1 /*- 2 * Copyright (c) 1998 Berkeley Software Design, Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 3. Berkeley Software Design Inc's name may not be used to endorse or 13 * promote products derived from this software without specific prior 14 * written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * from BSDI $Id: mutex_witness.c,v 1.1.2.20 2000/04/27 03:10:27 cp Exp $ 29 * and BSDI $Id: synch_machdep.c,v 2.3.2.39 2000/04/27 03:10:25 cp Exp $ 30 * $FreeBSD$ 31 */ 32 33 /* 34 * Implementation of the `witness' lock verifier. Originally implemented for 35 * mutexes in BSD/OS. Extended to handle generic lock objects and lock 36 * classes in FreeBSD. 37 */ 38 39 /* 40 * Main Entry: witness 41 * Pronunciation: 'wit-n&s 42 * Function: noun 43 * Etymology: Middle English witnesse, from Old English witnes knowledge, 44 * testimony, witness, from 2wit 45 * Date: before 12th century 46 * 1 : attestation of a fact or event : TESTIMONY 47 * 2 : one that gives evidence; specifically : one who testifies in 48 * a cause or before a judicial tribunal 49 * 3 : one asked to be present at a transaction so as to be able to 50 * testify to its having taken place 51 * 4 : one who has personal knowledge of something 52 * 5 a : something serving as evidence or proof : SIGN 53 * b : public affirmation by word or example of usually 54 * religious faith or conviction <the heroic witness to divine 55 * life -- Pilot> 56 * 6 capitalized : a member of the Jehovah's Witnesses 57 */ 58 59 #include "opt_ddb.h" 60 #include "opt_witness.h" 61 62 #include <sys/param.h> 63 #include <sys/bus.h> 64 #include <sys/kernel.h> 65 #include <sys/ktr.h> 66 #include <sys/lock.h> 67 #include <sys/malloc.h> 68 #include <sys/mutex.h> 69 #include <sys/proc.h> 70 #include <sys/sysctl.h> 71 #include <sys/systm.h> 72 73 #include <ddb/ddb.h> 74 75 #define WITNESS_COUNT 200 76 #define WITNESS_CHILDCOUNT (WITNESS_COUNT * 4) 77 /* 78 * XXX: This is somewhat bogus, as we assume here that at most 1024 processes 79 * will hold LOCK_NCHILDREN * 2 locks. We handle failure ok, and we should 80 * probably be safe for the most part, but it's still a SWAG. 81 */ 82 #define LOCK_CHILDCOUNT (MAXCPU + 1024) * 2 83 84 #define WITNESS_NCHILDREN 6 85 86 struct witness_child_list_entry; 87 88 struct witness { 89 const char *w_name; 90 struct lock_class *w_class; 91 STAILQ_ENTRY(witness) w_list; /* List of all witnesses. */ 92 STAILQ_ENTRY(witness) w_typelist; /* Witnesses of a type. */ 93 struct witness_child_list_entry *w_children; /* Great evilness... */ 94 const char *w_file; 95 int w_line; 96 u_int w_level; 97 u_int w_refcount; 98 u_char w_Giant_squawked:1; 99 u_char w_other_squawked:1; 100 u_char w_same_squawked:1; 101 }; 102 103 struct witness_child_list_entry { 104 struct witness_child_list_entry *wcl_next; 105 struct witness *wcl_children[WITNESS_NCHILDREN]; 106 u_int wcl_count; 107 }; 108 109 STAILQ_HEAD(witness_list, witness); 110 111 struct witness_blessed { 112 const char *b_lock1; 113 const char *b_lock2; 114 }; 115 116 struct witness_order_list_entry { 117 const char *w_name; 118 struct lock_class *w_class; 119 }; 120 121 static struct witness *enroll(const char *description, 122 struct lock_class *lock_class); 123 static int itismychild(struct witness *parent, struct witness *child); 124 static void removechild(struct witness *parent, struct witness *child); 125 static int isitmychild(struct witness *parent, struct witness *child); 126 static int isitmydescendant(struct witness *parent, struct witness *child); 127 static int dup_ok(struct witness *); 128 static int blessed(struct witness *, struct witness *); 129 static void witness_display_list(void(*prnt)(const char *fmt, ...), 130 struct witness_list *list); 131 static void witness_displaydescendants(void(*)(const char *fmt, ...), 132 struct witness *); 133 static void witness_leveldescendents(struct witness *parent, int level); 134 static void witness_levelall(void); 135 static struct witness *witness_get(void); 136 static void witness_free(struct witness *m); 137 static struct witness_child_list_entry *witness_child_get(void); 138 static void witness_child_free(struct witness_child_list_entry *wcl); 139 static struct lock_list_entry *witness_lock_list_get(void); 140 static void witness_lock_list_free(struct lock_list_entry *lle); 141 static void witness_display(void(*)(const char *fmt, ...)); 142 static struct lock_instance *find_instance(struct lock_list_entry *lock_list, 143 struct lock_object *lock); 144 145 MALLOC_DEFINE(M_WITNESS, "witness", "witness structure"); 146 147 static int witness_watch = 1; 148 TUNABLE_INT("debug.witness_watch", &witness_watch); 149 SYSCTL_INT(_debug, OID_AUTO, witness_watch, CTLFLAG_RD, &witness_watch, 0, ""); 150 151 #ifdef DDB 152 /* 153 * When DDB is enabled and witness_ddb is set to 1, it will cause the system to 154 * drop into kdebug() when: 155 * - a lock heirarchy violation occurs 156 * - locks are held when going to sleep. 