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subr_lockdebug.c revision 1.10.2.1
      1 /*	$NetBSD: subr_lockdebug.c,v 1.10.2.1 2007/11/13 16:02:19 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 1.10.2.1 2007/11/13 16:02:19 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 #ifdef LOCKDEBUG
     60 
     61 #define	LD_BATCH_SHIFT	9
     62 #define	LD_BATCH	(1 << LD_BATCH_SHIFT)
     63 #define	LD_BATCH_MASK	(LD_BATCH - 1)
     64 #define	LD_MAX_LOCKS	1048576
     65 #define	LD_SLOP		16
     66 
     67 #define	LD_LOCKED	0x01
     68 #define	LD_SLEEPER	0x02
     69 #define	LD_MLOCKS	8
     70 #define	LD_MLISTS	8192
     71 
     72 #define	LD_NOID		(LD_MAX_LOCKS + 1)
     73 
     74 typedef union lockdebuglk {
     75 	struct {
     76 		__cpu_simple_lock_t	lku_lock;
     77 		int			lku_oldspl;
     78 	} ul;
     79 	uint8_t	lk_pad[64];
     80 } volatile __aligned(64) lockdebuglk_t;
     81 
     82 #define	lk_lock		ul.lku_lock
     83 #define	lk_oldspl	ul.lku_oldspl
     84 
     85 typedef struct lockdebug {
     86 	_TAILQ_ENTRY(struct lockdebug, volatile) ld_chain;
     87 	_TAILQ_ENTRY(struct lockdebug, volatile) ld_achain;
     88 	_TAILQ_ENTRY(struct lockdebug, volatile) ld_mchain;
     89 	volatile void	*ld_lock;
     90 	lockops_t	*ld_lockops;
     91 	struct lwp	*ld_lwp;
     92 	uintptr_t	ld_locked;
     93 	uintptr_t	ld_unlocked;
     94 	uintptr_t	ld_initaddr;
     95 	u_int		ld_id;
     96 	uint16_t	ld_shares;
     97 	uint16_t	ld_cpu;
     98 	uint8_t		ld_flags;
     99 	uint8_t		ld_shwant;	/* advisory */
    100 	uint8_t		ld_exwant;	/* advisory */
    101 	uint8_t		ld_unused;
    102 } volatile lockdebug_t;
    103 
    104 typedef _TAILQ_HEAD(lockdebuglist, struct lockdebug, volatile) lockdebuglist_t;
    105 
    106 lockdebuglk_t		ld_sleeper_lk;
    107 lockdebuglk_t		ld_spinner_lk;
    108 lockdebuglk_t		ld_free_lk;
    109 lockdebuglk_t		ld_mem_lk[LD_MLOCKS];
    110 
    111 lockdebuglist_t		ld_mem_list[LD_MLISTS];
    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 inline void
    130 lockdebug_lock(lockdebuglk_t *lk)
    131 {
    132 	int s;
    133 
    134 	s = splhigh();
    135 	__cpu_simple_lock(&lk->lk_lock);
    136 	lk->lk_oldspl = s;
    137 }
    138 
    139 static inline void
    140 lockdebug_unlock(lockdebuglk_t *lk)
    141 {
    142 	int s;
    143 
    144 	s = lk->lk_oldspl;
    145 	__cpu_simple_unlock(&(lk->lk_lock));
    146 	splx(s);
    147 }
    148 
    149 static inline void
    150 lockdebug_mhash(volatile void *addr, lockdebuglk_t **lk, lockdebuglist_t **head)
    151 {
    152 	u_int hash;
    153 
    154 	hash = (uintptr_t)addr >> PGSHIFT;
    155 	*lk = &ld_mem_lk[hash & (LD_MLOCKS - 1)];
    156 	*head = &ld_mem_list[hash & (LD_MLISTS - 1)];
    157 	lockdebug_lock(*lk);
    158 }
    159 
    160 /*
    161  * lockdebug_lookup:
    162  *
    163  *	Find a lockdebug structure by ID and return it locked.
