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subr_lockdebug.c revision 1.11.2.2
      1 /*	$NetBSD: subr_lockdebug.c,v 1.11.2.2 2007/12/08 18:20:36 mjf 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 1.11.2.2 2007/12/08 18:20:36 mjf 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 #include <sys/atomic.h>
     59 
     60 #include <lib/libkern/rb.h>
     61 
     62 #ifdef LOCKDEBUG
     63 
     64 #define	LD_BATCH_SHIFT	9
     65 #define	LD_BATCH	(1 << LD_BATCH_SHIFT)
     66 #define	LD_BATCH_MASK	(LD_BATCH - 1)
     67 #define	LD_MAX_LOCKS	1048576
     68 #define	LD_SLOP		16
     69 
     70 #define	LD_LOCKED	0x01
     71 #define	LD_SLEEPER	0x02
     72 
     73 typedef union lockdebuglk {
     74 	struct {
     75 		__cpu_simple_lock_t	lku_lock;
     76 		int			lku_oldspl;
     77 	} ul;
     78 	uint8_t	lk_pad[64];
     79 } volatile __aligned(64) lockdebuglk_t;
     80 
     81 #define	lk_lock		ul.lku_lock
     82 #define	lk_oldspl	ul.lku_oldspl
     83 
     84 typedef struct lockdebug {
     85 	struct rb_node	ld_rb_node;	/* must be the first member */
     86 	_TAILQ_ENTRY(struct lockdebug, volatile) ld_chain;
     87 	_TAILQ_ENTRY(struct lockdebug, volatile) ld_achain;
     88 	volatile void	*ld_lock;
     89 	lockops_t	*ld_lockops;
     90 	struct lwp	*ld_lwp;
     91 	uintptr_t	ld_locked;
     92 	uintptr_t	ld_unlocked;
     93 	uintptr_t	ld_initaddr;
     94 	uint16_t	ld_shares;
     95 	uint16_t	ld_cpu;
     96 	uint8_t		ld_flags;
     97 	uint8_t		ld_shwant;	/* advisory */
     98 	uint8_t		ld_exwant;	/* advisory */
     99 	uint8_t		ld_unused;
    100 } volatile lockdebug_t;
    101 
    102 typedef _TAILQ_HEAD(lockdebuglist, struct lockdebug, volatile) lockdebuglist_t;
    103 
    104 lockdebuglk_t		ld_tree_lk;
    105 lockdebuglk_t		ld_sleeper_lk;
    106 lockdebuglk_t		ld_spinner_lk;
    107 lockdebuglk_t		ld_free_lk;
    108 
    109 lockdebuglist_t		ld_sleepers = TAILQ_HEAD_INITIALIZER(ld_sleepers);
    110 lockdebuglist_t		ld_spinners = TAILQ_HEAD_INITIALIZER(ld_spinners);
    111 lockdebuglist_t		ld_free = TAILQ_HEAD_INITIALIZER(ld_free);
    112 lockdebuglist_t		ld_all = TAILQ_HEAD_INITIALIZER(ld_all);
    113 int			ld_nfree;
    114 int			ld_freeptr;
    115 int			ld_recurse;
    116 bool			ld_nomore;
    117 lockdebug_t		*ld_table[LD_MAX_LOCKS / LD_BATCH];
    118 
    119 lockdebug_t		ld_prime[LD_BATCH];
    120 
    121 static void	lockdebug_abort1(lockdebug_t *, lockdebuglk_t *lk,
    122 				 const char *, const char *, bool);
    123 static void	lockdebug_more(void);
    124 static void	lockdebug_init(void);
    125 
    126 static signed int
    127 ld_rb_compare_nodes(const struct rb_node *n1, const struct rb_node *n2)
    128 {
    129 	const lockdebug_t *ld1 = (const void *)n1;
    130 	const lockdebug_t *ld2 = (const void *)n2;
    131 	const uintptr_t a = (uintptr_t)ld1->ld_lock;
    132 	const uintptr_t b = (uintptr_t)ld2->ld_lock;
    133 
    134 	if (a < b)
    135 		return 1;
    136 	if (a > b)
    137 		return -1;
    138 	return 0;
    139 }
    140 
    141 static signed int
