subr_witness.c revision 75273
1252190Srpaulo/*- 2252190Srpaulo * Copyright (c) 1998 Berkeley Software Design, Inc. All rights reserved. 3252190Srpaulo * 4252190Srpaulo * Redistribution and use in source and binary forms, with or without 5252190Srpaulo * modification, are permitted provided that the following conditions 6252190Srpaulo * are met: 7252190Srpaulo * 1. Redistributions of source code must retain the above copyright 8252190Srpaulo * notice, this list of conditions and the following disclaimer. 9252190Srpaulo * 2. Redistributions in binary form must reproduce the above copyright 10252190Srpaulo * notice, this list of conditions and the following disclaimer in the 11252190Srpaulo * documentation and/or other materials provided with the distribution. 12252190Srpaulo * 3. Berkeley Software Design Inc's name may not be used to endorse or 13252190Srpaulo * promote products derived from this software without specific prior 14252190Srpaulo * written permission. 15252190Srpaulo * 16252190Srpaulo * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND 17252190Srpaulo * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18252190Srpaulo * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19252190Srpaulo * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE 20252190Srpaulo * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21252190Srpaulo * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22252190Srpaulo * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23252190Srpaulo * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24252190Srpaulo * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25252190Srpaulo * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26252190Srpaulo * SUCH DAMAGE. 27252190Srpaulo * 28252190Srpaulo * from BSDI $Id: mutex_witness.c,v 1.1.2.20 2000/04/27 03:10:27 cp Exp $ 29252190Srpaulo * and BSDI $Id: synch_machdep.c,v 2.3.2.39 2000/04/27 03:10:25 cp Exp $ 30252190Srpaulo * $FreeBSD: head/sys/kern/subr_witness.c 75273 2001-04-06 21:37:52Z jhb $ 31252190Srpaulo */ 32252190Srpaulo 33252190Srpaulo/* 34252190Srpaulo * Implementation of the `witness' lock verifier. Originally implemented for 35252190Srpaulo * mutexes in BSD/OS. Extended to handle generic lock objects and lock 36252190Srpaulo * classes in FreeBSD. 37252190Srpaulo */ 38252190Srpaulo 39252190Srpaulo/* 40252190Srpaulo * Main Entry: witness 41252190Srpaulo * Pronunciation: 'wit-n&s 42252190Srpaulo * Function: noun 43252190Srpaulo * Etymology: Middle English witnesse, from Old English witnes knowledge, 44252190Srpaulo * testimony, witness, from 2wit 45252190Srpaulo * Date: before 12th century 46252190Srpaulo * 1 : attestation of a fact or event : TESTIMONY 47252190Srpaulo * 2 : one that gives evidence; specifically : one who testifies in 48252190Srpaulo * a cause or before a judicial tribunal 49252190Srpaulo * 3 : one asked to be present at a transaction so as to be able to 50252190Srpaulo * testify to its having taken place 51252190Srpaulo * 4 : one who has personal knowledge of something 52252190Srpaulo * 5 a : something serving as evidence or proof : SIGN 53252190Srpaulo * b : public affirmation by word or example of usually 54252190Srpaulo * religious faith or conviction <the heroic witness to divine 55252190Srpaulo * life -- Pilot> 56252190Srpaulo * 6 capitalized : a member of the Jehovah's Witnesses 57252190Srpaulo */ 58252190Srpaulo 59252190Srpaulo#include "opt_ddb.h" 60252190Srpaulo#include "opt_witness.h" 61252190Srpaulo 62252190Srpaulo#include <sys/param.h> 63252190Srpaulo#include <sys/bus.h> 64252190Srpaulo#include <sys/kernel.h> 65252190Srpaulo#include <sys/ktr.h> 66252190Srpaulo#include <sys/lock.h> 67252190Srpaulo#include <sys/malloc.h> 68252190Srpaulo#include <sys/mutex.h> 69252190Srpaulo#include <sys/proc.h> 70252190Srpaulo#include <sys/sysctl.h> 71252190Srpaulo#include <sys/systm.h> 72252190Srpaulo 73252190Srpaulo#include <ddb/ddb.h> 74252190Srpaulo 75252190Srpaulo#define WITNESS_COUNT 200 76252190Srpaulo#define WITNESS_CHILDCOUNT (WITNESS_COUNT * 4) 77252190Srpaulo/* 78252190Srpaulo * XXX: This is somewhat bogus, as we assume here that at most 1024 processes 79252190Srpaulo * will hold LOCK_NCHILDREN * 2 locks. We handle failure ok, and we should 80252190Srpaulo * probably be safe for the most part, but it's still a SWAG. 81252190Srpaulo */ 82252190Srpaulo#define LOCK_CHILDCOUNT (MAXCPU + 1024) * 2 83252190Srpaulo 84252190Srpaulo#define WITNESS_NCHILDREN 6 85252190Srpaulo 86252190Srpaulostruct witness_child_list_entry; 87252190Srpaulo 88252190Srpaulostruct witness { 89252190Srpaulo const char *w_name; 90252190Srpaulo struct lock_class *w_class; 91252190Srpaulo STAILQ_ENTRY(witness) w_list; /* List of all witnesses. */ 92252190Srpaulo STAILQ_ENTRY(witness) w_typelist; /* Witnesses of a type. */ 93252190Srpaulo struct witness_child_list_entry *w_children; /* Great evilness... */ 94252190Srpaulo const char *w_file; 95252190Srpaulo int w_line; 96252190Srpaulo u_int w_level; 97252190Srpaulo u_int w_refcount; 98252190Srpaulo u_char w_Giant_squawked:1; 99252190Srpaulo u_char w_other_squawked:1; 100252190Srpaulo u_char w_same_squawked:1; 101252190Srpaulo}; 102252190Srpaulo 103252190Srpaulostruct witness_child_list_entry { 104252190Srpaulo struct witness_child_list_entry *wcl_next; 105252190Srpaulo struct witness *wcl_children[WITNESS_NCHILDREN]; 106252190Srpaulo u_int wcl_count; 107252190Srpaulo}; 108252190Srpaulo 109252190SrpauloSTAILQ_HEAD(witness_list, witness); 110252190Srpaulo 111252190Srpaulostruct witness_blessed { 112252190Srpaulo const char *b_lock1; 113252190Srpaulo const char *b_lock2; 114252190Srpaulo}; 115252190Srpaulo 116252190Srpaulostruct witness_order_list_entry { 117252190Srpaulo const char *w_name; 118252190Srpaulo struct lock_class *w_class; 119252190Srpaulo}; 120252190Srpaulo 121252190Srpaulostatic struct witness *enroll(const char *description, 122252190Srpaulo struct lock_class *lock_class); 123252190Srpaulostatic int itismychild(struct witness *parent, struct witness *child); 124252190Srpaulostatic void removechild(struct witness *parent, struct witness *child); 125252190Srpaulostatic int isitmychild(struct witness *parent, struct