1 /* $NetBSD: subr_lockdebug.c,v 1.31 2008/04/28 20:24:04 martin Exp $ */ 2 3 /*- 4 * Copyright (c) 2006, 2007, 2008 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Andrew Doran. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 /* 33 * Basic lock debugging code shared among lock primitives. 34 */ 35 36 #include <sys/cdefs.h> 37 __KERNEL_RCSID(0, "$NetBSD: subr_lockdebug.c,v 1.31 2008/04/28 20:24:04 martin Exp $"); 38 39 #include "opt_ddb.h" 40 41 #include <sys/param.h> 42 #include <sys/proc.h> 43 #include <sys/systm.h> 44 #include <sys/kernel.h> 45 #include <sys/kmem.h> 46 #include <sys/lockdebug.h> 47 #include <sys/sleepq.h> 48 #include <sys/cpu.h> 49 #include <sys/atomic.h> 50 #include <sys/lock.h> 51 52 #include <lib/libkern/rb.h> 53 54 #include <machine/lock.h> 55 56 unsigned int ld_panic; 57 58 #ifdef LOCKDEBUG 59 60 #define LD_BATCH_SHIFT 9 61 #define LD_BATCH (1 << LD_BATCH_SHIFT) 62 #define LD_BATCH_MASK (LD_BATCH - 1) 63 #define LD_MAX_LOCKS 1048576 64 #define LD_SLOP 16 65 66 #define LD_LOCKED 0x01 67 #define LD_SLEEPER 0x02 68 69 #define LD_WRITE_LOCK 0x80000000 70 71 typedef union lockdebuglk { 72 struct { 73 u_int lku_lock; 74 int lku_oldspl; 75 } ul; 76 uint8_t lk_pad[COHERENCY_UNIT]; 77 } volatile __aligned(COHERENCY_UNIT) lockdebuglk_t; 78 79 #define lk_lock ul.lku_lock 80 #define lk_oldspl ul.lku_oldspl 81 82 typedef struct lockdebug { 83 struct rb_node ld_rb_node; /* must be the first member */ 84 _TAILQ_ENTRY(struct lockdebug, volatile) ld_chain; 85 _TAILQ_ENTRY(struct lockdebug, volatile) ld_achain; 86 volatile void *ld_lock; 87 lockops_t *ld_lockops; 88 struct lwp *ld_lwp; 89 uintptr_t ld_locked; 90 uintptr_t ld_unlocked; 91 uintptr_t ld_initaddr; 92 uint16_t ld_shares; 93 uint16_t ld_cpu; 94 uint8_t ld_flags; 95 uint8_t ld_shwant; /* advisory */ 96 uint8_t ld_exwant; /* advisory */ 97 uint8_t ld_unused; 98 } volatile lockdebug_t; 99 100 typedef _TAILQ_HEAD(lockdebuglist, struct lockdebug, volatile) lockdebuglist_t; 101 102 lockdebuglk_t ld_tree_lk; 103 lockdebuglk_t ld_sleeper_lk; 104 lockdebuglk_t ld_spinner_lk; 105 lockdebuglk_t ld_free_lk; 106 107 lockdebuglist_t ld_sleepers = TAILQ_HEAD_INITIALIZER(ld_sleepers); 108 lockdebuglist_t ld_spinners = TAILQ_HEAD_INITIALIZER(ld_spinners); 109 lockdebuglist_t ld_free = TAILQ_HEAD_INITIALIZER(ld_free); 110 lockdebuglist_t ld_all = TAILQ_HEAD_INITIALIZER(ld_all); 111 int ld_nfree; 112 int ld_freeptr; 113 int ld_recurse; 114 bool ld_nomore; 115 lockdebug_t *ld_table[LD_MAX_LOCKS / LD_BATCH]; 116 117 lockdebug_t ld_prime[LD_BATCH]; 118 119 static void lockdebug_abort1(lockdebug_t *, lockdebuglk_t *lk, 120 const char *, const char *, bool); 121 static void lockdebug_more(void); 122 static void lockdebug_init(void); 123 124 static signed int 125 ld_rb_compare_nodes(const struct rb_node *n1, const struct rb_node *n2) 126 { 127 const lockdebug_t *ld1 = (const void *)n1; 128 const