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subr_lockdebug.c revision 1.10.2.3
      1 /*	$NetBSD: subr_lockdebug.c,v 1.10.2.3 2007/11/22 15:18:24 bouyer 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 1.10.2.3 2007/11/22 15:18:24 bouyer Exp $");
     45 
     46 #include "opt_multiprocessor.h"
     47 #include "opt_ddb.h"
     48 
     49 #include <sys/param.h>
     50 #include <sys/proc.h>
     51 #include <sys/systm.h>
     52 #include <sys/kernel.h>
     53 #include <sys/kmem.h>
     54 #include <sys/lock.h>
     55 #include <sys/lockdebug.h>
     56 #include <sys/sleepq.h>
     57 #include <sys/cpu.h>
     58 
     59 #include <lib/libkern/rb.h>
     60 
     61 #ifdef LOCKDEBUG
     62 
     63 #define	LD_BATCH_SHIFT	9
     64 #define	LD_BATCH	(1 << LD_BATCH_SHIFT)
     65 #define	LD_BATCH_MASK	(LD_BATCH - 1)
     66 #define	LD_MAX_LOCKS	1048576
     67 #define	LD_SLOP		16
     68 
     69 #define	LD_LOCKED	0x01
     70 #define	LD_SLEEPER	0x02
     71 
     72 typedef union lockdebuglk {
     73 	struct {
     74 		__cpu_simple_lock_t	lku_lock;
     75 		int			lku_oldspl;
     76 	} ul;
     77 	uint8_t	lk_pad[64];
     78 } volatile __aligned(64) lockdebuglk_t;
     79 
     80 #define	lk_lock		ul.lku_lock
     81 #define	lk_oldspl	ul.lku_oldspl
     82 
     83 typedef struct lockdebug {
     84 	struct rb_node	ld_rb_node;	/* must be the first member */
     85 	_TAILQ_ENTRY(struct lockdebug, volatile) ld_chain;
     86 	_TAILQ_ENTRY(struct lockdebug, volatile) ld_achain;
     87 	volatile void	*ld_lock;
     88 	lockops_t	*ld_lockops;
     89 	struct lwp	*ld_lwp;
     90 	uintptr_t	ld_locked;
     91 	uintptr_t	ld_unlocked;
     92 	uintptr_t	ld_initaddr;
     93 	uint16_t	ld_shares;
     94 	uint16_t	ld_cpu;
     95 	uint8_t		ld_flags;
     96 	uint8_t		ld_shwant;	/* advisory */
     97 	uint8_t		ld_exwant;	/* advisory */
     98 	uint8_t		ld_unused;
     99 } volatile lockdebug_t;
    100 
    101 typedef _TAILQ_HEAD(lockdebuglist, struct lockdebug, volatile) lockdebuglist_t;
    102 
    103 lockdebuglk_t		ld_tree_lk;
    104 lockdebuglk_t		ld_sleeper_lk;
    105 lockdebuglk_t		ld_spinner_lk;
    106 lockdebuglk_t		ld_free_lk;
    107 
    108 lockdebuglist_t		ld_sleepers = TAILQ_HEAD_INITIALIZER(ld_sleepers);
    109 lockdebuglist_t		ld_spinners = TAILQ_HEAD_INITIALIZER(ld_spinners);
    110 lockdebuglist_t		ld_free = TAILQ_HEAD_INITIALIZER(ld_free);
    111 lockdebuglist_t		ld_all = TAILQ_HEAD_INITIALIZER(ld_all);
    112 int			ld_nfree;
    113 int			ld_freeptr;
    114 int			ld_recurse;
    115 bool			ld_nomore;
    116 lockdebug_t		*ld_table[LD_MAX_LOCKS / LD_BATCH];
    117 
    118 lockdebug_t		ld_prime[LD_BATCH];
    119 
    120 static void	lockdebug_abort1(lockdebug_t *, lockdebuglk_t *lk,
    121 				 const char *, const char *, bool);
    122 static void	lockdebug_more(void);
    123 static void	lockdebug_init(void);
    124 
    125 static signed int
    126 ld_rb_compare_nodes(const struct rb_node *n1, const struct rb_node *n2)
    127 {
    128 	const lockdebug_t *ld1 = (const void *)n1;
    129 	const lockdebug_t *ld2 = (const void *)n2;
    130 	const uintptr_t a = (uintptr_t)ld1->ld_lock;
    131 	const uintptr_t b = (uintptr_t)ld2->ld_lock;
    132 