    142 ld_rb_compare_key(const struct rb_node *n, const void *key)
    143 {
    144 	const lockdebug_t *ld = (const void *)n;
    145 	const uintptr_t a = (uintptr_t)ld->ld_lock;
    146 	const uintptr_t b = (uintptr_t)key;
    147 
    148 	if (a < b)
    149 		return 1;
    150 	if (a > b)
    151 		return -1;
    152 	return 0;
    153 }
    154 
    155 static struct rb_tree ld_rb_tree;
    156 
    157 static const struct rb_tree_ops ld_rb_tree_ops = {
    158 	.rb_compare_nodes = ld_rb_compare_nodes,
    159 	.rb_compare_key = ld_rb_compare_key,
    160 };
    161 
    162 static inline void
    163 lockdebug_lock(lockdebuglk_t *lk)
    164 {
    165 	int s;
    166 
    167 	s = splhigh();
    168 	__cpu_simple_lock(&lk->lk_lock);
    169 	lk->lk_oldspl = s;
    170 }
    171 
    172 static inline void
    173 lockdebug_unlock(lockdebuglk_t *lk)
    174 {
    175 	int s;
    176 
    177 	s = lk->lk_oldspl;
    178 	__cpu_simple_unlock(&(lk->lk_lock));
    179 	splx(s);
    180 }
    181 
    182 static inline lockdebug_t *
    183 lockdebug_lookup1(volatile void *lock, lockdebuglk_t **lk)
    184 {
    185 	lockdebug_t *ld;
    186 
    187 	lockdebug_lock(&ld_tree_lk);
    188 	ld = (lockdebug_t *)rb_tree_find_node(&ld_rb_tree, __UNVOLATILE(lock));
    189 	lockdebug_unlock(&ld_tree_lk);
    190 	if (ld == NULL)
    191 		return NULL;
    192 
    193 	if ((ld->ld_flags & LD_SLEEPER) != 0)
    194 		*lk = &ld_sleeper_lk;
    195 	else
    196 		*lk = &ld_spinner_lk;
    197 
    198 	lockdebug_lock(*lk);
    199 	return ld;
    200 }
    201 
    202 /*
    203  * lockdebug_lookup:
    204  *
    205  *	Find a lockdebug structure by a pointer to a lock and return it locked.
    206  */
    207 static inline lockdebug_t *
    208 lockdebug_lookup(volatile void *lock, lockdebuglk_t **lk)
    209 {
    210 	lockdebug_t *ld;
    211 
    212 	ld = lockdebug_lookup1(lock, lk);
    213 	if (ld == NULL)
    214 		panic("lockdebug_lookup: uninitialized lock (lock=%p)", lock);
    215 	return ld;
    216 }
    217 
    218 /*
    219  * lockdebug_init:
    220  *
    221  *	Initialize the lockdebug system.  Allocate an initial pool of
    222  *	lockdebug structures before the VM system is up and running.
    223  */
    224 static void
    225 lockdebug_init(void)
    226 {
    227 	lockdebug_t *ld;
    228 	int i;
    229 
    230 	__cpu_simple_lock_init(&ld_tree_lk.lk_lock);
    231 	__cpu_simple_lock_init(&ld_sleeper_lk.lk_lock);
    232 	__cpu_simple_lock_init(&ld_spinner_lk.lk_lock);
    233 	__cpu_simple_lock_init(&ld_free_lk.lk_lock);
    234 
    235 	rb_tree_init(&ld_rb_tree, &ld_rb_tree_ops);
    236 
    237 	ld = ld_prime;
    238 	ld_table[0] = ld;
    239 	for (i = 1, ld++; i < LD_BATCH; i++, ld++) {
    240 		TAILQ_INSERT_TAIL(&ld_free, ld, ld_chain);
    241 		TAILQ_INSERT_TAIL(&ld_all, ld, ld_achain);
    242 	}
    243 	ld_freeptr = 1;
    244 	ld_nfree = LD_BATCH - 1;
    245 }
    246 
    247 /*
    248  * lockdebug_alloc:
    249  *
    250  *	A lock is being initialized, so allocate an associated debug
    251  *	structure.