lockdebug_t *ld2 = (const void *)n2; 129 const uintptr_t a = (uintptr_t)ld1->ld_lock; 130 const uintptr_t b = (uintptr_t)ld2->ld_lock; 131 132 if (a < b) 133 return 1; 134 if (a > b) 135 return -1; 136 return 0; 137 } 138 139 static signed int 140 ld_rb_compare_key(const struct rb_node *n, const void *key) 141 { 142 const lockdebug_t *ld = (const void *)n; 143 const uintptr_t a = (uintptr_t)ld->ld_lock; 144 const uintptr_t b = (uintptr_t)key; 145 146 if (a < b) 147 return 1; 148 if (a > b) 149 return -1; 150 return 0; 151 } 152 153 static struct rb_tree ld_rb_tree; 154 155 static const struct rb_tree_ops ld_rb_tree_ops = { 156 .rb_compare_nodes = ld_rb_compare_nodes, 157 .rb_compare_key = ld_rb_compare_key, 158 }; 159 160 static void 161 lockdebug_lock_init(lockdebuglk_t *lk) 162 { 163 164 lk->lk_lock = 0; 165 } 166 167 static void 168 lockdebug_lock(lockdebuglk_t *lk) 169 { 170 int s; 171 172 s = splhigh(); 173 do { 174 while (lk->lk_lock != 0) { 175 SPINLOCK_SPIN_HOOK; 176 } 177 } while (atomic_cas_uint(&lk->lk_lock, 0, LD_WRITE_LOCK) != 0); 178 lk->lk_oldspl = s; 179 membar_enter(); 180 } 181 182 static void 183 lockdebug_unlock(lockdebuglk_t *lk) 184 { 185 int s; 186 187 s = lk->lk_oldspl; 188 membar_exit(); 189 lk->lk_lock = 0; 190 splx(s); 191 } 192 193 static int 194 lockdebug_lock_rd(lockdebuglk_t *lk) 195 { 196 u_int val; 197 int s; 198 199 s = splhigh(); 200 do { 201 while ((val = lk->lk_lock) == LD_WRITE_LOCK){ 202 SPINLOCK_SPIN_HOOK; 203 } 204 } while (atomic_cas_uint(&lk->lk_lock, val, val + 1) != val); 205 membar_enter(); 206 return s; 207 } 208 209 static void 210 lockdebug_unlock_rd(lockdebuglk_t *lk, int s) 211 { 212 213 membar_exit(); 214 atomic_dec_uint(&lk->lk_lock); 215 splx(s); 216 } 217 218 static inline lockdebug_t * 219 lockdebug_lookup1(volatile void *lock, lockdebuglk_t **lk) 220 { 221 lockdebug_t *ld; 222 int s; 223 224 s = lockdebug_lock_rd(&ld_tree_lk); 225 ld = (lockdebug_t *)rb_tree_find_node(&ld_rb_tree, __UNVOLATILE(lock)); 226 lockdebug_unlock_rd(&ld_tree_lk, s); 227 if (ld == NULL) 228 return NULL; 229 230 if ((ld->ld_flags & LD_SLEEPER) != 0) 231 *lk = &ld_sleeper_lk; 232 else 233 *lk = &ld_spinner_lk; 234 235 lockdebug_lock(*lk); 236 return ld; 237 } 238 239 /* 240 * lockdebug_lookup: 241 * 242 * Find a lockdebug structure by a pointer to a lock and return it locked. 243 */ 244 static inline lockdebug_t * 245 lockdebug_lookup(volatile void *lock, lockdebuglk_t **lk) 246 { 247 lockdebug_t *ld; 248 249 ld = lockdebug_lookup1(lock, lk); 250 if (ld == NULL) 251 panic("lockdebug_lookup: uninitialized lock (lock=%p)", lock); 252 return ld; 253 } 254 255 /* 256 * lockdebug_init: 257 * 258 * Initialize the lockdebug system. Allocate an initial pool of 259 * lockdebug structures before the VM system is up and running. 