diff options
Diffstat (limited to 'sys/kern/subr_witness.c')
| -rw-r--r-- | sys/kern/subr_witness.c | 1488 |
1 files changed, 1488 insertions, 0 deletions
diff --git a/sys/kern/subr_witness.c b/sys/kern/subr_witness.c new file mode 100644 index 0000000..182221d --- /dev/null +++ b/sys/kern/subr_witness.c @@ -0,0 +1,1488 @@ +/*- + * Copyright (c) 1998 Berkeley Software Design, Inc. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Berkeley Software Design Inc's name may not be used to endorse or + * promote products derived from this software without specific prior + * written permission. + * + * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * from BSDI $Id: mutex_witness.c,v 1.1.2.20 2000/04/27 03:10:27 cp Exp $ + * and BSDI $Id: synch_machdep.c,v 2.3.2.39 2000/04/27 03:10:25 cp Exp $ + * $FreeBSD$ + */ + +/* + * Implementation of the `witness' lock verifier. Originally implemented for + * mutexes in BSD/OS. Extended to handle generic lock objects and lock + * classes in FreeBSD. + */ + +/* + * Main Entry: witness + * Pronunciation: 'wit-n&s + * Function: noun + * Etymology: Middle English witnesse, from Old English witnes knowledge, + * testimony, witness, from 2wit + * Date: before 12th century + * 1 : attestation of a fact or event : TESTIMONY + * 2 : one that gives evidence; specifically : one who testifies in + * a cause or before a judicial tribunal + * 3 : one asked to be present at a transaction so as to be able to + * testify to its having taken place + * 4 : one who has personal knowledge of something + * 5 a : something serving as evidence or proof : SIGN + * b : public affirmation by word or example of usually + * religious faith or conviction <the heroic witness to divine + * life -- Pilot> + * 6 capitalized : a member of the Jehovah's Witnesses + */ + +#include "opt_ddb.h" +#include "opt_witness.h" + +#include <sys/param.h> +#include <sys/bus.h> +#include <sys/kernel.h> +#include <sys/ktr.h> +#include <sys/lock.h> +#include <sys/malloc.h> +#include <sys/mutex.h> +#include <sys/proc.h> +#include <sys/sysctl.h> +#include <sys/systm.h> + +#include <ddb/ddb.h> + +#define WITNESS_COUNT 200 +#define WITNESS_CHILDCOUNT (WITNESS_COUNT * 4) +/* + * XXX: This is somewhat bogus, as we assume here that at most 1024 threads + * will hold LOCK_NCHILDREN * 2 locks. We handle failure ok, and we should + * probably be safe for the most part, but it's still a SWAG. + */ +#define LOCK_CHILDCOUNT (MAXCPU + 1024) * 2 + +#define WITNESS_NCHILDREN 6 + +struct witness_child_list_entry; + +struct witness { + const char *w_name; + struct lock_class *w_class; + STAILQ_ENTRY(witness) w_list; /* List of all witnesses. */ + STAILQ_ENTRY(witness) w_typelist; /* Witnesses of a type. */ + struct witness_child_list_entry *w_children; /* Great evilness... */ + const char *w_file; + int w_line; + u_int w_level; + u_int w_refcount; + u_char w_Giant_squawked:1; + u_char w_other_squawked:1; + u_char w_same_squawked:1; +}; + +struct witness_child_list_entry { + struct witness_child_list_entry *wcl_next; + struct witness *wcl_children[WITNESS_NCHILDREN]; + u_int wcl_count; +}; + +STAILQ_HEAD(witness_list, witness); + +struct witness_blessed { + const char *b_lock1; + const char *b_lock2; +}; + +struct witness_order_list_entry { + const char *w_name; + struct lock_class *w_class; +}; + +static struct witness *enroll(const char *description, + struct lock_class *lock_class); +static int itismychild(struct witness *parent, struct witness *child); +static void removechild(struct witness *parent, struct witness *child); +static int isitmychild(struct witness *parent, struct witness *child); +static int isitmydescendant(struct witness *parent, struct witness *child); +static int blessed(struct witness *, struct witness *); +static void witness_display_list(void(*prnt)(const char *fmt, ...), + struct witness_list *list); +static void witness_displaydescendants(void(*)(const char *fmt, ...), + struct witness *); +static void witness_leveldescendents(struct witness *parent, int level); +static void witness_levelall(void); +static struct witness *witness_get(void); +static void witness_free(struct witness *m); +static struct witness_child_list_entry *witness_child_get(void); +static void witness_child_free(struct witness_child_list_entry *wcl); +static struct lock_list_entry *witness_lock_list_get(void); +static void witness_lock_list_free(struct lock_list_entry *lle); +static void witness_display(void(*)(const char *fmt, ...)); +static struct lock_instance *find_instance(struct lock_list_entry *lock_list, + struct lock_object *lock); + +MALLOC_DEFINE(M_WITNESS, "witness", "witness structure"); + +static int witness_watch = 1; +TUNABLE_INT("debug.witness_watch", &witness_watch); +SYSCTL_INT(_debug, OID_AUTO, witness_watch, CTLFLAG_RD, &witness_watch, 0, ""); + +#ifdef DDB +/* + * When DDB is enabled and witness_ddb is set to 1, it will cause the system to + * drop into kdebug() when: + * - a lock heirarchy violation occurs + * - locks are held when going to sleep. + */ +#ifdef WITNESS_DDB +int witness_ddb = 1; +#else +int witness_ddb = 0; +#endif +TUNABLE_INT("debug.witness_ddb", &witness_ddb); +SYSCTL_INT(_debug, OID_AUTO, witness_ddb, CTLFLAG_RW, &witness_ddb, 0, ""); +#endif /* DDB */ + +#ifdef WITNESS_SKIPSPIN +int witness_skipspin = 1; +#else +int witness_skipspin = 0; +#endif +TUNABLE_INT("debug.witness_skipspin", &witness_skipspin); +SYSCTL_INT(_debug, OID_AUTO, witness_skipspin, CTLFLAG_RD, &witness_skipspin, 0, + ""); + +static struct mtx w_mtx; +static struct witness_list w_free = STAILQ_HEAD_INITIALIZER(w_free); +static struct witness_list w_all = STAILQ_HEAD_INITIALIZER(w_all); +static struct witness_list w_spin = STAILQ_HEAD_INITIALIZER(w_spin); +static struct witness_list w_sleep = STAILQ_HEAD_INITIALIZER(w_sleep); +static struct witness_child_list_entry *w_child_free = NULL; +static struct lock_list_entry *w_lock_list_free = NULL; +static int witness_dead; /* fatal error, probably no memory */ + +static struct witness w_data[WITNESS_COUNT]; +static struct witness_child_list_entry w_childdata[WITNESS_CHILDCOUNT]; +static struct lock_list_entry w_locklistdata[LOCK_CHILDCOUNT]; + +static struct witness_order_list_entry order_lists[] = { + { "Giant", &lock_class_mtx_sleep }, + { "proctree", &lock_class_sx }, + { "allproc", &lock_class_sx }, + { "sigio lock", &lock_class_mtx_sleep }, + { "process group", &lock_class_mtx_sleep }, + { "process lock", &lock_class_mtx_sleep }, + { "session", &lock_class_mtx_sleep }, + { "uidinfo hash", &lock_class_mtx_sleep }, + { "uidinfo struct", &lock_class_mtx_sleep }, + { NULL, NULL }, + /* + * spin locks + */ +#ifdef SMP + { "ap boot", &lock_class_mtx_spin }, +#ifdef __i386__ + { "com", &lock_class_mtx_spin }, +#endif +#endif + { "sio", &lock_class_mtx_spin }, +#ifdef __i386__ + { "cy", &lock_class_mtx_spin }, +#endif + { "ng_node", &lock_class_mtx_spin }, + { "ng_worklist", &lock_class_mtx_spin }, + { "ithread table lock", &lock_class_mtx_spin }, + { "sched lock", &lock_class_mtx_spin }, + { "callout", &lock_class_mtx_spin }, + /* + * leaf locks + */ + { "allpmaps", &lock_class_mtx_spin }, + { "vm page buckets mutex", &lock_class_mtx_spin }, + { "icu", &lock_class_mtx_spin }, +#ifdef SMP + { "smp rendezvous", &lock_class_mtx_spin }, +#endif + { "clk", &lock_class_mtx_spin }, + { "mutex profiling lock", &lock_class_mtx_spin }, + { NULL, NULL }, + { NULL, NULL } +}; + +/* + * Pairs of locks which have been blessed + * Don't complain about order problems with blessed locks + */ +static struct witness_blessed blessed_list[] = { +}; +static int blessed_count = + sizeof(blessed_list) / sizeof(struct witness_blessed); + +/* + * List of all locks in the system. + */ +TAILQ_HEAD(, lock_object) all_locks = TAILQ_HEAD_INITIALIZER(all_locks); + +static struct mtx all_mtx = { + { &lock_class_mtx_sleep, /* mtx_object.lo_class */ + "All locks list", /* mtx_object.lo_name */ + "All locks list", /* mtx_object.lo_type */ + LO_INITIALIZED, /* mtx_object.lo_flags */ + { NULL, NULL }, /* mtx_object.lo_list */ + NULL }, /* mtx_object.lo_witness */ + MTX_UNOWNED, 0, /* mtx_lock, mtx_recurse */ + TAILQ_HEAD_INITIALIZER(all_mtx.mtx_blocked), + { NULL, NULL } /* mtx_contested */ +}; + +/* + * This global is set to 0 once it becomes safe to use the witness code. + */ +static int witness_cold = 1; + +/* + * Global variables for book keeping. + */ +static int lock_cur_cnt; +static int lock_max_cnt; + +/* + * The WITNESS-enabled diagnostic code. + */ +static void +witness_initialize(void *dummy __unused) +{ + struct lock_object *lock; + struct witness_order_list_entry *order; + struct witness *w, *w1; + int i; + + /* + * We have to release Giant before initializing its witness + * structure so that WITNESS doesn't get confused. + */ + mtx_unlock(&Giant); + mtx_assert(&Giant, MA_NOTOWNED); + + CTR1(KTR_WITNESS, "%s: initializing witness", __func__); + TAILQ_INSERT_HEAD(&all_locks, &all_mtx.mtx_object, lo_list); + mtx_init(&w_mtx, "witness lock", NULL, MTX_SPIN | MTX_QUIET | + MTX_NOWITNESS); + for (i = 0; i < WITNESS_COUNT; i++) + witness_free(&w_data[i]); + for (i = 0; i < WITNESS_CHILDCOUNT; i++) + witness_child_free(&w_childdata[i]); + for (i = 0; i < LOCK_CHILDCOUNT; i++) + witness_lock_list_free(&w_locklistdata[i]); + + /* First add in all the specified order lists. */ + for (order = order_lists; order->w_name != NULL; order++) { + w = enroll(order->w_name, order->w_class); + if (w == NULL) + continue; + w->w_file = "order list"; + for (order++; order->w_name != NULL; order++) { + w1 = enroll(order->w_name, order->w_class); + if (w1 == NULL) + continue; + w1->w_file = "order list"; + itismychild(w, w1); + w = w1; + } + } + + /* Iterate through all locks and add them to witness. */ + mtx_lock(&all_mtx); + TAILQ_FOREACH(lock, &all_locks, lo_list) { + if (lock->lo_flags & LO_WITNESS) + lock->lo_witness = enroll(lock->lo_type, + lock->lo_class); + else + lock->lo_witness = NULL; + } + mtx_unlock(&all_mtx); + + /* Mark the witness code as being ready for use. */ + atomic_store_rel_int(&witness_cold, 0); + + mtx_lock(&Giant); +} +SYSINIT(witness_init, SI_SUB_WITNESS, SI_ORDER_FIRST, witness_initialize, NULL) + +void +witness_init(struct lock_object *lock) +{ + struct lock_class *class; + + class = lock->lo_class; + if (lock->lo_flags & LO_INITIALIZED) + panic("%s: lock (%s) %s is already initialized", __func__, + class->lc_name, lock->lo_name); + if ((lock->lo_flags & LO_RECURSABLE) != 0 && + (class->lc_flags & LC_RECURSABLE) == 0) + panic("%s: lock (%s) %s can not be recursable", __func__, + class->lc_name, lock->lo_name); + if ((lock->lo_flags & LO_SLEEPABLE) != 0 && + (class->lc_flags & LC_SLEEPABLE) == 0) + panic("%s: lock (%s) %s can not be sleepable", __func__, + class->lc_name, lock->lo_name); + if ((lock->lo_flags & LO_UPGRADABLE) != 0 && + (class->lc_flags & LC_UPGRADABLE) == 0) + panic("%s: lock (%s) %s can not be upgradable", __func__, + class->lc_name, lock->lo_name); + + mtx_lock(&all_mtx); + TAILQ_INSERT_TAIL(&all_locks, lock, lo_list); + lock->lo_flags |= LO_INITIALIZED; + lock_cur_cnt++; + if (lock_cur_cnt > lock_max_cnt) + lock_max_cnt = lock_cur_cnt; + mtx_unlock(&all_mtx); + if (!witness_cold && !witness_dead && panicstr == NULL && + (lock->lo_flags & LO_WITNESS) != 0) + lock->lo_witness = enroll(lock->lo_type, class); + else + lock->lo_witness = NULL; +} + +void +witness_destroy(struct lock_object *lock) +{ + struct witness *w; + + if (witness_cold) + panic("lock (%s) %s destroyed while witness_cold", + lock->lo_class->lc_name, lock->lo_name); + if ((lock->lo_flags & LO_INITIALIZED) == 0) + panic("%s: lock (%s) %s is not initialized", __func__, + lock->lo_class->lc_name, lock->lo_name); + + /* XXX: need to verify that no one holds the lock */ + w = lock->lo_witness; + if (w != NULL) { + mtx_lock_spin(&w_mtx); + MPASS(w->w_refcount > 0); + w->w_refcount--; + mtx_unlock_spin(&w_mtx); + } + + mtx_lock(&all_mtx); + lock_cur_cnt--; + TAILQ_REMOVE(&all_locks, lock, lo_list); + lock->lo_flags &= ~LO_INITIALIZED; + mtx_unlock(&all_mtx); +} + +static void +witness_display_list(void(*prnt)(const char *fmt, ...), + struct witness_list *list) +{ + struct witness *w, *w1; + int found; + + STAILQ_FOREACH(w, list, w_typelist) { + if (w->w_file == NULL) + continue; + found = 0; + STAILQ_FOREACH(w1, list, w_typelist) { + if (isitmychild(w1, w)) { + found++; + break; + } + } + if (found) + continue; + /* + * This lock has no anscestors, display its descendants. + */ + witness_displaydescendants(prnt, w); + } +} + +static void +witness_display(void(*prnt)(const char *fmt, ...)) +{ + struct witness *w; + + KASSERT(!witness_cold, ("%s: witness_cold", __func__)); + witness_levelall(); + + /* + * First, handle sleep locks which have been acquired at least + * once. + */ + prnt("Sleep locks:\n"); + witness_display_list(prnt, &w_sleep); + + /* + * Now do spin locks which have been acquired at least once. + */ + prnt("\nSpin locks:\n"); + witness_display_list(prnt, &w_spin); + + /* + * Finally, any locks which have not been acquired yet. + */ + prnt("\nLocks which were never acquired:\n"); + STAILQ_FOREACH(w, &w_all, w_list) { + if (w->w_file != NULL || w->w_refcount == 0) + continue; + prnt("%s\n", w->w_name); + } +} + +void +witness_lock(struct lock_object *lock, int flags, const char *file, int line) +{ + struct lock_list_entry **lock_list, *lle; + struct lock_instance *lock1, *lock2; + struct lock_class *class; + struct witness *w, *w1; + struct thread *td; + int i, j; +#ifdef DDB + int go_into_ddb = 0; +#endif /* DDB */ + + if (witness_cold || witness_dead || lock->lo_witness == NULL || + panicstr != NULL) + return; + w = lock->lo_witness; + class = lock->lo_class; + td = curthread; + + if (class->lc_flags & LC_SLEEPLOCK) { + /* + * Since spin locks include a critical section, this check + * impliclty enforces a lock order of all sleep locks before + * all spin locks. + */ + if (td->td_critnest != 0 && (flags & LOP_TRYLOCK) == 0) + panic("blockable sleep lock (%s) %s @ %s:%d", + class->lc_name, lock->lo_name, file, line); + lock_list = &td->td_sleeplocks; + } else + lock_list = PCPU_PTR(spinlocks); + + /* + * Try locks do not block if they fail to acquire the lock, thus + * there is no danger of deadlocks or of switching while holding a + * spin lock if we acquire a lock via a try operation. + */ + if (flags & LOP_TRYLOCK) + goto out; + + /* + * Is this the first lock acquired? If so, then no order checking + * is needed. + */ + if (*lock_list == NULL) + goto out; + + /* + * Check to see if we are recursing on a lock we already own. + */ + lock1 = find_instance(*lock_list, lock); + if (lock1 != NULL) { + if ((lock1->li_flags & LI_EXCLUSIVE) != 0 && + (flags & LOP_EXCLUSIVE) == 0) { + printf("shared lock of (%s) %s @ %s:%d\n", + class->lc_name, lock->lo_name, file, line); + printf("while exclusively locked from %s:%d\n", + lock1->li_file, lock1->li_line); + panic("share->excl"); + } + if ((lock1->li_flags & LI_EXCLUSIVE) == 0 && + (flags & LOP_EXCLUSIVE) != 0) { + printf("exclusive lock of (%s) %s @ %s:%d\n", + class->lc_name, lock->lo_name, file, line); + printf("while share locked from %s:%d\n", + lock1->li_file, lock1->li_line); + panic("excl->share"); + } + lock1->li_flags++; + if ((lock->lo_flags & LO_RECURSABLE) == 0) { + printf( + "recursed on non-recursive lock (%s) %s @ %s:%d\n", + class->lc_name, lock->lo_name, file, line); + printf("first acquired @ %s:%d\n", lock1->li_file, + lock1->li_line); + panic("recurse"); + } + CTR4(KTR_WITNESS, "%s: pid %d recursed on %s r=%d", __func__, + td->td_proc->p_pid, lock->lo_name, + lock1->li_flags & LI_RECURSEMASK); + lock1->li_file = file; + lock1->li_line = line; + return; + } + + /* + * Check for duplicate locks of the same type. Note that we only + * have to check for this on the last lock we just acquired. Any + * other cases will be caught as lock order violations. + */ + lock1 = &(*lock_list)->ll_children[(*lock_list)->ll_count - 1]; + w1 = lock1->li_lock->lo_witness; + if (w1 == w) { + if (w->w_same_squawked || (lock->lo_flags & LO_DUPOK)) + goto out; + w->w_same_squawked = 1; + printf("acquiring duplicate lock of same type: \"%s\"\n", + lock->lo_type); + printf(" 1st %s @ %s:%d\n", lock1->li_lock->lo_name, + lock1->li_file, lock1->li_line); + printf(" 2nd %s @ %s:%d\n", lock->lo_name, file, line); +#ifdef DDB + go_into_ddb = 1; +#endif /* DDB */ + goto out; + } + MPASS(!mtx_owned(&w_mtx)); + mtx_lock_spin(&w_mtx); + /* + * If we have a known higher number just say ok + */ + if (witness_watch > 1 && w->w_level > w1->w_level) { + mtx_unlock_spin(&w_mtx); + goto out; + } + if (isitmydescendant(w1, w)) { + mtx_unlock_spin(&w_mtx); + goto out; + } + for (j = 0, lle = *lock_list; lle != NULL; lle = lle->ll_next) { + for (i = lle->ll_count - 1; i >= 0; i--, j++) { + + MPASS(j < WITNESS_COUNT); + lock1 = &lle->ll_children[i]; + w1 = lock1->li_lock->lo_witness; + + /* + * If this lock doesn't undergo witness checking, + * then skip it. + */ + if (w1 == NULL) { + KASSERT((lock1->li_lock->lo_flags & LO_WITNESS) == 0, + ("lock missing witness structure")); + continue; + } + /* + * If we are locking Giant and we slept with this + * lock, then skip it. + */ + if ((lock1->li_flags & LI_SLEPT) != 0 && + lock == &Giant.mtx_object) + continue; + /* + * If we are locking a sleepable lock and this lock + * isn't sleepable and isn't Giant, we want to treat + * it as a lock order violation to enfore a general + * lock order of sleepable locks before non-sleepable + * locks. Thus, we only bother checking the lock + * order hierarchy if we pass the initial test. + */ + if (!((lock->lo_flags & LO_SLEEPABLE) != 0 && + ((lock1->li_lock->lo_flags & LO_SLEEPABLE) == 0 && + lock1->li_lock != &Giant.mtx_object)) && + !isitmydescendant(w, w1)) + continue; + /* + * We have a lock order violation, check to see if it + * is allowed or has already been yelled about. + */ + mtx_unlock_spin(&w_mtx); + if (blessed(w, w1)) + goto out; + if (lock1->li_lock == &Giant.mtx_object) { + if (w1->w_Giant_squawked) + goto out; + else + w1->w_Giant_squawked = 1; + } else { + if (w1->w_other_squawked) + goto out; + else + w1->w_other_squawked = 1; + } + /* + * Ok, yell about it. + */ + printf("lock order reversal\n"); + /* + * Try to locate an earlier lock with + * witness w in our list. + */ + do { + lock2 = &lle->ll_children[i]; + MPASS(lock2->li_lock != NULL); + if (lock2->li_lock->lo_witness == w) + break; + i--; + if (i == 0 && lle->ll_next != NULL) { + lle = lle->ll_next; + i = lle->ll_count - 1; + MPASS(i != 0); + } + } while (i >= 0); + if (i < 0) { + printf(" 1st %p %s (%s) @ %s:%d\n", + lock1->li_lock, lock1->li_lock->lo_name, + lock1->li_lock->lo_type, lock1->li_file, + lock1->li_line); + printf(" 2nd %p %s (%s) @ %s:%d\n", lock, + lock->lo_name, lock->lo_type, file, line); + } else { + printf(" 1st %p %s (%s) @ %s:%d\n", + lock2->li_lock, lock2->li_lock->lo_name, + lock2->li_lock->lo_type, lock2->li_file, + lock2->li_line); + printf(" 2nd %p %s (%s) @ %s:%d\n", + lock1->li_lock, lock1->li_lock->lo_name, + lock1->li_lock->lo_type, lock1->li_file, + lock1->li_line); + printf(" 3rd %p %s (%s) @ %s:%d\n", lock, + lock->lo_name, lock->lo_type, file, line); + } +#ifdef DDB + go_into_ddb = 1; +#endif /* DDB */ + goto out; + } + } + lock1 = &(*lock_list)->ll_children[(*lock_list)->ll_count - 1]; + /* + * Don't build a new relationship if we are locking Giant just + * after waking up and the previous lock in the list was acquired + * prior to blocking. + */ + if (lock == &Giant.mtx_object && (lock1->li_flags & LI_SLEPT) != 0) + mtx_unlock_spin(&w_mtx); + else { + CTR3(KTR_WITNESS, "%s: adding %s as a child of %s", __func__, + lock->lo_type, lock1->li_lock->lo_type); + if (!itismychild(lock1->li_lock->lo_witness, w)) + mtx_unlock_spin(&w_mtx); + } + +out: +#ifdef DDB + if (witness_ddb && go_into_ddb) + Debugger(__func__); +#endif /* DDB */ + w->w_file = file; + w->w_line = line; + + lle = *lock_list; + if (lle == NULL || lle->ll_count == LOCK_NCHILDREN) { + lle = witness_lock_list_get(); + if (lle == NULL) + return; + lle->ll_next = *lock_list; + CTR3(KTR_WITNESS, "%s: pid %d added lle %p", __func__, + td->td_proc->p_pid, lle); + *lock_list = lle; + } + lock1 = &lle->ll_children[lle->ll_count++]; + lock1->li_lock = lock; + lock1->li_line = line; + lock1->li_file = file; + if ((flags & LOP_EXCLUSIVE) != 0) + lock1->li_flags = LI_EXCLUSIVE; + else + lock1->li_flags = 0; + CTR4(KTR_WITNESS, "%s: pid %d added %s as lle[%d]", __func__, + td->td_proc->p_pid, lock->lo_name, lle->ll_count - 1); +} + +void +witness_upgrade(struct lock_object *lock, int flags, const