witness *child); 126252190Srpaulostatic int isitmydescendant(struct witness *parent, struct witness *child); 127252190Srpaulostatic int dup_ok(struct witness *); 128252190Srpaulostatic int blessed(struct witness *, struct witness *); 129252190Srpaulostatic void witness_display_list(void(*prnt)(const char *fmt, ...), 130252190Srpaulo struct witness_list *list); 131252190Srpaulostatic void witness_displaydescendants(void(*)(const char *fmt, ...), 132252190Srpaulo struct witness *); 133252190Srpaulostatic void witness_leveldescendents(struct witness *parent, int level); 134252190Srpaulostatic void witness_levelall(void); 135252190Srpaulostatic struct witness *witness_get(void); 136252190Srpaulostatic void witness_free(struct witness *m); 137252190Srpaulostatic struct witness_child_list_entry *witness_child_get(void); 138252190Srpaulostatic void witness_child_free(struct witness_child_list_entry *wcl); 139252190Srpaulostatic struct lock_list_entry *witness_lock_list_get(void); 140252190Srpaulostatic void witness_lock_list_free(struct lock_list_entry *lle); 141252190Srpaulostatic void witness_display(void(*)(const char *fmt, ...)); 142252190Srpaulo 143252190SrpauloMALLOC_DEFINE(M_WITNESS, "witness", "witness structure"); 144252190Srpaulo 145252190Srpaulostatic int witness_watch; 146252190SrpauloTUNABLE_INT_DECL("debug.witness_watch", 1, witness_watch); 147252190SrpauloSYSCTL_INT(_debug, OID_AUTO, witness_watch, CTLFLAG_RD, &witness_watch, 0, ""); 148252190Srpaulo 149252190Srpaulo#ifdef DDB 150252190Srpaulo/* 151252190Srpaulo * When DDB is enabled and witness_ddb is set to 1, it will cause the system to 152252190Srpaulo * drop into kdebug() when: 153252190Srpaulo * - a lock heirarchy violation occurs 154252190Srpaulo * - locks are held when going to sleep. 155252190Srpaulo */ 156252190Srpauloint witness_ddb; 157252190Srpaulo#ifdef WITNESS_DDB 158252190SrpauloTUNABLE_INT_DECL("debug.witness_ddb", 1, witness_ddb); 159252190Srpaulo#else 160252190SrpauloTUNABLE_INT_DECL("debug.witness_ddb", 0, witness_ddb); 161252190Srpaulo#endif 162252190SrpauloSYSCTL_INT(_debug, OID_AUTO, witness_ddb, CTLFLAG_RW, &witness_ddb, 0, ""); 163252190Srpaulo#endif /* DDB */ 164252190Srpaulo 165252190Srpauloint witness_skipspin; 166252190Srpaulo#ifdef WITNESS_SKIPSPIN 167252190SrpauloTUNABLE_INT_DECL("debug.witness_skipspin", 1, witness_skipspin); 168252190Srpaulo#else 169252190SrpauloTUNABLE_INT_DECL("debug.witness_skipspin", 0, witness_skipspin); 170252190Srpaulo#endif 171252190SrpauloSYSCTL_INT(_debug, OID_AUTO, witness_skipspin, CTLFLAG_RD, &witness_skipspin, 0, 172252190Srpaulo ""); 173252190Srpaulo 174252190Srpaulostatic struct mtx w_mtx; 175252190Srpaulostatic struct witness_list w_free = STAILQ_HEAD_INITIALIZER(w_free); 176252190Srpaulostatic struct witness_list w_all = STAILQ_HEAD_INITIALIZER(w_all); 177252190Srpaulostatic struct witness_list w_spin = STAILQ_HEAD_INITIALIZER(w_spin); 178252190Srpaulostatic struct witness_list w_sleep = STAILQ_HEAD_INITIALIZER(w_sleep); 179252190Srpaulostatic struct witness_child_list_entry *w_child_free = NULL; 180252190Srpaulostatic struct lock_list_entry *w_lock_list_free = NULL; 181252190Srpaulostatic int witness_dead; /* fatal error, probably no memory */ 182252190Srpaulo 183252190Srpaulostatic struct witness w_data[WITNESS_COUNT]; 184252190Srpaulostatic struct witness_child_list_entry w_childdata[WITNESS_CHILDCOUNT]; 185252190Srpaulostatic struct lock_list_entry w_locklistdata[LOCK_CHILDCOUNT]; 186252190Srpaulo 187252190Srpaulostatic struct witness_order_list_entry order_lists[] = { 188252190Srpaulo { "Giant", &lock_class_mtx_sleep }, 189252190Srpaulo { "proctree", &lock_class_sx }, 190252190Srpaulo { "allproc", &lock_class_sx }, 191252190Srpaulo { "process lock", &lock_class_mtx_sleep }, 192252190Srpaulo { "uidinfo hash", &lock_class_mtx_sleep }, 193252190Srpaulo { "uidinfo struct", &lock_class_mtx_sleep }, 194252190Srpaulo { NULL, NULL }, 195252190Srpaulo#if defined(__i386__) && defined (SMP) 196252190Srpaulo { "com", &lock_class_mtx_spin }, 197252190Srpaulo#endif 198252190Srpaulo { "sio", &lock_class_mtx_spin }, 199252190Srpaulo#ifdef __i386__ 200252190Srpaulo { "cy", &lock_class_mtx_spin }, 201252190Srpaulo#endif 202252190Srpaulo { "ng_node", &lock_class_mtx_spin }, 203252190Srpaulo { "ng_worklist", &lock_class_mtx_spin }, 204252190Srpaulo { "ithread table lock", &lock_class_mtx_spin }, 205252190Srpaulo { "ithread list lock", &lock_class_mtx_spin }, 206252190Srpaulo { "sched lock", &lock_class_mtx_spin }, 207252190Srpaulo#ifdef __i386__ 208252190Srpaulo { "clk", &lock_class_mtx_spin }, 209252190Srpaulo#endif 210252190Srpaulo { "callout", &lock_class_mtx_spin }, 211252190Srpaulo /* 212252190Srpaulo * leaf locks 213252190Srpaulo */ 214252190Srpaulo#ifdef SMP 215252190Srpaulo#ifdef __i386__ 216252190Srpaulo { "ap boot", &lock_class_mtx_spin }, 217252190Srpaulo { "imen", &lock_class_mtx_spin }, 218252190Srpaulo#endif 219252190Srpaulo { "smp rendezvous", &lock_class_mtx_spin }, 220252190Srpaulo#endif 221252190Srpaulo { NULL, NULL }, 222252190Srpaulo { NULL, NULL } 223252190Srpaulo}; 224252190Srpaulo 225252190Srpaulostatic const char *dup_list[] = { 226252190Srpaulo "process lock", 227252190Srpaulo NULL 228252190Srpaulo}; 229252190Srpaulo 230252190Srpaulo/* 231252190Srpaulo * Pairs of locks which have been blessed 232252190Srpaulo * Don't complain about order problems with blessed locks 233252190Srpaulo */ 234252190Srpaulostatic struct witness_blessed blessed_list[] = { 235252190Srpaulo}; 236252190Srpaulostatic int blessed_count = 237252190Srpaulo sizeof(blessed_list) / sizeof(struct witness_blessed); 238252190Srpaulo 239252190Srpaulo/* 240252190Srpaulo * List of all locks in the system. 