260 */ 261 static void 262 lockdebug_init(void) 263 { 264 lockdebug_t *ld; 265 int i; 266 267 lockdebug_lock_init(&ld_tree_lk); 268 lockdebug_lock_init(&ld_sleeper_lk); 269 lockdebug_lock_init(&ld_spinner_lk); 270 lockdebug_lock_init(&ld_free_lk); 271 272 rb_tree_init(&ld_rb_tree, &ld_rb_tree_ops); 273 274 ld = ld_prime; 275 ld_table[0] = ld; 276 for (i = 1, ld++; i < LD_BATCH; i++, ld++) { 277 TAILQ_INSERT_TAIL(&ld_free, ld, ld_chain); 278 TAILQ_INSERT_TAIL(&ld_all, ld, ld_achain); 279 } 280 ld_freeptr = 1; 281 ld_nfree = LD_BATCH - 1; 282 } 283 284 /* 285 * lockdebug_alloc: 286 * 287 * A lock is being initialized, so allocate an associated debug 288 * structure. 289 */ 290 bool 291 lockdebug_alloc(volatile void *lock, lockops_t *lo, uintptr_t initaddr) 292 { 293 struct cpu_info *ci; 294 lockdebug_t *ld; 295 lockdebuglk_t *lk; 296 297 if (lo == NULL || panicstr != NULL || ld_panic) 298 return false; 299 if (ld_freeptr == 0) 300 lockdebug_init(); 301 302 if ((ld = lockdebug_lookup1(lock, &lk)) != NULL) { 303 lockdebug_abort1(ld, lk, __func__, "already initialized", true); 304 return false; 305 } 306 307 /* 308 * Pinch a new debug structure. We may recurse because we call 309 * kmem_alloc(), which may need to initialize new locks somewhere 310 * down the path. If not recursing, we try to maintain at least 311 * LD_SLOP structures free, which should hopefully be enough to 312 * satisfy kmem_alloc(). If we can't provide a structure, not to 313 * worry: we'll just mark the lock as not having an ID. 314 */ 315 lockdebug_lock(&ld_free_lk); 316 ci = curcpu(); 317 ci->ci_lkdebug_recurse++; 318 319 if (TAILQ_EMPTY(&ld_free)) { 320 if (ci->ci_lkdebug_recurse > 1 || ld_nomore) { 321 ci->ci_lkdebug_recurse--; 322 lockdebug_unlock(&ld_free_lk); 323 return false; 324 } 325 lockdebug_more(); 326 } else if (ci->ci_lkdebug_recurse == 1 && ld_nfree < LD_SLOP) 327 lockdebug_more(); 328 329 if ((ld = TAILQ_FIRST(&ld_free)) == NULL) { 330 lockdebug_unlock(&ld_free_lk); 331 return false; 332 } 333 334 TAILQ_REMOVE(&ld_free, ld, ld_chain); 335 ld_nfree--; 336 337 ci->ci_lkdebug_recurse--; 338 lockdebug_unlock(&ld_free_lk); 339 340 if (ld->ld_lock != NULL) 341 panic("lockdebug_alloc: corrupt table"); 342 343 if (lo->lo_sleeplock) 344 lockdebug_lock(&ld_sleeper_lk); 345 else 346 lockdebug_lock(&ld_spinner_lk); 347 348 /* Initialise the structure. */ 349 ld->ld_lock = lock; 350 ld->ld_lockops = lo; 351 ld->ld_locked = 0; 352 ld->ld_unlocked = 0; 353 ld->ld_lwp = NULL; 354 ld->ld_initaddr = initaddr; 355 356 lockdebug_lock(&ld_tree_lk); 357 rb_tree_insert_node(&ld_rb_tree, __UNVOLATILE(&ld->ld_rb_node)); 358 lockdebug_unlock(&ld_tree_lk); 359 360 if (lo->lo_sleeplock) { 361 ld->ld_flags = LD_SLEEPER; 362 lockdebug_unlock(&ld_sleeper_lk); 363 } else { 364 ld->ld_flags = 0; 365 lockdebug_unlock(&ld_spinner_lk); 366 } 367 368 return true; 369 } 370 371 /* 372 * lockdebug_free: 373 * 374 * A lock is being destroyed, so release debugging resources. 