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subr_lockdebug.c revision 1.19
      1  1.16     yamt /*	$NetBSD: subr_lockdebug.c,v 1.19 2007/11/21 11:33:11 yamt Exp $	*/
      2   1.2       ad 
      3   1.2       ad /*-
      4   1.2       ad  * Copyright (c) 2006, 2007 The NetBSD Foundation, Inc.
      5   1.2       ad  * All rights reserved.
      6   1.2       ad  *
      7   1.2       ad  * This code is derived from software contributed to The NetBSD Foundation
      8   1.2       ad  * by Andrew Doran.
      9   1.2       ad  *
     10   1.2       ad  * Redistribution and use in source and binary forms, with or without
     11   1.2       ad  * modification, are permitted provided that the following conditions
     12   1.2       ad  * are met:
     13   1.2       ad  * 1. Redistributions of source code must retain the above copyright
     14   1.2       ad  *    notice, this list of conditions and the following disclaimer.
     15   1.2       ad  * 2. Redistributions in binary form must reproduce the above copyright
     16   1.2       ad  *    notice, this list of conditions and the following disclaimer in the
     17   1.2       ad  *    documentation and/or other materials provided with the distribution.
     18   1.2       ad  * 3. All advertising materials mentioning features or use of this software
     19   1.2       ad  *    must display the following acknowledgement:
     20   1.2       ad  *	This product includes software developed by the NetBSD
     21   1.2       ad  *	Foundation, Inc. and its contributors.
     22   1.2       ad  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23   1.2       ad  *    contributors may be used to endorse or promote products derived
     24   1.2       ad  *    from this software without specific prior written permission.
     25   1.2       ad  *
     26   1.2       ad  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27   1.2       ad  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28   1.2       ad  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29   1.2       ad  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30   1.2       ad  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31   1.2       ad  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32   1.2       ad  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33   1.2       ad  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34   1.2       ad  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35   1.2       ad  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36   1.2       ad  * POSSIBILITY OF SUCH DAMAGE.
     37   1.2       ad  */
     38   1.2       ad 
     39   1.2       ad /*
     40  1.11       ad  * Basic lock debugging code shared among lock primitives.
     41   1.2       ad  */
     42   1.2       ad 
     43   1.9      dsl #include <sys/cdefs.h>
     44  1.16     yamt __KERNEL_RCSID(0, "$NetBSD: subr_lockdebug.c,v 1.19 2007/11/21 11:33:11 yamt Exp $");
     45   1.9      dsl 
     46   1.2       ad #include "opt_multiprocessor.h"
     47   1.2       ad #include "opt_ddb.h"
     48   1.2       ad 
     49   1.2       ad #include <sys/param.h>
     50   1.2       ad #include <sys/proc.h>
     51   1.2       ad #include <sys/systm.h>
     52  1.10       ad #include <sys/kernel.h>
     53   1.2       ad #include <sys/kmem.h>
     54   1.2       ad #include <sys/lock.h>
     55   1.2       ad #include <sys/lockdebug.h>
     56   1.2       ad #include <sys/sleepq.h>
     57  1.10       ad #include <sys/cpu.h>
     58   1.2       ad 
     59  1.16     yamt #include <lib/libkern/rb.h>
     60  1.16     yamt 
     61   1.2       ad #ifdef LOCKDEBUG
     62   1.2       ad 
     63   1.2       ad #define	LD_BATCH_SHIFT	9
     64   1.2       ad #define	LD_BATCH	(1 << LD_BATCH_SHIFT)
     65   1.2       ad #define	LD_BATCH_MASK	(LD_BATCH - 1)
     66   1.2       ad #define	LD_MAX_LOCKS	1048576
     67   1.2       ad #define	LD_SLOP		16
     68   1.2       ad 
     69   1.2       ad #define	LD_LOCKED	0x01
     70   1.2       ad #define	LD_SLEEPER	0x02
     71   1.2       ad 
     72   1.2       ad typedef union lockdebuglk {
     73   1.2       ad 	struct {
     74   1.2       ad 		__cpu_simple_lock_t	lku_lock;
     75   1.2       ad 		int			lku_oldspl;
     76   1.2       ad 	} ul;
     77   1.2       ad 	uint8_t	lk_pad[64];
     78   1.2       ad } volatile __aligned(64) lockdebuglk_t;
     79   1.2       ad 
     80   1.2       ad #define	lk_lock		ul.lku_lock
     81   1.2       ad #define	lk_oldspl	ul.lku_oldspl
     82   1.2       ad 
     83   1.2       ad typedef struct lockdebug {
     84  1.16     yamt 	struct rb_node	ld_rb_node;	/* must be the first member */
     85   1.2       ad 	_TAILQ_ENTRY(struct lockdebug, volatile) ld_chain;
     86   1.2       ad 	_TAILQ_ENTRY(struct lockdebug, volatile) ld_achain;
     87   1.2       ad 	volatile void	*ld_lock;
     88   1.2       ad 	lockops_t	*ld_lockops;
     89   1.2       ad 	struct lwp	*ld_lwp;
     90   1.2       ad 	uintptr_t	ld_locked;