char *file, int line) +{ + struct lock_instance *instance; + struct lock_class *class; + + KASSERT(!witness_cold, ("%s: witness_cold", __func__)); + if (lock->lo_witness == NULL || witness_dead || panicstr != NULL) + return; + class = lock->lo_class; + if ((lock->lo_flags & LO_UPGRADABLE) == 0) + panic("upgrade of non-upgradable lock (%s) %s @ %s:%d", + class->lc_name, lock->lo_name, file, line); + if ((flags & LOP_TRYLOCK) == 0) + panic("non-try upgrade of lock (%s) %s @ %s:%d", class->lc_name, + lock->lo_name, file, line); + if ((lock->lo_class->lc_flags & LC_SLEEPLOCK) == 0) + panic("upgrade of non-sleep lock (%s) %s @ %s:%d", + class->lc_name, lock->lo_name, file, line); + instance = find_instance(curthread->td_sleeplocks, lock); + if (instance == NULL) + panic("upgrade of unlocked lock (%s) %s @ %s:%d", + class->lc_name, lock->lo_name, file, line); + if ((instance->li_flags & LI_EXCLUSIVE) != 0) + panic("upgrade of exclusive lock (%s) %s @ %s:%d", + class->lc_name, lock->lo_name, file, line); + if ((instance->li_flags & LI_RECURSEMASK) != 0) + panic("upgrade of recursed lock (%s) %s r=%d @ %s:%d", + class->lc_name, lock->lo_name, + instance->li_flags & LI_RECURSEMASK, file, line); + instance->li_flags |= LI_EXCLUSIVE; +} + +void +witness_downgrade(struct lock_object *lock, int flags, const char *file, + int line) +{ + struct lock_instance *instance; + struct lock_class *class; + + KASSERT(!witness_cold, ("%s: witness_cold", __func__)); + if (lock->lo_witness == NULL || witness_dead || panicstr != NULL) + return; + class = lock->lo_class; + if ((lock->lo_flags & LO_UPGRADABLE) == 0) + panic("downgrade of non-upgradable lock (%s) %s @ %s:%d", + class->lc_name, lock->lo_name, file, line); + if ((lock->lo_class->lc_flags & LC_SLEEPLOCK) == 0) + panic("downgrade of non-sleep lock (%s) %s @ %s:%d", + class->lc_name, lock->lo_name, file, line); + instance = find_instance(curthread->td_sleeplocks, lock); + if (instance == NULL) + panic("downgrade of unlocked lock (%s) %s @ %s:%d", + class->lc_name, lock->lo_name, file, line); + if ((instance->li_flags & LI_EXCLUSIVE) == 0) + panic("downgrade of shared lock (%s) %s @ %s:%d", + class->lc_name, lock->lo_name, file, line); + if ((instance->li_flags & LI_RECURSEMASK) != 0) + panic("downgrade of recursed lock (%s) %s r=%d @ %s:%d", + class->lc_name, lock->lo_name, + instance->li_flags & LI_RECURSEMASK, file, line); + instance->li_flags &= ~LI_EXCLUSIVE; +} + +void +witness_unlock(struct lock_object *lock, int flags, const char *file, int line) +{ + struct lock_list_entry **lock_list, *lle; + struct lock_instance *instance; + struct lock_class *class; + struct thread *td; + register_t s; + int i, j; + + if (witness_cold || witness_dead || lock->lo_witness == NULL || + panicstr != NULL) + return; + td = curthread; + class = lock->lo_class; + if (class->lc_flags & LC_SLEEPLOCK) + lock_list = &td->td_sleeplocks; + else + lock_list = PCPU_PTR(spinlocks); + for (; *lock_list != NULL; lock_list = &(*lock_list)->ll_next) + for (i = 0; i < (*lock_list)->ll_count; i++) { + instance = &(*lock_list)->ll_children[i]; + if (instance->li_lock == lock) { + if ((instance->li_flags & LI_EXCLUSIVE) != 0 && + (flags & LOP_EXCLUSIVE) == 0) { + printf( + "shared unlock of (%s) %s @ %s:%d\n", + class->lc_name, lock->lo_name, + file, line); + printf( + "while exclusively locked from %s:%d\n", + instance->li_file, + instance->li_line); + panic("excl->ushare"); + } + if ((instance->li_flags & LI_EXCLUSIVE) == 0 && + (flags & LOP_EXCLUSIVE) != 0) { + printf( + "exclusive unlock of (%s) %s @ %s:%d\n", + class->lc_name, lock->lo_name, + file, line); + printf( + "while share locked from %s:%d\n", + instance->li_file, + instance->li_line); + panic("share->uexcl"); + } + /* If we are recursed, unrecurse. */ + if ((instance->li_flags & LI_RECURSEMASK) > 0) { + CTR4(KTR_WITNESS, + "%s: pid %d unrecursed on %s r=%d", __func__, + td->td_proc->p_pid, + instance->li_lock->lo_name, + instance->li_flags); + instance->li_flags--; + return; + } + s = intr_disable(); + CTR4(KTR_WITNESS, + "%s: pid %d removed %s from lle[%d]", __func__, + td->td_proc->p_pid, + instance->li_lock->lo_name, + (*lock_list)->ll_count - 1); + for (j = i; j < (*lock_list)->ll_count - 1; j++) + (*lock_list)->ll_children[j] = + (*lock_list)->ll_children[j + 1]; + (*lock_list)->ll_count--; + intr_restore(s); + if ((*lock_list)->ll_count == 0) { + lle = *lock_list; + *lock_list = lle->ll_next; + CTR3(KTR_WITNESS, + "%s: pid %d removed lle %p", __func__, + td->td_proc->p_pid, lle); + witness_lock_list_free(lle); + } + return; + } + } + panic("lock (%s) %s not locked @ %s:%d", class->lc_name, lock->lo_name, + file, line); +} + +/* + * Warn if any held locks are not sleepable. Note that Giant and the lock + * passed in are both special cases since they are both released during the + * sleep process and aren't actually held while the thread is asleep. + */ +int +witness_sleep(int check_only, struct lock_object *lock, const char *file, + int line) +{ + struct lock_list_entry **lock_list, *lle; + struct lock_instance *lock1; + struct thread *td; + int i, n; + + if (witness_cold || witness_dead || panicstr != NULL) + return (0); + n = 0; + td = curthread; + lock_list = &td->td_sleeplocks; +again: + for (lle = *lock_list; lle != NULL; lle = lle->ll_next) + for (i = lle->ll_count - 1; i >= 0; i--) { + lock1 = &lle->ll_children[i]; + if (lock1->li_lock == lock || + lock1->li_lock == &Giant.mtx_object) + continue; + if ((lock1->li_lock->lo_flags & LO_SLEEPABLE) != 0) { + if (check_only == 0) { + CTR3(KTR_WITNESS, + "pid %d: sleeping with lock (%s) %s held", + td->td_proc->p_pid, + lock1->li_lock->lo_class->lc_name, + lock1->li_lock->lo_name); + lock1->li_flags |= LI_SLEPT; + } + continue; + } + n++; + printf("%s:%d: %s with \"%s\" locked from %s:%d\n", + file, line, check_only ? "could sleep" : "sleeping", + lock1->li_lock->lo_name, lock1->li_file, + lock1->li_line); + } + if (lock_list == &td->td_sleeplocks && PCPU_GET(spinlocks) != NULL) { + /* + * Since we already hold a spinlock preemption is + * already blocked. + */ + lock_list = PCPU_PTR(spinlocks); + goto again; + } +#ifdef DDB + if (witness_ddb && n) + Debugger(__func__); +#endif /* DDB */ + return (n); +} + +static struct witness * +enroll(const char *description, struct lock_class *lock_class) +{ + struct witness *w; + + if (!witness_watch || witness_dead || panicstr != NULL) + return (NULL); + if ((lock_class->lc_flags & LC_SPINLOCK) && witness_skipspin) + return (NULL); + mtx_lock_spin(&w_mtx); + STAILQ_FOREACH(w, &w_all, w_list) { + if (w->w_name == description || (w->w_refcount > 0 && + strcmp(description, w->w_name) == 0)) { + w->w_refcount++; + mtx_unlock_spin(&w_mtx); + if (lock_class != w->w_class) + panic( + "lock (%s) %s does not match earlier (%s) lock", + description, lock_class->lc_name, + w->w_class->lc_name); + return (w); + } + } + /* + * This isn't quite right, as witness_cold is still 0 while we + * enroll all the locks initialized before witness_initialize(). + */ + if ((lock_class->lc_flags & LC_SPINLOCK) && !witness_cold) { + mtx_unlock_spin(&w_mtx); + panic("spin lock %s not in order list", description); + } + if ((w = witness_get()) == NULL) + return (NULL); + w->w_name = description; + w->w_class = lock_class; + w->w_refcount = 1; + STAILQ_INSERT_HEAD(&w_all, w, w_list); + if (lock_class->lc_flags & LC_SPINLOCK) + STAILQ_INSERT_HEAD(&w_spin, w, w_typelist); + else if (lock_class->lc_flags & LC_SLEEPLOCK) + STAILQ_INSERT_HEAD(&w_sleep, w, w_typelist); + else { + mtx_unlock_spin(&w_mtx); + panic("lock class %s is not sleep or spin", + lock_class->lc_name); + } + mtx_unlock_spin(&w_mtx); + return (w); +} + +static int +itismychild(struct witness *parent, struct witness *child) +{ + static int recursed; + struct witness_child_list_entry **wcl; + struct witness_list *list; + + MPASS(child != NULL && parent != NULL); + if ((parent->w_class->lc_flags & (LC_SLEEPLOCK | LC_SPINLOCK)) != + (child->w_class->lc_flags & (LC_SLEEPLOCK | LC_SPINLOCK))) + panic( + "%s: parent (%s) and child (%s) are not the same lock type", + __func__, parent->w_class->lc_name, + child->w_class->lc_name); + + /* + * Insert "child" after "parent" + */ + wcl = &parent->w_children; + while (*wcl != NULL && (*wcl)->wcl_count == WITNESS_NCHILDREN) + wcl = &(*wcl)->wcl_next; + if (*wcl == NULL) { + *wcl = witness_child_get(); + if (*wcl == NULL) + return (1); + } + (*wcl)->wcl_children[(*wcl)->wcl_count++] = child; + + /* + * Now prune whole tree. We look for cases where a lock is now + * both a descendant and a direct child of a given lock. In that + * case, we want to remove the direct child link from the tree. + */ + if (recursed) + return (0); + recursed = 1; + if (parent->w_class->lc_flags & LC_SLEEPLOCK) + list = &w_sleep; + else + list = &w_spin; + STAILQ_FOREACH(child, list, w_typelist) { + STAILQ_FOREACH(parent, list, w_typelist) { + if (!isitmychild(parent, child)) + continue; + removechild(parent, child); + if (isitmydescendant(parent, child)) + continue; + itismychild(parent, child); + } + } + recursed = 0; + witness_levelall(); + return (0); +} + +static void +removechild(struct witness *parent, struct witness *child) +{ + struct witness_child_list_entry **wcl, *wcl1; + int i; + + for (wcl = &parent->w_children; *wcl != NULL; wcl = &(*wcl)->wcl_next) + for (i = 0; i < (*wcl)->wcl_count; i++) + if ((*wcl)->wcl_children[i] == child) + goto found; + return; +found: + (*wcl)->wcl_count--; + if ((*wcl)->wcl_count > i) + (*wcl)->wcl_children[i] = + (*wcl)->wcl_children[(*wcl)->wcl_count]; + MPASS((*wcl)->wcl_children[i] != NULL); + if ((*wcl)->wcl_count != 0) + return; + wcl1 = *wcl; + *wcl = wcl1->wcl_next; + witness_child_free(wcl1); +} + +static int +isitmychild(struct witness *parent, struct witness *child) +{ + struct witness_child_list_entry *wcl; + int i; + + for (wcl = parent->w_children; wcl != NULL; wcl = wcl->wcl_next) { + for (i = 0; i < wcl->wcl_count; i++) { + if (wcl->wcl_children[i] == child) + return (1); + } + } + return (0); +} + +static int +isitmydescendant(struct witness *parent, struct witness *child) +{ + struct witness_child_list_entry *wcl; + int i, j; + + if (isitmychild(parent, child)) + return (1); + j = 0; + for (wcl = parent->w_children; wcl != NULL; wcl = wcl->wcl_next) { + MPASS(j < 