    252  */
    253 bool
    254 lockdebug_alloc(volatile void *lock, lockops_t *lo, uintptr_t initaddr)
    255 {
    256 	struct cpu_info *ci;
    257 	lockdebug_t *ld;
    258 	lockdebuglk_t *lk;
    259 
    260 	if (lo == NULL || panicstr != NULL)
    261 		return false;
    262 	if (ld_freeptr == 0)
    263 		lockdebug_init();
    264 
    265 	if ((ld = lockdebug_lookup1(lock, &lk)) != NULL) {
    266 		lockdebug_abort1(ld, lk, __func__, "already initialized", true);
    267 		/* NOTREACHED */
    268 	}
    269 
    270 	ci = curcpu();
    271 
    272 	/*
    273 	 * Pinch a new debug structure.  We may recurse because we call
    274 	 * kmem_alloc(), which may need to initialize new locks somewhere
    275 	 * down the path.  If not recursing, we try to maintain at least
    276 	 * LD_SLOP structures free, which should hopefully be enough to
    277 	 * satisfy kmem_alloc().  If we can't provide a structure, not to
    278 	 * worry: we'll just mark the lock as not having an ID.
    279 	 */
    280 	lockdebug_lock(&ld_free_lk);
    281 	ci->ci_lkdebug_recurse++;
    282 
    283 	if (TAILQ_EMPTY(&ld_free)) {
    284 		if (ci->ci_lkdebug_recurse > 1 || ld_nomore) {
    285 			ci->ci_lkdebug_recurse--;
    286 			lockdebug_unlock(&ld_free_lk);
    287 			return false;
    288 		}
    289 		lockdebug_more();
    290 	} else if (ci->ci_lkdebug_recurse == 1 && ld_nfree < LD_SLOP)
    291 		lockdebug_more();
    292 
    293 	if ((ld = TAILQ_FIRST(&ld_free)) == NULL) {
    294 		lockdebug_unlock(&ld_free_lk);
    295 		return false;
    296 	}
    297 
    298 	TAILQ_REMOVE(&ld_free, ld, ld_chain);
    299 	ld_nfree--;
    300 
    301 	ci->ci_lkdebug_recurse--;
    302 	lockdebug_unlock(&ld_free_lk);
    303 
    304 	if (ld->ld_lock != NULL)
    305 		panic("lockdebug_alloc: corrupt table");
    306 
    307 	if (lo->lo_sleeplock)
    308 		lockdebug_lock(&ld_sleeper_lk);
    309 	else
    310 		lockdebug_lock(&ld_spinner_lk);
    311 
    312 	/* Initialise the structure. */
    313 	ld->ld_lock = lock;
    314 	ld->ld_lockops = lo;
    315 	ld->ld_locked = 0;
    316 	ld->ld_unlocked = 0;
    317 	ld->ld_lwp = NULL;
    318 	ld->ld_initaddr = initaddr;
    319 
    320 	lockdebug_lock(&ld_tree_lk);
    321 	rb_tree_insert_node(&ld_rb_tree, __UNVOLATILE(&ld->ld_rb_node));
    322 	lockdebug_unlock(&ld_tree_lk);
    323 
    324 	if (lo->lo_sleeplock) {
    325 		ld->ld_flags = LD_SLEEPER;
    326 		lockdebug_unlock(&ld_sleeper_lk);
    327 	} else {
    328 		ld->ld_flags = 0;
    329 		lockdebug_unlock(&ld_spinner_lk);
    330 	}
    331 
    332 	return true;
    333 }
    334 
    335 /*
    336  * lockdebug_free:
    337  *
    338  *	A lock is being destroyed, so release debugging resources.