    164  */
    165 static inline lockdebug_t *
    166 lockdebug_lookup(u_int id, lockdebuglk_t **lk)
    167 {
    168 	lockdebug_t *base, *ld;
    169 
    170 	if (id == LD_NOID)
    171 		return NULL;
    172 
    173 	if (id == 0 || id >= LD_MAX_LOCKS)
    174 		panic("lockdebug_lookup: uninitialized lock (1, id=%d)", id);
    175 
    176 	base = ld_table[id >> LD_BATCH_SHIFT];
    177 	ld = base + (id & LD_BATCH_MASK);
    178 
    179 	if (base == NULL || ld->ld_lock == NULL || ld->ld_id != id)
    180 		panic("lockdebug_lookup: uninitialized lock (2, id=%d)", id);
    181 
    182 	if ((ld->ld_flags & LD_SLEEPER) != 0)
    183 		*lk = &ld_sleeper_lk;
    184 	else
    185 		*lk = &ld_spinner_lk;
    186 
    187 	lockdebug_lock(*lk);
    188 	return ld;
    189 }
    190 
    191 /*
    192  * lockdebug_init:
    193  *
    194  *	Initialize the lockdebug system.  Allocate an initial pool of
    195  *	lockdebug structures before the VM system is up and running.
    196  */
    197 static void
    198 lockdebug_init(void)
    199 {
    200 	lockdebug_t *ld;
    201 	int i;
    202 
    203 	__cpu_simple_lock_init(&ld_sleeper_lk.lk_lock);
    204 	__cpu_simple_lock_init(&ld_spinner_lk.lk_lock);
    205 	__cpu_simple_lock_init(&ld_free_lk.lk_lock);
    206 
    207 	ld = ld_prime;
    208 	ld_table[0] = ld;
    209 	for (i = 1, ld++; i < LD_BATCH; i++, ld++) {
    210 		ld->ld_id = i;
    211 		TAILQ_INSERT_TAIL(&ld_free, ld, ld_chain);
    212 		TAILQ_INSERT_TAIL(&ld_all, ld, ld_achain);
    213 	}
    214 	ld_freeptr = 1;
    215 	ld_nfree = LD_BATCH - 1;
    216 
    217 	for (i = 0; i < LD_MLOCKS; i++)
    218 		__cpu_simple_lock_init(&ld_mem_lk[i].lk_lock);
    219 	for (i = 0; i < LD_MLISTS; i++)
    220 		TAILQ_INIT(&ld_mem_list[i]);
    221 }
    222 
    223 /*
    224  * lockdebug_alloc:
    225  *
    226  *	A lock is being initialized, so allocate an associated debug
    227  *	structure.
    228  */
    229 u_int
    230 lockdebug_alloc(volatile void *lock, lockops_t *lo, uintptr_t initaddr)
    231 {
    232 #if 0
    233 	lockdebuglist_t *head;
    234 	lockdebuglk_t *lk;
    235 #endif
    236 	struct cpu_info *ci;
    237 	lockdebug_t *ld;
    238 
    239 	if (lo == NULL || panicstr != NULL)
    240 		return LD_NOID;
    241 	if (ld_freeptr == 0)
    242 		lockdebug_init();
    243 
    244 	ci = curcpu();
    245 
    246 	/*
    247 	 * Pinch a new debug structure.  We may recurse because we call
    248 	 * kmem_alloc(), which may need to initialize new locks somewhere
    249 	 * down the path.  If not recursing, we try to maintain at least
    250 	 * LD_SLOP structures free, which should hopefully be enough to
    251 	 * satisfy kmem_alloc().  If we can't provide a structure, not to
    252 	 * worry: we'll just mark the lock as not having an ID.