157 */ 158 #ifdef WITNESS_DDB 159 int witness_ddb = 1; 160 #else 161 int witness_ddb = 0; 162 #endif 163 TUNABLE_INT("debug.witness_ddb", &witness_ddb); 164 SYSCTL_INT(_debug, OID_AUTO, witness_ddb, CTLFLAG_RW, &witness_ddb, 0, ""); 165 #endif /* DDB */ 166 167 #ifdef WITNESS_SKIPSPIN 168 int witness_skipspin = 1; 169 #else 170 int witness_skipspin = 0; 171 #endif 172 TUNABLE_INT("debug.witness_skipspin", &witness_skipspin); 173 SYSCTL_INT(_debug, OID_AUTO, witness_skipspin, CTLFLAG_RD, &witness_skipspin, 0, 174 ""); 175 176 static struct mtx w_mtx; 177 static struct witness_list w_free = STAILQ_HEAD_INITIALIZER(w_free); 178 static struct witness_list w_all = STAILQ_HEAD_INITIALIZER(w_all); 179 static struct witness_list w_spin = STAILQ_HEAD_INITIALIZER(w_spin); 180 static struct witness_list w_sleep = STAILQ_HEAD_INITIALIZER(w_sleep); 181 static struct witness_child_list_entry *w_child_free = NULL; 182 static struct lock_list_entry *w_lock_list_free = NULL; 183 static int witness_dead; /* fatal error, probably no memory */ 184 185 static struct witness w_data[WITNESS_COUNT]; 186 static struct witness_child_list_entry w_childdata[WITNESS_CHILDCOUNT]; 187 static struct lock_list_entry w_locklistdata[LOCK_CHILDCOUNT]; 188 189 static struct witness_order_list_entry order_lists[] = { 190 { "Giant", &lock_class_mtx_sleep }, 191 { "proctree", &lock_class_sx }, 192 { "allproc", &lock_class_sx }, 193 { "process lock", &lock_class_mtx_sleep }, 194 { "uidinfo hash", &lock_class_mtx_sleep }, 195 { "uidinfo struct", &lock_class_mtx_sleep }, 196 { NULL, NULL }, 197 /* 198 * spin locks 199 */ 200 #if defined(__i386__) && defined (SMP) 201 { "com", &lock_class_mtx_spin }, 202 #endif 203 { "sio", &lock_class_mtx_spin }, 204 #ifdef __i386__ 205 { "cy", &lock_class_mtx_spin }, 206 #endif 207 { "ng_node", &lock_class_mtx_spin }, 208 { "ng_worklist", &lock_class_mtx_spin }, 209 { "ithread table lock", &lock_class_mtx_spin }, 210 { "sched lock", &lock_class_mtx_spin }, 211 { "callout", &lock_class_mtx_spin }, 212 /* 213 * leaf locks 214 */ 215 #ifdef SMP 216 { "ap boot", &lock_class_mtx_spin }, 217 #ifdef __i386__ 218 { "imen", &lock_class_mtx_spin }, 219 #endif 220 { "smp rendezvous", &lock_class_mtx_spin }, 221 #endif 222 { "clk", &lock_class_mtx_spin }, 223 { NULL, NULL }, 224 { NULL, NULL } 225 }; 226 227 static const char *dup_list[] = { 228 "process lock", 229 NULL 230 }; 231 232 /* 233 * Pairs of locks which have been blessed 234 * Don't complain about order problems with blessed locks 235 */ 236 static struct witness_blessed blessed_list[] = { 237 }; 238 static int blessed_count = 239 sizeof(blessed_list) / sizeof(struct witness_blessed); 240 241 /* 242 * List of all locks in the system. 243 */ 244 STAILQ_HEAD(, lock_object) all_locks = STAILQ_HEAD_INITIALIZER(all_locks); 245 246 static struct mtx all_mtx = { 247 { &lock_class_mtx_sleep, /* mtx_object.lo_class */ 248 "All locks list", /* mtx_object.lo_name */ 249 LO_INITIALIZED, /* mtx_object.lo_flags */ 250 { NULL }, /* mtx_object.lo_list */ 251 NULL }, /* mtx_object.lo_witness */ 252 MTX_UNOWNED, 0, /* mtx_lock, mtx_recurse */ 253 0, /* mtx_savecrit */ 254 TAILQ_HEAD_INITIALIZER(all_mtx.mtx_blocked), 255 { NULL, NULL } /* mtx_contested */ 256 }; 257 258 /* 259 * This global is set to 0 once it becomes safe to use the witness code. 260 */ 261 static int witness_cold = 1; 262 263 /* 264 * Global variables for book keeping. 265 */ 266 static int lock_cur_cnt; 267 static int lock_max_cnt; 268 269 /* 270 * The WITNESS-enabled diagnostic code. 271 */ 272 static void 273 witness_initialize(void *dummy __unused) 274 { 275 struct lock_object *lock; 276 struct witness_order_list_entry *order; 277 struct witness *w, *w1; 278 int i; 279 280 /* 281 * We have to release Giant before initializing its witness 282 * structure so that WITNESS doesn't get confused. 283 */ 284 mtx_unlock(&Giant); 285 mtx_assert(&Giant, MA_NOTOWNED); 286 287 CTR0(KTR_WITNESS, __func__ ": initializing witness"); 288 STAILQ_INSERT_HEAD(&all_locks, &all_mtx.mtx_object, lo_list); 289 mtx_init(&w_mtx, "witness lock", MTX_SPIN | MTX_QUIET | MTX_NOWITNESS); 290 for (i = 0; i < WITNESS_COUNT; i++) 291 witness_free(&w_data[i]); 292 for (i = 0; i < WITNESS_CHILDCOUNT; i++) 293 witness_child_free(&w_childdata[i]); 294 for (i = 0; i < LOCK_CHILDCOUNT; i++) 295 witness_lock_list_free(&w_locklistdata[i]); 296 297 /* First add in all the specified order lists. */ 298 for (order = order_lists; order->w_name != NULL; order++) { 299 w = enroll(order->w_name, order->w_class); 300 if (w == NULL) 301 continue; 302 w->w_file = "order list"; 303 for (order++; order->w_name != NULL; order++) { 304 w1 = enroll(order->w_name, order->w_class); 305 if (w1 == NULL) 306 continue; 307 w1->w_file = "order list"; 308 itismychild(w, w1); 309 w = w1; 310 } 311 } 312 313 /* Iterate through all locks and add them to witness. */ 314 mtx_lock(&all_mtx); 315 STAILQ_FOREACH(lock, &all_locks, lo_list) { 316 if (lock->lo_flags & LO_WITNESS) 317 lock->lo_witness = enroll(lock->lo_name, 318 lock->lo_class); 319 else 320 lock->lo_witness = NULL; 321 } 322 mtx_unlock(&all_mtx); 323 324 /* Mark the witness code as being ready for use. */ 325 atomic_store_rel_int(&witness_cold, 0); 326 327 mtx_lock(&Giant); 328 } 329 SYSINIT(witness_init, SI_SUB_WITNESS, SI_ORDER_FIRST, witness_initialize, NULL) 330 331 void 332 witness_init(struct lock_object *lock) 333 { 334 struct lock_class *class; 335 336 class = lock->lo_class; 337 if (lock->lo_flags & LO_INITIALIZED) 338 panic("%s: lock (%s) %s is already initialized!