    339  */
    340 void
    341 lockdebug_free(volatile void *lock)
    342 {
    343 	lockdebug_t *ld;
    344 	lockdebuglk_t *lk;
    345 
    346 	if (panicstr != NULL)
    347 		return;
    348 
    349 	ld = lockdebug_lookup(lock, &lk);
    350 	if (ld == NULL) {
    351 		panic("lockdebug_free: destroying uninitialized lock %p"
    352 		    "(ld_lock=%p)", lock, ld->ld_lock);
    353 		lockdebug_abort1(ld, lk, __func__, "lock record follows",
    354 		    true);
    355 	}
    356 	if ((ld->ld_flags & LD_LOCKED) != 0 || ld->ld_shares != 0)
    357 		lockdebug_abort1(ld, lk, __func__, "is locked", true);
    358 	lockdebug_lock(&ld_tree_lk);
    359 	rb_tree_remove_node(&ld_rb_tree, __UNVOLATILE(&ld->ld_rb_node));
    360 	lockdebug_unlock(&ld_tree_lk);
    361 	ld->ld_lock = NULL;
    362 	lockdebug_unlock(lk);
    363 
    364 	lockdebug_lock(&ld_free_lk);
    365 	TAILQ_INSERT_TAIL(&ld_free, ld, ld_chain);
    366 	ld_nfree++;
    367 	lockdebug_unlock(&ld_free_lk);
    368 }
    369 
    370 /*
    371  * lockdebug_more:
    372  *
    373  *	Allocate a batch of debug structures and add to the free list.
    374  *	Must be called with ld_free_lk held.
    375  */
    376 static void
    377 lockdebug_more(void)
    378 {
    379 	lockdebug_t *ld;
    380 	void *block;
    381 	int i, base, m;
    382 
    383 	while (ld_nfree < LD_SLOP) {
    384 		lockdebug_unlock(&ld_free_lk);
    385 		block = kmem_zalloc(LD_BATCH * sizeof(lockdebug_t), KM_SLEEP);
    386 		lockdebug_lock(&ld_free_lk);
    387 
    388 		if (block == NULL)
    389 			return;
    390 
    391 		if (ld_nfree > LD_SLOP) {
    392 			/* Somebody beat us to it. */
    393 			lockdebug_unlock(&ld_free_lk);
    394 			kmem_free(block, LD_BATCH * sizeof(lockdebug_t));
    395 			lockdebug_lock(&ld_free_lk);
    396 			continue;
    397 		}
    398 
    399 		base = ld_freeptr;
    400 		ld_nfree += LD_BATCH;
    401 		ld = block;
    402 		base <<= LD_BATCH_SHIFT;
    403 		m = min(LD_MAX_LOCKS, base + LD_BATCH);
    404 
    405 		if (m == LD_MAX_LOCKS)
    406 			ld_nomore = true;
    407 
    408 		for (i = base; i < m; i++, ld++) {
    409 			TAILQ_INSERT_TAIL(&ld_free, ld, ld_chain);
    410 			TAILQ_INSERT_TAIL(&ld_all, ld, ld_achain);
    411 		}
    412 
    413 		membar_producer();
    414 		ld_table[ld_freeptr++] = block;
    415 	}
    416 }
    417 
    418 /*
    419  * lockdebug_wantlock:
    420  *
    421  *	Process the preamble to a lock acquire.
    422  */
    423 void
    424 lockdebug_wantlock(volatile void *lock, uintptr_t where, int shared)
    425 {
    426 	struct lwp *l = curlwp;
    427 	lockdebuglk_t *lk;
    428 	lockdebug_t *ld;
    429 	bool recurse;
    430 
    431 	(void)shared;
    432 	recurse = false;
    433 
    434 	if (panicstr != NULL)
    435 		return;
    436 
    437 	if ((ld = lockdebug_lookup(lock, &lk)) == NULL)
    438 		return;
    439 
    440 	if ((ld->ld_flags & LD_LOCKED) != 0) {
    441 		if ((ld->ld_flags & LD_SLEEPER) != 0) {
    442 			if (ld->ld_lwp == l)
    443 				recurse = true;
    444 		} else if (ld->ld_cpu == (uint16_t)cpu_number())
    445 			recurse = true;
    446 	}
    447 
    448 #ifdef notyet
    449 	if (cpu_intr_p()) {
    450 		if ((ld->ld_flags & LD_SLEEPER) != 0)
    451 			lockdebug_abort1(ld, lk, __func__,
    452 			    "acquiring sleep lock from interrupt context",
    453 			    true);
    454 	}
    455 #endif
    456 
    457 	if (shared)
    458 		ld->ld_shwant++;
    459 	else
    460 		ld->ld_exwant++;
    461 
    462 	if (recurse)
    463 		lockdebug_abort1(ld, lk, __func__, "locking against myself",
    464 		    true);
    465 
    466 	lockdebug_unlock(lk);
    467 }
    468 
    469 /*
    470  * lockdebug_locked:
    471  *
    472  *	Process a lock acquire operation.