241252190Srpaulo */ 242252190SrpauloSTAILQ_HEAD(, lock_object) all_locks = STAILQ_HEAD_INITIALIZER(all_locks); 243252190Srpaulo 244252190Srpaulostatic struct mtx all_mtx = { 245252190Srpaulo { &lock_class_mtx_sleep, /* mtx_object.lo_class */ 246252190Srpaulo "All locks list", /* mtx_object.lo_name */ 247252190Srpaulo NULL, /* mtx_object.lo_file */ 248252190Srpaulo 0, /* mtx_object.lo_line */ 249252190Srpaulo LO_INITIALIZED, /* mtx_object.lo_flags */ 250252190Srpaulo { NULL }, /* mtx_object.lo_list */ 251252190Srpaulo NULL }, /* mtx_object.lo_witness */ 252252190Srpaulo MTX_UNOWNED, 0, /* mtx_lock, mtx_recurse */ 253252190Srpaulo 0, /* mtx_savecrit */ 254252190Srpaulo TAILQ_HEAD_INITIALIZER(all_mtx.mtx_blocked), 255252190Srpaulo { NULL, NULL } /* mtx_contested */ 256252190Srpaulo}; 257252190Srpaulo 258252190Srpaulo/* 259252190Srpaulo * This global is set to 0 once it becomes safe to use the witness code. 260252190Srpaulo */ 261252190Srpaulostatic int witness_cold = 1; 262252190Srpaulo 263252190Srpaulo/* 264252190Srpaulo * Global variables for book keeping. 265252190Srpaulo */ 266252190Srpaulostatic int lock_cur_cnt; 267252190Srpaulostatic int lock_max_cnt; 268252190Srpaulo 269252190Srpaulo/* 270252190Srpaulo * The WITNESS-enabled diagnostic code. 271252190Srpaulo */ 272252190Srpaulostatic void 273252190Srpaulowitness_initialize(void *dummy __unused) 274252190Srpaulo{ 275252190Srpaulo struct lock_object *lock; 276252190Srpaulo struct witness_order_list_entry *order; 277252190Srpaulo struct witness *w, *w1; 278252190Srpaulo int i; 279252190Srpaulo 280252190Srpaulo /* 281252190Srpaulo * We have to release Giant before initializing its witness 282252190Srpaulo * structure so that WITNESS doesn't get confused. 283252190Srpaulo */ 284252190Srpaulo mtx_unlock(&Giant); 285252190Srpaulo mtx_assert(&Giant, MA_NOTOWNED); 286252190Srpaulo 287252190Srpaulo STAILQ_INSERT_HEAD(&all_locks, &all_mtx.mtx_object, lo_list); 288252190Srpaulo mtx_init(&w_mtx, "witness lock", MTX_SPIN | MTX_QUIET | MTX_NOWITNESS); 289252190Srpaulo for (i = 0; i < WITNESS_COUNT; i++) 290252190Srpaulo witness_free(&w_data[i]); 291252190Srpaulo for (i = 0; i < WITNESS_CHILDCOUNT; i++) 292252190Srpaulo witness_child_free(&w_childdata[i]); 293252190Srpaulo for (i = 0; i < LOCK_CHILDCOUNT; i++) 294252190Srpaulo witness_lock_list_free(&w_locklistdata[i]); 295252190Srpaulo 296252190Srpaulo /* First add in all the specified order lists. */ 297252190Srpaulo for (order = order_lists; order->w_name != NULL; order++) { 298252190Srpaulo w = enroll(order->w_name, order->w_class); 299252190Srpaulo w->w_file = "order list"; 300252190Srpaulo for (order++; order->w_name != NULL; order++) { 301252190Srpaulo w1 = enroll(order->w_name, order->w_class); 302252190Srpaulo w1->w_file = "order list"; 303252190Srpaulo itismychild(w, w1); 304252190Srpaulo w = w1; 305252190Srpaulo } 306252190Srpaulo } 307252190Srpaulo 308252190Srpaulo /* Iterate through all locks and add them to witness. */ 309252190Srpaulo mtx_lock(&all_mtx); 310252190Srpaulo STAILQ_FOREACH(lock, &all_locks, lo_list) { 311252190Srpaulo if (lock->lo_flags & LO_WITNESS) 312252190Srpaulo lock->lo_witness = enroll(lock->lo_name, 313252190Srpaulo lock->lo_class); 314252190Srpaulo else 315252190Srpaulo lock->lo_witness = NULL; 316252190Srpaulo } 317252190Srpaulo mtx_unlock(&all_mtx); 318252190Srpaulo 319252190Srpaulo /* Mark the witness code as being ready for use. */ 320252190Srpaulo atomic_store_rel_int(&witness_cold, 0); 321252190Srpaulo 322252190Srpaulo mtx_lock(&Giant); 323252190Srpaulo} 324252190SrpauloSYSINIT(witness_init, SI_SUB_WITNESS, SI_ORDER_FIRST, witness_initialize, NULL) 325252190Srpaulo 326252190Srpaulovoid 327252190Srpaulowitness_init(struct lock_object *lock) 328252190Srpaulo{ 329252190Srpaulo struct lock_class *class; 330252190Srpaulo 331252190Srpaulo class = lock->lo_class; 332252190Srpaulo if (lock->lo_flags & LO_INITIALIZED) 333252190Srpaulo panic("%s: lock (%s) %s is already initialized!\n", __func__, 334252190Srpaulo class->lc_name, lock->lo_name); 335252190Srpaulo 336252190Srpaulo if ((lock->lo_flags & LO_RECURSABLE) != 0 && 337252190Srpaulo (class->lc_flags & LC_RECURSABLE) == 0) 338252190Srpaulo panic("%s: lock (%s) %s can not be recursable!\n", __func__, 339252190Srpaulo class->lc_name, lock->lo_name); 340252190Srpaulo 341252190Srpaulo if ((lock->lo_flags & LO_SLEEPABLE) != 0 && 342252190Srpaulo (class->lc_flags & LC_SLEEPABLE) == 0) 343252190Srpaulo panic("%s: lock (%s) %s can not be sleepable!\n", __func__, 344252190Srpaulo class->lc_name, lock->lo_name); 345252190Srpaulo 346252190Srpaulo mtx_lock(&all_mtx); 347252190Srpaulo STAILQ_INSERT_TAIL(&all_locks, lock, lo_list); 348252190Srpaulo lock->lo_flags |= LO_INITIALIZED; 349252190Srpaulo lock_cur_cnt++; 350252190Srpaulo if (lock_cur_cnt > lock_max_cnt) 351252190Srpaulo lock_max_cnt = lock_cur_cnt; 352252190Srpaulo mtx_unlock(&all_mtx); 353252190Srpaulo if (!witness_cold && !witness_dead && 354252190Srpaulo (lock->lo_flags & LO_WITNESS) != 0) 355252190Srpaulo lock->lo_witness = enroll(lock->lo_name, class); 356252190Srpaulo else 357252190Srpaulo lock->lo_witness = NULL; 358252190Srpaulo} 359252190Srpaulo 360252190Srpaulovoid 361252190Srpaulowitness_destroy(struct lock_object *lock) 362252190Srpaulo{ 363252190Srpaulo 364252190Srpaulo if (witness_cold) 365252190Srpaulo panic("lock (%s) %s destroyed while witness_cold", 366252190Srpaulo lock->lo_class->lc_name, lock->lo_name); 367252190Srpaulo 368252190Srpaulo if ((lock->lo_flags & LO_INITIALIZED) == 0) 369252190Srpaulo panic("%s: lock (%s) %s is not initialized!\n", __func__, 370252190Srpaulo lock->lo_class->lc_name, lock->lo_name); 371252190Srpaulo 372252190Srpaulo if (lock->lo_flags & LO_LOCKED) 373252190Srpaulo panic("lock (%s) %s destroyed while held", 374252190Srpaulo lock->lo_class->lc_name, lock->lo_name); 375252190Srpaulo 376252190Srpaulo mtx_lock(&all_mtx); 377252190Srpaulo lock_cur_cnt--; 378252190Srpaulo STAILQ_REMOVE(&all_locks, lock, lock_object, lo_list); 379252190Srpaulo lock->lo_flags &= LO_INITIALIZED; 380252190Srpaulo mtx_unlock(&all_mtx); 381252190Srpaulo} 382252190Srpaulo 383252190Srpaulostatic void 384252190Srpaulowitness_display_list(void(*prnt)(const char *fmt, ...), 385252190Srpaulo struct witness_list *list) 386252190Srpaulo{ 387252190Srpaulo struct witness *w, *w1; 388252190Srpaulo int found; 389252190Srpaulo 390252190Srpaulo STAILQ_FOREACH(w, list, w_typelist) { 391252190Srpaulo if (w->w_file == NULL) 392252190Srpaulo continue; 393252190Srpaulo found = 0; 394252190Srpaulo STAILQ_FOREACH(w1, list, w_typelist) { 395252190Srpaulo if (isitmychild(w1, w)) { 396252190Srpaulo found++; 397252190Srpaulo break; 398252190Srpaulo } 399252190Srpaulo } 400252190Srpaulo if (found) 401252190Srpaulo continue; 402252190Srpaulo /* 403252190Srpaulo * This lock has no anscestors, display its descendants. 