSD: subr_lockdebug.c,v 1.26 2008/01/05 12:39:27 ad Exp $");
45 
46 #include "opt_ddb.h"
47 
48 #include <sys/param.h>
49 #include <sys/proc.h>
50 #include <sys/systm.h>
51 #include <sys/kernel.h>
52 #include <sys/kmem.h>
53 #include <sys/lockdebug.h>
54 #include <sys/sleepq.h>
55 #include <sys/cpu.h>
56 #include <sys/atomic.h>
57 #include <sys/lock.h>
58 
59 #include <lib/libkern/rb.h>
60 
61 #include <machine/lock.h>
62 
63 #ifdef LOCKDEBUG
64 
65 #define	LD_BATCH_SHIFT	9
66 #define	LD_BATCH	(1 << LD_BATCH_SHIFT)
67 #define	LD_BATCH_MASK	(LD_BATCH - 1)
68 #define	LD_MAX_LOCKS	1048576
69 #define	LD_SLOP		16
70 
71 #define	LD_LOCKED	0x01
72 #define	LD_SLEEPER	0x02
73 
74 #define	LD_WRITE_LOCK	0x80000000
75 
76 typedef union lockdebuglk {
77 	struct {
78 		u_int	lku_lock;
79 		int	lku_oldspl;
80 	} ul;
81 	uint8_t	lk_pad[CACHE_LINE_SIZE];
82 } volatile __aligned(CACHE_LINE_SIZE) lockdebuglk_t;
83 
84 #define	lk_lock		ul.lku_lock
85 #define	lk_oldspl	ul.lku_oldspl
86 
87 typedef struct lockdebug {
88 	struct rb_node	ld_rb_node;	/* must be the first member */
89 	_TAILQ_ENTRY(struct lockdebug, volatile) ld_chain;
90 	_TAILQ_ENTRY(struct lockdebug, volatile) ld_achain;
91 	volatile void	*ld_lock;
92 	lockops_t	*ld_lockops;
93 	struct lwp	*ld_lwp;
94 	uintptr_t	ld_locked;
95 	uintptr_t	ld_unlocked;
96 	uintptr_t	ld_initaddr;
97 	uint16_t	ld_shares;
98 	uint16_t	ld_cpu;
99 	uint8_t		ld_flags;
100 	uint8_t		ld_shwant;	/* advisory */
101 	uint8_t		ld_exwant;	/* advisory */
102 	uint8_t		ld_unused;
103 } volatile lockdebug_t;
104 
105 typedef _TAILQ_HEAD(lockdebuglist, struct lockdebug, volatile) lockdebuglist_t;
106 
107 lockdebuglk_t		ld_tree_lk;
108 lockdebuglk_t		ld_sleeper_lk;
109 lockdebuglk_t		ld_spinner_lk;
110 lockdebuglk_t		ld_free_lk;
111 
112 lockdebuglist_t		ld_sleepers = TAILQ_HEAD_INITIALIZER(ld_sleepers);
113 lockdebuglist_t		ld_spinners = TAILQ_HEAD_INITIALIZER(ld_spinners);
114 lockdebuglist_t		ld_free = TAILQ_HEAD_INITIALIZER(ld_free);
115 lockdebuglist_t		ld_all = TAILQ_HEAD_INITIALIZER(ld_all);
116 int			ld_nfree;
117 int			ld_freeptr;
118 int			ld_recurse;
119 bool			ld_nomore;
120 lockdebug_t		*ld_table[LD_MAX_LOCKS / LD_BATCH];
121 
122 lockdebug_t		ld_prime[LD_BATCH];
123 
124 static void	lockdebug_abort1(lockdebug_t *, lockdebuglk_t *lk,
125 				 const char *, const char *, bool);
126 static void	lockdebug_more(void);
127 static void	lockdebug_init(void);
128 
129 static signed int
130 ld_rb_compare_nodes(const struct rb_node *n1, const struct rb_node *n2)
131 {
132 	const lockdebug_t *ld1 = (const void *)n1;
133 	const lockdebug_t *ld2 = (const void *)n2;
134 	const uintptr_t a = (uintptr_t)ld1->ld_lock;
135 	const uintptr_t b = (uintptr_t)ld2->ld_lock;
136 
137 	if (a < b)