375 */ 376 void 377 lockdebug_free(volatile void *lock) 378 { 379 lockdebug_t *ld; 380 lockdebuglk_t *lk; 381 382 if (panicstr != NULL || ld_panic) 383 return; 384 385 ld = lockdebug_lookup(lock, &lk); 386 if (ld == NULL) { 387 panic("lockdebug_free: destroying uninitialized lock %p" 388 "(ld_lock=%p)", lock, ld->ld_lock); 389 lockdebug_abort1(ld, lk, __func__, "lock record follows", 390 true); 391 return; 392 } 393 if ((ld->ld_flags & LD_LOCKED) != 0 || ld->ld_shares != 0) { 394 lockdebug_abort1(ld, lk, __func__, "is locked", true); 395 return; 396 } 397 lockdebug_lock(&ld_tree_lk); 398 rb_tree_remove_node(&ld_rb_tree, __UNVOLATILE(&ld->ld_rb_node)); 399 lockdebug_unlock(&ld_tree_lk); 400 ld->ld_lock = NULL; 401 lockdebug_unlock(lk); 402 403 lockdebug_lock(&ld_free_lk); 404 TAILQ_INSERT_TAIL(&ld_free, ld, ld_chain); 405 ld_nfree++; 406 lockdebug_unlock(&ld_free_lk); 407 } 408 409 /* 410 * lockdebug_more: 411 * 412 * Allocate a batch of debug structures and add to the free list. 413 * Must be called with ld_free_lk held. 414 */ 415 static void 416 lockdebug_more(void) 417 { 418 lockdebug_t *ld; 419 void *block; 420 int i, base, m; 421 422 while (ld_nfree < LD_SLOP) { 423 lockdebug_unlock(&ld_free_lk); 424 block = kmem_zalloc(LD_BATCH * sizeof(lockdebug_t), KM_SLEEP); 425 lockdebug_lock(&ld_free_lk); 426 427 if (block == NULL) 428 return; 429 430 if (ld_nfree > LD_SLOP) { 431 /* Somebody beat us to it. */ 432 lockdebug_unlock(&ld_free_lk); 433 kmem_free(block, LD_BATCH * sizeof(lockdebug_t)); 434 lockdebug_lock(&ld_free_lk); 435 continue; 436 } 437 438 base = ld_freeptr; 439 ld_nfree += LD_BATCH; 440 ld = block; 441 base <<= LD_BATCH_SHIFT; 442 m = min(LD_MAX_LOCKS, base + LD_BATCH); 443 444 if (m == LD_MAX_LOCKS) 445 ld_nomore = true; 446 447 for (i = base; i < m; i++, ld++) { 448 TAILQ_INSERT_TAIL(&ld_free, ld, ld_chain); 449 TAILQ_INSERT_TAIL(&ld_all, ld, ld_achain); 450 } 451 452 membar_producer(); 453 ld_table[ld_freeptr++] = block; 454 } 455 } 456 457 /* 458 * lockdebug_wantlock: 459 * 460 * Process the preamble to a lock acquire. 461 */ 462 void 463 lockdebug_wantlock(volatile void *lock, uintptr_t where, int shared) 464 { 465 struct lwp *l = curlwp; 466 lockdebuglk_t *lk; 467 lockdebug_t *ld; 468 bool recurse; 469 470 (void)shared; 471 recurse = false; 472 473 if (panicstr != NULL || ld_panic) 474 return; 475 476 if ((ld = lockdebug_lookup(lock, &lk)) == NULL) 477 return; 478 479 if ((ld->ld_flags & LD_LOCKED) != 0) { 480 if ((ld->ld_flags & LD_SLEEPER) != 0) { 481 if (ld->ld_lwp == l) 482 recurse = true; 483 } else if (ld->ld_cpu == (uint16_t)cpu_number()) 484 recurse = true; 485 } 486 487 if (cpu_intr_p()) { 488 if ((ld->ld_flags & LD_SLEEPER) != 0) { 489 lockdebug_abort1(ld, lk, __func__, 490 "acquiring sleep lock from interrupt context", 491 true); 492 return; 493 } 494 } 495 496 if (shared) 497 ld->ld_shwant++; 498 else 499 ld->ld_exwant++; 500 501 if (recurse) { 502 lockdebug_abort1(ld, lk, __func__, "locking against myself", 503 true); 504 return; 505 } 506 507 lockdebug_unlock(lk); 508 } 509 510 /* 511 * lockdebug_locked: 512 * 513 * Process a lock acquire operation. 