404252190Srpaulo */ 405252190Srpaulo witness_displaydescendants(prnt, w); 406252190Srpaulo } 407252190Srpaulo} 408252190Srpaulo 409252190Srpaulostatic void 410252190Srpaulowitness_display(void(*prnt)(const char *fmt, ...)) 411252190Srpaulo{ 412252190Srpaulo struct witness *w; 413252190Srpaulo 414252190Srpaulo KASSERT(!witness_cold, ("%s: witness_cold\n", __func__)); 415252190Srpaulo witness_levelall(); 416252190Srpaulo 417252190Srpaulo /* 418252190Srpaulo * First, handle sleep locks which have been acquired at least 419252190Srpaulo * once. 420252190Srpaulo */ 421252190Srpaulo prnt("Sleep locks:\n"); 422252190Srpaulo witness_display_list(prnt, &w_sleep); 423252190Srpaulo 424252190Srpaulo /* 425252190Srpaulo * Now do spin locks which have been acquired at least once. 426252190Srpaulo */ 427252190Srpaulo prnt("\nSpin locks:\n"); 428252190Srpaulo witness_display_list(prnt, &w_spin); 429252190Srpaulo 430252190Srpaulo /* 431252190Srpaulo * Finally, any locks which have not been acquired yet. 432252190Srpaulo */ 433252190Srpaulo prnt("\nLocks which were never acquired:\n"); 434252190Srpaulo STAILQ_FOREACH(w, &w_all, w_list) { 435252190Srpaulo if (w->w_file != NULL) 436252190Srpaulo continue; 437252190Srpaulo prnt("%s\n", w->w_name); 438252190Srpaulo } 439252190Srpaulo} 440252190Srpaulo 441252190Srpaulovoid 442252190Srpaulowitness_lock(struct lock_object *lock, int flags, const char *file, int line) 443252190Srpaulo{ 444252190Srpaulo struct lock_list_entry **lock_list, *lle; 445252190Srpaulo struct lock_object *lock1, *lock2; 446252190Srpaulo struct lock_class *class; 447252190Srpaulo struct witness *w, *w1; 448252190Srpaulo struct proc *p; 449252190Srpaulo int i, j; 450252190Srpaulo#ifdef DDB 451252190Srpaulo int go_into_ddb = 0; 452252190Srpaulo#endif /* DDB */ 453252190Srpaulo 454252190Srpaulo if (witness_cold || witness_dead || lock->lo_witness == NULL || 455252190Srpaulo panicstr) 456252190Srpaulo return; 457252190Srpaulo w = lock->lo_witness; 458252190Srpaulo class = lock->lo_class; 459252190Srpaulo p = curproc; 460252190Srpaulo 461252190Srpaulo if ((lock->lo_flags & LO_LOCKED) == 0) 462252190Srpaulo panic("%s: lock (%s) %s is not locked @ %s:%d", __func__, 463252190Srpaulo class->lc_name, lock->lo_name, file, line); 464252190Srpaulo 465252190Srpaulo if ((lock->lo_flags & LO_RECURSED) != 0) { 466252190Srpaulo if ((lock->lo_flags & LO_RECURSABLE) == 0) 467252190Srpaulo panic( 468252190Srpaulo "%s: recursed on non-recursive lock (%s) %s @ %s:%d", 469252190Srpaulo __func__, class->lc_name, lock->lo_name, file, 470252190Srpaulo line); 471252190Srpaulo return; 472252190Srpaulo } 473252190Srpaulo 474252190Srpaulo /* 475252190Srpaulo * We have to hold a spinlock to keep lock_list valid across the check 476252190Srpaulo * in the LC_SLEEPLOCK case. In the LC_SPINLOCK case, it is already 477252190Srpaulo * protected by the spinlock we are currently performing the witness 478252190Srpaulo * checks on, so it is ok to release the lock after performing this 479252190Srpaulo * check. All we have to protect is the LC_SLEEPLOCK case when no 480252190Srpaulo * spinlocks are held as we may get preempted during this check and 481252190Srpaulo * lock_list could end up pointing to some other CPU's spinlock list. 482252190Srpaulo */ 483252190Srpaulo mtx_lock_spin(&w_mtx); 484252190Srpaulo lock_list = PCPU_PTR(spinlocks); 485252190Srpaulo if (class->lc_flags & LC_SLEEPLOCK) { 486252190Srpaulo if (*lock_list != NULL) { 487252190Srpaulo mtx_unlock_spin(&w_mtx); 488252190Srpaulo panic("blockable sleep lock (%s) %s @ %s:%d", 489252190Srpaulo class->lc_name, lock->lo_name, file, line); 490252190Srpaulo } 491252190Srpaulo lock_list = &p->p_sleeplocks; 492252190Srpaulo } 493252190Srpaulo mtx_unlock_spin(&w_mtx); 494252190Srpaulo 495252190Srpaulo if (flags & LOP_TRYLOCK) 496252190Srpaulo goto out; 497252190Srpaulo 498252190Srpaulo /* 499252190Srpaulo * Is this the first lock acquired? If so, then no order checking 500252190Srpaulo * is needed. 501252190Srpaulo */ 502252190Srpaulo if (*lock_list == NULL) 503252190Srpaulo goto out; 504252190Srpaulo 505252190Srpaulo /* 506252190Srpaulo * Check for duplicate locks of the same type. Note that we only 507252190Srpaulo * have to check for this on the last lock we just acquired. Any 508252190Srpaulo * other cases will be caught as lock order violations. 509252190Srpaulo */ 510252190Srpaulo lock1 = (*lock_list)->ll_children[(*lock_list)->ll_count - 1]; 511252190Srpaulo w1 = lock1->lo_witness; 512252190Srpaulo if (w1 == w) { 513252190Srpaulo if (w->w_same_squawked || dup_ok(w)) 514252190Srpaulo goto out; 515252190Srpaulo w->w_same_squawked = 1; 516252190Srpaulo printf("acquring duplicate lock of same type: \"%s\"\n", 517252190Srpaulo lock->lo_name); 518252190Srpaulo printf(" 1st @ %s:%d\n", w->w_file, w->w_line); 519252190Srpaulo printf(" 2nd @ %s:%d\n", file, line); 520252190Srpaulo#ifdef DDB 521252190Srpaulo go_into_ddb = 1; 522252190Srpaulo#endif /* DDB */ 523252190Srpaulo goto out; 524252190Srpaulo } 525252190Srpaulo MPASS(!mtx_owned(&w_mtx)); 526252190Srpaulo mtx_lock_spin(&w_mtx); 527252190Srpaulo /* 528252190Srpaulo * If we have a known higher number just say ok 529252190Srpaulo */ 530252190Srpaulo if (witness_watch > 1 && w->w_level > w1->w_level) { 531252190Srpaulo mtx_unlock_spin(&w_mtx); 532252190Srpaulo goto out; 533252190Srpaulo } 534252190Srpaulo if (isitmydescendant(w1, w)) { 535252190Srpaulo mtx_unlock_spin(&w_mtx); 536252190Srpaulo goto out; 537252190Srpaulo } 538252190Srpaulo for (j = 0, lle = *lock_list; lle != NULL; lle = lle->ll_next) { 539252190Srpaulo for (i = lle->ll_count - 1; i >= 0; i--, j++) { 540252190Srpaulo 541252190Srpaulo MPASS(j < WITNESS_COUNT); 542252190Srpaulo lock1 = lle->ll_children[i]; 543252190Srpaulo w1 = lock1->lo_witness; 544252190Srpaulo 545252190Srpaulo /* 546252190Srpaulo * If this lock doesn't undergo witness checking, 547252190Srpaulo * then skip it. 548252190Srpaulo */ 549252190Srpaulo if (w1 == NULL) { 550252190Srpaulo KASSERT((lock1->lo_flags & LO_WITNESS) == 0, 551252190Srpaulo ("lock missing witness structure")); 552252190Srpaulo continue; 553252190Srpaulo } 554252190Srpaulo if (!isitmydescendant(w, w1)) 555252190Srpaulo continue; 556252190Srpaulo /* 557252190Srpaulo * We have a lock order violation, check to see if it 558252190Srpaulo * is allowed or has already been yelled about. 