    473  */
    474 void
    475 lockdebug_locked(volatile void *lock, uintptr_t where, int shared)
    476 {
    477 	struct lwp *l = curlwp;
    478 	lockdebuglk_t *lk;
    479 	lockdebug_t *ld;
    480 
    481 	if (panicstr != NULL)
    482 		return;
    483 
    484 	if ((ld = lockdebug_lookup(lock, &lk)) == NULL)
    485 		return;
    486 
    487 	if (shared) {
    488 		l->l_shlocks++;
    489 		ld->ld_shares++;
    490 		ld->ld_shwant--;
    491 	} else {
    492 		if ((ld->ld_flags & LD_LOCKED) != 0)
    493 			lockdebug_abort1(ld, lk, __func__,
    494 			    "already locked", true);
    495 
    496 		ld->ld_flags |= LD_LOCKED;
    497 		ld->ld_locked = where;
    498 		ld->ld_cpu = (uint16_t)cpu_number();
    499 		ld->ld_lwp = l;
    500 		ld->ld_exwant--;
    501 
    502 		if ((ld->ld_flags & LD_SLEEPER) != 0) {
    503 			l->l_exlocks++;
    504 			TAILQ_INSERT_TAIL(&ld_sleepers, ld, ld_chain);
    505 		} else {
    506 			curcpu()->ci_spin_locks2++;
    507 			TAILQ_INSERT_TAIL(&ld_spinners, ld, ld_chain);
    508 		}
    509 	}
    510 
    511 	lockdebug_unlock(lk);
    512 }
    513 
    514 /*
    515  * lockdebug_unlocked:
    516  *
    517  *	Process a lock release operation.
    518  */
    519 void
    520 lockdebug_unlocked(volatile void *lock, uintptr_t where, int shared)
    521 {
    522 	struct lwp *l = curlwp;
    523 	lockdebuglk_t *lk;
    524 	lockdebug_t *ld;
    525 
    526 	if (panicstr != NULL)
    527 		return;
    528 
    529 	if ((ld = lockdebug_lookup(lock, &lk)) == NULL)
    530 		return;
    531 
    532 	if (shared) {
    533 		if (l->l_shlocks == 0)
    534 			lockdebug_abort1(ld, lk, __func__,
    535 			    "no shared locks held by LWP", true);
    536 		if (ld->ld_shares == 0)
    537 			lockdebug_abort1(ld, lk, __func__,
    538 			    "no shared holds on this lock", true);
    539 		l->l_shlocks--;
    540 		ld->ld_shares--;
    541 	} else {
    542 		if ((ld->ld_flags & LD_LOCKED) == 0)
    543 			lockdebug_abort1(ld, lk, __func__, "not locked",
    544 			    true);
    545 
    546 		if ((ld->ld_flags & LD_SLEEPER) != 0) {
    547 			if (ld->ld_lwp != curlwp)
    548 				lockdebug_abort1(ld, lk, __func__,
    549 				    "not held by current LWP", true);
    550 			ld->ld_flags &= ~LD_LOCKED;
    551 			ld->ld_unlocked = where;
    552 			ld->ld_lwp = NULL;
    553 			curlwp->l_exlocks--;
    554 			TAILQ_REMOVE(&ld_sleepers, ld, ld_chain);
    555 		} else {
    556 			if (ld->ld_cpu != (uint16_t)cpu_number())
    557 				lockdebug_abort1(ld, lk, __func__,
    558 				    "not held by current CPU", true);
    559 			ld->ld_flags &= ~LD_LOCKED;
    560 			ld->ld_unlocked = where;
    561 			ld->ld_lwp = NULL;
    562 			curcpu()->ci_spin_locks2--;
    563 			TAILQ_REMOVE(&ld_spinners, ld, ld_chain);
    564 		}
    565 	}
    566 
    567 	lockdebug_unlock(lk);
    568 }
    569 
    570 /*
    571  * lockdebug_barrier:
    572  *
    573  *	Panic if we hold more than one specified spin lock, and optionally,
    574  *	if we hold sleep locks.