138 		return 1;
139 	if (a > b)
140 		return -1;
141 	return 0;
142 }
143 
144 static signed int
145 ld_rb_compare_key(const struct rb_node *n, const void *key)
146 {
147 	const lockdebug_t *ld = (const void *)n;
148 	const uintptr_t a = (uintptr_t)ld->ld_lock;
149 	const uintptr_t b = (uintptr_t)key;
150 
151 	if (a < b)
152 		return 1;
153 	if (a > b)
154 		return -1;
155 	return 0;
156 }
157 
158 static struct rb_tree ld_rb_tree;
159 
160 static const struct rb_tree_ops ld_rb_tree_ops = {
161 	.rb_compare_nodes = ld_rb_compare_nodes,
162 	.rb_compare_key = ld_rb_compare_key,
163 };
164 
165 static void
166 lockdebug_lock_init(lockdebuglk_t *lk)
167 {
168 
169 	lk->lk_lock = 0;
170 }
171 
172 static void
173 lockdebug_lock(lockdebuglk_t *lk)
174 {
175 	int s;
176 
177 	s = splhigh();
178 	do {
179 		while (lk->lk_lock != 0) {
180 			SPINLOCK_SPIN_HOOK;
181 		}
182 	} while (atomic_cas_uint(&lk->lk_lock, 0, LD_WRITE_LOCK) != 0);
183 	lk->lk_oldspl = s;
184 	membar_enter();
185 }
186 
187 static void
188 lockdebug_unlock(lockdebuglk_t *lk)
189 {
190 	int s;
191 
192 	s = lk->lk_oldspl;
193 	membar_exit();
194 	lk->lk_lock = 0;
195 	splx(s);
196 }
197 
198 static int
199 lockdebug_lock_rd(lockdebuglk_t *lk)
200 {
201 	u_int val;
202 	int s;
203 
204 	s = splhigh();
205 	do {
206 		while ((val = lk->lk_lock) == LD_WRITE_LOCK){
207 			SPINLOCK_SPIN_HOOK;
208 		}
209 	} while (atomic_cas_uint(&lk->lk_lock, val, val + 1) != val);
210 	membar_enter();
211 	return s;
212 }
213 
214 static void
215 lockdebug_unlock_rd(lockdebuglk_t *lk, int s)
216 {
217 
218 	membar_exit();
219 	atomic_dec_uint(&lk->lk_lock);
220 	splx(s);
221 }
222 
223 static inline lockdebug_t *
224 lockdebug_lookup1(volatile void *lock, lockdebuglk_t **lk)
225 {
226 	lockdebug_t *ld;
227 	int s;
228 
229 	s = lockdebug_lock_rd(&ld_tree_lk);
230 	ld = (lockdebug_t *)rb_tree_find_node(&ld_rb_tree, __UNVOLATILE(lock));
231 	lockdebug_unlock_rd(&ld_tree_lk, s);
232 	if (ld == NULL)
233 		return NULL;
234 
235 	if ((ld->ld_flags & LD_SLEEPER) != 0)
236 		*lk = &ld_sleeper_lk;
237 	else
238 		*lk = &ld_spinner_lk;
239 
240 	lockdebug_lock(*lk);
241 	return ld;
242 }
243 
244 /*
245  * lockdebug_lookup:
246  *
247  *	Find a lockdebug structure by a pointer to a lock and return it locked.
248  */
249 static inline lockdebug_t *
250 lockdebug_lookup(volatile void *lock, lockdebuglk_t **lk)
251 {
252 	lockdebug_t *ld;
253 
254 	ld = lockdebug_lookup1(lock, lk);
255 	if (ld == NULL)
256 		panic("lockdebug_lookup: uninitialized lock (lock=%p)", lock);
257 	return ld;
258 }
259 
260 /*
261  * lockdebug_init:
262  *
263  *	Initialize the lockdebug system.  Allocate an initial pool of
264  *	lockdebug structures before the VM system is up and running.