    133 	if (a < b)
    134 		return 1;
    135 	if (a > b)
    136 		return -1;
    137 	return 0;
    138 }
    139 
    140 static signed int
    141 ld_rb_compare_key(const struct rb_node *n, const void *key)
    142 {
    143 	const lockdebug_t *ld = (const void *)n;
    144 	const uintptr_t a = (uintptr_t)ld->ld_lock;
    145 	const uintptr_t b = (uintptr_t)key;
    146 
    147 	if (a < b)
    148 		return 1;
    149 	if (a > b)
    150 		return -1;
    151 	return 0;
    152 }
    153 
    154 static struct rb_tree ld_rb_tree;
    155 
    156 static const struct rb_tree_ops ld_rb_tree_ops = {
    157 	.rb_compare_nodes = ld_rb_compare_nodes,
    158 	.rb_compare_key = ld_rb_compare_key,
    159 };
    160 
    161 static inline void
    162 lockdebug_lock(lockdebuglk_t *lk)
    163 {
    164 	int s;
    165 
    166 	s = splhigh();
    167 	__cpu_simple_lock(&lk->lk_lock);
    168 	lk->lk_oldspl = s;
    169 }
    170 
    171 static inline void
    172 lockdebug_unlock(lockdebuglk_t *lk)
    173 {
    174 	int s;
    175 
    176 	s = lk->lk_oldspl;
    177 	__cpu_simple_unlock(&(lk->lk_lock));
    178 	splx(s);
    179 }
    180 
    181 static inline lockdebug_t *
    182 lockdebug_lookup1(volatile void *lock, lockdebuglk_t **lk)
    183 {
    184 	lockdebug_t *ld;
    185 
    186 	lockdebug_lock(&ld_tree_lk);
    187 	ld = (lockdebug_t *)rb_tree_find_node(&ld_rb_tree, __UNVOLATILE(lock));
    188 	lockdebug_unlock(&ld_tree_lk);
    189 	if (ld == NULL)
    190 		return NULL;
    191 
    192 	if ((ld->ld_flags & LD_SLEEPER) != 0)
    193 		*lk = &ld_sleeper_lk;
    194 	else
    195 		*lk = &ld_spinner_lk;
    196 
    197 	lockdebug_lock(*lk);
    198 	return ld;
    199 }
    200 
    201 /*
    202  * lockdebug_lookup:
    203  *
    204  *	Find a lockdebug structure by a pointer to a lock and return it locked.
    205  */
    206 static inline lockdebug_t *
    207 lockdebug_lookup(volatile void *lock, lockdebuglk_t **lk)
    208 {
    209 	lockdebug_t *ld;
    210 
    211 	ld = lockdebug_lookup1(lock, lk);
    212 	if (ld == NULL)
    213 		panic("lockdebug_lookup: uninitialized lock (lock=%p)", lock);
    214 	return ld;
    215 }
    216 
    217 /*
    218  * lockdebug_init:
    219  *
    220  *	Initialize the lockdebug system.  Allocate an initial pool of
    221  *	lockdebug structures before the VM system is up and running.
    222  */
    223 static void
    224 lockdebug_init(void)
    225 {
    226 	lockdebug_t *ld;
    227 	int i;
    228 
    229 	__cpu_simple_lock_init(&ld_tree_lk.lk_lock);
    230 	__cpu_simple_lock_init(&ld_sleeper_lk.lk_lock);
    231 	__cpu_simple_lock_init(&ld_spinner_lk.lk_lock);
    232 	__cpu_simple_lock_init(&ld_free_lk.lk_lock);
    233 
    234 	rb_tree_init(&ld_rb_tree, &ld_rb_tree_ops);
    235 
    236 	ld = ld_prime;
    237 	ld_table[0] = ld;
    238 	for (i = 1, ld++; i < LD_BATCH; i++, ld++) {
    239 		TAILQ_INSERT_TAIL(&ld_free, ld, ld_chain);
    240 		TAILQ_INSERT_TAIL(&ld_all, ld, ld_achain);
    241 	}
    242 	ld_freeptr = 1;
    243 	ld_nfree = LD_BATCH - 1;
    244 }
    245 
    246 /*
    247  * lockdebug_alloc:
    248  *
    249  *	A lock is being initialized, so allocate an associated debug
    250  *	structure.