\n", __func__, 339 class->lc_name, lock->lo_name); 340 341 if ((lock->lo_flags & LO_RECURSABLE) != 0 && 342 (class->lc_flags & LC_RECURSABLE) == 0) 343 panic("%s: lock (%s) %s can not be recursable!\n", __func__, 344 class->lc_name, lock->lo_name); 345 346 if ((lock->lo_flags & LO_SLEEPABLE) != 0 && 347 (class->lc_flags & LC_SLEEPABLE) == 0) 348 panic("%s: lock (%s) %s can not be sleepable!\n", __func__, 349 class->lc_name, lock->lo_name); 350 351 mtx_lock(&all_mtx); 352 STAILQ_INSERT_TAIL(&all_locks, lock, lo_list); 353 lock->lo_flags |= LO_INITIALIZED; 354 lock_cur_cnt++; 355 if (lock_cur_cnt > lock_max_cnt) 356 lock_max_cnt = lock_cur_cnt; 357 mtx_unlock(&all_mtx); 358 if (!witness_cold && !witness_dead && 359 (lock->lo_flags & LO_WITNESS) != 0) 360 lock->lo_witness = enroll(lock->lo_name, class); 361 else 362 lock->lo_witness = NULL; 363 } 364 365 void 366 witness_destroy(struct lock_object *lock) 367 { 368 struct witness *w; 369 370 if (witness_cold) 371 panic("lock (%s) %s destroyed while witness_cold", 372 lock->lo_class->lc_name, lock->lo_name); 373 374 if ((lock->lo_flags & LO_INITIALIZED) == 0) 375 panic("%s: lock (%s) %s is not initialized!\n", __func__, 376 lock->lo_class->lc_name, lock->lo_name); 377 378 /* XXX: need to verify that no one holds the lock */ 379 w = lock->lo_witness; 380 if (w != NULL) { 381 mtx_lock_spin(&w_mtx); 382 w->w_refcount--; 383 if (w->w_refcount == 0) { 384 CTR1(KTR_WITNESS, 385 __func__ ": marking witness %s as dead", w->w_name); 386 w->w_name = "(dead)"; 387 w->w_file = "(dead)"; 388 w->w_line = 0; 389 } 390 mtx_unlock_spin(&w_mtx); 391 } 392 393 mtx_lock(&all_mtx); 394 lock_cur_cnt--; 395 STAILQ_REMOVE(&all_locks, lock, lock_object, lo_list); 396 lock->lo_flags &= LO_INITIALIZED; 397 mtx_unlock(&all_mtx); 398 } 399 400 static void 401 witness_display_list(void(*prnt)(const char *fmt, ...), 402 struct witness_list *list) 403 { 404 struct witness *w, *w1; 405 int found; 406 407 STAILQ_FOREACH(w, list, w_typelist) { 408 if (w->w_file == NULL) 409 continue; 410 found = 0; 411 STAILQ_FOREACH(w1, list, w_typelist) { 412 if (isitmychild(w1, w)) { 413 found++; 414 break; 415 } 416 } 417 if (found) 418 continue; 419 /* 420 * This lock has no anscestors, display its descendants. 421 */ 422 witness_displaydescendants(prnt, w); 423 } 424 } 425 426 static void 427 witness_display(void(*prnt)(const char *fmt, ...)) 428 { 429 struct witness *w; 430 431 KASSERT(!witness_cold, ("%s: witness_cold\n", __func__)); 432 witness_levelall(); 433 434 /* 435 * First, handle sleep locks which have been acquired at least 436 * once. 437 */ 438 prnt("Sleep locks:\n"); 439 witness_display_list(prnt, &w_sleep); 440 441 /* 442 * Now do spin locks which have been acquired at least once. 443 */ 444 prnt("\nSpin locks:\n"); 445 witness_display_list(prnt, &w_spin); 446 447 /* 448 * Finally, any locks which have not been acquired yet. 449 */ 450 prnt("\nLocks which were never acquired:\n"); 451 STAILQ_FOREACH(w, &w_all, w_list) { 452 if (w->w_file != NULL) 453 continue; 454 prnt("%s\n", w->w_name); 455 } 456 } 457 458 void 459 witness_lock(struct lock_object *lock, int flags, const char *file, int line) 460 { 461 struct lock_list_entry **lock_list, *lle; 462 struct lock_instance *lock1, *lock2; 463 struct lock_class *class; 464 struct witness *w, *w1; 465 struct proc *p; 466 int i, j; 467 #ifdef DDB 468 int go_into_ddb = 0; 469 #endif /* DDB */ 470 471 if (witness_cold || witness_dead || lock->lo_witness == NULL || 472 panicstr) 473 return; 474 w = lock->lo_witness; 475 class = lock->lo_class; 476 p = curproc; 477 478 /* 479 * We have to hold a spinlock to keep lock_list valid across the check 480 * in the LC_SLEEPLOCK case. In the LC_SPINLOCK case, it is already 481 * protected by the spinlock we are currently performing the witness 482 * checks on, so it is ok to release the lock after performing this 483 * check. All we have to protect is the LC_SLEEPLOCK case when no 484 * spinlocks are held as we may get preempted during this check and 485 * lock_list could end up pointing to some other CPU's spinlock list. 486 */ 487 mtx_lock_spin(&w_mtx); 488 lock_list = PCPU_PTR(spinlocks); 489 if (class->lc_flags & LC_SLEEPLOCK) { 490 if (*lock_list != NULL && (flags & LOP_TRYLOCK) == 0) { 491 mtx_unlock_spin(&w_mtx); 492 panic("blockable sleep lock (%s) %s @ %s:%d", 493 class->lc_name, lock->lo_name, file, line); 494 } 495 lock_list = &p->p_sleeplocks; 496 } 497 mtx_unlock_spin(&w_mtx); 498 499 /* 500 * Try locks do not block if they fail to acquire the lock, thus 501 * there is no danger of deadlocks or of switching while holding a 502 * spin lock if we acquire a lock via a try operation. 503 */ 504 if (flags & LOP_TRYLOCK) 505 goto out; 506 507 /* 508 * Is this the first lock acquired? If so, then no order checking 509 * is needed. 