    253 	 */
    254 	lockdebug_lock(&ld_free_lk);
    255 	ci->ci_lkdebug_recurse++;
    256 
    257 	if (TAILQ_EMPTY(&ld_free)) {
    258 		if (ci->ci_lkdebug_recurse > 1 || ld_nomore) {
    259 			ci->ci_lkdebug_recurse--;
    260 			lockdebug_unlock(&ld_free_lk);
    261 			return LD_NOID;
    262 		}
    263 		lockdebug_more();
    264 	} else if (ci->ci_lkdebug_recurse == 1 && ld_nfree < LD_SLOP)
    265 		lockdebug_more();
    266 
    267 	if ((ld = TAILQ_FIRST(&ld_free)) == NULL) {
    268 		lockdebug_unlock(&ld_free_lk);
    269 		return LD_NOID;
    270 	}
    271 
    272 	TAILQ_REMOVE(&ld_free, ld, ld_chain);
    273 	ld_nfree--;
    274 
    275 	ci->ci_lkdebug_recurse--;
    276 	lockdebug_unlock(&ld_free_lk);
    277 
    278 	if (ld->ld_lock != NULL)
    279 		panic("lockdebug_alloc: corrupt table");
    280 
    281 	if (lo->lo_sleeplock)
    282 		lockdebug_lock(&ld_sleeper_lk);
    283 	else
    284 		lockdebug_lock(&ld_spinner_lk);
    285 
    286 	/* Initialise the structure. */
    287 	ld->ld_lock = lock;
    288 	ld->ld_lockops = lo;
    289 	ld->ld_locked = 0;
    290 	ld->ld_unlocked = 0;
    291 	ld->ld_lwp = NULL;
    292 	ld->ld_initaddr = initaddr;
    293 
    294 	if (lo->lo_sleeplock) {
    295 		ld->ld_flags = LD_SLEEPER;
    296 		lockdebug_unlock(&ld_sleeper_lk);
    297 	} else {
    298 		ld->ld_flags = 0;
    299 		lockdebug_unlock(&ld_spinner_lk);
    300 	}
    301 
    302 #if 0
    303 	/* Insert into address hash. */
    304 	lockdebug_mhash(lock, &lk, &head);
    305 	TAILQ_INSERT_HEAD(head, ld, ld_mchain);
    306 	lockdebug_unlock(lk);
    307 #endif
    308 
    309 	return ld->ld_id;
    310 }
    311 
    312 /*
    313  * lockdebug_free:
    314  *
    315  *	A lock is being destroyed, so release debugging resources.
    316  */
    317 void
    318 lockdebug_free(volatile void *lock, u_int id)
    319 {
    320 #if 0
    321 	lockdebuglist_t *head;
    322 #endif
    323 	lockdebug_t *ld;
    324 	lockdebuglk_t *lk;
    325 
    326 	if (panicstr != NULL)
    327 		return;
    328 
    329 	if ((ld = lockdebug_lookup(id, &lk)) == NULL)
    330 		return;
    331 
    332 	if (ld->ld_lock != lock) {
    333 		panic("lockdebug_free: destroying uninitialized lock %p"
    334 		    "(ld_id=%d ld_lock=%p)", lock, id, ld->ld_lock);
    335 		lockdebug_abort1(ld, lk, __func__, "lock record follows",
    336 		    true);
    337 	}
    338 	if ((ld->ld_flags & LD_LOCKED) != 0 || ld->ld_shares != 0)
    339 		lockdebug_abort1(ld, lk, __func__, "is locked", true);
    340 
    341 	ld->ld_lock = NULL;
    342 
    343 	lockdebug_unlock(lk);
    344 
    345 	lockdebug_lock(&ld_free_lk);
    346 	TAILQ_INSERT_TAIL(&ld_free, ld, ld_chain);
    347 	ld_nfree++;
    348 	lockdebug_unlock(&ld_free_lk);
    349 
    350 #if 0
    351 	/* Remove from address hash. */
    352 	lockdebug_mhash(lock, &lk, &head);
    353 	TAILQ_REMOVE(head, ld, ld_mchain);
    354 	lockdebug_unlock(lk);
    355 #endif
    356 }
    357 
    358 /*
    359  * lockdebug_more:
    360  *
    361  *	Allocate a batch of debug structures and add to the free list.