    251  */
    252 bool
    253 lockdebug_alloc(volatile void *lock, lockops_t *lo, uintptr_t initaddr)
    254 {
    255 	struct cpu_info *ci;
    256 	lockdebug_t *ld;
    257 	lockdebuglk_t *lk;
    258 
    259 	if (lo == NULL || panicstr != NULL)
    260 		return false;
    261 	if (ld_freeptr == 0)
    262 		lockdebug_init();
    263 
    264 	if ((ld = lockdebug_lookup1(lock, &lk)) != NULL) {
    265 		lockdebug_abort1(ld, lk, __func__, "already initialized", true);
    266 		/* NOTREACHED */
    267 	}
    268 
    269 	ci = curcpu();
    270 
    271 	/*
    272 	 * Pinch a new debug structure.  We may recurse because we call
    273 	 * kmem_alloc(), which may need to initialize new locks somewhere
    274 	 * down the path.  If not recursing, we try to maintain at least
    275 	 * LD_SLOP structures free, which should hopefully be enough to
    276 	 * satisfy kmem_alloc().  If we can't provide a structure, not to
    277 	 * worry: we'll just mark the lock as not having an ID.
    278 	 */
    279 	lockdebug_lock(&ld_free_lk);
    280 	ci->ci_lkdebug_recurse++;
    281 
    282 	if (TAILQ_EMPTY(&ld_free)) {
    283 		if (ci->ci_lkdebug_recurse > 1 || ld_nomore) {
    284 			ci->ci_lkdebug_recurse--;
    285 			lockdebug_unlock(&ld_free_lk);
    286 			return false;
    287 		}
    288 		lockdebug_more();
    289 	} else if (ci->ci_lkdebug_recurse == 1 && ld_nfree < LD_SLOP)
    290 		lockdebug_more();
    291 
    292 	if ((ld = TAILQ_FIRST(&ld_free)) == NULL) {
    293 		lockdebug_unlock(&ld_free_lk);
    294 		return false;
    295 	}
    296 
    297 	TAILQ_REMOVE(&ld_free, ld, ld_chain);
    298 	ld_nfree--;
    299 
    300 	ci->ci_lkdebug_recurse--;
    301 	lockdebug_unlock(&ld_free_lk);
    302 
    303 	if (ld->ld_lock != NULL)
    304 		panic("lockdebug_alloc: corrupt table");
    305 
    306 	if (lo->lo_sleeplock)
    307 		lockdebug_lock(&ld_sleeper_lk);
    308 	else
    309 		lockdebug_lock(&ld_spinner_lk);
    310 
    311 	/* Initialise the structure. */
    312 	ld->ld_lock = lock;
    313 	ld->ld_lockops = lo;
    314 	ld->ld_locked = 0;
    315 	ld->ld_unlocked = 0;
    316 	ld->ld_lwp = NULL;
    317 	ld->ld_initaddr = initaddr;
    318 
    319 	lockdebug_lock(&ld_tree_lk);
    320 	rb_tree_insert_node(&ld_rb_tree, __UNVOLATILE(&ld->ld_rb_node));
    321 	lockdebug_unlock(&ld_tree_lk);
    322 
    323 	if (lo->lo_sleeplock) {
    324 		ld->ld_flags = LD_SLEEPER;
    325 		lockdebug_unlock(&ld_sleeper_lk);
    326 	} else {
    327 		ld->ld_flags = 0;
    328 		lockdebug_unlock(&ld_spinner_lk);
    329 	}
    330 
    331 	return true;
    332 }
    333 
    334 /*
    335  * lockdebug_free:
    336  *
    337  *	A lock is being destroyed, so release debugging resources.