     91   1.2       ad 	uintptr_t	ld_unlocked;
     92  1.10       ad 	uintptr_t	ld_initaddr;
     93   1.2       ad 	uint16_t	ld_shares;
     94   1.2       ad 	uint16_t	ld_cpu;
     95   1.2       ad 	uint8_t		ld_flags;
     96   1.2       ad 	uint8_t		ld_shwant;	/* advisory */
     97   1.2       ad 	uint8_t		ld_exwant;	/* advisory */
     98   1.2       ad 	uint8_t		ld_unused;
     99   1.2       ad } volatile lockdebug_t;
    100   1.2       ad 
    101   1.2       ad typedef _TAILQ_HEAD(lockdebuglist, struct lockdebug, volatile) lockdebuglist_t;
    102   1.2       ad 
    103  1.16     yamt lockdebuglk_t		ld_tree_lk;
    104  1.15     matt lockdebuglk_t		ld_sleeper_lk;
    105  1.15     matt lockdebuglk_t		ld_spinner_lk;
    106  1.15     matt lockdebuglk_t		ld_free_lk;
    107   1.2       ad 
    108  1.13     matt lockdebuglist_t		ld_sleepers = TAILQ_HEAD_INITIALIZER(ld_sleepers);
    109  1.13     matt lockdebuglist_t		ld_spinners = TAILQ_HEAD_INITIALIZER(ld_spinners);
    110  1.13     matt lockdebuglist_t		ld_free = TAILQ_HEAD_INITIALIZER(ld_free);
    111  1.13     matt lockdebuglist_t		ld_all = TAILQ_HEAD_INITIALIZER(ld_all);
    112   1.2       ad int			ld_nfree;
    113   1.2       ad int			ld_freeptr;
    114   1.2       ad int			ld_recurse;
    115   1.5       ad bool			ld_nomore;
    116   1.2       ad lockdebug_t		*ld_table[LD_MAX_LOCKS / LD_BATCH];
    117   1.2       ad 
    118   1.2       ad lockdebug_t		ld_prime[LD_BATCH];
    119   1.2       ad 
    120   1.5       ad static void	lockdebug_abort1(lockdebug_t *, lockdebuglk_t *lk,
    121  1.10       ad 				 const char *, const char *, bool);
    122   1.5       ad static void	lockdebug_more(void);
    123   1.5       ad static void	lockdebug_init(void);
    124   1.2       ad 
    125  1.16     yamt static signed int
    126  1.16     yamt ld_rb_compare_nodes(const struct rb_node *n1, const struct rb_node *n2)
    127  1.16     yamt {
    128  1.16     yamt 	const lockdebug_t *ld1 = (const void *)n1;
    129  1.16     yamt 	const lockdebug_t *ld2 = (const void *)n2;
    130  1.16     yamt 	intptr_t diff = (intptr_t)ld1->ld_lock - (intptr_t)ld2->ld_lock;
    131  1.16     yamt 	if (diff < 0)
    132  1.16     yamt 		return -1;
    133  1.16     yamt 	else if (diff > 0)
    134  1.16     yamt 		return 1;
    135  1.16     yamt 	return 0;
    136  1.16     yamt }
    137  1.16     yamt 
    138  1.16     yamt static signed int
    139  1.16     yamt ld_rb_compare_key(const struct rb_node *n, const void *key)
    140  1.16     yamt {
    141  1.16     yamt 	const lockdebug_t *ld = (const void *)n;
    142  1.16     yamt 	intptr_t diff = (intptr_t)ld->ld_lock - (intptr_t)key;
    143  1.16     yamt 	if (diff < 0)
    144  1.16     yamt 		return -1;
    145  1.16     yamt 	else if (diff > 0)
    146  1.16     yamt 		return 1;
    147  1.16     yamt 	return 0;
    148  1.16     yamt }
    149  1.16     yamt 
    150  1.16     yamt static struct rb_tree ld_rb_tree;
    151  1.16     yamt 
    152  1.16     yamt static const struct rb_tree_ops ld_rb_tree_ops = {
    153  1.16     yamt 	.rb_compare_nodes = ld_rb_compare_nodes,
    154  1.16     yamt 	.rb_compare_key = ld_rb_compare_key,
    155  1.16     yamt };
    156  1.16     yamt 
    157   1.2       ad static inline void
    158   1.2       ad lockdebug_lock(lockdebuglk_t *lk)
    159   1.2       ad {
    160   1.2       ad 	int s;
    161   1.2       ad 
    162   1.8       ad 	s = splhigh();
    163   1.2       ad 	__cpu_simple_lock(&lk->lk_lock);
    164   1.2       ad 	lk->lk_oldspl = s;
    165   1.2       ad }
    166   1.2       ad 
    167   1.2       ad static inline void
    168   1.2       ad lockdebug_unlock(lockdebuglk_t *lk)
    169   1.2       ad {
    170   1.2       ad 	int s;
    171   1.2       ad 
    172   1.2       ad 	s = lk->lk_oldspl;
    173   1.2       ad 	__cpu_simple_unlock(&(lk->lk_lock));
    174   1.2       ad 	splx(s);
    175   1.2       ad }
    176   1.2       ad 
    177   1.2       ad static inline lockdebug_t *
    178  1.19     yamt lockdebug_lookup1(volatile void *lock, lockdebuglk_t **lk)
    179   1.2       ad {
    180  1.16     yamt 	lockdebug_t *ld;
    181   1.2       ad 
    182  1.16     yamt 	lockdebug_lock(&ld_tree_lk);
    183  1.16     yamt 	ld = (lockdebug_t *)rb_tree_find_node(&ld_rb_tree, __UNVOLATILE(lock));
    184  1.16     yamt 	lockdebug_unlock(&ld_tree_lk);
    185  1.16     yamt 	if (ld == NULL)
    186  1.19     yamt 		return NULL;
    187   1.2       ad 
    188   1.2       ad 	if ((ld->ld_flags & LD_SLEEPER) != 0)
    189   1.2       ad 		*lk = &ld_sleeper_lk;
    190   1.2       ad 	else
    191   1.2       ad 		*lk = &ld_spinner_lk;
    192   1.2       ad 
    193   1.2       ad 	lockdebug_lock(*lk);
    194   1.2       ad 	return ld;
    195   1.2       ad }
    196   1.2       ad 
    197   1.2       ad /*
    198  1.19     yamt  * lockdebug_lookup:
    199  1.19     yamt  *
    200  1.19     yamt  *	Find a lockdebug structure by a pointer to a lock and return it locked.