514 */ 515 void 516 lockdebug_locked(volatile void *lock, uintptr_t where, int shared) 517 { 518 struct lwp *l = curlwp; 519 lockdebuglk_t *lk; 520 lockdebug_t *ld; 521 522 if (panicstr != NULL || ld_panic) 523 return; 524 525 if ((ld = lockdebug_lookup(lock, &lk)) == NULL) 526 return; 527 528 if (shared) { 529 l->l_shlocks++; 530 ld->ld_shares++; 531 ld->ld_shwant--; 532 } else { 533 if ((ld->ld_flags & LD_LOCKED) != 0) { 534 lockdebug_abort1(ld, lk, __func__, 535 "already locked", true); 536 return; 537 } 538 539 ld->ld_flags |= LD_LOCKED; 540 ld->ld_locked = where; 541 ld->ld_cpu = (uint16_t)cpu_number(); 542 ld->ld_lwp = l; 543 ld->ld_exwant--; 544 545 if ((ld->ld_flags & LD_SLEEPER) != 0) { 546 l->l_exlocks++; 547 TAILQ_INSERT_TAIL(&ld_sleepers, ld, ld_chain); 548 } else { 549 curcpu()->ci_spin_locks2++; 550 TAILQ_INSERT_TAIL(&ld_spinners, ld, ld_chain); 551 } 552 } 553 554 lockdebug_unlock(lk); 555 } 556 557 /* 558 * lockdebug_unlocked: 559 * 560 * Process a lock release operation. 561 */ 562 void 563 lockdebug_unlocked(volatile void *lock, uintptr_t where, int shared) 564 { 565 struct lwp *l = curlwp; 566 lockdebuglk_t *lk; 567 lockdebug_t *ld; 568 569 if (panicstr != NULL || ld_panic) 570 return; 571 572 if ((ld = lockdebug_lookup(lock, &lk)) == NULL) 573 return; 574 575 if (shared) { 576 if (l->l_shlocks == 0) { 577 lockdebug_abort1(ld, lk, __func__, 578 "no shared locks held by LWP", true); 579 return; 580 } 581 if (ld->ld_shares == 0) { 582 lockdebug_abort1(ld, lk, __func__, 583 "no shared holds on this lock", true); 584 return; 585 } 586 l->l_shlocks--; 587 ld->ld_shares--; 588 } else { 589 if ((ld->ld_flags & LD_LOCKED) == 0) { 590 lockdebug_abort1(ld, lk, __func__, "not locked", 591 true); 592 return; 593 } 594 595 if ((ld->ld_flags & LD_SLEEPER) != 0) { 596 if (ld->ld_lwp != curlwp) { 597 lockdebug_abort1(ld, lk, __func__, 598 "not held by current LWP", true); 599 return; 600 } 601 ld->ld_flags &= ~LD_LOCKED; 602 ld->ld_unlocked = where; 603 ld->ld_lwp = NULL; 604 curlwp->l_exlocks--; 605 TAILQ_REMOVE(&ld_sleepers, ld, ld_chain); 606 } else { 607 if (ld->ld_cpu != (uint16_t)cpu_number()) { 608 lockdebug_abort1(ld, lk, __func__, 609 "not held by current CPU", true); 610 return; 611 } 612 ld->ld_flags &= ~LD_LOCKED; 613 ld->ld_unlocked = where; 614 ld->ld_lwp = NULL; 615 curcpu()->ci_spin_locks2--; 616 TAILQ_REMOVE(&ld_spinners, ld, ld_chain); 617 } 618 } 619 620 lockdebug_unlock(lk); 621 } 622 623 /* 624 * lockdebug_barrier: 625 * 626 * Panic if we hold more than one specified spin lock, and optionally, 627 * if we hold sleep locks. 