559252190Srpaulo */ 560252190Srpaulo mtx_unlock_spin(&w_mtx); 561252190Srpaulo if (blessed(w, w1)) 562252190Srpaulo goto out; 563252190Srpaulo if (lock1 == &Giant.mtx_object) { 564252190Srpaulo if (w1->w_Giant_squawked) 565252190Srpaulo goto out; 566252190Srpaulo else 567252190Srpaulo w1->w_Giant_squawked = 1; 568252190Srpaulo } else { 569252190Srpaulo if (w1->w_other_squawked) 570252190Srpaulo goto out; 571252190Srpaulo else 572252190Srpaulo w1->w_other_squawked = 1; 573252190Srpaulo } 574252190Srpaulo /* 575252190Srpaulo * Ok, yell about it. 576252190Srpaulo */ 577252190Srpaulo printf("lock order reversal\n"); 578252190Srpaulo /* 579252190Srpaulo * Try to locate an earlier lock with 580252190Srpaulo * witness w in our list. 581252190Srpaulo */ 582252190Srpaulo do { 583252190Srpaulo lock2 = lle->ll_children[i]; 584252190Srpaulo MPASS(lock2 != NULL); 585252190Srpaulo if (lock2->lo_witness == w) 586252190Srpaulo break; 587252190Srpaulo i--; 588252190Srpaulo if (i == 0 && lle->ll_next != NULL) { 589252190Srpaulo lle = lle->ll_next; 590252190Srpaulo i = lle->ll_count - 1; 591252190Srpaulo MPASS(i != 0); 592252190Srpaulo } 593252190Srpaulo } while (i >= 0); 594252190Srpaulo if (i < 0) 595252190Srpaulo /* 596252190Srpaulo * We are very likely bogus in this case. 597252190Srpaulo */ 598252190Srpaulo printf(" 1st %s last acquired @ %s:%d\n", 599252190Srpaulo w->w_name, w->w_file, w->w_line); 600252190Srpaulo else 601252190Srpaulo printf(" 1st %p %s @ %s:%d\n", lock2, 602252190Srpaulo lock2->lo_name, lock2->lo_file, 603252190Srpaulo lock2->lo_line); 604252190Srpaulo printf(" 2nd %p %s @ %s:%d\n", 605252190Srpaulo lock1, lock1->lo_name, lock1->lo_file, 606252190Srpaulo lock1->lo_line); 607252190Srpaulo printf(" 3rd %p %s @ %s:%d\n", 608252190Srpaulo lock, lock->lo_name, file, line); 609252190Srpaulo#ifdef DDB 610252190Srpaulo go_into_ddb = 1; 611252190Srpaulo#endif /* DDB */ 612252190Srpaulo goto out; 613252190Srpaulo } 614252190Srpaulo } 615252190Srpaulo lock1 = (*lock_list)->ll_children[(*lock_list)->ll_count - 1]; 616252190Srpaulo if (!itismychild(lock1->lo_witness, w)) 617252190Srpaulo mtx_unlock_spin(&w_mtx); 618252190Srpaulo 619252190Srpauloout: 620252190Srpaulo#ifdef DDB 621252190Srpaulo if (witness_ddb && go_into_ddb) 622252190Srpaulo Debugger("witness_enter"); 623252190Srpaulo#endif /* DDB */ 624252190Srpaulo w->w_file = file; 625252190Srpaulo w->w_line = line; 626252190Srpaulo lock->lo_line = line; 627252190Srpaulo lock->lo_file = file; 628252190Srpaulo 629252190Srpaulo lle = *lock_list; 630252190Srpaulo if (lle == NULL || lle->ll_count == LOCK_CHILDCOUNT) { 631252190Srpaulo *lock_list = witness_lock_list_get(); 632252190Srpaulo if (*lock_list == NULL) 633252190Srpaulo return; 634252190Srpaulo (*lock_list)->ll_next = lle; 635252190Srpaulo lle = *lock_list; 636252190Srpaulo } 637252190Srpaulo lle->ll_children[lle->ll_count++] = lock; 638252190Srpaulo} 639252190Srpaulo 640252190Srpaulovoid 641252190Srpaulowitness_unlock(struct lock_object *lock, int flags, const char *file, int line) 642252190Srpaulo{ 643252190Srpaulo struct lock_list_entry **lock_list, *lle; 644252190Srpaulo struct lock_class *class; 645252190Srpaulo struct proc *p; 646252190Srpaulo int i, j; 647252190Srpaulo 648252190Srpaulo if (witness_cold || witness_dead || lock->lo_witness == NULL || 649252190Srpaulo panicstr) 650252190Srpaulo return; 651252190Srpaulo p = curproc; 652252190Srpaulo class = lock->lo_class; 653252190Srpaulo 654252190Srpaulo if (lock->lo_flags & LO_RECURSED) { 655252190Srpaulo if ((lock->lo_flags & LO_LOCKED) == 0) 656252190Srpaulo panic("%s: recursed lock (%s) %s is not locked @ %s:%d", 657252190Srpaulo __func__, class->lc_name, lock->lo_name, file, 658252190Srpaulo line); 659252190Srpaulo return; 660252190Srpaulo } 661252190Srpaulo 662252190Srpaulo /* 663252190Srpaulo * We don't need to protect this PCPU_GET() here against preemption 664252190Srpaulo * because if we hold any spinlocks then we are already protected, 665252190Srpaulo * and if we don't we will get NULL if we hold no spinlocks even if 666252190Srpaulo * we switch CPU's while reading it. 667252190Srpaulo */ 668252190Srpaulo if (class->lc_flags & LC_SLEEPLOCK) { 669252190Srpaulo if ((flags & LOP_NOSWITCH) == 0 && PCPU_GET(spinlocks) != NULL) 670252190Srpaulo panic("switchable sleep unlock (%s) %s @ %s:%d", 671252190Srpaulo class->lc_name, lock->lo_name, file, line); 672252190Srpaulo lock_list = &p->p_sleeplocks; 673252190Srpaulo } else 674252190Srpaulo lock_list = PCPU_PTR(spinlocks); 675252190Srpaulo 676252190Srpaulo for (; *lock_list != NULL; lock_list = &(*lock_list)->ll_next) 677252190Srpaulo for (i = 0; i < (*lock_list)->ll_count; i++) 678252190Srpaulo if ((*lock_list)->ll_children[i] == lock) { 679252190Srpaulo (*lock_list)->ll_count--; 680252190Srpaulo for (j = i; j < (*lock_list)->ll_count; j++) 681252190Srpaulo (*lock_list)->ll_children[j] = 682252190Srpaulo (*lock_list)->ll_children[j + 1]; 683252190Srpaulo if ((*lock_list)->ll_count == 0) { 684252190Srpaulo lle = *lock_list; 685252190Srpaulo *lock_list = lle->ll_next; 686252190Srpaulo witness_lock_list_free(lle); 687252190Srpaulo } 688252190Srpaulo return; 689252190Srpaulo } 690252190Srpaulo} 691252190Srpaulo 692252190Srpaulo/* 693252190Srpaulo * Warn if any held locks are not sleepable. Note that Giant and the lock 694252190Srpaulo * passed in are both special cases since they are both released during the 695252190Srpaulo * sleep process and aren't actually held while the process is asleep. 