265  */
266 static void
267 lockdebug_init(void)
268 {
269 	lockdebug_t *ld;
270 	int i;
271 
272 	lockdebug_lock_init(&ld_tree_lk);
273 	lockdebug_lock_init(&ld_sleeper_lk);
274 	lockdebug_lock_init(&ld_spinner_lk);
275 	lockdebug_lock_init(&ld_free_lk);
276 
277 	rb_tree_init(&ld_rb_tree, &ld_rb_tree_ops);
278 
279 	ld = ld_prime;
280 	ld_table[0] = ld;
281 	for (i = 1, ld++; i < LD_BATCH; i++, ld++) {
282 		TAILQ_INSERT_TAIL(&ld_free, ld, ld_chain);
283 		TAILQ_INSERT_TAIL(&ld_all, ld, ld_achain);
284 	}
285 	ld_freeptr = 1;
286 	ld_nfree = LD_BATCH - 1;
287 }
288 
289 /*
290  * lockdebug_alloc:
291  *
292  *	A lock is being initialized, so allocate an associated debug
293  *	structure.
294  */
295 bool
296 lockdebug_alloc(volatile void *lock, lockops_t *lo, uintptr_t initaddr)
297 {
298 	struct cpu_info *ci;
299 	lockdebug_t *ld;
300 	lockdebuglk_t *lk;
301 
302 	if (lo == NULL || panicstr != NULL)
303 		return false;
304 	if (ld_freeptr == 0)
305 		lockdebug_init();
306 
307 	if ((ld = lockdebug_lookup1(lock, &lk)) != NULL) {
308 		lockdebug_abort1(ld, lk, __func__, "already initialized", true);
309 		/* NOTREACHED */
310 	}
311 
312 	/*
313 	 * Pinch a new debug structure.  We may recurse because we call
314 	 * kmem_alloc(), which may need to initialize new locks somewhere
315 	 * down the path.  If not recursing, we try to maintain at least
316 	 * LD_SLOP structures free, which should hopefully be enough to
317 	 * satisfy kmem_alloc().  If we can't provide a structure, not to
318 	 * worry: we'll just mark the lock as not having an ID.
319 	 */
320 	lockdebug_lock(&ld_free_lk);
321 	ci = curcpu();
322 	ci->ci_lkdebug_recurse++;
323 
324 	if (TAILQ_EMPTY(&ld_free)) {
325 		if (ci->ci_lkdebug_recurse > 1 || ld_nomore) {
326 			ci->ci_lkdebug_recurse--;
327 			lockdebug_unlock(&ld_free_lk);
328 			return false;
329 		}
330 		lockdebug_more();
331 	} else if (ci->ci_lkdebug_recurse == 1 && ld_nfree < LD_SLOP)
332 		lockdebug_more();
333 
334 	if ((ld = TAILQ_FIRST(&ld_free)) == NULL) {
335 		lockdebug_unlock(&ld_free_lk);
336 		return false;
337 	}
338 
339 	TAILQ_REMOVE(&ld_free, ld, ld_chain);
340 	ld_nfree--;
341 
342 	ci->ci_lkdebug_recurse--;
343 	lockdebug_unlock(&ld_free_lk);
344 
345 	if (ld->ld_lock != NULL)
346 		panic("lockdebug_alloc: corrupt table");
347 
348 	if (lo->lo_sleeplock)
349 		lockdebug_lock(&ld_sleeper_lk);
350 	else
351 		lockdebug_lock(&ld_spinner_lk);
352 
353 	/* Initialise the structure. */
354 	ld->ld_lock = lock;
355 	ld->ld_lockops = lo;
356 	ld->ld_locked = 0;
357 	ld->ld_unlocked = 0;
358 	ld->ld_lwp = NULL;
359 	ld->ld_initaddr = initaddr;
360 
361 	lockdebug_lock(&ld_tree_lk);
362 	rb_tree_insert_node(&ld_rb_tree, __UNVOLATILE(&ld->ld_rb_node));
363 	lockdebug_unlock(&ld_tree_lk);
364 
365 	if (lo->lo_sleeplock) {
366 		ld->ld_flags = LD_SLEEPER;
367 		lockdebug_unlock(&ld_sleeper_lk);
368 	} else {
369 		ld->ld_flags = 0;
370 		lockdebug_unlock(&ld_spinner_lk);
371 	}
372 
373 	return true;
374 }
375 
376 /*
377  * lockdebug_free:
378  *
379  *	A lock is being destroyed, so release debugging resources.
