Loading...
   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
/*
 * Copyright (c) 1999, 2006-2008 Apple Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
 
#include <pthread_internals.h>
#include "magmallocProvider.h"

#import <stdlib.h>
#import <stdio.h>
#import <string.h>
#import <unistd.h>
#import <malloc/malloc.h>
#import <fcntl.h>
#import <crt_externs.h>
#import <errno.h>
#import <pthread_internals.h>
#import <limits.h>
#import <dlfcn.h>
#import <mach/mach_vm.h>
#import <mach/mach_init.h>
#import <sys/mman.h>

#import "scalable_malloc.h"
#import "stack_logging.h"
#import "malloc_printf.h"
#import "_simple.h"

/*
 * MALLOC_ABSOLUTE_MAX_SIZE - There are many instances of addition to a
 * user-specified size_t, which can cause overflow (and subsequent crashes)
 * for values near SIZE_T_MAX.  Rather than add extra "if" checks everywhere
 * this occurs, it is easier to just set an absolute maximum request size,
 * and immediately return an error if the requested size exceeds this maximum.
 * Of course, values less than this absolute max can fail later if the value
 * is still too large for the available memory.  The largest value added
 * seems to be PAGE_SIZE (in the macro round_page()), so to be safe, we set
 * the maximum to be 2 * PAGE_SIZE less than SIZE_T_MAX.
 */
#define MALLOC_ABSOLUTE_MAX_SIZE	(SIZE_T_MAX - (2 * PAGE_SIZE))

#define USE_SLEEP_RATHER_THAN_ABORT	0

typedef void (malloc_logger_t)(uint32_t type, uintptr_t arg1, uintptr_t arg2, uintptr_t arg3, uintptr_t result, uint32_t num_hot_frames_to_skip);

__private_extern__ pthread_lock_t _malloc_lock = 0; // initialized in __libc_init

/* The following variables are exported for the benefit of performance tools
 *
 * It should always be safe to first read malloc_num_zones, then read
 * malloc_zones without taking the lock, if only iteration is required
 */
unsigned malloc_num_zones = 0;
unsigned malloc_num_zones_allocated = 0;
malloc_zone_t **malloc_zones = 0;
malloc_logger_t *malloc_logger = NULL;

unsigned malloc_debug_flags = 0;

unsigned malloc_check_start = 0; // 0 means don't check
unsigned malloc_check_counter = 0;
unsigned malloc_check_each = 1000;

/* global flag to suppress ASL logging e.g. for syslogd */
int _malloc_no_asl_log = 0;

static int malloc_check_sleep = 100; // default 100 second sleep
static int malloc_check_abort = 0; // default is to sleep, not abort

static int malloc_debug_file = STDERR_FILENO;
/*
 * State indicated by malloc_def_zone_state
 * 0 - the default zone has not yet been created
 * 1 - a Malloc* environment variable has been set
 * 2 - the default zone has been created and an environment variable scan done
 * 3 - a new default zone has been created and another environment variable scan
 */
__private_extern__ int malloc_def_zone_state = 0;
__private_extern__ malloc_zone_t *__zone0 = NULL;

static const char Malloc_Facility[] = "com.apple.Libsystem.malloc";

#define MALLOC_LOCK()		LOCK(_malloc_lock)
#define MALLOC_UNLOCK()		UNLOCK(_malloc_lock)

#define MALLOC_LOG_TYPE_ALLOCATE	stack_logging_type_alloc
#define MALLOC_LOG_TYPE_DEALLOCATE	stack_logging_type_dealloc
#define MALLOC_LOG_TYPE_HAS_ZONE	stack_logging_flag_zone
#define MALLOC_LOG_TYPE_CLEARED		stack_logging_flag_cleared

/*********	Utilities	************/

static inline malloc_zone_t * find_registered_zone(const void *, size_t *) __attribute__((always_inline));
static inline malloc_zone_t *
find_registered_zone(const void *ptr, size_t *returned_size) {
    // Returns a zone which contains ptr, else NULL
    unsigned index;
    malloc_zone_t	**zones = malloc_zones;
    
    for (index = 0; index < malloc_num_zones; ++index, ++zones) {
        malloc_zone_t *zone = *zones;
        size_t size = zone->size(zone, ptr);
        if (size) { // Claimed by this zone?
            if (returned_size) *returned_size = size;
            return zone;
        }
    }
    // Unclaimed by any zone.
    if (returned_size) *returned_size = 0;
    return NULL;
}

__private_extern__ __attribute__((noinline)) void
malloc_error_break(void) {
	// Provides a non-inlined place for various malloc error procedures to call
	// that will be called after an error message appears.  It does not make
	// sense for developers to call this function, so it is marked
	// __private_extern__ to prevent it from becoming API.
	MAGMALLOC_MALLOCERRORBREAK(); // DTrace USDT probe
}