1000); + for (i = 0; i < wcl->wcl_count; i++) { + if (isitmydescendant(wcl->wcl_children[i], child)) + return (1); + } + j++; + } + return (0); +} + +void +witness_levelall (void) +{ + struct witness_list *list; + struct witness *w, *w1; + + /* + * First clear all levels. + */ + STAILQ_FOREACH(w, &w_all, w_list) { + w->w_level = 0; + } + + /* + * Look for locks with no parent and level all their descendants. + */ + STAILQ_FOREACH(w, &w_all, w_list) { + /* + * This is just an optimization, technically we could get + * away just walking the all list each time. + */ + if (w->w_class->lc_flags & LC_SLEEPLOCK) + list = &w_sleep; + else + list = &w_spin; + STAILQ_FOREACH(w1, list, w_typelist) { + if (isitmychild(w1, w)) + goto skip; + } + witness_leveldescendents(w, 0); + skip: + ; /* silence GCC 3.x */ + } +} + +static void +witness_leveldescendents(struct witness *parent, int level) +{ + struct witness_child_list_entry *wcl; + int i; + + if (parent->w_level < level) + parent->w_level = level; + level++; + for (wcl = parent->w_children; wcl != NULL; wcl = wcl->wcl_next) + for (i = 0; i < wcl->wcl_count; i++) + witness_leveldescendents(wcl->wcl_children[i], level); +} + +static void +witness_displaydescendants(void(*prnt)(const char *fmt, ...), + struct witness *parent) +{ + struct witness_child_list_entry *wcl; + int i, level; + + level = parent->w_level; + prnt("%-2d", level); + for (i = 0; i < level; i++) + prnt(" "); + if (parent->w_refcount > 0) { + prnt("%s", parent->w_name); + if (parent->w_file != NULL) + prnt(" -- last acquired @ %s:%d\n", parent->w_file, + parent->w_line); + } else + prnt("(dead)\n"); + for (wcl = parent->w_children; wcl != NULL; wcl = wcl->wcl_next) + for (i = 0; i < wcl->wcl_count; i++) + witness_displaydescendants(prnt, + wcl->wcl_children[i]); +} + +static int +blessed(struct witness *w1, struct witness *w2) +{ + int i; + struct witness_blessed *b; + + for (i = 0; i < blessed_count; i++) { + b = &blessed_list[i]; + if (strcmp(w1->w_name, b->b_lock1) == 0) { + if (strcmp(w2->w_name, b->b_lock2) == 0) + return (1); + continue; + } + if (strcmp(w1->w_name, b->b_lock2) == 0) + if (strcmp(w2->w_name, b->b_lock1) == 0) + return (1); + } + return (0); +} + +static struct witness * +witness_get(void) +{ + struct witness *w; + + if (witness_dead) { + mtx_unlock_spin(&w_mtx); + return (NULL); + } + if (STAILQ_EMPTY(&w_free)) { + witness_dead = 1; + mtx_unlock_spin(&w_mtx); + printf("%s: witness exhausted\n", __func__); + return (NULL); + } + w = STAILQ_FIRST(&w_free); + STAILQ_REMOVE_HEAD(&w_free, w_list); + bzero(w, sizeof(*w)); + return (w); +} + +static void +witness_free(struct witness *w) +{ + + STAILQ_INSERT_HEAD(&w_free, w, w_list); +} + +static struct witness_child_list_entry * +witness_child_get(void) +{ + struct witness_child_list_entry *wcl; + + if (witness_dead) { + mtx_unlock_spin(&w_mtx); + return (NULL); + } + wcl = w_child_free; + if (wcl == NULL) { + witness_dead = 1; + mtx_unlock_spin(&w_mtx); + printf("%s: witness exhausted\n", __func__); + return (NULL); + } + w_child_free = wcl->wcl_next; + bzero(wcl, sizeof(*wcl)); + return (wcl); +} + +static void +witness_child_free(struct witness_child_list_entry *wcl) +{ + + wcl->wcl_next = w_child_free; + w_child_free = wcl; +} + +static struct lock_list_entry * +witness_lock_list_get(void) +{ + struct lock_list_entry *lle; + + if (witness_dead) + return (NULL); + mtx_lock_spin(&w_mtx); + lle = w_lock_list_free; + if (lle == NULL) { + witness_dead = 1; + mtx_unlock_spin(&w_mtx); + printf("%s: witness exhausted\n", __func__); + return (NULL); + } + w_lock_list_free = lle->ll_next; + mtx_unlock_spin(&w_mtx); + bzero(lle, sizeof(*lle)); + return (lle); +} + +static void +witness_lock_list_free(struct lock_list_entry *lle) +{ + + mtx_lock_spin(&w_mtx); + lle->ll_next = w_lock_list_free; + w_lock_list_free = lle; + mtx_unlock_spin(&w_mtx); +} + +static struct lock_instance * +find_instance(struct lock_list_entry *lock_list, struct lock_object *lock) +{ + struct lock_list_entry *lle; + struct lock_instance *instance; + int i; + + for (lle = lock_list; lle != NULL; lle = lle->ll_next) + for (i = lle->ll_count - 1; i >= 0; i--) { + instance = &lle->ll_children[i]; + if (instance->li_lock == lock) + return (instance); + } + return (NULL); +} + +int +witness_list_locks(struct lock_list_entry **lock_list) +{ + struct lock_list_entry *lle; + struct lock_instance *instance; + struct lock_object *lock; + int i, nheld; + + nheld = 0; + for (lle = *lock_list; lle != NULL; lle = lle->ll_next) + for (i = lle->ll_count - 1; i >= 0; i--) { + instance = &lle->ll_children[i]; + lock = instance->li_lock; + printf("%s %s %s", + (instance->li_flags & LI_EXCLUSIVE) != 0 ? + "exclusive" : "shared", + lock->lo_class->lc_name, lock->lo_name); + if (lock->lo_type != lock->lo_name) + printf(" (%s)", lock->lo_type); + printf(" r = %d (%p) locked @ %s:%d\n", + instance->li_flags & LI_RECURSEMASK, lock, + instance->li_file, instance->li_line); + nheld++; + } + return (nheld); +} + +/* + * Calling this on td != curthread is bad unless we are in ddb. + */ +int +witness_list(struct thread *td) +{ + int nheld; + + KASSERT(!witness_cold, ("%s: witness_cold", __func__)); +#ifdef DDB + KASSERT(td == curthread || db_active, + ("%s: td != curthread and we aren't in the debugger", __func__)); + if (!db_active && witness_dead) + return (0); +#else + KASSERT(td == curthread, ("%s: p != curthread", __func__)); + if (witness_dead) + return (0); +#endif + nheld = witness_list_locks(&td->td_sleeplocks); + + /* + * We only handle spinlocks if td == curthread. This is somewhat broken + * if td is currently executing on some other CPU and holds spin locks + * as we won't display those locks. If we had a MI way of getting + * the per-cpu data for a given cpu then we could use + * td->td_kse->ke_oncpu to get the list of spinlocks for this thread + * and "fix" this. + * + * That still wouldn't really fix this unless we locked sched_lock + * or stopped the other CPU to make sure it wasn't changing the list + * out from under us. It is probably best to just not try to handle + * threads on other CPU's for now. + */ + if (td == curthread && PCPU_GET(spinlocks) != NULL) + nheld += witness_list_locks(PCPU_PTR(spinlocks)); + + return (nheld); +} + +void +witness_save(struct lock_object *lock, const char **filep, int *linep) +{ + struct lock_instance *instance; + + KASSERT(!witness_cold, ("%s: witness_cold", __func__)); + if (lock->lo_witness == NULL || witness_dead || panicstr != NULL) + return; + if ((lock->lo_class->lc_flags & LC_SLEEPLOCK) == 0) + panic("%s: lock (%s) %s is not a sleep lock", __func__, + lock->lo_class->lc_name, lock->lo_name); + instance = find_instance(curthread->td_sleeplocks, lock); + if (instance == NULL) + panic("%s: lock (%s) %s not locked", __func__, + lock->lo_class->lc_name, lock->lo_name); + *filep = instance->li_file; + *linep = instance->li_line; +} + +void +witness_restore(struct lock_object *lock, const char *file, int line) +{ + struct lock_instance *instance; + + KASSERT(!witness_cold, ("%s: witness_cold", __func__)); + if (lock->lo_witness == NULL || witness_dead || panicstr != NULL) + return; + if ((lock->lo_class->lc_flags & LC_SLEEPLOCK) == 0) + panic("%s: lock (%s) %s is not a sleep lock", __func__, + lock->lo_class->lc_name, lock->lo_name); + instance = find_instance(curthread->td_sleeplocks, lock); + if (instance == NULL) + panic("%s: lock (%s) %s not locked", __func__, + lock->lo_class->lc_name, lock->lo_name); + lock->lo_witness->w_file = file; + lock->lo_witness->w_line = line; + instance->li_file = file; + instance->li_line = line; +} + +void +witness_assert(struct lock_object *lock, int flags, const char *file, int line) +{ +#ifdef INVARIANT_SUPPORT + struct lock_instance *instance; + + if (lock->lo_witness == NULL || witness_dead || panicstr != NULL) + return; + if ((lock->lo_class->lc_flags & LC_SLEEPLOCK) != 0) + instance = find_instance(curthread->td_sleeplocks, lock); + else if ((lock->lo_class->lc_flags & LC_SPINLOCK) != 0) + instance = find_instance(PCPU_GET(spinlocks), lock); + else { + panic("Lock (%s) %s is not sleep or spin!", + lock->lo_class->lc_name, lock->lo_name); + return; + } + switch (flags) { + case LA_UNLOCKED: + if (instance != NULL) + panic("Lock (%s) %s locked @ %s:%d.", + lock->lo_class->lc_name, lock->lo_name, file, line); + break; + case LA_LOCKED: + case LA_LOCKED | LA_RECURSED: + case LA_LOCKED | LA_NOTRECURSED: + case LA_SLOCKED: + case LA_SLOCKED | LA_RECURSED: + case LA_SLOCKED | LA_NOTRECURSED: + case LA_XLOCKED: + case LA_XLOCKED | LA_RECURSED: + case LA_XLOCKED | LA_NOTRECURSED: + if (instance == NULL) { + panic("Lock (%s) %s not locked @ %s:%d.", + lock->lo_class->lc_name, lock->lo_name, file, line); + break; + } + if ((flags & LA_XLOCKED) != 0 && + (instance->li_flags & LI_EXCLUSIVE) == 0) + panic("Lock (%s) %s not exclusively locked @ %s:%d.", + lock->lo_class->lc_name, lock->lo_name, file, line); + if ((flags & LA_SLOCKED) != 0 && + (instance->li_flags & LI_EXCLUSIVE) != 0) + panic("Lock (%s) %s exclusively locked @ %s:%d.", + lock->lo_class->lc_name, lock->lo_name, file, line); + if ((flags & LA_RECURSED) != 0 && + (instance->li_flags & LI_RECURSEMASK) == 0) + panic("Lock (%s) %s not recursed @ %s:%d.", + lock->lo_class->lc_name, lock->lo_name, file, line); + if ((flags & LA_NOTRECURSED) != 0 && + (instance->li_flags & LI_RECURSEMASK) != 0) + panic("Lock (%s) %s recursed @ %s:%d.", + lock->lo_class->lc_name, lock->lo_name, file, line); + break; + default: + panic("Invalid lock assertion at %s:%d.", file, line); + + } +#endif /* INVARIANT_SUPPORT */ +} + +#ifdef DDB + +DB_SHOW_COMMAND(locks, db_witness_list) +{ + struct thread *td; + pid_t pid; + struct proc *p; + + if (have_addr) { + pid = (addr % 16) + ((addr >> 4) % 16) * 10 + + ((addr >> 8) % 16) * 100 + ((addr >> 12) % 16) * 1000 + + ((addr >> 16) % 16) * 10000; + /* sx_slock(&allproc_lock); */ + FOREACH_PROC_IN_SYSTEM(p) { + if (p->p_pid == pid) + break; + } + /* sx_sunlock(&allproc_lock); */ + if (p == NULL) { + db_printf("pid %d not found\n", pid); + return; + } + FOREACH_THREAD_IN_PROC(p, td) { + witness_list(td); + } + } else { + td = curthread; + witness_list(td); + } +} + +DB_SHOW_COMMAND(witness, db_witness_display) +{ + + witness_display(db_printf); +} +#endif |