380  */
381 void
382 lockdebug_free(volatile void *lock)
383 {
384 	lockdebug_t *ld;
385 	lockdebuglk_t *lk;
386 
387 	if (panicstr != NULL)
388 		return;
389 
390 	ld = lockdebug_lookup(lock, &lk);
391 	if (ld == NULL) {
392 		panic("lockdebug_free: destroying uninitialized lock %p"
393 		    "(ld_lock=%p)", lock, ld->ld_lock);
394 		lockdebug_abort1(ld, lk, __func__, "lock record follows",
395 		    true);
396 	}
397 	if ((ld->ld_flags & LD_LOCKED) != 0 || ld->ld_shares != 0)
398 		lockdebug_abort1(ld, lk, __func__, "is locked", true);
399 	lockdebug_lock(&ld_tree_lk);
400 	rb_tree_remove_node(&ld_rb_tree, __UNVOLATILE(&ld->ld_rb_node));
401 	lockdebug_unlock(&ld_tree_lk);
402 	ld->ld_lock = NULL;
403 	lockdebug_unlock(lk);
404 
405 	lockdebug_lock(&ld_free_lk);
406 	TAILQ_INSERT_TAIL(&ld_free, ld, ld_chain);
407 	ld_nfree++;
408 	lockdebug_unlock(&ld_free_lk);
409 }
410 
411 /*
412  * lockdebug_more:
413  *
414  *	Allocate a batch of debug structures and add to the free list.
415  *	Must be called with ld_free_lk held.
416  */
417 static void
418 lockdebug_more(void)
419 {
420 	lockdebug_t *ld;
421 	void *block;
422 	int i, base, m;
423 
424 	while (ld_nfree < LD_SLOP) {
425 		lockdebug_unlock(&ld_free_lk);
426 		block = kmem_zalloc(LD_BATCH * sizeof(lockdebug_t), KM_SLEEP);
427 		lockdebug_lock(&ld_free_lk);
428 
429 		if (block == NULL)
430 			return;
431 
432 		if (ld_nfree > LD_SLOP) {
433 			/* Somebody beat us to it. */
434 			lockdebug_unlock(&ld_free_lk);
435 			kmem_free(block, LD_BATCH * sizeof(lockdebug_t));
436 			lockdebug_lock(&ld_free_lk);
437 			continue;
438 		}
439 
440 		base = ld_freeptr;
441 		ld_nfree += LD_BATCH;
442 		ld = block;
443 		base <<= LD_BATCH_SHIFT;
444 		m = min(LD_MAX_LOCKS, base + LD_BATCH);
445 
446 		if (m == LD_MAX_LOCKS)
447 			ld_nomore = true;
448 
449 		for (i = base; i < m; i++, ld++) {
450 			TAILQ_INSERT_TAIL(&ld_free, ld, ld_chain);
451 			TAILQ_INSERT_TAIL(&ld_all, ld, ld_achain);
452 		}
453 
454 		membar_producer();
455 		ld_table[ld_freeptr++] = block;
456 	}
457 }
458 
459 /*
460  * lockdebug_wantlock:
461  *
462  *	Process the preamble to a lock acquire.