__private_extern__ boolean_t __stack_logging_locked();

__private_extern__ __attribute__((noinline)) int
malloc_gdb_po_unsafe(void) {
  // In order to implement "po" other data formatters in gdb, the debugger
  // calls functions that call malloc.  The debugger will  only run one thread 
  // of the program in this case, so if another thread is holding a zone lock,
  // gdb may deadlock in this case.
  //
  // Iterate over the zones in malloc_zones, and call "trylock" on the zone 
  // lock.  If trylock succeeds, unlock it, otherwise return "locked".  Returns
  // 0 == safe, 1 == locked/unsafe.
  
  if (__stack_logging_locked())
    return 1;

  malloc_zone_t **zones = malloc_zones;
  unsigned i, e = malloc_num_zones;
  
  for (i = 0; i != e; ++i) {
    malloc_zone_t *zone = zones[i];

    // Version must be >= 5 to look at the new introspection field.
    if (zone->version < 5)
      continue;

    if (zone->introspect->zone_locked && zone->introspect->zone_locked(zone))
      return 1;
  }
  return 0;
}

/*********	Creation and destruction	************/

static void set_flags_from_environment(void);

static void
malloc_zone_register_while_locked(malloc_zone_t *zone) {
    size_t protect_size;
    unsigned i;
    
    /* scan the list of zones, to see if this zone is already registered.  If
     * so, print an error message and return. */
    for (i = 0; i != malloc_num_zones; ++i)
        if (zone == malloc_zones[i]) {
            _malloc_printf(ASL_LEVEL_ERR, "Attempted to register zone more than once: %p\n", zone);
            return;
        }
  
    if (malloc_num_zones == malloc_num_zones_allocated) {
        size_t malloc_zones_size = malloc_num_zones * sizeof(malloc_zone_t *);
        size_t alloc_size = malloc_zones_size + vm_page_size;
        
        malloc_zone_t **new_zones = mmap(0, alloc_size, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, VM_MAKE_TAG(VM_MEMORY_MALLOC), 0);
        
        /* If there were previously allocated malloc zones, we need to copy them
         * out of the previous array and into the new zones array */
        if (malloc_zones)
            memcpy(new_zones, malloc_zones, malloc_zones_size);
            
        /* Update the malloc_zones pointer, which we leak if it was previously
         * allocated, and the number of zones allocated */
        protect_size = alloc_size;
        malloc_zones = new_zones;
        malloc_num_zones_allocated = alloc_size / sizeof(malloc_zone_t *);
    } else {
        /* If we don't need to reallocate zones, we need to briefly change the
         * page protection the malloc zones to allow writes */
        protect_size = malloc_num_zones_allocated * sizeof(malloc_zone_t *);
        vm_protect(mach_task_self(), (uintptr_t)malloc_zones, protect_size, 0, VM_PROT_READ | VM_PROT_WRITE);
    }
    malloc_zones[malloc_num_zones++] = zone;
    
    /* Finally, now that the zone is registered, disallow write access to the
     * malloc_zones array */
    vm_protect(mach_task_self(), (uintptr_t)malloc_zones, protect_size, 0, VM_PROT_READ);
    //_malloc_printf(ASL_LEVEL_INFO, "Registered malloc_zone %p in malloc_zones %p [%u zones, %u bytes]\n", zone, malloc_zones, malloc_num_zones, protect_size);
}

static void
_malloc_initialize(void) {
    MALLOC_LOCK();
    if (malloc_def_zone_state < 2) {
	unsigned n;
	malloc_zone_t	*zone;

	malloc_def_zone_state += 2;
	set_flags_from_environment(); // will only set flags up to two times
	n = malloc_num_zones;
	zone = create_scalable_zone(0, malloc_debug_flags);
	malloc_zone_register_while_locked(zone);
	malloc_set_zone_name(zone, "DefaultMallocZone");
	if (n != 0) { // make the default first, for efficiency
		unsigned protect_size = malloc_num_zones_allocated * sizeof(malloc_zone_t *);
		malloc_zone_t *hold = malloc_zones[0];
		if(hold->zone_name && strcmp(hold->zone_name, "DefaultMallocZone") == 0) {
			free((void *)hold->zone_name);
			hold->zone_name = NULL;
		}
		vm_protect(mach_task_self(), (uintptr_t)malloc_zones, protect_size, 0, VM_PROT_READ | VM_PROT_WRITE);
		malloc_zones[0] = malloc_zones[n];
		malloc_zones[n] = hold;
		vm_protect(mach_task_self(), (uintptr_t)malloc_zones, protect_size, 0, VM_PROT_READ);
	}
	// _malloc_printf(ASL_LEVEL_INFO, "%d registered zones\n", malloc_num_zones);
	// _malloc_printf(ASL_LEVEL_INFO, "malloc_zones is at %p; malloc_num_zones is at %p\n", (unsigned)&malloc_zones, (unsigned)&malloc_num_zones);
    }
    MALLOC_UNLOCK();
}