    575  */
    576 void
    577 lockdebug_barrier(volatile void *spinlock, int slplocks)
    578 {
    579 	struct lwp *l = curlwp;
    580 	lockdebug_t *ld;
    581 	uint16_t cpuno;
    582 
    583 	if (panicstr != NULL)
    584 		return;
    585 
    586 	if (curcpu()->ci_spin_locks2 != 0) {
    587 		cpuno = (uint16_t)cpu_number();
    588 
    589 		lockdebug_lock(&ld_spinner_lk);
    590 		TAILQ_FOREACH(ld, &ld_spinners, ld_chain) {
    591 			if (ld->ld_lock == spinlock) {
    592 				if (ld->ld_cpu != cpuno)
    593 					lockdebug_abort1(ld, &ld_spinner_lk,
    594 					    __func__,
    595 					    "not held by current CPU", true);
    596 				continue;
    597 			}
    598 			if (ld->ld_cpu == cpuno && (l->l_pflag & LP_INTR) == 0)
    599 				lockdebug_abort1(ld, &ld_spinner_lk,
    600 				    __func__, "spin lock held", true);
    601 		}
    602 		lockdebug_unlock(&ld_spinner_lk);
    603 	}
    604 
    605 	if (!slplocks) {
    606 		if (l->l_exlocks != 0) {
    607 			lockdebug_lock(&ld_sleeper_lk);
    608 			TAILQ_FOREACH(ld, &ld_sleepers, ld_chain) {
    609 				if (ld->ld_lwp == l)
    610 					lockdebug_abort1(ld, &ld_sleeper_lk,
    611 					    __func__, "sleep lock held", true);
    612 			}
    613 			lockdebug_unlock(&ld_sleeper_lk);
    614 		}
    615 		if (l->l_shlocks != 0)
    616 			panic("lockdebug_barrier: holding %d shared locks",
    617 			    l->l_shlocks);
    618 	}
    619 }
    620 
    621 /*
    622  * lockdebug_mem_check:
    623  *
    624  *	Check for in-use locks within a memory region that is
    625  *	being freed.
    626  */
    627 void
    628 lockdebug_mem_check(const char *func, void *base, size_t sz)
    629 {
    630 	lockdebug_t *ld;
    631 	lockdebuglk_t *lk;
    632 	uintptr_t lock;
    633 
    634 	lockdebug_lock(&ld_tree_lk);
    635 	ld = (lockdebug_t *)rb_tree_find_node_geq(&ld_rb_tree, base);
    636 	lockdebug_unlock(&ld_tree_lk);
    637 	if (ld == NULL)
    638 		return;
    639 
    640 	if ((ld->ld_flags & LD_SLEEPER) != 0)
    641 		lk = &ld_sleeper_lk;
    642 	else
    643 		lk = &ld_spinner_lk;
    644 
    645 	lockdebug_lock(lk);
    646 	lock = (uintptr_t)ld->ld_lock;
    647 	if ((uintptr_t)base > lock)
    648 		lockdebug_abort1(ld, lk, func, "corrupt tree", true);
    649 	if (lock < (uintptr_t)base + sz) {
    650 		lockdebug_abort1(ld, lk, func,
    651 		    "allocation contains active lock", !cold);
    652 		return;
    653 	}
    654 	lockdebug_unlock(lk);
    655 }
    656 
    657 /*
    658  * lockdebug_dump:
    659  *
    660  *	Dump information about a lock on panic, or for DDB.
    661  */
    662 static void
    663 lockdebug_dump(lockdebug_t *ld, void (*pr)(const char *, ...))