463  */
464 void
465 lockdebug_wantlock(volatile void *lock, uintptr_t where, int shared)
466 {
467 	struct lwp *l = curlwp;
468 	lockdebuglk_t *lk;
469 	lockdebug_t *ld;
470 	bool recurse;
471 
472 	(void)shared;
473 	recurse = false;
474 
475 	if (panicstr != NULL)
476 		return;
477 
478 	if ((ld = lockdebug_lookup(lock, &lk)) == NULL)
479 		return;
480 
481 	if ((ld->ld_flags & LD_LOCKED) != 0) {
482 		if ((ld->ld_flags & LD_SLEEPER) != 0) {
483 			if (ld->ld_lwp == l)
484 				recurse = true;
485 		} else if (ld->ld_cpu == (uint16_t)cpu_number())
486 			recurse = true;
487 	}
488 
489 	if (cpu_intr_p()) {
490 		if ((ld->ld_flags & LD_SLEEPER) != 0)
491 			lockdebug_abort1(ld, lk, __func__,
492 			    "acquiring sleep lock from interrupt context",
493 			    true);
494 	}
495 
496 	if (shared)
497 		ld->ld_shwant++;
498 	else
499 		ld->ld_exwant++;
500 
501 	if (recurse)
502 		lockdebug_abort1(ld, lk, __func__, "locking against myself",
503 		    true);
504 
505 	lockdebug_unlock(lk);
506 }
507 
508 /*
509  * lockdebug_locked:
510  *
511  *	Process a lock acquire operation.
512  */
513 void
514 lockdebug_locked(volatile void *lock, uintptr_t where, int shared)
515 {
516 	struct lwp *l = curlwp;
517 	lockdebuglk_t *lk;
518 	lockdebug_t *ld;
519 
520 	if (panicstr != NULL)
521 		return;
522 
523 	if ((ld = lockdebug_lookup(lock, &lk)) == NULL)
524 		return;
525 
526 	if (shared) {
527 		l->l_shlocks++;
528 		ld->ld_shares++;
529 		ld->ld_shwant--;
530 	} else {
531 		if ((ld->ld_flags & LD_LOCKED) != 0)
532 			lockdebug_abort1(ld, lk, __func__,
533 			    "already locked", true);
534 
535 		ld->ld_flags |= LD_LOCKED;
536 		ld->ld_locked = where;
537 		ld->ld_cpu = (uint16_t)cpu_number();
538 		ld->ld_lwp = l;
539 		ld->ld_exwant--;
540 
541 		if ((ld->ld_flags & LD_SLEEPER) != 0) {
542 			l->l_exlocks++;
543 			TAILQ_INSERT_TAIL(&ld_sleepers, ld, ld_chain);
544 		} else {
545 			curcpu()->ci_spin_locks2++;
546 			TAILQ_INSERT_TAIL(&ld_spinners, ld, ld_chain);
547 		}
548 	}
549 
550 	lockdebug_unlock(lk);
551 }
552 
553 /*
554  * lockdebug_unlocked:
555  *
556  *	Process a lock release operation.
557  */
558 void
559 lockdebug_unlocked(volatile void *lock, uintptr_t where, int shared)
560 {
561 	struct lwp *l = curlwp;
562 	lockdebuglk_t *lk;
563 	lockdebug_t *ld;
564 
565 	if (panicstr != NULL)
566 		return;
567 
568 	if ((ld = lockdebug_lookup(lock, &lk)) == NULL)
569 		return;
570 
571 	if (shared) {
572 		if (l->l_shlocks == 0)
573 			lockdebug_abort1(ld, lk, __func__,
574 			    "no shared locks held by LWP", true);
575 		if (ld->ld_shares == 0)
576 			lockdebug_abort1(ld, lk, __func__,
577 			    "no shared holds on this lock", true);
578 		l->l_shlocks--;
579 		ld->ld_shares--;
580 	} else {
581 		if ((ld->ld_flags & LD_LOCKED) == 0)
582 			lockdebug_abort1(ld, lk, __func__, "not locked",
583 			    true);
584 
585 		if ((ld->ld_flags & LD_SLEEPER) != 0) {
586 			if (ld->ld_lwp != curlwp)
587 				lockdebug_abort1(ld, lk, __func__,
588 				    "not held by current LWP", true);
589 			ld->ld_flags &= ~LD_LOCKED;
590 			ld->ld_unlocked = where;
591 			ld->ld_lwp = NULL;
592 			curlwp->l_exlocks--;
593 			TAILQ_REMOVE(&ld_sleepers, ld, ld_chain);
594 		} else {
595 			if (ld->ld_cpu != (uint16_t)cpu_number())
596 				lockdebug_abort1(ld, lk, __func__,
597 				    "not held by current CPU", true);
598 			ld->ld_flags &= ~LD_LOCKED;
599 			ld->ld_unlocked = where;
600 			ld->ld_lwp = NULL;
601 			curcpu()->ci_spin_locks2--;
602 			TAILQ_REMOVE(&ld_spinners, ld, ld_chain);
603 		}
604 	}
605 
606 	lockdebug_unlock(lk);
607 }
608 
609 /*
610  * lockdebug_barrier:
611  *
612  *	Panic if we hold more than one specified spin lock, and optionally,
613  *	if we hold sleep locks.