696252190Srpaulo */ 697252190Srpauloint 698252190Srpaulowitness_sleep(int check_only, struct lock_object *lock, const char *file, 699252190Srpaulo int line) 700252190Srpaulo{ 701252190Srpaulo struct lock_list_entry **lock_list, *lle; 702252190Srpaulo struct lock_object *lock1; 703252190Srpaulo struct proc *p; 704252190Srpaulo critical_t savecrit; 705252190Srpaulo int i, n; 706252190Srpaulo 707252190Srpaulo if (witness_dead || panicstr) 708252190Srpaulo return (0); 709252190Srpaulo KASSERT(!witness_cold, ("%s: witness_cold\n", __func__)); 710252190Srpaulo n = 0; 711252190Srpaulo /* 712252190Srpaulo * Preemption bad because we need PCPU_PTR(spinlocks) to not change. 713252190Srpaulo */ 714252190Srpaulo savecrit = critical_enter(); 715252190Srpaulo p = curproc; 716252190Srpaulo lock_list = &p->p_sleeplocks; 717252190Srpauloagain: 718252190Srpaulo for (lle = *lock_list; lle != NULL; lle = lle->ll_next) 719252190Srpaulo for (i = lle->ll_count - 1; i >= 0; i--) { 720252190Srpaulo lock1 = lle->ll_children[i]; 721252190Srpaulo if (lock1 == lock || lock1 == &Giant.mtx_object || 722252190Srpaulo (lock1->lo_flags & LO_SLEEPABLE)) 723252190Srpaulo continue; 724252190Srpaulo n++; 725252190Srpaulo printf("%s:%d: %s with \"%s\" locked from %s:%d\n", 726252190Srpaulo file, line, check_only ? "could sleep" : "sleeping", 727252190Srpaulo lock1->lo_name, lock1->lo_file, lock1->lo_line); 728252190Srpaulo } 729252190Srpaulo if (lock_list == &p->p_sleeplocks) { 730252190Srpaulo lock_list = PCPU_PTR(spinlocks); 731252190Srpaulo goto again; 732252190Srpaulo } 733252190Srpaulo#ifdef DDB 734252190Srpaulo if (witness_ddb && n) 735252190Srpaulo Debugger("witness_sleep"); 736252190Srpaulo#endif /* DDB */ 737252190Srpaulo critical_exit(savecrit); 738252190Srpaulo return (n); 739252190Srpaulo} 740252190Srpaulo 741252190Srpaulostatic struct witness * 742252190Srpauloenroll(const char *description, struct lock_class *lock_class) 743252190Srpaulo{ 744252190Srpaulo struct witness *w; 745252190Srpaulo 746252190Srpaulo if (!witness_watch) 747252190Srpaulo return (NULL); 748252190Srpaulo 749252190Srpaulo if ((lock_class->lc_flags & LC_SPINLOCK) && witness_skipspin) 750252190Srpaulo return (NULL); 751252190Srpaulo mtx_lock_spin(&w_mtx); 752252190Srpaulo STAILQ_FOREACH(w, &w_all, w_list) { 753252190Srpaulo if (strcmp(description, w->w_name) == 0) { 754252190Srpaulo mtx_unlock_spin(&w_mtx); 755252190Srpaulo if (lock_class != w->w_class) 756252190Srpaulo panic( 757252190Srpaulo "lock (%s) %s does not match earlier (%s) lock", 758252190Srpaulo description, lock_class->lc_name, 759252190Srpaulo w->w_class->lc_name); 760252190Srpaulo return (w); 761252190Srpaulo } 762252190Srpaulo } 763252190Srpaulo /* 764252190Srpaulo * This isn't quite right, as witness_cold is still 0 while we 765252190Srpaulo * enroll all the locks initialized before witness_initialize(). 766252190Srpaulo */ 767252190Srpaulo if ((lock_class->lc_flags & LC_SPINLOCK) && !witness_cold) 768252190Srpaulo panic("spin lock %s not in order list", description); 769252190Srpaulo if ((w = witness_get()) == NULL) 770252190Srpaulo return (NULL); 771252190Srpaulo w->w_name = description; 772252190Srpaulo w->w_class = lock_class; 773252190Srpaulo STAILQ_INSERT_HEAD(&w_all, w, w_list); 774252190Srpaulo if (lock_class->lc_flags & LC_SPINLOCK) 775252190Srpaulo STAILQ_INSERT_HEAD(&w_spin, w, w_typelist); 776252190Srpaulo else if (lock_class->lc_flags & LC_SLEEPLOCK) 777252190Srpaulo STAILQ_INSERT_HEAD(&w_sleep, w, w_typelist); 778252190Srpaulo else 779252190Srpaulo panic("lock class %s is not sleep or spin", 780252190Srpaulo lock_class->lc_name); 781252190Srpaulo mtx_unlock_spin(&w_mtx); 782252190Srpaulo 783252190Srpaulo return (w); 784252190Srpaulo} 785252190Srpaulo 786252190Srpaulostatic int 787252190Srpauloitismychild(struct witness *parent, struct witness *child) 788252190Srpaulo{ 789252190Srpaulo static int recursed; 790252190Srpaulo struct witness_child_list_entry **wcl; 791252190Srpaulo struct witness_list *list; 792252190Srpaulo 793252190Srpaulo MPASS(child != NULL && parent != NULL); 794252190Srpaulo if ((parent->w_class->lc_flags & (LC_SLEEPLOCK | LC_SPINLOCK)) != 795252190Srpaulo (child->w_class->lc_flags & (LC_SLEEPLOCK | LC_SPINLOCK))) 796252190Srpaulo panic( 797252190Srpaulo "%s: parent (%s) and child (%s) are not the same lock type", 798252190Srpaulo __func__, parent->w_class->lc_name, 799252190Srpaulo child->w_class->lc_name); 800252190Srpaulo 801252190Srpaulo /* 802252190Srpaulo * Insert "child" after "parent" 803252190Srpaulo */ 804252190Srpaulo wcl = &parent->w_children; 805252190Srpaulo while (*wcl != NULL && (*wcl)->wcl_count == WITNESS_NCHILDREN) 806252190Srpaulo wcl = &(*wcl)->wcl_next; 807252190Srpaulo 808252190Srpaulo if (*wcl == NULL) { 809252190Srpaulo *wcl = witness_child_get(); 810252190Srpaulo if (*wcl == NULL) 811252190Srpaulo return (1); 812252190Srpaulo } 813252190Srpaulo 814252190Srpaulo (*wcl)->wcl_children[(*wcl)->wcl_count++] = child; 815252190Srpaulo 816252190Srpaulo /* 817252190Srpaulo * Now prune whole tree. We look for cases where a lock is now 818252190Srpaulo * both a descendant and a direct child of a given lock. In that 819252190Srpaulo * case, we want to remove the direct child link from the tree. 820252190Srpaulo */ 821252190Srpaulo if (recursed) 822252190Srpaulo return (0); 823252190Srpaulo recursed = 1; 824252190Srpaulo if (parent->w_class->lc_flags & LC_SLEEPLOCK) 825252190Srpaulo list = &w_sleep; 826252190Srpaulo else 827252190Srpaulo list = &w_spin; 828252190Srpaulo STAILQ_FOREACH(child, list, w_typelist) { 829252190Srpaulo STAILQ_FOREACH(parent, list, w_typelist) { 830252190Srpaulo if (!isitmychild(parent, child)) 831252190Srpaulo continue; 832252190Srpaulo removechild(parent, child); 833252190Srpaulo if (isitmydescendant(parent, child)) 834252190Srpaulo continue; 835252190Srpaulo itismychild(parent, child); 836252190Srpaulo } 837252190Srpaulo } 838252190Srpaulo recursed = 0; 839252190Srpaulo witness_levelall(); 840252190Srpaulo return (0); 841252190Srpaulo} 842252190Srpaulo 843252190Srpaulostatic void 844252190Srpauloremovechild(struct witness *parent, struct witness *child) 845252190Srpaulo{ 846252190Srpaulo struct witness_child_list_entry **wcl, *wcl1; 847252190Srpaulo int i; 848252190Srpaulo 849252190Srpaulo for (wcl = &parent->w_children; *wcl != NULL; wcl = &(*wcl)->wcl_next) 850252190Srpaulo for (i = 0; i < (*wcl)->wcl_count; i++) 851252190Srpaulo if ((*wcl)->wcl_children[i] == child) 852252190Srpaulo goto found; 853252190Srpaulo return; 854252190Srpaulofound: 855252190Srpaulo (*wcl)->wcl_count--; 856252190Srpaulo if ((*wcl)->wcl_count > i) 857252190Srpaulo (*wcl)->wcl_children[i] = 858252190Srpaulo (*wcl)->wcl_children[(*wcl)->wcl_count]; 859252190Srpaulo MPASS((*wcl)->wcl_children[i] != NULL); 860252190Srpaulo 861252190Srpaulo if ((*wcl)->wcl_count != 0) 862252190Srpaulo return; 863252190Srpaulo 864252190Srpaulo wcl1 = *wcl; 865252190Srpaulo *wcl = wcl1->wcl_next; 866252190Srpaulo witness_child_free(wcl1); 867252190Srpaulo} 868252190Srpaulo 869252190Srpaulostatic int 870252190Srpauloisitmychild(struct witness *parent, struct witness *child) 871252190Srpaulo{ 872252190Srpaulo struct witness_child_list_entry *wcl; 873252190Srpaulo int i; 874252190Srpaulo 875252190Srpaulo for (wcl = parent->w_children; wcl != NULL; wcl = wcl->wcl_next) { 876252190Srpaulo for (i = 0; i < wcl->wcl_count; i++) { 877252190Srpaulo if (wcl->wcl_children[i] == child) 878252190Srpaulo return (1); 879252190Srpaulo } 880252190Srpaulo } 881252190Srpaulo return (0); 882252190Srpaulo} 883252190Srpaulo 884252190Srpaulostatic int 885252190Srpauloisitmydescendant(struct witness *parent, struct witness *child) 886252190Srpaulo{ 887252190Srpaulo struct witness_child_list_entry *wcl; 888252190Srpaulo int i, j; 889252190Srpaulo 890252190Srpaulo if (isitmychild(parent, child)) 891252190Srpaulo return (1); 892252190Srpaulo j = 0; 893252190Srpaulo for (wcl = parent->w_children; wcl != NULL; wcl = wcl->wcl_next) { 894252190Srpaulo MPASS(j < 1000); 895252190Srpaulo for (i = 0; i < wcl->wcl_count; i++) { 896252190Srpaulo if (isitmydescendant(wcl->wcl_children[i], child)) 897252190Srpaulo return (1); 898252190Srpaulo } 899252190Srpaulo j++; 900252190Srpaulo } 901252190Srpaulo return (0); 902252190Srpaulo} 903252190Srpaulo 904252190Srpaulovoid 905252190Srpaulowitness_levelall (void) 906252190Srpaulo{ 907252190Srpaulo struct witness_list *list; 908252190Srpaulo struct witness *w, *w1; 909252190Srpaulo 910252190Srpaulo /* 911252190Srpaulo * First clear all levels. 912252190Srpaulo */ 913252190Srpaulo STAILQ_FOREACH(w, &w_all, w_list) { 914252190Srpaulo w->w_level = 0; 915252190Srpaulo } 916252190Srpaulo 917252190Srpaulo /* 918252190Srpaulo * Look for locks with no parent and level all their descendants. 919252190Srpaulo */ 920252190Srpaulo STAILQ_FOREACH(w, &w_all, w_list) { 921252190Srpaulo /* 922252190Srpaulo * This is just an optimization, technically we could get 923252190Srpaulo * away just walking the all list each time. 924252190Srpaulo */ 925252190Srpaulo if (w->w_class->lc_flags & LC_SLEEPLOCK) 926252190Srpaulo list = &w_sleep; 927252190Srpaulo else 928252190Srpaulo list = &w_spin; 929252190Srpaulo STAILQ_FOREACH(w1, list, w_typelist) { 930252190Srpaulo if (isitmychild(w1, w)) 931252190Srpaulo goto skip; 932252190Srpaulo } 933252190Srpaulo witness_leveldescendents(w, 0); 934252190Srpaulo skip: 935252190Srpaulo } 936252190Srpaulo} 937252190Srpaulo 938252190Srpaulostatic void 939252190Srpaulowitness_leveldescendents(struct witness *parent, int level) 940252190Srpaulo{ 941252190Srpaulo struct witness_child_list_entry *wcl; 942252190Srpaulo int i; 943252190Srpaulo 944252190Srpaulo if (parent->w_level < level) 945252190Srpaulo parent->w_level = level; 946252190Srpaulo level++; 947252190Srpaulo for (wcl = parent->w_children; wcl != NULL; wcl = wcl->wcl_next) 948252190Srpaulo for (i = 0; i < wcl->wcl_count; i++) 949252190Srpaulo witness_leveldescendents(wcl->wcl_children[i], level); 950252190Srpaulo} 951252190Srpaulo 952252190Srpaulostatic void 953252190Srpaulowitness_displaydescendants(void(*prnt)(const char *fmt, ...), 954252190Srpaulo struct witness *parent) 955252190Srpaulo{ 956252190Srpaulo struct witness_child_list_entry *wcl; 957252190Srpaulo int i, level; 958252190Srpaulo 959252190Srpaulo level = parent->w_level; 960252190Srpaulo 961252190Srpaulo prnt("%-2d", level); 962252190Srpaulo for (i = 0; i < level; i++) 963252190Srpaulo prnt(" "); 964252190Srpaulo prnt("%s", parent->w_name); 965252190Srpaulo if (parent->w_file != NULL) 966252190Srpaulo prnt(" -- last acquired @ %s:%d\n", parent->w_file, 967252190Srpaulo parent->w_line); 968252190Srpaulo 969252190Srpaulo for (wcl = parent->w_children; wcl != NULL; wcl = wcl->wcl_next) 970252190Srpaulo for (i = 0; i < wcl->wcl_count; i++) 971252190Srpaulo witness_displaydescendants(prnt, 972252190Srpaulo wcl->wcl_children[i]); 973252190Srpaulo} 974252190Srpaulo 975252190Srpaulostatic int 976252190Srpaulodup_ok(struct witness *w) 977252190Srpaulo{ 978252190Srpaulo const char **dup; 979252190Srpaulo 980252190Srpaulo for (dup = dup_list; *dup != NULL; dup++) 981252190Srpaulo if (strcmp(w->w_name, *dup) == 0) 982252190Srpaulo return (1); 983252190Srpaulo return (0); 984252190Srpaulo} 985252190Srpaulo 986252190Srpaulostatic int 987252190Srpauloblessed(struct witness *w1, struct witness *w2) 988252190Srpaulo{ 989252190Srpaulo int i; 990252190Srpaulo struct witness_blessed *b; 991252190Srpaulo 992252190Srpaulo for (i = 0; i < blessed_count; i++) { 993252190Srpaulo b = &blessed_list[i]; 994252190Srpaulo if (strcmp(w1->w_name, b->b_lock1) == 0) { 995252190Srpaulo if (strcmp(w2->w_name, b->b_lock2) == 0) 996252190Srpaulo return (1); 997252190Srpaulo continue; 998252190Srpaulo } 999252190Srpaulo if (strcmp(w1->w_name, b->b_lock2) == 0) 1000252190Srpaulo if (strcmp(w2->w_name, b->b_lock1) == 0) 1001252190Srpaulo return (1); 1002252190Srpaulo } 1003252190Srpaulo return (0); 1004252190Srpaulo} 1005252190Srpaulo 1006252190Srpaulostatic struct witness * 1007252190Srpaulowitness_get(void) 1008252190Srpaulo{ 1009252190Srpaulo struct witness *w; 1010252190Srpaulo 1011252190Srpaulo if (STAILQ_EMPTY(&w_free)) { 1012252190Srpaulo witness_dead = 1; 1013252190Srpaulo mtx_unlock_spin(&w_mtx); 1014252190Srpaulo printf("%s: witness exhausted\n", __func__); 1015252190Srpaulo return (NULL); 1016252190Srpaulo } 1017252190Srpaulo w = STAILQ_FIRST(&w_free); 1018252190Srpaulo STAILQ_REMOVE_HEAD(&w_free, w_list); 1019252190Srpaulo bzero(w, sizeof(*w)); 1020252190Srpaulo return (w); 1021252190Srpaulo} 1022252190Srpaulo 1023252190Srpaulostatic void 