    362  *	Must be called with ld_free_lk held.
    363  */
    364 static void
    365 lockdebug_more(void)
    366 {
    367 	lockdebug_t *ld;
    368 	void *block;
    369 	int i, base, m;
    370 
    371 	while (ld_nfree < LD_SLOP) {
    372 		lockdebug_unlock(&ld_free_lk);
    373 		block = kmem_zalloc(LD_BATCH * sizeof(lockdebug_t), KM_SLEEP);
    374 		lockdebug_lock(&ld_free_lk);
    375 
    376 		if (block == NULL)
    377 			return;
    378 
    379 		if (ld_nfree > LD_SLOP) {
    380 			/* Somebody beat us to it. */
    381 			lockdebug_unlock(&ld_free_lk);
    382 			kmem_free(block, LD_BATCH * sizeof(lockdebug_t));
    383 			lockdebug_lock(&ld_free_lk);
    384 			continue;
    385 		}
    386 
    387 		base = ld_freeptr;
    388 		ld_nfree += LD_BATCH;
    389 		ld = block;
    390 		base <<= LD_BATCH_SHIFT;
    391 		m = min(LD_MAX_LOCKS, base + LD_BATCH);
    392 
    393 		if (m == LD_MAX_LOCKS)
    394 			ld_nomore = true;
    395 
    396 		for (i = base; i < m; i++, ld++) {
    397 			ld->ld_id = i;
    398 			TAILQ_INSERT_TAIL(&ld_free, ld, ld_chain);
    399 			TAILQ_INSERT_TAIL(&ld_all, ld, ld_achain);
    400 		}
    401 
    402 		mb_write();
    403 		ld_table[ld_freeptr++] = block;
    404 	}
    405 }
    406 
    407 /*
    408  * lockdebug_wantlock:
    409  *
    410  *	Process the preamble to a lock acquire.
    411  */
    412 void
    413 lockdebug_wantlock(u_int id, uintptr_t where, int shared)
    414 {
    415 	struct lwp *l = curlwp;
    416 	lockdebuglk_t *lk;
    417 	lockdebug_t *ld;
    418 	bool recurse;
    419 
    420 	(void)shared;
    421 	recurse = false;
    422 
    423 	if (panicstr != NULL)
    424 		return;
    425 
    426 	if ((ld = lockdebug_lookup(id, &lk)) == NULL)
    427 		return;
    428 
    429 	if ((ld->ld_flags & LD_LOCKED) != 0) {
    430 		if ((ld->ld_flags & LD_SLEEPER) != 0) {
    431 			if (ld->ld_lwp == l)
    432 				recurse = true;
    433 		} else if (ld->ld_cpu == (uint16_t)cpu_number())
    434 			recurse = true;
    435 	}
    436 
    437 #ifdef notyet
    438 	if (cpu_intr_p()) {
    439 		if ((ld->ld_flags & LD_SLEEPER) != 0)
    440 			lockdebug_abort1(ld, lk, __func__,
    441 			    "acquiring sleep lock from interrupt context",
    442 			    true);
    443 	}
    444 #endif
    445 
    446 	if (shared)
    447 		ld->ld_shwant++;
    448 	else
    449 		ld->ld_exwant++;
    450 
    451 	if (recurse)
    452 		lockdebug_abort1(ld, lk, __func__, "locking against myself",
    453 		    true);
    454 
    455 	lockdebug_unlock(lk);
    456 }
    457 
    458 /*
    459  * lockdebug_locked:
    460  *
    461  *	Process a lock acquire operation.