614  */
615 void
616 lockdebug_barrier(volatile void *spinlock, int slplocks)
617 {
618 	struct lwp *l = curlwp;
619 	lockdebug_t *ld;
620 	uint16_t cpuno;
621 	int s;
622 
623 	if (panicstr != NULL)
624 		return;
625 
626 	crit_enter();
627 
628 	if (curcpu()->ci_spin_locks2 != 0) {
629 		cpuno = (uint16_t)cpu_number();
630 
631 		s = lockdebug_lock_rd(&ld_spinner_lk);
632 		TAILQ_FOREACH(ld, &ld_spinners, ld_chain) {
633 			if (ld->ld_lock == spinlock) {
634 				if (ld->ld_cpu != cpuno)
635 					lockdebug_abort1(ld, &ld_spinner_lk,
636 					    __func__,
637 					    "not held by current CPU", true);
638 				continue;
639 			}
640 			if (ld->ld_cpu == cpuno && (l->l_pflag & LP_INTR) == 0)
641 				lockdebug_abort1(ld, &ld_spinner_lk,
642 				    __func__, "spin lock held", true);
643 		}
644 		lockdebug_unlock_rd(&ld_spinner_lk, s);
645 	}
646 
647 	if (!slplocks) {
648 		if (l->l_exlocks != 0) {
649 			s = lockdebug_lock_rd(&ld_sleeper_lk);
650 			TAILQ_FOREACH(ld, &ld_sleepers, ld_chain) {
651 				if (ld->ld_lwp == l)
652 					lockdebug_abort1(ld, &ld_sleeper_lk,
653 					    __func__, "sleep lock held", true);
654 			}
655 			lockdebug_unlock_rd(&ld_sleeper_lk, s);
656 		}
657 		if (l->l_shlocks != 0)
658 			panic("lockdebug_barrier: holding %d shared locks",
659 			    l->l_shlocks);
660 	}
661 
662 	crit_exit();
663 }
664 
665 /*
666  * lockdebug_mem_check:
667  *
668  *	Check for in-use locks within a memory region that is
669  *	being freed.
670  */
671 void
672 lockdebug_mem_check(const char *func, void *base, size_t sz)
673 {
674 	lockdebug_t *ld;
675 	lockdebuglk_t *lk;
676 	int s;
677 
678 	if (panicstr != NULL)
679 		return;
680 
681 	s = lockdebug_lock_rd(&ld_tree_lk);
682 	ld = (lockdebug_t *)rb_tree_find_node_geq(&ld_rb_tree, base);
683 	if (ld != NULL) {
684 		const uintptr_t lock = (uintptr_t)ld->ld_lock;
685 
686 		if ((uintptr_t)base > lock)
687 			panic("%s: corrupt tree ld=%p, base=%p, sz=%zu",
688 			    __func__, ld, base, sz);
689 		if (lock >= (uintptr_t)base + sz)
690 			ld = NULL;
691 	}
692 	lockdebug_unlock_rd(&ld_tree_lk, s);
693 	if (ld == NULL)
694 		return;
695 
696 	if ((ld->ld_flags & LD_SLEEPER) != 0)
697 		lk = &ld_sleeper_lk;
698 	else
699 		lk = &ld_spinner_lk;
700 
701 	lockdebug_lock(lk);
702 	lockdebug_abort1(ld, lk, func,
703 	    "allocation contains active lock", !cold);
704 	return;
705 }
706 
707 /*
708  * lockdebug_dump:
709  *
710  *	Dump information about a lock on panic, or for DDB.
711  */
712 static void
713 lockdebug_dump(lockdebug_t *ld, void (*pr)(const char *, ...))