510 */ 511 if (*lock_list == NULL) 512 goto out; 513 514 /* 515 * Check to see if we are recursing on a lock we already own. 516 */ 517 lock1 = find_instance(*lock_list, lock); 518 if (lock1 != NULL) { 519 if ((lock1->li_flags & LI_EXCLUSIVE) != 0 && 520 (flags & LOP_EXCLUSIVE) == 0) { 521 printf("shared lock of (%s) %s @ %s:%d\n", 522 class->lc_name, lock->lo_name, file, line); 523 printf("while exclusively locked from %s:%d\n", 524 lock1->li_file, lock1->li_line); 525 panic("share->excl"); 526 } 527 if ((lock1->li_flags & LI_EXCLUSIVE) == 0 && 528 (flags & LOP_EXCLUSIVE) != 0) { 529 printf("exclusive lock of (%s) %s @ %s:%d\n", 530 class->lc_name, lock->lo_name, file, line); 531 printf("while share locked from %s:%d\n", 532 lock1->li_file, lock1->li_line); 533 panic("excl->share"); 534 } 535 lock1->li_flags++; 536 if ((lock->lo_flags & LO_RECURSABLE) == 0) { 537 printf( 538 "recursed on non-recursive lock (%s) %s @ %s:%d\n", 539 class->lc_name, lock->lo_name, file, line); 540 printf("first acquired @ %s:%d\n", lock1->li_file, 541 lock1->li_line); 542 panic("recurse"); 543 } 544 CTR3(KTR_WITNESS, __func__ ": pid %d recursed on %s r=%d", 545 curproc->p_pid, lock->lo_name, 546 lock1->li_flags & LI_RECURSEMASK); 547 lock1->li_file = file; 548 lock1->li_line = line; 549 return; 550 } 551 552 /* 553 * Check for duplicate locks of the same type. Note that we only 554 * have to check for this on the last lock we just acquired. Any 555 * other cases will be caught as lock order violations. 556 */ 557 lock1 = &(*lock_list)->ll_children[(*lock_list)->ll_count - 1]; 558 w1 = lock1->li_lock->lo_witness; 559 if (w1 == w) { 560 if (w->w_same_squawked || dup_ok(w)) 561 goto out; 562 w->w_same_squawked = 1; 563 printf("acquiring duplicate lock of same type: \"%s\"\n", 564 lock->lo_name); 565 printf(" 1st @ %s:%d\n", lock1->li_file, lock1->li_line); 566 printf(" 2nd @ %s:%d\n", file, line); 567 #ifdef DDB 568 go_into_ddb = 1; 569 #endif /* DDB */ 570 goto out; 571 } 572 MPASS(!mtx_owned(&w_mtx)); 573 mtx_lock_spin(&w_mtx); 574 /* 575 * If we have a known higher number just say ok 576 */ 577 if (witness_watch > 1 && w->w_level > w1->w_level) { 578 mtx_unlock_spin(&w_mtx); 579 goto out; 580 } 581 if (isitmydescendant(w1, w)) { 582 mtx_unlock_spin(&w_mtx); 583 goto out; 584 } 585 for (j = 0, lle = *lock_list; lle != NULL; lle = lle->ll_next) { 586 for (i = lle->ll_count - 1; i >= 0; i--, j++) { 587 588 MPASS(j < WITNESS_COUNT); 589 lock1 = &lle->ll_children[i]; 590 w1 = lock1->li_lock->lo_witness; 591 592 /* 593 * If this lock doesn't undergo witness checking, 594 * then skip it. 595 */ 596 if (w1 == NULL) { 597 KASSERT((lock1->li_lock->lo_flags & LO_WITNESS) == 0, 598 ("lock missing witness structure")); 599 continue; 600 } 601 /* 602 * If we are locking Giant and we slept with this 603 * lock, then skip it. 604 */ 605 if ((lock1->li_flags & LI_SLEPT) != 0 && 606 lock == &Giant.mtx_object) 607 continue; 608 if (!isitmydescendant(w, w1)) 609 continue; 610 /* 611 * We have a lock order violation, check to see if it 612 * is allowed or has already been yelled about. 613 */ 614 mtx_unlock_spin(&w_mtx); 615 if (blessed(w, w1)) 616 goto out; 617 if (lock1->li_lock == &Giant.mtx_object) { 618 if (w1->w_Giant_squawked) 619 goto out; 620 else 621 w1->w_Giant_squawked = 1; 622 } else { 623 if (w1->w_other_squawked) 624 goto out; 625 else 626 w1->w_other_squawked = 1; 627 } 628 /* 629 * Ok, yell about it. 630 */ 631 printf("lock order reversal\n"); 632 /* 633 * Try to locate an earlier lock with 634 * witness w in our list. 635 */ 636 do { 637 lock2 = &lle->ll_children[i]; 638 MPASS(lock2->li_lock != NULL); 639 if (lock2->li_lock->lo_witness == w) 640 break; 641 i--; 642 if (i == 0 && lle->ll_next != NULL) { 643 lle = lle->ll_next; 644 i = lle->ll_count - 1; 645 MPASS(i != 0); 646 } 647 } while (i >= 0); 648 if (i < 0) { 649 printf(" 1st %p %s @ %s:%d\n", lock1->li_lock, 650 lock1->li_lock->lo_name, lock1->li_file, 651 lock1->li_line); 652 printf(" 2nd %p %s @ %s:%d\n", lock, 653 lock->lo_name, file, line); 654 } else { 655 printf(" 1st %p %s @ %s:%d\n", lock2->li_lock, 656 lock2->li_lock->lo_name, lock2->li_file, 657 lock2->li_line); 658 printf(" 2nd %p %s @ %s:%d\n", lock1->li_lock, 659 lock1->li_lock->lo_name, lock1->li_file, 660 lock1->li_line); 661 printf(" 3rd %p %s @ %s:%d\n", lock, 662 lock->lo_name, file, line); 663 } 664 #ifdef DDB 665 go_into_ddb = 1; 666 #endif /* DDB */ 667 goto out; 668 } 669 } 670 lock1 = &(*lock_list)->ll_children[(*lock_list)->ll_count - 1]; 671 /* 672 * Don't build a new relationship if we are locking Giant just 673 * after waking up and the previous lock in the list was acquired 674 * prior to blocking. 