    338  */
    339 void
    340 lockdebug_free(volatile void *lock)
    341 {
    342 	lockdebug_t *ld;
    343 	lockdebuglk_t *lk;
    344 
    345 	if (panicstr != NULL)
    346 		return;
    347 
    348 	ld = lockdebug_lookup(lock, &lk);
    349 	if (ld == NULL) {
    350 		panic("lockdebug_free: destroying uninitialized lock %p"
    351 		    "(ld_lock=%p)", lock, ld->ld_lock);
    352 		lockdebug_abort1(ld, lk, __func__, "lock record follows",
    353 		    true);
    354 	}
    355 	if ((ld->ld_flags & LD_LOCKED) != 0 || ld->ld_shares != 0)
    356 		lockdebug_abort1(ld, lk, __func__, "is locked", true);
    357 	lockdebug_lock(&ld_tree_lk);
    358 	rb_tree_remove_node(&ld_rb_tree, __UNVOLATILE(&ld->ld_rb_node));
    359 	lockdebug_unlock(&ld_tree_lk);
    360 	ld->ld_lock = NULL;
    361 	lockdebug_unlock(lk);
    362 
    363 	lockdebug_lock(&ld_free_lk);
    364 	TAILQ_INSERT_TAIL(&ld_free, ld, ld_chain);
    365 	ld_nfree++;
    366 	lockdebug_unlock(&ld_free_lk);
    367 }
    368 
    369 /*
    370  * lockdebug_more:
    371  *
    372  *	Allocate a batch of debug structures and add to the free list.
    373  *	Must be called with ld_free_lk held.
    374  */
    375 static void
    376 lockdebug_more(void)
    377 {
    378 	lockdebug_t *ld;
    379 	void *block;
    380 	int i, base, m;
    381 
    382 	while (ld_nfree < LD_SLOP) {
    383 		lockdebug_unlock(&ld_free_lk);
    384 		block = kmem_zalloc(LD_BATCH * sizeof(lockdebug_t), KM_SLEEP);
    385 		lockdebug_lock(&ld_free_lk);
    386 
    387 		if (block == NULL)
    388 			return;
    389 
    390 		if (ld_nfree > LD_SLOP) {
    391 			/* Somebody beat us to it. */
    392 			lockdebug_unlock(&ld_free_lk);
    393 			kmem_free(block, LD_BATCH * sizeof(lockdebug_t));
    394 			lockdebug_lock(&ld_free_lk);
    395 			continue;
    396 		}
    397 
    398 		base = ld_freeptr;
    399 		ld_nfree += LD_BATCH;
    400 		ld = block;
    401 		base <<= LD_BATCH_SHIFT;
    402 		m = min(LD_MAX_LOCKS, base + LD_BATCH);
    403 
    404 		if (m == LD_MAX_LOCKS)
    405 			ld_nomore = true;
    406 
    407 		for (i = base; i < m; i++, ld++) {
    408 			TAILQ_INSERT_TAIL(&ld_free, ld, ld_chain);
    409 			TAILQ_INSERT_TAIL(&ld_all, ld, ld_achain);
    410 		}
    411 
    412 		mb_write();
    413 		ld_table[ld_freeptr++] = block;
    414 	}
    415 }
    416 
    417 /*
    418  * lockdebug_wantlock:
    419  *
    420  *	Process the preamble to a lock acquire.
    421  */
    422 void
    423 lockdebug_wantlock(volatile void *lock, uintptr_t where, int shared)
    424 {
    425 	struct lwp *l = curlwp;
    426 	lockdebuglk_t *lk;
    427 	lockdebug_t *ld;
    428 	bool recurse;
    429 
    430 	(void)shared;
    431 	recurse = false;
    432 
    433 	if (panicstr != NULL)
    434 		return;
    435 
    436 	if ((ld = lockdebug_lookup(lock, &lk)) == NULL)
    437 		return;
    438 
    439 	if ((ld->ld_flags & LD_LOCKED) != 0) {
    440 		if ((ld->ld_flags & LD_SLEEPER) != 0) {
    441 			if (ld->ld_lwp == l)
    442 				recurse = true;
    443 		} else if (ld->ld_cpu == (uint16_t)cpu_number())
    444 			recurse = true;
    445 	}
    446 
    447 #ifdef notyet
    448 	if (cpu_intr_p()) {
    449 		if ((ld->ld_flags & LD_SLEEPER) != 0)
    450 			lockdebug_abort1(ld, lk, __func__,
    451 			    "acquiring sleep lock from interrupt context",
    452 			    true);
    453 	}
    454 #endif
    455 
    456 	if (shared)
    457 		ld->ld_shwant++;
    458 	else
    459 		ld->ld_exwant++;
    460 
    461 	if (recurse)
    462 		lockdebug_abort1(ld, lk, __func__, "locking against myself",
    463 		    true);
    464 
    465 	lockdebug_unlock(lk);
    466 }
    467 
    468 /*
    469  * lockdebug_locked:
    470  *
    471  *	Process a lock acquire operation.