714 {
715 	int sleeper = (ld->ld_flags & LD_SLEEPER);
716 
717 	(*pr)(
718 	    "lock address : %#018lx type     : %18s\n"
719 	    "shared holds : %18u exclusive: %18u\n"
720 	    "shares wanted: %18u exclusive: %18u\n"
721 	    "current cpu  : %18u last held: %18u\n"
722 	    "current lwp  : %#018lx last held: %#018lx\n"
723 	    "last locked  : %#018lx unlocked : %#018lx\n"
724 	    "initialized  : %#018lx\n",
725 	    (long)ld->ld_lock, (sleeper ? "sleep/adaptive" : "spin"),
726 	    (unsigned)ld->ld_shares, ((ld->ld_flags & LD_LOCKED) != 0),
727 	    (unsigned)ld->ld_shwant, (unsigned)ld->ld_exwant,
728 	    (unsigned)cpu_number(), (unsigned)ld->ld_cpu,
729 	    (long)curlwp, (long)ld->ld_lwp,
730 	    (long)ld->ld_locked, (long)ld->ld_unlocked,
731 	    (long)ld->ld_initaddr);
732 
733 	if (ld->ld_lockops->lo_dump != NULL)
734 		(*ld->ld_lockops->lo_dump)(ld->ld_lock);
735 
736 	if (sleeper) {
737 		(*pr)("\n");
738 		turnstile_print(ld->ld_lock, pr);
739 	}
740 }
741 
742 /*
743  * lockdebug_dump:
744  *
745  *	Dump information about a known lock.
746  */
747 static void
748 lockdebug_abort1(lockdebug_t *ld, lockdebuglk_t *lk, const char *func,
749 		 const char *msg, bool dopanic)
750 {
751 
752 	printf_nolog("%s error: %s: %s\n\n", ld->ld_lockops->lo_name,
753 	    func, msg);
754 	lockdebug_dump(ld, printf_nolog);
755 	lockdebug_unlock(lk);
756 	printf_nolog("\n");
757 	if (dopanic)
758 		panic("LOCKDEBUG");
759 }
760 
761 #endif	/* LOCKDEBUG */
762 
763 /*
764  * lockdebug_lock_print:
765  *
766  *	Handle the DDB 'show lock' command.
767  */
768 #ifdef DDB
769 void
770 lockdebug_lock_print(void *addr, void (*pr)(const char *, ...))
771 {
772 #ifdef LOCKDEBUG
773 	lockdebug_t *ld;
774 
775 	TAILQ_FOREACH(ld, &ld_all, ld_achain) {
776 		if (ld->ld_lock == addr) {
777 			lockdebug_dump(ld, pr);
778 			return;
779 		}
780 	}
781 	(*pr)("Sorry, no record of a lock with address %p found.\n", addr);
782 #else
783 	(*pr)("Sorry, kernel not built with the LOCKDEBUG option.\n");
784 #endif	/* LOCKDEBUG */
785 }
786 #endif	/* DDB */
787 
788 /*
789  * lockdebug_abort:
790  *
791  *	An error has been trapped - dump lock info and call panic().
792  */
793 void
794 lockdebug_abort(volatile void *lock, lockops_t *ops, const char *func,
795 		const char *msg)
796 {
797 #ifdef LOCKDEBUG
798 	lockdebug_t *ld;
799 	lockdebuglk_t *lk;
800 
801 	if ((ld = lockdebug_lookup(lock, &lk)) != NULL) {
802 		lockdebug_abort1(ld, lk, func, msg, true);
803 		/* NOTREACHED */
804 	}
805 #endif	/* LOCKDEBUG */
806 
807 	printf_nolog("%s error: %s: %s\n\n"
808 	    "lock address : %#018lx\n"
809 	    "current cpu  : %18d\n"
810 	    "current lwp  : %#018lx\n",
811 	    ops->lo_name, func, msg, (long)lock, (int)cpu_number(),
812 	    (long)curlwp);
813 
814 	(*ops->lo_dump)(lock);
815 
816 	printf_nolog("\n");
817 	panic("lock error");
818 }
819