    201  1.19     yamt  */
    202  1.19     yamt static inline lockdebug_t *
    203  1.19     yamt lockdebug_lookup(volatile void *lock, lockdebuglk_t **lk)
    204  1.19     yamt {
    205  1.19     yamt 	lockdebug_t *ld;
    206  1.19     yamt 
    207  1.19     yamt 	ld = lockdebug_lookup1(lock, lk);
    208  1.19     yamt 	if (ld == NULL)
    209  1.19     yamt 		panic("lockdebug_lookup: uninitialized lock (lock=%p)", lock);
    210  1.19     yamt 	return ld;
    211  1.19     yamt }
    212  1.19     yamt 
    213  1.19     yamt /*
    214   1.2       ad  * lockdebug_init:
    215   1.2       ad  *
    216   1.2       ad  *	Initialize the lockdebug system.  Allocate an initial pool of
    217   1.2       ad  *	lockdebug structures before the VM system is up and running.
    218   1.2       ad  */
    219   1.5       ad static void
    220   1.2       ad lockdebug_init(void)
    221   1.2       ad {
    222   1.2       ad 	lockdebug_t *ld;
    223   1.2       ad 	int i;
    224   1.2       ad 
    225  1.16     yamt 	__cpu_simple_lock_init(&ld_tree_lk.lk_lock);
    226  1.15     matt 	__cpu_simple_lock_init(&ld_sleeper_lk.lk_lock);
    227  1.15     matt 	__cpu_simple_lock_init(&ld_spinner_lk.lk_lock);
    228  1.15     matt 	__cpu_simple_lock_init(&ld_free_lk.lk_lock);
    229  1.15     matt 
    230  1.16     yamt 	rb_tree_init(&ld_rb_tree, &ld_rb_tree_ops);
    231  1.16     yamt 
    232   1.2       ad 	ld = ld_prime;
    233   1.2       ad 	ld_table[0] = ld;
    234   1.2       ad 	for (i = 1, ld++; i < LD_BATCH; i++, ld++) {
    235   1.2       ad 		TAILQ_INSERT_TAIL(&ld_free, ld, ld_chain);
    236   1.2       ad 		TAILQ_INSERT_TAIL(&ld_all, ld, ld_achain);
    237   1.2       ad 	}
    238   1.2       ad 	ld_freeptr = 1;
    239   1.2       ad 	ld_nfree = LD_BATCH - 1;
    240   1.2       ad }
    241   1.2       ad 
    242   1.2       ad /*
    243   1.2       ad  * lockdebug_alloc:
    244   1.2       ad  *
    245   1.2       ad  *	A lock is being initialized, so allocate an associated debug
    246   1.2       ad  *	structure.
    247   1.2       ad  */
    248  1.16     yamt bool
    249  1.10       ad lockdebug_alloc(volatile void *lock, lockops_t *lo, uintptr_t initaddr)
    250   1.2       ad {
    251   1.2       ad 	struct cpu_info *ci;
    252   1.2       ad 	lockdebug_t *ld;
    253  1.19     yamt 	lockdebuglk_t *lk;
    254   1.2       ad 
    255   1.5       ad 	if (lo == NULL || panicstr != NULL)
    256  1.16     yamt 		return false;
    257   1.5       ad 	if (ld_freeptr == 0)
    258   1.5       ad 		lockdebug_init();
    259   1.2       ad 
    260  1.19     yamt 	if ((ld = lockdebug_lookup1(lock, &lk)) != NULL) {
    261  1.19     yamt 		lockdebug_abort1(ld, lk, __func__, "already initialized", true);
    262  1.19     yamt 		/* NOTREACHED */
    263  1.19     yamt 	}
    264  1.19     yamt 
    265   1.2       ad 	ci = curcpu();
    266   1.2       ad 
    267   1.2       ad 	/*
    268   1.2       ad 	 * Pinch a new debug structure.  We may recurse because we call
    269   1.2       ad 	 * kmem_alloc(), which may need to initialize new locks somewhere
    270   1.7    skrll 	 * down the path.  If not recursing, we try to maintain at least
    271   1.2       ad 	 * LD_SLOP structures free, which should hopefully be enough to
    272   1.2       ad 	 * satisfy kmem_alloc().  If we can't provide a structure, not to
    273   1.2       ad 	 * worry: we'll just mark the lock as not having an ID.