1024252190Srpaulowitness_free(struct witness *w) 1025252190Srpaulo{ 1026252190Srpaulo 1027252190Srpaulo STAILQ_INSERT_HEAD(&w_free, w, w_list); 1028252190Srpaulo} 1029252190Srpaulo 1030252190Srpaulostatic struct witness_child_list_entry * 1031252190Srpaulowitness_child_get(void) 1032252190Srpaulo{ 1033252190Srpaulo struct witness_child_list_entry *wcl; 1034252190Srpaulo 1035252190Srpaulo wcl = w_child_free; 1036252190Srpaulo if (wcl == NULL) { 1037252190Srpaulo witness_dead = 1; 1038252190Srpaulo mtx_unlock_spin(&w_mtx); 1039252190Srpaulo printf("%s: witness exhausted\n", __func__); 1040252190Srpaulo return (NULL); 1041252190Srpaulo } 1042252190Srpaulo w_child_free = wcl->wcl_next; 1043252190Srpaulo bzero(wcl, sizeof(*wcl)); 1044252190Srpaulo return (wcl); 1045252190Srpaulo} 1046252190Srpaulo 1047252190Srpaulostatic void 1048252190Srpaulowitness_child_free(struct witness_child_list_entry *wcl) 1049252190Srpaulo{ 1050252190Srpaulo 1051252190Srpaulo wcl->wcl_next = w_child_free; 1052252190Srpaulo w_child_free = wcl; 1053252190Srpaulo} 1054252190Srpaulo 1055252190Srpaulostatic struct lock_list_entry * 1056252190Srpaulowitness_lock_list_get(void) 1057252190Srpaulo{ 1058252190Srpaulo struct lock_list_entry *lle; 1059252190Srpaulo 1060252190Srpaulo mtx_lock_spin(&w_mtx); 1061252190Srpaulo lle = w_lock_list_free; 1062252190Srpaulo if (lle == NULL) { 1063252190Srpaulo witness_dead = 1; 1064252190Srpaulo mtx_unlock_spin(&w_mtx); 1065252190Srpaulo printf("%s: witness exhausted\n", __func__); 1066252190Srpaulo return (NULL); 1067252190Srpaulo } 1068252190Srpaulo w_lock_list_free = lle->ll_next; 1069252190Srpaulo mtx_unlock_spin(&w_mtx); 1070252190Srpaulo bzero(lle, sizeof(*lle)); 1071252190Srpaulo return (lle); 1072252190Srpaulo} 1073252190Srpaulo 1074252190Srpaulostatic void 1075252190Srpaulowitness_lock_list_free(struct lock_list_entry *lle) 1076252190Srpaulo{ 1077252190Srpaulo 1078252190Srpaulo mtx_lock_spin(&w_mtx); 1079252190Srpaulo lle->ll_next = w_lock_list_free; 1080252190Srpaulo w_lock_list_free = lle; 1081252190Srpaulo mtx_unlock_spin(&w_mtx); 1082252190Srpaulo} 1083252190Srpaulo 1084252190Srpauloint 1085252190Srpaulowitness_list_locks(struct lock_list_entry **lock_list) 1086252190Srpaulo{ 1087252190Srpaulo struct lock_list_entry *lle; 1088252190Srpaulo struct lock_object *lock; 1089252190Srpaulo int i, nheld; 1090252190Srpaulo 1091252190Srpaulo nheld = 0; 1092252190Srpaulo for (lle = *lock_list; lle != NULL; lle = lle->ll_next) 1093252190Srpaulo for (i = lle->ll_count - 1; i >= 0; i--) { 1094252190Srpaulo lock = lle->ll_children[i]; 1095252190Srpaulo printf("\t(%s) %s (%p) locked at %s:%d\n", 1096252190Srpaulo lock->lo_class->lc_name, lock->lo_name, lock, 1097252190Srpaulo lock->lo_file, lock->lo_line); 1098252190Srpaulo nheld++; 1099252190Srpaulo } 1100252190Srpaulo return (nheld); 1101252190Srpaulo} 1102252190Srpaulo 1103252190Srpaulo/* 1104252190Srpaulo * Calling this on p != curproc is bad unless we are in ddb. 1105252190Srpaulo */ 1106252190Srpauloint 1107252190Srpaulowitness_list(struct proc *p) 1108252190Srpaulo{ 1109252190Srpaulo critical_t savecrit; 1110252190Srpaulo int nheld; 1111252190Srpaulo 1112252190Srpaulo KASSERT(p == curproc || db_active, 1113252190Srpaulo ("%s: p != curproc and we aren't in the debugger", __func__)); 1114252190Srpaulo KASSERT(!witness_cold, ("%s: witness_cold", __func__)); 1115252190Srpaulo 1116252190Srpaulo nheld = witness_list_locks(&p->p_sleeplocks); 1117252190Srpaulo 1118252190Srpaulo /* 1119252190Srpaulo * We only handle spinlocks if p == curproc. This is somewhat broken 1120252190Srpaulo * if p is currently executing on some other CPU and holds spin locks 1121252190Srpaulo * as we won't display those locks. If we had a MI way of getting 1122252190Srpaulo * the per-cpu data for a given cpu then we could use p->p_oncpu to 1123252190Srpaulo * get the list of spinlocks for this process and "fix" this. 1124252190Srpaulo */ 1125252190Srpaulo if (p == curproc) { 1126252190Srpaulo /* 1127252190Srpaulo * Preemption bad because we need PCPU_PTR(spinlocks) to not 1128252190Srpaulo * change. 1129252190Srpaulo */ 1130252190Srpaulo savecrit = critical_enter(); 1131252190Srpaulo nheld += witness_list_locks(PCPU_PTR(spinlocks)); 1132252190Srpaulo critical_exit(savecrit); 1133252190Srpaulo } 1134252190Srpaulo 1135252190Srpaulo return (nheld); 1136252190Srpaulo} 1137252190Srpaulo 1138252190Srpaulovoid 1139252190Srpaulowitness_save(struct lock_object *lock, const char **filep, int *linep) 1140252190Srpaulo{ 1141252190Srpaulo 1142252190Srpaulo KASSERT(!witness_cold, ("%s: witness_cold\n", __func__)); 1143252190Srpaulo if (lock->lo_witness == NULL) 1144252190Srpaulo return; 1145252190Srpaulo 1146252190Srpaulo *filep = lock->lo_file; 1147252190Srpaulo *linep = lock->lo_line; 1148252190Srpaulo} 1149252190Srpaulo 1150252190Srpaulovoid 1151252190Srpaulowitness_restore(struct lock_object *lock, const char *file, int line) 1152252190Srpaulo{ 1153252190Srpaulo 1154252190Srpaulo KASSERT(!witness_cold, ("%s: witness_cold\n", __func__)); 1155252190Srpaulo if (lock->lo_witness == NULL) 1156252190Srpaulo return; 1157252190Srpaulo 1158252190Srpaulo lock->lo_witness->w_file = file; 1159252190Srpaulo lock->lo_witness->w_line = line; 1160252190Srpaulo lock->lo_file = file; 1161252190Srpaulo lock->lo_line = line; 1162252190Srpaulo} 1163252190Srpaulo 1164252190Srpaulo#ifdef DDB 1165252190Srpaulo 1166252190SrpauloDB_SHOW_COMMAND(locks, db_witness_list) 1167252190Srpaulo{ 1168252190Srpaulo struct proc *p; 1169252190Srpaulo pid_t pid; 1170252190Srpaulo 1171252190Srpaulo if (have_addr) { 1172252190Srpaulo pid = (addr % 16) + ((addr >> 4) % 16) * 10 + 1173 ((addr >> 8) % 16) * 100 + ((addr >> 12) % 16) * 1000 + 1174 ((addr >> 16) % 16) * 10000; 1175 1176 /* sx_slock(&allproc_lock); */ 1177 LIST_FOREACH(p, &allproc, p_list) { 1178 if (p->p_pid == pid) 1179 break; 1180 } 1181 /* sx_sunlock(&allproc_lock); */ 1182 if (p == NULL) { 1183 db_printf("pid %d not found\n", pid); 1184 return; 1185 } 1186 } else 1187 p = curproc; 1188 1189 witness_list(p); 1190} 1191 1192DB_SHOW_COMMAND(witness, db_witness_display) 1193{ 1194 1195 witness_display(db_printf); 1196} 1197#endif 1198