628 */ 629 void 630 lockdebug_barrier(volatile void *spinlock, int slplocks) 631 { 632 struct lwp *l = curlwp; 633 lockdebug_t *ld; 634 uint16_t cpuno; 635 int s, s0; 636 637 if (panicstr != NULL || ld_panic) 638 return; 639 640 /* 641 * Use splsoftclock() and not a critical section to block preemption. 642 * kpreempt_disable() will skew preemption statistics by firing again 643 * in mi_switch(), while we are preempting! 644 */ 645 s0 = splsoftclock(); 646 647 if (curcpu()->ci_spin_locks2 != 0) { 648 cpuno = (uint16_t)cpu_number(); 649 650 s = lockdebug_lock_rd(&ld_spinner_lk); 651 TAILQ_FOREACH(ld, &ld_spinners, ld_chain) { 652 if (ld->ld_lock == spinlock) { 653 if (ld->ld_cpu != cpuno) { 654 lockdebug_abort1(ld, &ld_spinner_lk, 655 __func__, 656 "not held by current CPU", true); 657 splx(s0); 658 return; 659 } 660 continue; 661 } 662 if (ld->ld_cpu == cpuno && (l->l_pflag & LP_INTR) == 0) { 663 lockdebug_abort1(ld, &ld_spinner_lk, 664 __func__, "spin lock held", true); 665 splx(s0); 666 return; 667 } 668 } 669 lockdebug_unlock_rd(&ld_spinner_lk, s); 670 } 671 672 if (!slplocks) { 673 if (l->l_exlocks != 0) { 674 s = lockdebug_lock_rd(&ld_sleeper_lk); 675 TAILQ_FOREACH(ld, &ld_sleepers, ld_chain) { 676 if (ld->ld_lwp == l) { 677 lockdebug_abort1(ld, &ld_sleeper_lk, 678 __func__, "sleep lock held", true); 679 splx(s0); 680 return; 681 } 682 } 683 lockdebug_unlock_rd(&ld_sleeper_lk, s); 684 } 685 if (l->l_shlocks != 0) 686 panic("lockdebug_barrier: holding %d shared locks", 687 l->l_shlocks); 688 } 689 690 splx(s0); 691 } 692 693 /* 694 * lockdebug_mem_check: 695 * 696 * Check for in-use locks within a memory region that is 697 * being freed. 698 */ 699 void 700 lockdebug_mem_check(const char *func, void *base, size_t sz) 701 { 702 lockdebug_t *ld; 703 lockdebuglk_t *lk; 704 int s; 705 706 if (panicstr != NULL || ld_panic) 707 return; 708 709 s = lockdebug_lock_rd(&ld_tree_lk); 710 ld = (lockdebug_t *)rb_tree_find_node_geq(&ld_rb_tree, base); 711 if (ld != NULL) { 712 const uintptr_t lock = (uintptr_t)ld->ld_lock; 713 714 if ((uintptr_t)base > lock) 715 panic("%s: corrupt tree ld=%p, base=%p, sz=%zu", 716 __func__, ld, base, sz); 717 if (lock >= (uintptr_t)base + sz) 718 ld = NULL; 719 } 720 lockdebug_unlock_rd(&ld_tree_lk, s); 721 if (ld == NULL) 722 return; 723 724 if ((ld->ld_flags & LD_SLEEPER) != 0) 725 lk = &ld_sleeper_lk; 726 else 727 lk = &ld_spinner_lk; 728 729 lockdebug_lock(lk); 730 lockdebug_abort1(ld, lk, func, 731 "allocation contains active lock", !cold); 732 } 733 734 /* 735 * lockdebug_dump: 736 * 737 * Dump information about a lock on panic, or for DDB. 738 */ 739 static void 740 lockdebug_dump(lockdebug_t *ld, void (*pr)(const char *, ...)) 