    274   1.2       ad 	 */
    275   1.2       ad 	lockdebug_lock(&ld_free_lk);
    276   1.2       ad 	ci->ci_lkdebug_recurse++;
    277   1.2       ad 
    278   1.2       ad 	if (TAILQ_EMPTY(&ld_free)) {
    279   1.5       ad 		if (ci->ci_lkdebug_recurse > 1 || ld_nomore) {
    280   1.2       ad 			ci->ci_lkdebug_recurse--;
    281   1.2       ad 			lockdebug_unlock(&ld_free_lk);
    282  1.16     yamt 			return false;
    283   1.2       ad 		}
    284   1.2       ad 		lockdebug_more();
    285   1.2       ad 	} else if (ci->ci_lkdebug_recurse == 1 && ld_nfree < LD_SLOP)
    286   1.2       ad 		lockdebug_more();
    287   1.2       ad 
    288   1.2       ad 	if ((ld = TAILQ_FIRST(&ld_free)) == NULL) {
    289   1.2       ad 		lockdebug_unlock(&ld_free_lk);
    290  1.16     yamt 		return false;
    291   1.2       ad 	}
    292   1.2       ad 
    293   1.2       ad 	TAILQ_REMOVE(&ld_free, ld, ld_chain);
    294   1.2       ad 	ld_nfree--;
    295   1.2       ad 
    296   1.2       ad 	ci->ci_lkdebug_recurse--;
    297   1.2       ad 	lockdebug_unlock(&ld_free_lk);
    298   1.2       ad 
    299   1.2       ad 	if (ld->ld_lock != NULL)
    300   1.2       ad 		panic("lockdebug_alloc: corrupt table");
    301   1.2       ad 
    302   1.2       ad 	if (lo->lo_sleeplock)
    303   1.2       ad 		lockdebug_lock(&ld_sleeper_lk);
    304   1.2       ad 	else
    305   1.2       ad 		lockdebug_lock(&ld_spinner_lk);
    306   1.2       ad 
    307   1.2       ad 	/* Initialise the structure. */
    308   1.2       ad 	ld->ld_lock = lock;
    309   1.2       ad 	ld->ld_lockops = lo;
    310   1.2       ad 	ld->ld_locked = 0;
    311   1.2       ad 	ld->ld_unlocked = 0;
    312   1.2       ad 	ld->ld_lwp = NULL;
    313  1.10       ad 	ld->ld_initaddr = initaddr;
    314   1.2       ad 
    315  1.16     yamt 	lockdebug_lock(&ld_tree_lk);
    316  1.16     yamt 	rb_tree_insert_node(&ld_rb_tree, __UNVOLATILE(&ld->ld_rb_node));
    317  1.16     yamt 	lockdebug_unlock(&ld_tree_lk);
    318  1.16     yamt 
    319   1.2       ad 	if (lo->lo_sleeplock) {
    320   1.2       ad 		ld->ld_flags = LD_SLEEPER;
    321   1.2       ad 		lockdebug_unlock(&ld_sleeper_lk);
    322   1.2       ad 	} else {
    323   1.2       ad 		ld->ld_flags = 0;
    324   1.2       ad 		lockdebug_unlock(&ld_spinner_lk);
    325   1.2       ad 	}
    326   1.2       ad 
    327  1.16     yamt 	return true;
    328   1.2       ad }
    329   1.2       ad 
    330   1.2       ad /*
    331   1.2       ad  * lockdebug_free:
    332   1.2       ad  *
    333   1.2       ad  *	A lock is being destroyed, so release debugging resources.
    334   1.2       ad  */
    335   1.2       ad void
    336  1.16     yamt lockdebug_free(volatile void *lock)
    337   1.2       ad {
    338   1.2       ad 	lockdebug_t *ld;
    339   1.2       ad 	lockdebuglk_t *lk;
    340   1.2       ad 
    341   1.2       ad 	if (panicstr != NULL)
    342   1.2       ad 		return;
    343   1.2       ad 
    344  1.16     yamt 	ld = lockdebug_lookup(lock, &lk);
    345  1.16     yamt 	if (ld == NULL) {
    346   1.2       ad 		panic("lockdebug_free: destroying uninitialized lock %p"
    347  1.16     yamt 		    "(ld_lock=%p)", lock, ld->ld_lock);
    348  1.10       ad 		lockdebug_abort1(ld, lk, __func__, "lock record follows",
    349  1.10       ad 		    true);
    350   1.2       ad 	}
    351   1.2       ad 	if ((ld->ld_flags & LD_LOCKED) != 0 || ld->ld_shares != 0)
    352  1.10       ad 		lockdebug_abort1(ld, lk, __func__, "is locked", true);
    353  1.16     yamt 	lockdebug_lock(&ld_tree_lk);
    354  1.16     yamt 	rb_tree_remove_node(&ld_rb_tree, __UNVOLATILE(&ld->ld_rb_node));
    355  1.16     yamt 	lockdebug_unlock(&ld_tree_lk);
    356   1.2       ad 	ld->ld_lock = NULL;
    357   1.2       ad 	lockdebug_unlock(lk);
    358   1.2       ad 
    359   1.2       ad 	lockdebug_lock(&ld_free_lk);
    360   1.2       ad 	TAILQ_INSERT_TAIL(&ld_free, ld, ld_chain);
    361   1.2       ad 	ld_nfree++;
    362   1.2       ad 	lockdebug_unlock(&ld_free_lk);
    363   1.2       ad }
    364   1.2       ad 
    365   1.2       ad /*
    366   1.2       ad  * lockdebug_more:
    367   1.2       ad  *
    368   1.2       ad  *	Allocate a batch of debug structures and add to the free list.
    369   1.2       ad  *	Must be called with ld_free_lk held.