675 */ 676 if (lock == &Giant.mtx_object && (lock1->li_flags & LI_SLEPT) != 0) 677 mtx_unlock_spin(&w_mtx); 678 else { 679 CTR2(KTR_WITNESS, __func__ ": adding %s as a child of %s", 680 lock->lo_name, lock1->li_lock->lo_name); 681 if (!itismychild(lock1->li_lock->lo_witness, w)) 682 mtx_unlock_spin(&w_mtx); 683 } 684 685 out: 686 #ifdef DDB 687 if (witness_ddb && go_into_ddb) 688 Debugger(__func__); 689 #endif /* DDB */ 690 w->w_file = file; 691 w->w_line = line; 692 693 lle = *lock_list; 694 if (lle == NULL || lle->ll_count == LOCK_NCHILDREN) { 695 lle = witness_lock_list_get(); 696 if (lle == NULL) 697 return; 698 lle->ll_next = *lock_list; 699 CTR2(KTR_WITNESS, __func__ ": pid %d added lle %p", 700 curproc->p_pid, lle); 701 *lock_list = lle; 702 } 703 lock1 = &lle->ll_children[lle->ll_count++]; 704 lock1->li_lock = lock; 705 lock1->li_line = line; 706 lock1->li_file = file; 707 if ((flags & LOP_EXCLUSIVE) != 0) 708 lock1->li_flags = LI_EXCLUSIVE; 709 else 710 lock1->li_flags = 0; 711 CTR3(KTR_WITNESS, __func__ ": pid %d added %s as lle[%d]", 712 curproc->p_pid, lock->lo_name, lle->ll_count - 1); 713 } 714 715 void 716 witness_unlock(struct lock_object *lock, int flags, const char *file, int line) 717 { 718 struct lock_list_entry **lock_list, *lle; 719 struct lock_instance *instance; 720 struct lock_class *class; 721 struct proc *p; 722 critical_t s; 723 int i, j; 724 725 if (witness_cold || witness_dead || lock->lo_witness == NULL || 726 panicstr) 727 return; 728 p = curproc; 729 class = lock->lo_class; 730 if (class->lc_flags & LC_SLEEPLOCK) 731 lock_list = &p->p_sleeplocks; 732 else 733 lock_list = PCPU_PTR(spinlocks); 734 for (; *lock_list != NULL; lock_list = &(*lock_list)->ll_next) 735 for (i = 0; i < (*lock_list)->ll_count; i++) { 736 instance = &(*lock_list)->ll_children[i]; 737 if (instance->li_lock == lock) { 738 if ((instance->li_flags & LI_EXCLUSIVE) != 0 && 739 (flags & LOP_EXCLUSIVE) == 0) { 740 printf( 741 "shared unlock of (%s) %s @ %s:%d\n", 742 class->lc_name, lock->lo_name, 743 file, line); 744 printf( 745 "while exclusively locked from %s:%d\n", 746 instance->li_file, 747 instance->li_line); 748 panic("excl->ushare"); 749 } 750 if ((instance->li_flags & LI_EXCLUSIVE) == 0 && 751 (flags & LOP_EXCLUSIVE) != 0) { 752 printf( 753 "exclusive unlock of (%s) %s @ %s:%d\n", 754 class->lc_name, lock->lo_name, 755 file, line); 756 printf( 757 "while share locked from %s:%d\n", 758 instance->li_file, 759 instance->li_line); 760 panic("share->uexcl"); 761 } 762 /* If we are recursed, unrecurse. */ 763 if ((instance->li_flags & LI_RECURSEMASK) > 0) { 764 CTR3(KTR_WITNESS, 765 __func__ ": pid %d unrecursed on %s r=%d", 766 curproc->p_pid, 767 instance->li_lock->lo_name, 768 instance->li_flags); 769 instance->li_flags--; 770 goto out; 771 } 772 s = critical_enter(); 773 CTR3(KTR_WITNESS, 774 __func__ ": pid %d removed %s from lle[%d]", 775 curproc->p_pid, instance->li_lock->lo_name, 776 (*lock_list)->ll_count - 1); 777 (*lock_list)->ll_count--; 778 for (j = i; j < (*lock_list)->ll_count; j++) 779 (*lock_list)->ll_children[j] = 780 (*lock_list)->ll_children[j + 1]; 781 critical_exit(s); 782 if ((*lock_list)->ll_count == 0) { 783 lle = *lock_list; 784 *lock_list = lle->ll_next; 785 CTR2(KTR_WITNESS, 786 __func__ ": pid %d removed lle %p", 787 curproc->p_pid, lle); 788 witness_lock_list_free(lle); 789 } 790 goto out; 791 } 792 } 793 panic("lock (%s) %s not locked @ %s:%d", class->lc_name, lock->lo_name, 794 file, line); 795 out: 796 /* 797 * We don't need to protect this PCPU_GET() here against preemption 798 * because if we hold any spinlocks then we are already protected, 799 * and if we don't we will get NULL if we hold no spinlocks even if 800 * we switch CPU's while reading it. 801 */ 802 if (class->lc_flags & LC_SLEEPLOCK) { 803 if ((flags & LOP_NOSWITCH) == 0 && PCPU_GET(spinlocks) != NULL) 804 panic("switchable sleep unlock (%s) %s @ %s:%d", 805 class->lc_name, lock->lo_name, file, line); 806 } 807 } 808 809 /* 810 * Warn if any held locks are not sleepable. Note that Giant and the lock 811 * passed in are both special cases since they are both released during the 812 * sleep process and aren't actually held while the process is asleep. 813 */ 814 int 815 witness_sleep(int check_only, struct lock_object *lock, const char *file, 816 int line) 817 { 818 struct lock_list_entry **lock_list, *lle; 819 struct lock_instance *lock1; 820 struct proc *p; 821 critical_t savecrit; 822 int i, n; 823 824 if (witness_dead || panicstr) 825 return (0); 826 KASSERT(!witness_cold, ("%s: witness_cold\n", __func__)); 827 n = 0; 828 /* 829 * Preemption bad because we need PCPU_PTR(spinlocks) to not change. 830 */ 831 savecrit = critical_enter(); 832 p = curproc; 833 lock_list = &p->p_sleeplocks; 834 again: 835 for (lle = *lock_list; lle != NULL; lle = lle->ll_next) 836 for (i = lle->ll_count - 1; i >= 0; i--) { 837 lock1 = &lle->ll_children[i]; 838 if (lock1->li_lock == lock || 839 lock1->li_lock == &Giant.mtx_object) 840 continue; 841 if ((lock1->li_lock->lo_flags & LO_SLEEPABLE) != 0) { 842 if (check_only == 0) { 843 CTR3(KTR_WITNESS, 844 "pid %d: sleeping with lock (%s) %s held", 845 curproc->p_pid, 846 lock1->li_lock->lo_class->lc_name, 847 lock1->li_lock->lo_name); 848 lock1->li_flags |= LI_SLEPT; 849 } 850 continue; 851 } 852 n++; 853 printf("%s:%d: %s with \"%s\" locked from %s:%d\n", 854 file, line, check_only ? "could sleep" : "sleeping", 855 lock1->li_lock->lo_name, lock1->li_file, 856 lock1->li_line); 857 } 858 if (lock_list == &p->p_sleeplocks) { 859 lock_list = PCPU_PTR(spinlocks); 860 goto again; 861 } 862 #ifdef DDB 863 if (witness_ddb && n) 864 Debugger(__func__); 865 #endif /* DDB */ 866 critical_exit(savecrit); 867 return (n); 868 } 869 870 static struct witness * 871 enroll(const char *description, struct lock_class *lock_class) 872 { 873 struct witness *w; 874 875 if (!witness_watch || witness_dead) 876 return (NULL); 877 878 if ((lock_class->lc_flags & LC_SPINLOCK) && witness_skipspin) 879 return (NULL); 880 mtx_lock_spin(&w_mtx); 881 STAILQ_FOREACH(w, &w_all, w_list) { 882 if (strcmp(description, w->w_name) == 0) { 883 w->w_refcount++; 884 mtx_unlock_spin(&w_mtx); 885 if (lock_class != w->w_class) 886 panic( 887 "lock (%s) %s does not match earlier (%s) lock", 888 description, lock_class->lc_name, 889 w->w_class->lc_name); 890 return (w); 891 } 892 } 893 /* 894 * This isn't quite right, as witness_cold is still 0 while we 895 * enroll all the locks initialized before witness_initialize(). 