    462  */
    463 void
    464 lockdebug_locked(u_int id, uintptr_t where, int shared)
    465 {
    466 	struct lwp *l = curlwp;
    467 	lockdebuglk_t *lk;
    468 	lockdebug_t *ld;
    469 
    470 	if (panicstr != NULL)
    471 		return;
    472 
    473 	if ((ld = lockdebug_lookup(id, &lk)) == NULL)
    474 		return;
    475 
    476 	if (shared) {
    477 		l->l_shlocks++;
    478 		ld->ld_shares++;
    479 		ld->ld_shwant--;
    480 	} else {
    481 		if ((ld->ld_flags & LD_LOCKED) != 0)
    482 			lockdebug_abort1(ld, lk, __func__,
    483 			    "already locked", true);
    484 
    485 		ld->ld_flags |= LD_LOCKED;
    486 		ld->ld_locked = where;
    487 		ld->ld_cpu = (uint16_t)cpu_number();
    488 		ld->ld_lwp = l;
    489 		ld->ld_exwant--;
    490 
    491 		if ((ld->ld_flags & LD_SLEEPER) != 0) {
    492 			l->l_exlocks++;
    493 			TAILQ_INSERT_TAIL(&ld_sleepers, ld, ld_chain);
    494 		} else {
    495 			curcpu()->ci_spin_locks2++;
    496 			TAILQ_INSERT_TAIL(&ld_spinners, ld, ld_chain);
    497 		}
    498 	}
    499 
    500 	lockdebug_unlock(lk);
    501 }
    502 
    503 /*
    504  * lockdebug_unlocked:
    505  *
    506  *	Process a lock release operation.
    507  */
    508 void
    509 lockdebug_unlocked(u_int id, uintptr_t where, int shared)
    510 {
    511 	struct lwp *l = curlwp;
    512 	lockdebuglk_t *lk;
    513 	lockdebug_t *ld;
    514 
    515 	if (panicstr != NULL)
    516 		return;
    517 
    518 	if ((ld = lockdebug_lookup(id, &lk)) == NULL)
    519 		return;
    520 
    521 	if (shared) {
    522 		if (l->l_shlocks == 0)
    523 			lockdebug_abort1(ld, lk, __func__,
    524 			    "no shared locks held by LWP", true);
    525 		if (ld->ld_shares == 0)
    526 			lockdebug_abort1(ld, lk, __func__,
    527 			    "no shared holds on this lock", true);
    528 		l->l_shlocks--;
    529 		ld->ld_shares--;
    530 	} else {
    531 		if ((ld->ld_flags & LD_LOCKED) == 0)
    532 			lockdebug_abort1(ld, lk, __func__, "not locked",
    533 			    true);
    534 
    535 		if ((ld->ld_flags & LD_SLEEPER) != 0) {
    536 			if (ld->ld_lwp != curlwp)
    537 				lockdebug_abort1(ld, lk, __func__,
    538 				    "not held by current LWP", true);
    539 			ld->ld_flags &= ~LD_LOCKED;
    540 			ld->ld_unlocked = where;
    541 			ld->ld_lwp = NULL;
    542 			curlwp->l_exlocks--;
    543 			TAILQ_REMOVE(&ld_sleepers, ld, ld_chain);
    544 		} else {
    545 			if (ld->ld_cpu != (uint16_t)cpu_number())
    546 				lockdebug_abort1(ld, lk, __func__,
    547 				    "not held by current CPU", true);
    548 			ld->ld_flags &= ~LD_LOCKED;
    549 			ld->ld_unlocked = where;
    550 			ld->ld_lwp = NULL;
    551 			curcpu()->ci_spin_locks2--;
    552 			TAILQ_REMOVE(&ld_spinners, ld, ld_chain);
    553 		}
    554 	}
    555 
    556 	lockdebug_unlock(lk);
    557 }
    558 
    559 /*
    560  * lockdebug_barrier:
    561  *
    562  *	Panic if we hold more than one specified spin lock, and optionally,
    563  *	if we hold sleep locks.