    370   1.2       ad  */
    371   1.5       ad static void
    372   1.2       ad lockdebug_more(void)
    373   1.2       ad {
    374   1.2       ad 	lockdebug_t *ld;
    375   1.2       ad 	void *block;
    376   1.5       ad 	int i, base, m;
    377   1.2       ad 
    378   1.2       ad 	while (ld_nfree < LD_SLOP) {
    379   1.2       ad 		lockdebug_unlock(&ld_free_lk);
    380   1.2       ad 		block = kmem_zalloc(LD_BATCH * sizeof(lockdebug_t), KM_SLEEP);
    381   1.2       ad 		lockdebug_lock(&ld_free_lk);
    382   1.2       ad 
    383   1.2       ad 		if (block == NULL)
    384   1.2       ad 			return;
    385   1.2       ad 
    386   1.2       ad 		if (ld_nfree > LD_SLOP) {
    387   1.2       ad 			/* Somebody beat us to it. */
    388   1.2       ad 			lockdebug_unlock(&ld_free_lk);
    389   1.2       ad 			kmem_free(block, LD_BATCH * sizeof(lockdebug_t));
    390   1.2       ad 			lockdebug_lock(&ld_free_lk);
    391   1.2       ad 			continue;
    392   1.2       ad 		}
    393   1.2       ad 
    394   1.2       ad 		base = ld_freeptr;
    395   1.2       ad 		ld_nfree += LD_BATCH;
    396   1.2       ad 		ld = block;
    397   1.2       ad 		base <<= LD_BATCH_SHIFT;
    398   1.5       ad 		m = min(LD_MAX_LOCKS, base + LD_BATCH);
    399   1.5       ad 
    400   1.5       ad 		if (m == LD_MAX_LOCKS)
    401   1.5       ad 			ld_nomore = true;
    402   1.2       ad 
    403   1.5       ad 		for (i = base; i < m; i++, ld++) {
    404   1.2       ad 			TAILQ_INSERT_TAIL(&ld_free, ld, ld_chain);
    405   1.2       ad 			TAILQ_INSERT_TAIL(&ld_all, ld, ld_achain);
    406   1.2       ad 		}
    407   1.2       ad 
    408   1.2       ad 		mb_write();
    409   1.2       ad 		ld_table[ld_freeptr++] = block;
    410   1.2       ad 	}
    411   1.2       ad }
    412   1.2       ad 
    413   1.2       ad /*
    414   1.2       ad  * lockdebug_wantlock:
    415   1.2       ad  *
    416   1.2       ad  *	Process the preamble to a lock acquire.
    417   1.2       ad  */
    418   1.2       ad void
    419  1.16     yamt lockdebug_wantlock(volatile void *lock, uintptr_t where, int shared)
    420   1.2       ad {
    421   1.2       ad 	struct lwp *l = curlwp;
    422   1.2       ad 	lockdebuglk_t *lk;
    423   1.2       ad 	lockdebug_t *ld;
    424   1.3  thorpej 	bool recurse;
    425   1.2       ad 
    426   1.2       ad 	(void)shared;
    427   1.4  thorpej 	recurse = false;
    428   1.2       ad 
    429   1.2       ad 	if (panicstr != NULL)
    430   1.2       ad 		return;
    431   1.2       ad 
    432  1.16     yamt 	if ((ld = lockdebug_lookup(lock, &lk)) == NULL)
    433   1.2       ad 		return;
    434   1.2       ad 
    435   1.2       ad 	if ((ld->ld_flags & LD_LOCKED) != 0) {
    436   1.2       ad 		if ((ld->ld_flags & LD_SLEEPER) != 0) {
    437   1.2       ad 			if (ld->ld_lwp == l)
    438   1.4  thorpej 				recurse = true;
    439   1.2       ad 		} else if (ld->ld_cpu == (uint16_t)cpu_number())
    440   1.4  thorpej 			recurse = true;
    441   1.2       ad 	}
    442   1.2       ad 
    443  1.10       ad #ifdef notyet
    444  1.10       ad 	if (cpu_intr_p()) {
    445  1.10       ad 		if ((ld->ld_flags & LD_SLEEPER) != 0)
    446  1.10       ad 			lockdebug_abort1(ld, lk, __func__,
    447  1.10       ad 			    "acquiring sleep lock from interrupt context",
    448  1.10       ad 			    true);
    449  1.10       ad 	}
    450  1.10       ad #endif
    451  1.10       ad 
    452   1.2       ad 	if (shared)
    453   1.2       ad 		ld->ld_shwant++;
    454   1.2       ad 	else
    455   1.2       ad 		ld->ld_exwant++;
    456   1.2       ad 
    457   1.2       ad 	if (recurse)
    458  1.10       ad 		lockdebug_abort1(ld, lk, __func__, "locking against myself",
    459  1.10       ad 		    true);
    460   1.2       ad 
    461   1.2       ad 	lockdebug_unlock(lk);
    462   1.2       ad }
    463   1.2       ad 
    464   1.2       ad /*
    465   1.2       ad  * lockdebug_locked:
    466   1.2       ad  *
    467   1.2       ad  *	Process a lock acquire operation.