    472  */
    473 void
    474 lockdebug_locked(volatile void *lock, uintptr_t where, int shared)
    475 {
    476 	struct lwp *l = curlwp;
    477 	lockdebuglk_t *lk;
    478 	lockdebug_t *ld;
    479 
    480 	if (panicstr != NULL)
    481 		return;
    482 
    483 	if ((ld = lockdebug_lookup(lock, &lk)) == NULL)
    484 		return;
    485 
    486 	if (shared) {
    487 		l->l_shlocks++;
    488 		ld->ld_shares++;
    489 		ld->ld_shwant--;
    490 	} else {
    491 		if ((ld->ld_flags & LD_LOCKED) != 0)
    492 			lockdebug_abort1(ld, lk, __func__,
    493 			    "already locked", true);
    494 
    495 		ld->ld_flags |= LD_LOCKED;
    496 		ld->ld_locked = where;
    497 		ld->ld_cpu = (uint16_t)cpu_number();
    498 		ld->ld_lwp = l;
    499 		ld->ld_exwant--;
    500 
    501 		if ((ld->ld_flags & LD_SLEEPER) != 0) {
    502 			l->l_exlocks++;
    503 			TAILQ_INSERT_TAIL(&ld_sleepers, ld, ld_chain);
    504 		} else {
    505 			curcpu()->ci_spin_locks2++;
    506 			TAILQ_INSERT_TAIL(&ld_spinners, ld, ld_chain);
    507 		}
    508 	}
    509 
    510 	lockdebug_unlock(lk);
    511 }
    512 
    513 /*
    514  * lockdebug_unlocked:
    515  *
    516  *	Process a lock release operation.
    517  */
    518 void
    519 lockdebug_unlocked(volatile void *lock, uintptr_t where, int shared)
    520 {
    521 	struct lwp *l = curlwp;
    522 	lockdebuglk_t *lk;
    523 	lockdebug_t *ld;
    524 
    525 	if (panicstr != NULL)
    526 		return;
    527 
    528 	if ((ld = lockdebug_lookup(lock, &lk)) == NULL)
    529 		return;
    530 
    531 	if (shared) {
    532 		if (l->l_shlocks == 0)
    533 			lockdebug_abort1(ld, lk, __func__,
    534 			    "no shared locks held by LWP", true);
    535 		if (ld->ld_shares == 0)
    536 			lockdebug_abort1(ld, lk, __func__,
    537 			    "no shared holds on this lock", true);
    538 		l->l_shlocks--;
    539 		ld->ld_shares--;
    540 	} else {
    541 		if ((ld->ld_flags & LD_LOCKED) == 0)
    542 			lockdebug_abort1(ld, lk, __func__, "not locked",
    543 			    true);
    544 
    545 		if ((ld->ld_flags & LD_SLEEPER) != 0) {
    546 			if (ld->ld_lwp != curlwp)
    547 				lockdebug_abort1(ld, lk, __func__,
    548 				    "not held by current LWP", true);
    549 			ld->ld_flags &= ~LD_LOCKED;
    550 			ld->ld_unlocked = where;
    551 			ld->ld_lwp = NULL;
    552 			curlwp->l_exlocks--;
    553 			TAILQ_REMOVE(&ld_sleepers, ld, ld_chain);
    554 		} else {
    555 			if (ld->ld_cpu != (uint16_t)cpu_number())
    556 				lockdebug_abort1(ld, lk, __func__,
    557 				    "not held by current CPU", true);
    558 			ld->ld_flags &= ~LD_LOCKED;
    559 			ld->ld_unlocked = where;
    560 			ld->ld_lwp = NULL;
    561 			curcpu()->ci_spin_locks2--;
    562 			TAILQ_REMOVE(&ld_spinners, ld, ld_chain);
    563 		}
    564 	}
    565 
    566 	lockdebug_unlock(lk);
    567 }
    568 
    569 /*
    570  * lockdebug_barrier:
    571  *
    572  *	Panic if we hold more than one specified spin lock, and optionally,
    573  *	if we hold sleep locks.