896 */ 897 if ((lock_class->lc_flags & LC_SPINLOCK) && !witness_cold) { 898 mtx_unlock_spin(&w_mtx); 899 panic("spin lock %s not in order list", description); 900 } 901 if ((w = witness_get()) == NULL) 902 return (NULL); 903 w->w_name = description; 904 w->w_class = lock_class; 905 w->w_refcount = 1; 906 STAILQ_INSERT_HEAD(&w_all, w, w_list); 907 if (lock_class->lc_flags & LC_SPINLOCK) 908 STAILQ_INSERT_HEAD(&w_spin, w, w_typelist); 909 else if (lock_class->lc_flags & LC_SLEEPLOCK) 910 STAILQ_INSERT_HEAD(&w_sleep, w, w_typelist); 911 else { 912 mtx_unlock_spin(&w_mtx); 913 panic("lock class %s is not sleep or spin", 914 lock_class->lc_name); 915 } 916 mtx_unlock_spin(&w_mtx); 917 918 return (w); 919 } 920 921 static int 922 itismychild(struct witness *parent, struct witness *child) 923 { 924 static int recursed; 925 struct witness_child_list_entry **wcl; 926 struct witness_list *list; 927 928 MPASS(child != NULL && parent != NULL); 929 if ((parent->w_class->lc_flags & (LC_SLEEPLOCK | LC_SPINLOCK)) != 930 (child->w_class->lc_flags & (LC_SLEEPLOCK | LC_SPINLOCK))) 931 panic( 932 "%s: parent (%s) and child (%s) are not the same lock type", 933 __func__, parent->w_class->lc_name, 934 child->w_class->lc_name); 935 936 /* 937 * Insert "child" after "parent" 938 */ 939 wcl = &parent->w_children; 940 while (*wcl != NULL && (*wcl)->wcl_count == WITNESS_NCHILDREN) 941 wcl = &(*wcl)->wcl_next; 942 943 if (*wcl == NULL) { 944 *wcl = witness_child_get(); 945 if (*wcl == NULL) 946 return (1); 947 } 948 949 (*wcl)->wcl_children[(*wcl)->wcl_count++] = child; 950 951 /* 952 * Now prune whole tree. We look for cases where a lock is now 953 * both a descendant and a direct child of a given lock. In that 954 * case, we want to remove the direct child link from the tree. 955 */ 956 if (recursed) 957 return (0); 958 recursed = 1; 959 if (parent->w_class->lc_flags & LC_SLEEPLOCK) 960 list = &w_sleep; 961 else 962 list = &w_spin; 963 STAILQ_FOREACH(child, list, w_typelist) { 964 STAILQ_FOREACH(parent, list, w_typelist) { 965 if (!isitmychild(parent, child)) 966 continue; 967 removechild(parent, child); 968 if (isitmydescendant(parent, child)) 969 continue; 970 itismychild(parent, child); 971 } 972 } 973 recursed = 0; 974 witness_levelall(); 975 return (0); 976 } 977 978 static void 979 removechild(struct witness *parent, struct witness *child) 980 { 981 struct witness_child_list_entry **wcl, *wcl1; 982 int i; 983 984 for (wcl = &parent->w_children; *wcl != NULL; wcl = &(*wcl)->wcl_next) 985 for (i = 0; i < (*wcl)->wcl_count; i++) 986 if ((*wcl)->wcl_children[i] == child) 987 goto found; 988 return; 989 found: 990 (*wcl)->wcl_count--; 991 if ((*wcl)->wcl_count > i) 992 (*wcl)->wcl_children[i] = 993 (*wcl)->wcl_children[(*wcl)->wcl_count]; 994 MPASS((*wcl)->wcl_children[i] != NULL); 995 996 if ((*wcl)->wcl_count != 0) 997 return; 998 999 wcl1 = *wcl; 1000 *wcl = wcl1->wcl_next; 1001 witness_child_free(wcl1); 1002 } 1003 1004 static int 1005 isitmychild(struct witness *parent, struct witness *child) 1006 { 1007 struct witness_child_list_entry *wcl; 1008 int i; 1009 1010 for (wcl = parent->w_children; wcl != NULL; wcl = wcl->wcl_next) { 1011 for (i = 0; i < wcl->wcl_count; i++) { 1012 if (wcl->wcl_children[i] == child) 1013 return (1); 1014 } 1015 } 1016 return (0); 1017 } 1018 1019 static int 1020 isitmydescendant(struct witness *parent, struct witness *child) 1021 { 1022 struct witness_child_list_entry *wcl; 1023 int i, j; 1024 1025 if (isitmychild(parent, child)) 1026 return (1); 1027 j = 0; 1028 for (wcl = parent->w_children; wcl != NULL; wcl = wcl->wcl_next) { 1029 MPASS(j < 1000); 1030 for (i = 0; i < wcl->wcl_count; i++) { 1031 if (isitmydescendant(wcl->wcl_children[i], child)) 1032 return (1); 1033 } 1034 j++; 1035 } 1036 return (0); 1037 } 1038 1039 void 1040 witness_levelall (void) 1041 { 1042 struct witness_list *list; 1043 struct witness *w, *w1; 1044 1045 /* 1046 * First clear all levels. 1047 */ 1048 STAILQ_FOREACH(w, &w_all, w_list) { 1049 w->w_level = 0; 1050 } 1051 1052 /* 1053 * Look for locks with no parent and level all their descendants. 