    468   1.2       ad  */
    469   1.2       ad void
    470  1.16     yamt lockdebug_locked(volatile void *lock, uintptr_t where, int shared)
    471   1.2       ad {
    472   1.2       ad 	struct lwp *l = curlwp;
    473   1.2       ad 	lockdebuglk_t *lk;
    474   1.2       ad 	lockdebug_t *ld;
    475   1.2       ad 
    476   1.2       ad 	if (panicstr != NULL)
    477   1.2       ad 		return;
    478   1.2       ad 
    479  1.16     yamt 	if ((ld = lockdebug_lookup(lock, &lk)) == NULL)
    480   1.2       ad 		return;
    481   1.2       ad 
    482   1.2       ad 	if (shared) {
    483   1.2       ad 		l->l_shlocks++;
    484   1.2       ad 		ld->ld_shares++;
    485   1.2       ad 		ld->ld_shwant--;
    486   1.2       ad 	} else {
    487   1.2       ad 		if ((ld->ld_flags & LD_LOCKED) != 0)
    488   1.2       ad 			lockdebug_abort1(ld, lk, __func__,
    489  1.10       ad 			    "already locked", true);
    490   1.2       ad 
    491   1.2       ad 		ld->ld_flags |= LD_LOCKED;
    492   1.2       ad 		ld->ld_locked = where;
    493   1.2       ad 		ld->ld_cpu = (uint16_t)cpu_number();
    494   1.2       ad 		ld->ld_lwp = l;
    495   1.2       ad 		ld->ld_exwant--;
    496   1.2       ad 
    497   1.2       ad 		if ((ld->ld_flags & LD_SLEEPER) != 0) {
    498   1.2       ad 			l->l_exlocks++;
    499   1.2       ad 			TAILQ_INSERT_TAIL(&ld_sleepers, ld, ld_chain);
    500   1.2       ad 		} else {
    501   1.2       ad 			curcpu()->ci_spin_locks2++;
    502   1.2       ad 			TAILQ_INSERT_TAIL(&ld_spinners, ld, ld_chain);
    503   1.2       ad 		}
    504   1.2       ad 	}
    505   1.2       ad 
    506   1.2       ad 	lockdebug_unlock(lk);
    507   1.2       ad }
    508   1.2       ad 
    509   1.2       ad /*
    510   1.2       ad  * lockdebug_unlocked:
    511   1.2       ad  *
    512   1.2       ad  *	Process a lock release operation.
    513   1.2       ad  */
    514   1.2       ad void
    515  1.16     yamt lockdebug_unlocked(volatile void *lock, uintptr_t where, int shared)
    516   1.2       ad {
    517   1.2       ad 	struct lwp *l = curlwp;
    518   1.2       ad 	lockdebuglk_t *lk;
    519   1.2       ad 	lockdebug_t *ld;
    520   1.2       ad 
    521   1.2       ad 	if (panicstr != NULL)
    522   1.2       ad 		return;
    523   1.2       ad 
    524  1.16     yamt 	if ((ld = lockdebug_lookup(lock, &lk)) == NULL)
    525   1.2       ad 		return;
    526   1.2       ad 
    527   1.2       ad 	if (shared) {
    528   1.2       ad 		if (l->l_shlocks == 0)
    529   1.2       ad 			lockdebug_abort1(ld, lk, __func__,
    530  1.10       ad 			    "no shared locks held by LWP", true);
    531   1.2       ad 		if (ld->ld_shares == 0)
    532   1.2       ad 			lockdebug_abort1(ld, lk, __func__,
    533  1.10       ad 			    "no shared holds on this lock", true);
    534   1.2       ad 		l->l_shlocks--;
    535   1.2       ad 		ld->ld_shares--;
    536   1.2       ad 	} else {
    537   1.2       ad 		if ((ld->ld_flags & LD_LOCKED) == 0)
    538  1.10       ad 			lockdebug_abort1(ld, lk, __func__, "not locked",
    539  1.10       ad 			    true);
    540   1.2       ad 
    541   1.2       ad 		if ((ld->ld_flags & LD_SLEEPER) != 0) {
    542   1.2       ad 			if (ld->ld_lwp != curlwp)
    543   1.2       ad 				lockdebug_abort1(ld, lk, __func__,
    544  1.10       ad 				    "not held by current LWP", true);
    545   1.2       ad 			ld->ld_flags &= ~LD_LOCKED;
    546   1.2       ad 			ld->ld_unlocked = where;
    547   1.2       ad 			ld->ld_lwp = NULL;
    548   1.2       ad 			curlwp->l_exlocks--;
    549   1.2       ad 			TAILQ_REMOVE(&ld_sleepers, ld, ld_chain);
    550   1.2       ad 		} else {
    551   1.2       ad 			if (ld->ld_cpu != (uint16_t)cpu_number())
    552   1.2       ad 				lockdebug_abort1(ld, lk, __func__,
    553  1.10       ad 				    "not held by current CPU", true);
    554   1.2       ad 			ld->ld_flags &= ~LD_LOCKED;
    555   1.2       ad 			ld->ld_unlocked = where;
    556   1.2       ad 			ld->ld_lwp = NULL;
    557   1.2       ad 			curcpu()->ci_spin_locks2--;
    558   1.2       ad 			TAILQ_REMOVE(&ld_spinners, ld, ld_chain);
    559   1.2       ad 		}
    560   1.2       ad 	}
    561   1.2       ad 
    562   1.2       ad 	lockdebug_unlock(lk);
    563   1.2       ad }
    564   1.2       ad 
    565   1.2       ad /*
    566   1.2       ad  * lockdebug_barrier:
    567   1.2       ad  *
    568   1.2       ad  *	Panic if we hold more than one specified spin lock, and optionally,
    569   1.2       ad  *	if we hold sleep locks.