    574  */
    575 void
    576 lockdebug_barrier(volatile void *spinlock, int slplocks)
    577 {
    578 	struct lwp *l = curlwp;
    579 	lockdebug_t *ld;
    580 	uint16_t cpuno;
    581 
    582 	if (panicstr != NULL)
    583 		return;
    584 
    585 	if (curcpu()->ci_spin_locks2 != 0) {
    586 		cpuno = (uint16_t)cpu_number();
    587 
    588 		lockdebug_lock(&ld_spinner_lk);
    589 		TAILQ_FOREACH(ld, &ld_spinners, ld_chain) {
    590 			if (ld->ld_lock == spinlock) {
    591 				if (ld->ld_cpu != cpuno)
    592 					lockdebug_abort1(ld, &ld_spinner_lk,
    593 					    __func__,
    594 					    "not held by current CPU", true);
    595 				continue;
    596 			}
    597 			if (ld->ld_cpu == cpuno && (l->l_pflag & LP_INTR) == 0)
    598 				lockdebug_abort1(ld, &ld_spinner_lk,
    599 				    __func__, "spin lock held", true);
    600 		}
    601 		lockdebug_unlock(&ld_spinner_lk);
    602 	}
    603 
    604 	if (!slplocks) {
    605 		if (l->l_exlocks != 0) {
    606 			lockdebug_lock(&ld_sleeper_lk);
    607 			TAILQ_FOREACH(ld, &ld_sleepers, ld_chain) {
    608 				if (ld->ld_lwp == l)
    609 					lockdebug_abort1(ld, &ld_sleeper_lk,
    610 					    __func__, "sleep lock held", true);
    611 			}
    612 			lockdebug_unlock(&ld_sleeper_lk);
    613 		}
    614 		if (l->l_shlocks != 0)
    615 			panic("lockdebug_barrier: holding %d shared locks",
    616 			    l->l_shlocks);
    617 	}
    618 }
    619 
    620 /*
    621  * lockdebug_mem_check:
    622  *
    623  *	Check for in-use locks within a memory region that is
    624  *	being freed.
    625  */
    626 void
    627 lockdebug_mem_check(const char *func, void *base, size_t sz)
    628 {
    629 	lockdebug_t *ld;
    630 	lockdebuglk_t *lk;
    631 	uintptr_t lock;
    632 
    633 	lockdebug_lock(&ld_tree_lk);
    634 	ld = (lockdebug_t *)rb_tree_find_node_geq(&ld_rb_tree, base);
    635 	lockdebug_unlock(&ld_tree_lk);
    636 	if (ld == NULL)
    637 		return;
    638 
    639 	if ((ld->ld_flags & LD_SLEEPER) != 0)
    640 		lk = &ld_sleeper_lk;
    641 	else
    642 		lk = &ld_spinner_lk;
    643 
    644 	lockdebug_lock(lk);
    645 	lock = (uintptr_t)ld->ld_lock;
    646 	if ((uintptr_t)base <= lock && lock < (uintptr_t)base + sz) {
    647 		lockdebug_abort1(ld, lk, func,
    648 		    "allocation contains active lock", !cold);
    649 		return;
    650 	}
    651 	lockdebug_unlock(lk);
    652 }
    653 
    654 /*
    655  * lockdebug_dump:
    656  *
    657  *	Dump information about a lock on panic, or for DDB.
    658  */
    659 static void
    660 lockdebug_dump(lockdebug_t *ld, void (*pr)(const char *, ...))