    564  */
    565 void
    566 lockdebug_barrier(volatile void *spinlock, int slplocks)
    567 {
    568 	struct lwp *l = curlwp;
    569 	lockdebug_t *ld;
    570 	uint16_t cpuno;
    571 
    572 	if (panicstr != NULL)
    573 		return;
    574 
    575 	if (curcpu()->ci_spin_locks2 != 0) {
    576 		cpuno = (uint16_t)cpu_number();
    577 
    578 		lockdebug_lock(&ld_spinner_lk);
    579 		TAILQ_FOREACH(ld, &ld_spinners, ld_chain) {
    580 			if (ld->ld_lock == spinlock) {
    581 				if (ld->ld_cpu != cpuno)
    582 					lockdebug_abort1(ld, &ld_spinner_lk,
    583 					    __func__,
    584 					    "not held by current CPU", true);
    585 				continue;
    586 			}
    587 			if (ld->ld_cpu == cpuno && (l->l_pflag & LP_INTR) == 0)
    588 				lockdebug_abort1(ld, &ld_spinner_lk,
    589 				    __func__, "spin lock held", true);
    590 		}
    591 		lockdebug_unlock(&ld_spinner_lk);
    592 	}
    593 
    594 	if (!slplocks) {
    595 		if (l->l_exlocks != 0) {
    596 			lockdebug_lock(&ld_sleeper_lk);
    597 			TAILQ_FOREACH(ld, &ld_sleepers, ld_chain) {
    598 				if (ld->ld_lwp == l)
    599 					lockdebug_abort1(ld, &ld_sleeper_lk,
    600 					    __func__, "sleep lock held", true);
    601 			}
    602 			lockdebug_unlock(&ld_sleeper_lk);
    603 		}
    604 		if (l->l_shlocks != 0)
    605 			panic("lockdebug_barrier: holding %d shared locks",
    606 			    l->l_shlocks);
    607 	}
    608 }
    609 
    610 /*
    611  * lockdebug_mem_check:
    612  *
    613  *	Check for in-use locks within a memory region that is
    614  *	being freed.  We only check for active locks within the
    615  *	first page of the allocation.
    616  */
    617 void
    618 lockdebug_mem_check(const char *func, void *base, size_t sz)
    619 {
    620 #if 0
    621 	lockdebuglist_t *head;
    622 	lockdebuglk_t *lk;
    623 	lockdebug_t *ld;
    624 	uintptr_t sa, ea, la;
    625 
    626 	sa = (uintptr_t)base;
    627 	ea = sa + sz;
    628 
    629 	lockdebug_mhash(base, &lk, &head);
    630 	TAILQ_FOREACH(ld, head, ld_mchain) {
    631 		la = (uintptr_t)ld->ld_lock;
    632 		if (la >= sa && la < ea) {
    633 			lockdebug_abort1(ld, lk, func,
    634 			    "allocation contains active lock", !cold);
    635 			return;
    636 		}
    637 	}
    638 	lockdebug_unlock(lk);
    639 #endif
    640 }
    641 
    642 /*
    643  * lockdebug_dump:
    644  *
    645  *	Dump information about a lock on panic, or for DDB.
    646  */
    647 static void
    648 lockdebug_dump(lockdebug_t *ld, void (*pr)(const char *, ...))