    570   1.2       ad  */
    571   1.2       ad void
    572   1.2       ad lockdebug_barrier(volatile void *spinlock, int slplocks)
    573   1.2       ad {
    574   1.2       ad 	struct lwp *l = curlwp;
    575   1.2       ad 	lockdebug_t *ld;
    576   1.2       ad 	uint16_t cpuno;
    577   1.2       ad 
    578   1.2       ad 	if (panicstr != NULL)
    579   1.2       ad 		return;
    580   1.2       ad 
    581   1.2       ad 	if (curcpu()->ci_spin_locks2 != 0) {
    582   1.2       ad 		cpuno = (uint16_t)cpu_number();
    583   1.2       ad 
    584   1.2       ad 		lockdebug_lock(&ld_spinner_lk);
    585   1.2       ad 		TAILQ_FOREACH(ld, &ld_spinners, ld_chain) {
    586   1.2       ad 			if (ld->ld_lock == spinlock) {
    587   1.2       ad 				if (ld->ld_cpu != cpuno)
    588   1.2       ad 					lockdebug_abort1(ld, &ld_spinner_lk,
    589   1.2       ad 					    __func__,
    590  1.10       ad 					    "not held by current CPU", true);
    591   1.2       ad 				continue;
    592   1.2       ad 			}
    593  1.12       ad 			if (ld->ld_cpu == cpuno && (l->l_pflag & LP_INTR) == 0)
    594   1.2       ad 				lockdebug_abort1(ld, &ld_spinner_lk,
    595  1.10       ad 				    __func__, "spin lock held", true);
    596   1.2       ad 		}
    597   1.2       ad 		lockdebug_unlock(&ld_spinner_lk);
    598   1.2       ad 	}
    599   1.2       ad 
    600   1.2       ad 	if (!slplocks) {
    601   1.2       ad 		if (l->l_exlocks != 0) {
    602   1.2       ad 			lockdebug_lock(&ld_sleeper_lk);
    603   1.2       ad 			TAILQ_FOREACH(ld, &ld_sleepers, ld_chain) {
    604   1.2       ad 				if (ld->ld_lwp == l)
    605   1.2       ad 					lockdebug_abort1(ld, &ld_sleeper_lk,
    606  1.10       ad 					    __func__, "sleep lock held", true);
    607   1.2       ad 			}
    608   1.2       ad 			lockdebug_unlock(&ld_sleeper_lk);
    609   1.2       ad 		}
    610   1.2       ad 		if (l->l_shlocks != 0)
    611   1.2       ad 			panic("lockdebug_barrier: holding %d shared locks",
    612   1.2       ad 			    l->l_shlocks);
    613   1.2       ad 	}
    614   1.2       ad }
    615   1.2       ad 
    616   1.2       ad /*
    617  1.10       ad  * lockdebug_mem_check:
    618  1.10       ad  *
    619  1.10       ad  *	Check for in-use locks within a memory region that is
    620  1.16     yamt  *	being freed.
    621  1.10       ad  */
    622  1.10       ad void
    623  1.10       ad lockdebug_mem_check(const char *func, void *base, size_t sz)
    624  1.10       ad {
    625  1.16     yamt 	lockdebug_t *ld;
    626  1.10       ad 	lockdebuglk_t *lk;
    627  1.16     yamt 	uintptr_t lock;
    628  1.10       ad 
    629  1.16     yamt 	lockdebug_lock(&ld_tree_lk);
    630  1.16     yamt 	ld = (lockdebug_t *)rb_tree_find_node_geq(&ld_rb_tree, base);
    631  1.16     yamt 	lockdebug_unlock(&ld_tree_lk);
    632  1.16     yamt 	if (ld == NULL)
    633  1.16     yamt 		return;
    634  1.16     yamt 
    635  1.16     yamt 	if ((ld->ld_flags & LD_SLEEPER) != 0)
    636  1.16     yamt 		lk = &ld_sleeper_lk;
    637  1.16     yamt 	else
    638  1.16     yamt 		lk = &ld_spinner_lk;
    639  1.10       ad 
    640  1.16     yamt 	lockdebug_lock(lk);
    641  1.16     yamt 	lock = (uintptr_t)ld->ld_lock;
    642  1.16     yamt 	if ((uintptr_t)base <= lock && lock < (uintptr_t)base + sz) {
    643  1.16     yamt 		lockdebug_abort1(ld, lk, func,
    644  1.16     yamt 		    "allocation contains active lock", !cold);
    645  1.16     yamt 		return;
    646  1.10       ad 	}
    647  1.10       ad 	lockdebug_unlock(lk);
    648  1.10       ad }
    649  1.10       ad 
    650  1.10       ad /*
    651   1.2       ad  * lockdebug_dump:
    652   1.2       ad  *
    653   1.2       ad  *	Dump information about a lock on panic, or for DDB.
    654   1.2       ad  */
    655   1.2       ad static void
    656   1.2       ad lockdebug_dump(lockdebug_t *ld, void (*pr)(const char *, ...))