    661 {
    662 	int sleeper = (ld->ld_flags & LD_SLEEPER);
    663 
    664 	(*pr)(
    665 	    "lock address : %#018lx type     : %18s\n"
    666 	    "shared holds : %18u exclusive: %18u\n"
    667 	    "shares wanted: %18u exclusive: %18u\n"
    668 	    "current cpu  : %18u last held: %18u\n"
    669 	    "current lwp  : %#018lx last held: %#018lx\n"
    670 	    "last locked  : %#018lx unlocked : %#018lx\n"
    671 	    "initialized  : %#018lx\n",
    672 	    (long)ld->ld_lock, (sleeper ? "sleep/adaptive" : "spin"),
    673 	    (unsigned)ld->ld_shares, ((ld->ld_flags & LD_LOCKED) != 0),
    674 	    (unsigned)ld->ld_shwant, (unsigned)ld->ld_exwant,
    675 	    (unsigned)cpu_number(), (unsigned)ld->ld_cpu,
    676 	    (long)curlwp, (long)ld->ld_lwp,
    677 	    (long)ld->ld_locked, (long)ld->ld_unlocked,
    678 	    (long)ld->ld_initaddr);
    679 
    680 	if (ld->ld_lockops->lo_dump != NULL)
    681 		(*ld->ld_lockops->lo_dump)(ld->ld_lock);
    682 
    683 	if (sleeper) {
    684 		(*pr)("\n");
    685 		turnstile_print(ld->ld_lock, pr);
    686 	}
    687 }
    688 
    689 /*
    690  * lockdebug_dump:
    691  *
    692  *	Dump information about a known lock.
    693  */
    694 static void
    695 lockdebug_abort1(lockdebug_t *ld, lockdebuglk_t *lk, const char *func,
    696 		 const char *msg, bool dopanic)
    697 {
    698 
    699 	printf_nolog("%s error: %s: %s\n\n", ld->ld_lockops->lo_name,
    700 	    func, msg);
    701 	lockdebug_dump(ld, printf_nolog);
    702 	lockdebug_unlock(lk);
    703 	printf_nolog("\n");
    704 	if (dopanic)
    705 		panic("LOCKDEBUG");
    706 }
    707 
    708 #endif	/* LOCKDEBUG */
    709 
    710 /*
    711  * lockdebug_lock_print:
    712  *
    713  *	Handle the DDB 'show lock' command.
    714  */
    715 #ifdef DDB
    716 void
    717 lockdebug_lock_print(void *addr, void (*pr)(const char *, ...))
    718 {
    719 #ifdef LOCKDEBUG
    720 	lockdebug_t *ld;
    721 
    722 	TAILQ_FOREACH(ld, &ld_all, ld_achain) {
    723 		if (ld->ld_lock == addr) {
    724 			lockdebug_dump(ld, pr);
    725 			return;
    726 		}
    727 	}
    728 	(*pr)("Sorry, no record of a lock with address %p found.\n", addr);
    729 #else
    730 	(*pr)("Sorry, kernel not built with the LOCKDEBUG option.\n");
    731 #endif	/* LOCKDEBUG */
    732 }
    733 #endif	/* DDB */
    734 
    735 /*
    736  * lockdebug_abort:
    737  *
    738  *	An error has been trapped - dump lock info and call panic().
    739  */
    740 void
    741 lockdebug_abort(volatile void *lock, lockops_t *ops, const char *func,
    742 		const char *msg)
    743 {
    744 #ifdef LOCKDEBUG
    745 	lockdebug_t *ld;
    746 	lockdebuglk_t *lk;
    747 
    748 	if ((ld = lockdebug_lookup(lock, &lk)) != NULL) {
    749 		lockdebug_abort1(ld, lk, func, msg, true);
    750 		/* NOTREACHED */
    751 	}
    752 #endif	/* LOCKDEBUG */
    753 
    754 	printf_nolog("%s error: %s: %s\n\n"
    755 	    "lock address : %#018lx\n"
    756 	    "current cpu  : %18d\n"
    757 	    "current lwp  : %#018lx\n",
    758 	    ops->lo_name, func, msg, (long)lock, (int)cpu_number(),
    759 	    (long)curlwp);
    760 
    761 	(*ops->lo_dump)(lock);
    762 
    763 	printf_nolog("\n");
    764 	panic("lock error");
    765 }
    766