    649 {
    650 	int sleeper = (ld->ld_flags & LD_SLEEPER);
    651 
    652 	(*pr)(
    653 	    "lock address : %#018lx type     : %18s\n"
    654 	    "shared holds : %18u exclusive: %18u\n"
    655 	    "shares wanted: %18u exclusive: %18u\n"
    656 	    "current cpu  : %18u last held: %18u\n"
    657 	    "current lwp  : %#018lx last held: %#018lx\n"
    658 	    "last locked  : %#018lx unlocked : %#018lx\n"
    659 	    "initialized  : %#018lx\n",
    660 	    (long)ld->ld_lock, (sleeper ? "sleep/adaptive" : "spin"),
    661 	    (unsigned)ld->ld_shares, ((ld->ld_flags & LD_LOCKED) != 0),
    662 	    (unsigned)ld->ld_shwant, (unsigned)ld->ld_exwant,
    663 	    (unsigned)cpu_number(), (unsigned)ld->ld_cpu,
    664 	    (long)curlwp, (long)ld->ld_lwp,
    665 	    (long)ld->ld_locked, (long)ld->ld_unlocked,
    666 	    (long)ld->ld_initaddr);
    667 
    668 	if (ld->ld_lockops->lo_dump != NULL)
    669 		(*ld->ld_lockops->lo_dump)(ld->ld_lock);
    670 
    671 	if (sleeper) {
    672 		(*pr)("\n");
    673 		turnstile_print(ld->ld_lock, pr);
    674 	}
    675 }
    676 
    677 /*
    678  * lockdebug_dump:
    679  *
    680  *	Dump information about a known lock.
    681  */
    682 static void
    683 lockdebug_abort1(lockdebug_t *ld, lockdebuglk_t *lk, const char *func,
    684 		 const char *msg, bool dopanic)
    685 {
    686 
    687 	printf_nolog("%s error: %s: %s\n\n", ld->ld_lockops->lo_name,
    688 	    func, msg);
    689 	lockdebug_dump(ld, printf_nolog);
    690 	lockdebug_unlock(lk);
    691 	printf_nolog("\n");
    692 	if (dopanic)
    693 		panic("LOCKDEBUG");
    694 }
    695 
    696 #endif	/* LOCKDEBUG */
    697 
    698 /*
    699  * lockdebug_lock_print:
    700  *
    701  *	Handle the DDB 'show lock' command.
    702  */
    703 #ifdef DDB
    704 void
    705 lockdebug_lock_print(void *addr, void (*pr)(const char *, ...))
    706 {
    707 #ifdef LOCKDEBUG
    708 	lockdebug_t *ld;
    709 
    710 	TAILQ_FOREACH(ld, &ld_all, ld_achain) {
    711 		if (ld->ld_lock == addr) {
    712 			lockdebug_dump(ld, pr);
    713 			return;
    714 		}
    715 	}
    716 	(*pr)("Sorry, no record of a lock with address %p found.\n", addr);
    717 #else
    718 	(*pr)("Sorry, kernel not built with the LOCKDEBUG option.\n");
    719 #endif	/* LOCKDEBUG */
    720 }
    721 #endif	/* DDB */
    722 
    723 /*
    724  * lockdebug_abort:
    725  *
    726  *	An error has been trapped - dump lock info and call panic().
    727  */
    728 void
    729 lockdebug_abort(u_int id, volatile void *lock, lockops_t *ops,
    730 		const char *func, const char *msg)
    731 {
    732 #ifdef LOCKDEBUG
    733 	lockdebug_t *ld;
    734 	lockdebuglk_t *lk;
    735 
    736 	if ((ld = lockdebug_lookup(id, &lk)) != NULL) {
    737 		lockdebug_abort1(ld, lk, func, msg, true);
    738 		/* NOTREACHED */
    739 	}
    740 #endif	/* LOCKDEBUG */
    741 
    742 	printf_nolog("%s error: %s: %s\n\n"
    743 	    "lock address : %#018lx\n"
    744 	    "current cpu  : %18d\n"
    745 	    "current lwp  : %#018lx\n",
    746 	    ops->lo_name, func, msg, (long)lock, (int)cpu_number(),
    747 	    (long)curlwp);
    748 
    749 	(*ops->lo_dump)(lock);
    750 
    751 	printf_nolog("\n");
    752 	panic("lock error");
    753 }
    754