    657   1.2       ad {
    658   1.2       ad 	int sleeper = (ld->ld_flags & LD_SLEEPER);
    659   1.2       ad 
    660   1.2       ad 	(*pr)(
    661   1.2       ad 	    "lock address : %#018lx type     : %18s\n"
    662   1.2       ad 	    "shared holds : %18u exclusive: %18u\n"
    663   1.2       ad 	    "shares wanted: %18u exclusive: %18u\n"
    664   1.2       ad 	    "current cpu  : %18u last held: %18u\n"
    665   1.2       ad 	    "current lwp  : %#018lx last held: %#018lx\n"
    666  1.10       ad 	    "last locked  : %#018lx unlocked : %#018lx\n"
    667  1.10       ad 	    "initialized  : %#018lx\n",
    668   1.2       ad 	    (long)ld->ld_lock, (sleeper ? "sleep/adaptive" : "spin"),
    669   1.2       ad 	    (unsigned)ld->ld_shares, ((ld->ld_flags & LD_LOCKED) != 0),
    670   1.2       ad 	    (unsigned)ld->ld_shwant, (unsigned)ld->ld_exwant,
    671   1.2       ad 	    (unsigned)cpu_number(), (unsigned)ld->ld_cpu,
    672   1.2       ad 	    (long)curlwp, (long)ld->ld_lwp,
    673  1.10       ad 	    (long)ld->ld_locked, (long)ld->ld_unlocked,
    674  1.10       ad 	    (long)ld->ld_initaddr);
    675   1.2       ad 
    676   1.2       ad 	if (ld->ld_lockops->lo_dump != NULL)
    677   1.2       ad 		(*ld->ld_lockops->lo_dump)(ld->ld_lock);
    678   1.2       ad 
    679   1.2       ad 	if (sleeper) {
    680   1.2       ad 		(*pr)("\n");
    681   1.2       ad 		turnstile_print(ld->ld_lock, pr);
    682   1.2       ad 	}
    683   1.2       ad }
    684   1.2       ad 
    685   1.2       ad /*
    686   1.2       ad  * lockdebug_dump:
    687   1.2       ad  *
    688   1.2       ad  *	Dump information about a known lock.
    689   1.2       ad  */
    690   1.5       ad static void
    691   1.2       ad lockdebug_abort1(lockdebug_t *ld, lockdebuglk_t *lk, const char *func,
    692  1.10       ad 		 const char *msg, bool dopanic)
    693   1.2       ad {
    694   1.2       ad 
    695   1.2       ad 	printf_nolog("%s error: %s: %s\n\n", ld->ld_lockops->lo_name,
    696   1.2       ad 	    func, msg);
    697   1.2       ad 	lockdebug_dump(ld, printf_nolog);
    698   1.2       ad 	lockdebug_unlock(lk);
    699   1.2       ad 	printf_nolog("\n");
    700  1.10       ad 	if (dopanic)
    701  1.10       ad 		panic("LOCKDEBUG");
    702   1.2       ad }
    703   1.2       ad 
    704   1.2       ad #endif	/* LOCKDEBUG */
    705   1.2       ad 
    706   1.2       ad /*
    707   1.2       ad  * lockdebug_lock_print:
    708   1.2       ad  *
    709   1.2       ad  *	Handle the DDB 'show lock' command.
    710   1.2       ad  */
    711   1.2       ad #ifdef DDB
    712   1.2       ad void
    713   1.2       ad lockdebug_lock_print(void *addr, void (*pr)(const char *, ...))
    714   1.2       ad {
    715   1.2       ad #ifdef LOCKDEBUG
    716   1.2       ad 	lockdebug_t *ld;
    717   1.2       ad 
    718   1.2       ad 	TAILQ_FOREACH(ld, &ld_all, ld_achain) {
    719   1.2       ad 		if (ld->ld_lock == addr) {
    720   1.2       ad 			lockdebug_dump(ld, pr);
    721   1.2       ad 			return;
    722   1.2       ad 		}
    723   1.2       ad 	}
    724   1.2       ad 	(*pr)("Sorry, no record of a lock with address %p found.\n", addr);
    725   1.2       ad #else
    726   1.2       ad 	(*pr)("Sorry, kernel not built with the LOCKDEBUG option.\n");
    727   1.2       ad #endif	/* LOCKDEBUG */
    728   1.2       ad }
    729   1.2       ad #endif	/* DDB */
    730   1.2       ad 
    731   1.2       ad /*
    732   1.2       ad  * lockdebug_abort:
    733   1.2       ad  *
    734   1.2       ad  *	An error has been trapped - dump lock info and call panic().
    735   1.2       ad  */
    736   1.2       ad void
    737  1.16     yamt lockdebug_abort(volatile void *lock, lockops_t *ops, const char *func,
    738  1.16     yamt 		const char *msg)
    739   1.2       ad {
    740   1.2       ad #ifdef LOCKDEBUG
    741   1.2       ad 	lockdebug_t *ld;
    742   1.2       ad 	lockdebuglk_t *lk;
    743   1.2       ad 
    744  1.16     yamt 	if ((ld = lockdebug_lookup(lock, &lk)) != NULL) {
    745  1.10       ad 		lockdebug_abort1(ld, lk, func, msg, true);
    746   1.2       ad 		/* NOTREACHED */
    747   1.2       ad 	}
    748   1.2       ad #endif	/* LOCKDEBUG */
    749   1.2       ad 
    750   1.2       ad 	printf_nolog("%s error: %s: %s\n\n"
    751   1.2       ad 	    "lock address : %#018lx\n"
    752   1.2       ad 	    "current cpu  : %18d\n"
    753   1.2       ad 	    "current lwp  : %#018lx\n",
    754   1.2       ad 	    ops->lo_name, func, msg, (long)lock, (int)cpu_number(),
    755   1.2       ad 	    (long)curlwp);
    756   1.2       ad 
    757   1.2       ad 	(*ops->lo_dump)(lock);
    758   1.2       ad 
    759   1.2       ad 	printf_nolog("\n");
    760   1.2       ad 	panic("lock error");
    761   1.2       ad }
    762