1054 */ 1055 STAILQ_FOREACH(w, &w_all, w_list) { 1056 /* 1057 * This is just an optimization, technically we could get 1058 * away just walking the all list each time. 1059 */ 1060 if (w->w_class->lc_flags & LC_SLEEPLOCK) 1061 list = &w_sleep; 1062 else 1063 list = &w_spin; 1064 STAILQ_FOREACH(w1, list, w_typelist) { 1065 if (isitmychild(w1, w)) 1066 goto skip; 1067 } 1068 witness_leveldescendents(w, 0); 1069 skip: 1070 } 1071 } 1072 1073 static void 1074 witness_leveldescendents(struct witness *parent, int level) 1075 { 1076 struct witness_child_list_entry *wcl; 1077 int i; 1078 1079 if (parent->w_level < level) 1080 parent->w_level = level; 1081 level++; 1082 for (wcl = parent->w_children; wcl != NULL; wcl = wcl->wcl_next) 1083 for (i = 0; i < wcl->wcl_count; i++) 1084 witness_leveldescendents(wcl->wcl_children[i], level); 1085 } 1086 1087 static void 1088 witness_displaydescendants(void(*prnt)(const char *fmt, ...), 1089 struct witness *parent) 1090 { 1091 struct witness_child_list_entry *wcl; 1092 int i, level; 1093 1094 level = parent->w_level; 1095 1096 prnt("%-2d", level); 1097 for (i = 0; i < level; i++) 1098 prnt(" "); 1099 prnt("%s", parent->w_name); 1100 if (parent->w_file != NULL) 1101 prnt(" -- last acquired @ %s:%d\n", parent->w_file, 1102 parent->w_line); 1103 1104 for (wcl = parent->w_children; wcl != NULL; wcl = wcl->wcl_next) 1105 for (i = 0; i < wcl->wcl_count; i++) 1106 witness_displaydescendants(prnt, 1107 wcl->wcl_children[i]); 1108 } 1109 1110 static int 1111 dup_ok(struct witness *w) 1112 { 1113 const char **dup; 1114 1115 for (dup = dup_list; *dup != NULL; dup++) 1116 if (strcmp(w->w_name, *dup) == 0) 1117 return (1); 1118 return (0); 1119 } 1120 1121 static int 1122 blessed(struct witness *w1, struct witness *w2) 1123 { 1124 int i; 1125 struct witness_blessed *b; 1126 1127 for (i = 0; i < blessed_count; i++) { 1128 b = &blessed_list[i]; 1129 if (strcmp(w1->w_name, b->b_lock1) == 0) { 1130 if (strcmp(w2->w_name, b->b_lock2) == 0) 1131 return (1); 1132 continue; 1133 } 1134 if (strcmp(w1->w_name, b->b_lock2) == 0) 1135 if (strcmp(w2->w_name, b->b_lock1) == 0) 1136 return (1); 1137 } 1138 return (0); 1139 } 1140 1141 static struct witness * 1142 witness_get(void) 1143 { 1144 struct witness *w; 1145 1146 if (witness_dead) { 1147 mtx_unlock_spin(&w_mtx); 1148 return (NULL); 1149 } 1150 if (STAILQ_EMPTY(&w_free)) { 1151 witness_dead = 1; 1152 mtx_unlock_spin(&w_mtx); 1153 printf("%s: witness exhausted\n", __func__); 1154 return (NULL); 1155 } 1156 w = STAILQ_FIRST(&w_free); 1157 STAILQ_REMOVE_HEAD(&w_free, w_list); 1158 bzero(w, sizeof(*w)); 1159 return (w); 1160 } 1161 1162 static void 1163 witness_free(struct witness *w) 1164 { 1165 1166 STAILQ_INSERT_HEAD(&w_free, w, w_list); 1167 } 1168 1169 static struct witness_child_list_entry * 1170 witness_child_get(void) 1171 { 1172 struct witness_child_list_entry *wcl; 1173 1174 if (witness_dead) { 1175 mtx_unlock_spin(&w_mtx); 1176 return (NULL); 1177 } 1178 wcl = w_child_free; 1179 if (wcl == NULL) { 1180 witness_dead = 1; 1181 mtx_unlock_spin(&w_mtx); 1182 printf("%s: witness exhausted\n", __func__); 1183 return (NULL); 1184 } 1185 w_child_free = wcl->wcl_next; 1186 bzero(wcl, sizeof(*wcl)); 1187 return (wcl); 1188 } 1189 1190 static void 1191 witness_child_free(struct witness_child_list_entry *wcl) 1192 { 1193 1194 wcl->wcl_next = w_child_free; 1195 w_child_free = wcl; 1196 } 1197 1198 static struct lock_list_entry * 1199 witness_lock_list_get(void) 1200 { 1201 struct lock_list_entry *lle; 1202 1203 if (witness_dead) 1204 return (NULL); 1205 mtx_lock_spin(&w_mtx); 1206 lle = w_lock_list_free; 1207 if (lle == NULL) { 1208 witness_dead = 1; 1209 mtx_unlock_spin(&w_mtx); 1210 printf("%s: witness exhausted\n", __func__); 1211 return (NULL); 1212 } 1213 w_lock_list_free = lle->ll_next; 1214 mtx_unlock_spin(&w_mtx); 1215 bzero(lle, sizeof(*lle)); 1216 return (lle); 1217 } 1218 1219 static void 1220 witness_lock_list_free(struct lock_list_entry *lle) 1221 { 1222 1223 mtx_lock_spin(&w_mtx); 1224 lle->ll_next = w_lock_list_free; 1225 w_lock_list_free = lle; 1226 mtx_unlock_spin(&w_mtx); 1227 } 1228 1229 static struct lock_instance * 1230 find_instance(struct lock_list_entry *lock_list, struct lock_object *lock) 1231 { 1232 struct lock_list_entry *lle; 1233 struct lock_instance *instance; 1234 int i; 1235 1236 for (lle = lock_list; lle != NULL; lle = lle->ll_next) 1237 for (i = lle->ll_count - 1; i >= 0; i--) { 1238 instance = &lle->ll_children[i]; 1239 if (instance->li_lock == lock) 1240 return (instance); 1241 } 1242 return (NULL); 1243 } 1244 1245 int 1246 witness_list_locks(struct lock_list_entry **lock_list) 1247 { 1248 struct lock_list_entry *lle; 1249 struct lock_instance *instance; 1250 struct lock_object *lock; 1251 int i, nheld; 1252 1253 nheld = 0; 1254 for (lle = *lock_list; lle != NULL; lle = lle->ll_next) 1255 for (i = lle->ll_count - 1; i >= 0; i--) { 1256 instance = &lle->ll_children[i]; 1257 lock = instance->li_lock; 1258 printf("%s (%s) %s (%p) locked @ %s:%d\n", 1259 (instance->li_flags & LI_EXCLUSIVE) != 0 ? 