    664 {
    665 	int sleeper = (ld->ld_flags & LD_SLEEPER);
    666 
    667 	(*pr)(
    668 	    "lock address : %#018lx type     : %18s\n"
    669 	    "shared holds : %18u exclusive: %18u\n"
    670 	    "shares wanted: %18u exclusive: %18u\n"
    671 	    "current cpu  : %18u last held: %18u\n"
    672 	    "current lwp  : %#018lx last held: %#018lx\n"
    673 	    "last locked  : %#018lx unlocked : %#018lx\n"
    674 	    "initialized  : %#018lx\n",
    675 	    (long)ld->ld_lock, (sleeper ? "sleep/adaptive" : "spin"),
    676 	    (unsigned)ld->ld_shares, ((ld->ld_flags & LD_LOCKED) != 0),
    677 	    (unsigned)ld->ld_shwant, (unsigned)ld->ld_exwant,
    678 	    (unsigned)cpu_number(), (unsigned)ld->ld_cpu,
    679 	    (long)curlwp, (long)ld->ld_lwp,
    680 	    (long)ld->ld_locked, (long)ld->ld_unlocked,
    681 	    (long)ld->ld_initaddr);
    682 
    683 	if (ld->ld_lockops->lo_dump != NULL)
    684 		(*ld->ld_lockops->lo_dump)(ld->ld_lock);
    685 
    686 	if (sleeper) {
    687 		(*pr)("\n");
    688 		turnstile_print(ld->ld_lock, pr);
    689 	}
    690 }
    691 
    692 /*
    693  * lockdebug_dump:
    694  *
    695  *	Dump information about a known lock.
    696  */
    697 static void
    698 lockdebug_abort1(lockdebug_t *ld, lockdebuglk_t *lk, const char *func,
    699 		 const char *msg, bool dopanic)
    700 {
    701 
    702 	printf_nolog("%s error: %s: %s\n\n", ld->ld_lockops->lo_name,
    703 	    func, msg);
    704 	lockdebug_dump(ld, printf_nolog);
    705 	lockdebug_unlock(lk);
    706 	printf_nolog("\n");
    707 	if (dopanic)
    708 		panic("LOCKDEBUG");
    709 }
    710 
    711 #endif	/* LOCKDEBUG */
    712 
    713 /*
    714  * lockdebug_lock_print:
    715  *
    716  *	Handle the DDB 'show lock' command.
    717  */
    718 #ifdef DDB
    719 void
    720 lockdebug_lock_print(void *addr, void (*pr)(const char *, ...))
    721 {
    722 #ifdef LOCKDEBUG
    723 	lockdebug_t *ld;
    724 
    725 	TAILQ_FOREACH(ld, &ld_all, ld_achain) {
    726 		if (ld->ld_lock == addr) {
    727 			lockdebug_dump(ld, pr);
    728 			return;
    729 		}
    730 	}
    731 	(*pr)("Sorry, no record of a lock with address %p found.\n", addr);
    732 #else
    733 	(*pr)("Sorry, kernel not built with the LOCKDEBUG option.\n");
    734 #endif	/* LOCKDEBUG */
    735 }
    736 #endif	/* DDB */
    737 
    738 /*
    739  * lockdebug_abort:
    740  *
    741  *	An error has been trapped - dump lock info and call panic().
    742  */
    743 void
    744 lockdebug_abort(volatile void *lock, lockops_t *ops, const char *func,
    745 		const char *msg)
    746 {
    747 #ifdef LOCKDEBUG
    748 	lockdebug_t *ld;
    749 	lockdebuglk_t *lk;
    750 
    751 	if ((ld = lockdebug_lookup(lock, &lk)) != NULL) {
    752 		lockdebug_abort1(ld, lk, func, msg, true);
    753 		/* NOTREACHED */
    754 	}
    755 #endif	/* LOCKDEBUG */
    756 
    757 	printf_nolog("%s error: %s: %s\n\n"
    758 	    "lock address : %#018lx\n"
    759 	    "current cpu  : %18d\n"
    760 	    "current lwp  : %#018lx\n",
    761 	    ops->lo_name, func, msg, (long)lock, (int)cpu_number(),
    762 	    (long)curlwp);
    763 
    764 	(*ops->lo_dump)(lock);
    765 
    766 	printf_nolog("\n");
    767 	panic("lock error");
    768 }
    769