741 { 742 int sleeper = (ld->ld_flags & LD_SLEEPER); 743 744 (*pr)( 745 "lock address : %#018lx type : %18s\n" 746 "shared holds : %18u exclusive: %18u\n" 747 "shares wanted: %18u exclusive: %18u\n" 748 "current cpu : %18u last held: %18u\n" 749 "current lwp : %#018lx last held: %#018lx\n" 750 "last locked : %#018lx unlocked : %#018lx\n" 751 "initialized : %#018lx\n", 752 (long)ld->ld_lock, (sleeper ? "sleep/adaptive" : "spin"), 753 (unsigned)ld->ld_shares, ((ld->ld_flags & LD_LOCKED) != 0), 754 (unsigned)ld->ld_shwant, (unsigned)ld->ld_exwant, 755 (unsigned)cpu_number(), (unsigned)ld->ld_cpu, 756 (long)curlwp, (long)ld->ld_lwp, 757 (long)ld->ld_locked, (long)ld->ld_unlocked, 758 (long)ld->ld_initaddr); 759 760 if (ld->ld_lockops->lo_dump != NULL) 761 (*ld->ld_lockops->lo_dump)(ld->ld_lock); 762 763 if (sleeper) { 764 (*pr)("\n"); 765 turnstile_print(ld->ld_lock, pr); 766 } 767 } 768 769 /* 770 * lockdebug_abort1: 771 * 772 * An error has been trapped - dump lock info and panic. 773 */ 774 static void 775 lockdebug_abort1(lockdebug_t *ld, lockdebuglk_t *lk, const char *func, 776 const char *msg, bool dopanic) 777 { 778 779 /* 780 * Don't make the situation wose if the system is already going 781 * down in flames. Once a panic is triggered, lockdebug state 782 * becomes stale and cannot be trusted. 783 */ 784 if (atomic_inc_uint_nv(&ld_panic) != 1) { 785 lockdebug_unlock(lk); 786 return; 787 } 788 789 printf_nolog("%s error: %s: %s\n\n", ld->ld_lockops->lo_name, 790 func, msg); 791 lockdebug_dump(ld, printf_nolog); 792 lockdebug_unlock(lk); 793 printf_nolog("\n"); 794 if (dopanic) 795 panic("LOCKDEBUG"); 796 } 797 798 #endif /* LOCKDEBUG */ 799 800 /* 801 * lockdebug_lock_print: 802 * 803 * Handle the DDB 'show lock' command. 804 */ 805 #ifdef DDB 806 void 807 lockdebug_lock_print(void *addr, void (*pr)(const char *, ...)) 808 { 809 #ifdef LOCKDEBUG 810 lockdebug_t *ld; 811 812 TAILQ_FOREACH(ld, &ld_all, ld_achain) { 813 if (ld->ld_lock == addr) { 814 lockdebug_dump(ld, pr); 815 return; 816 } 817 } 818 (*pr)("Sorry, no record of a lock with address %p found.\n", addr); 819 #else 820 (*pr)("Sorry, kernel not built with the LOCKDEBUG option.\n"); 821 #endif /* LOCKDEBUG */ 822 } 823 #endif /* DDB */ 824 825 /* 826 * lockdebug_abort: 827 * 828 * An error has been trapped - dump lock info and call panic(). 829 */ 830 void 831 lockdebug_abort(volatile void *lock, lockops_t *ops, const char *func, 832 const char *msg) 833 { 834 #ifdef LOCKDEBUG 835 lockdebug_t *ld; 836 lockdebuglk_t *lk; 837 838 if ((ld = lockdebug_lookup(lock, &lk)) != NULL) { 839 lockdebug_abort1(ld, lk, func, msg, true); 840 /* NOTREACHED */ 841 } 842 #endif /* LOCKDEBUG */ 843 844 /* 845 * Complain first on the occurrance only. Otherwise proceeed to 846 * panic where we will `rendezvous' with other CPUs if the machine 847 * is going down in flames. 848 */ 849 if (atomic_inc_uint_nv(&ld_panic) == 1) { 850 printf_nolog("%s error: %s: %s\n\n" 851 "lock address : %#018lx\n" 852 "current cpu : %18d\n" 853 "current lwp : %#018lx\n", 854 ops->lo_name, func, msg, (long)lock, (int)cpu_number(), 855 (long)curlwp); 856 (*ops->lo_dump)(lock); 857 printf_nolog("\n"); 858 } 859 860 panic("lock error"); 861 } 862