1260 "exclusive" : "shared", 1261 lock->lo_class->lc_name, lock->lo_name, lock, 1262 instance->li_file, instance->li_line); 1263 nheld++; 1264 } 1265 return (nheld); 1266 } 1267 1268 /* 1269 * Calling this on p != curproc is bad unless we are in ddb. 1270 */ 1271 int 1272 witness_list(struct proc *p) 1273 { 1274 critical_t savecrit; 1275 int nheld; 1276 1277 KASSERT(p == curproc || db_active, 1278 ("%s: p != curproc and we aren't in the debugger", __func__)); 1279 KASSERT(!witness_cold, ("%s: witness_cold", __func__)); 1280 1281 if (!db_active && witness_dead) 1282 return (0); 1283 1284 nheld = witness_list_locks(&p->p_sleeplocks); 1285 1286 /* 1287 * We only handle spinlocks if p == curproc. This is somewhat broken 1288 * if p is currently executing on some other CPU and holds spin locks 1289 * as we won't display those locks. If we had a MI way of getting 1290 * the per-cpu data for a given cpu then we could use p->p_oncpu to 1291 * get the list of spinlocks for this process and "fix" this. 1292 */ 1293 if (p == curproc) { 1294 /* 1295 * Preemption bad because we need PCPU_PTR(spinlocks) to not 1296 * change. 1297 */ 1298 savecrit = critical_enter(); 1299 nheld += witness_list_locks(PCPU_PTR(spinlocks)); 1300 critical_exit(savecrit); 1301 } 1302 1303 return (nheld); 1304 } 1305 1306 void 1307 witness_save(struct lock_object *lock, const char **filep, int *linep) 1308 { 1309 struct lock_instance *instance; 1310 1311 KASSERT(!witness_cold, ("%s: witness_cold\n", __func__)); 1312 if (lock->lo_witness == NULL || witness_dead) 1313 return; 1314 1315 KASSERT(lock->lo_class->lc_flags & LC_SLEEPLOCK, 1316 ("%s: lock (%s) %s is not a sleep lock", __func__, 1317 lock->lo_class->lc_name, lock->lo_name)); 1318 instance = find_instance(curproc->p_sleeplocks, lock); 1319 KASSERT(instance != NULL, ("%s: lock (%s) %s not locked", __func__, 1320 lock->lo_class->lc_name, lock->lo_name)); 1321 1322 *filep = instance->li_file; 1323 *linep = instance->li_line; 1324 } 1325 1326 void 1327 witness_restore(struct lock_object *lock, const char *file, int line) 1328 { 1329 struct lock_instance *instance; 1330 1331 KASSERT(!witness_cold, ("%s: witness_cold\n", __func__)); 1332 if (lock->lo_witness == NULL || witness_dead) 1333 return; 1334 1335 KASSERT(lock->lo_class->lc_flags & LC_SLEEPLOCK, 1336 ("%s: lock (%s) %s is not a sleep lock", __func__, 1337 lock->lo_class->lc_name, lock->lo_name)); 1338 instance = find_instance(curproc->p_sleeplocks, lock); 1339 KASSERT(instance != NULL, ("%s: lock (%s) %s not locked", __func__, 1340 lock->lo_class->lc_name, lock->lo_name)); 1341 1342 lock->lo_witness->w_file = file; 1343 lock->lo_witness->w_line = line; 1344 instance->li_file = file; 1345 instance->li_line = line; 1346 } 1347 1348 void 1349 witness_assert(struct lock_object *lock, int flags, const char *file, int line) 1350 { 1351 #ifdef INVARIANT_SUPPORT 1352 struct lock_instance *instance; 1353 1354 if (lock->lo_witness == NULL || witness_dead) 1355 return; 1356 1357 if ((lock->lo_class->lc_flags & LC_SLEEPLOCK) != 0) 1358 instance = find_instance(curproc->p_sleeplocks, lock); 1359 else if ((lock->lo_class->lc_flags & LC_SPINLOCK) != 0) 1360 instance = find_instance(PCPU_GET(spinlocks), lock); 1361 else 1362 panic("Lock (%s) %s is not sleep or spin!", 1363 lock->lo_class->lc_name, lock->lo_name); 1364 switch (flags) { 1365 case LA_UNLOCKED: 1366 if (instance != NULL) 1367 panic("Lock (%s) %s locked @ %s:%d.", 1368 lock->lo_class->lc_name, lock->lo_name, file, line); 1369 break; 1370 case LA_LOCKED: 1371 case LA_LOCKED | LA_RECURSED: 1372 case LA_LOCKED | LA_NOTRECURSED: 1373 case LA_SLOCKED: 1374 case LA_SLOCKED | LA_RECURSED: 1375 case LA_SLOCKED | LA_NOTRECURSED: 1376 case LA_XLOCKED: 1377 case LA_XLOCKED | LA_RECURSED: 1378 case LA_XLOCKED | LA_NOTRECURSED: 1379 if (instance == NULL) 1380 panic("Lock (%s) %s not locked @ %s:%d.", 1381 lock->lo_class->lc_name, lock->lo_name, file, line); 1382 if ((flags & LA_XLOCKED) != 0 && 1383 (instance->li_flags & LI_EXCLUSIVE) == 0) 1384 panic("Lock (%s) %s not exclusively locked @ %s:%d.", 1385 lock->lo_class->lc_name, lock->lo_name, file, line); 1386 if ((flags & LA_SLOCKED) != 0 && 1387 (instance->li_flags & LI_EXCLUSIVE) != 0) 1388 panic("Lock (%s) %s exclusively locked @ %s:%d.", 1389 lock->lo_class->lc_name, lock->lo_name, file, line); 1390 if ((flags & LA_RECURSED) != 0 && 1391 (instance->li_flags & LI_RECURSEMASK) == 0) 1392 panic("Lock (%s) %s not recursed @ %s:%d.", 1393 lock->lo_class->lc_name, lock->lo_name, file, line); 1394 if ((flags & LA_NOTRECURSED) != 0 && 1395 (instance->li_flags & LI_RECURSEMASK) != 0) 1396 panic("Lock (%s) %s recursed @ %s:%d.", 1397 lock->lo_class->lc_name, lock->lo_name, file, line); 1398 break; 1399 default: 1400 panic("Invalid lock assertion at %s:%d.", file, line); 1401 1402 } 1403 #endif /* INVARIANT_SUPPORT */ 1404 } 1405 1406 #ifdef DDB 1407 1408 DB_SHOW_COMMAND(locks, db_witness_list) 1409 { 1410 struct proc *p; 1411 pid_t pid; 1412 1413 if (have_addr) { 1414 pid = (addr % 16) + ((addr >> 4) % 16) * 10 + 1415 ((addr >> 8) % 16) * 100 + ((addr >> 12) % 16) * 1000 + 1416 ((addr >> 16) % 16) * 10000; 1417 1418 /* sx_slock(&allproc_lock); */ 1419 LIST_FOREACH(p, &allproc, p_list) { 1420 if (p->p_pid == pid) 1421 break; 1422 } 1423 /* sx_sunlock(&allproc_lock); */ 1424 if (p == NULL) { 1425 db_printf("pid %d not found\n", pid); 1426 return; 1427 } 1428 } else 1429 p = curproc; 1430 1431 witness_list(p); 1432 } 1433 1434 DB_SHOW_COMMAND(witness, db_witness_display) 1435 { 1436 1437 witness_display(db_printf); 1438 } 1439 #endif 1440