static inline malloc_zone_t *inline_malloc_default_zone(void) __attribute__((always_inline));
static inline malloc_zone_t *
inline_malloc_default_zone(void) {
    if (malloc_def_zone_state < 2) _malloc_initialize();
    // _malloc_printf(ASL_LEVEL_INFO, "In inline_malloc_default_zone with %d %d\n", malloc_num_zones, malloc_has_debug_zone);
    return malloc_zones[0];
}

malloc_zone_t *
malloc_default_zone(void) {
    return inline_malloc_default_zone();
}

malloc_zone_t *
malloc_default_purgeable_zone(void) {
    static malloc_zone_t *dpz;

    if (!dpz) {
        malloc_zone_t *tmp = create_purgeable_zone(0, malloc_default_zone(), malloc_debug_flags);
	malloc_zone_register(tmp);
        malloc_set_zone_name(tmp, "DefaultPurgeableMallocZone");
        if (!__sync_bool_compare_and_swap(&dpz, NULL, tmp))
            malloc_destroy_zone(tmp);
    }
    return dpz;
}

// For debugging, allow stack logging to both memory and disk to compare their results.
static void
stack_logging_log_stack_debug(uint32_t type_flags, uintptr_t zone_ptr, uintptr_t size, uintptr_t ptr_arg, uintptr_t return_val, uint32_t num_hot_to_skip)
{
    __disk_stack_logging_log_stack(type_flags, zone_ptr, size, ptr_arg, return_val, num_hot_to_skip);
    stack_logging_log_stack(type_flags, zone_ptr, size, ptr_arg, return_val, num_hot_to_skip);
}

static void
set_flags_from_environment(void) {
    const char	*flag;
    int		fd;
    char	**env = * _NSGetEnviron();
    char	**p;
    char	*c;

    if (malloc_debug_file != STDERR_FILENO) {
	close(malloc_debug_file);
	malloc_debug_file = STDERR_FILENO;
    }
#if __LP64__
    malloc_debug_flags = SCALABLE_MALLOC_ABORT_ON_CORRUPTION; // Set always on 64-bit processes
#else
    malloc_debug_flags = 0;
#endif
    stack_logging_enable_logging = 0;
    stack_logging_dontcompact = 0;
    malloc_logger = NULL;
    malloc_check_start = 0;
    malloc_check_each = 1000;
    malloc_check_abort = 0;
    malloc_check_sleep = 100;
    /*
     * Given that all environment variables start with "Malloc" we optimize by scanning quickly
     * first the environment, therefore avoiding repeated calls to getenv().
     * If we are setu/gid these flags are ignored to prevent a malicious invoker from changing
     * our behaviour.
     */
    for (p = env; (c = *p) != NULL; ++p) {
	if (!strncmp(c, "Malloc", 6)) {
	    if (issetugid())
		return;
	    break;
	}
    }
    if (c == NULL)
	return;
    flag = getenv("MallocLogFile");
    if (flag) {
	fd = open(flag, O_WRONLY|O_APPEND|O_CREAT, 0644);
	if (fd >= 0) {
           malloc_debug_file = fd;
	   fcntl(fd, F_SETFD, 0); // clear close-on-exec flag  XXX why?
	} else {
	    malloc_printf("Could not open %s, using stderr\n", flag);
	}
    }
    if (getenv("MallocGuardEdges")) {
	malloc_debug_flags = SCALABLE_MALLOC_ADD_GUARD_PAGES;
	_malloc_printf(ASL_LEVEL_INFO, "protecting edges\n");
	if (getenv("MallocDoNotProtectPrelude")) {
	    malloc_debug_flags |= SCALABLE_MALLOC_DONT_PROTECT_PRELUDE;
	    _malloc_printf(ASL_LEVEL_INFO, "... but not protecting prelude guard page\n");
	}
	if (getenv("MallocDoNotProtectPostlude")) {
	    malloc_debug_flags |= SCALABLE_MALLOC_DONT_PROTECT_POSTLUDE;
	    _malloc_printf(ASL_LEVEL_INFO, "... but not protecting postlude guard page\n");
	}
    }
    flag = getenv("MallocStackLogging");
    if (!flag) {
	flag = getenv("MallocStackLoggingNoCompact");
	stack_logging_dontcompact = 1;
    } 
    // For debugging, the MallocStackLogging or MallocStackLoggingNoCompact environment variables can be set to
    // values of "memory", "disk", or "both" to control which stack logging mechanism to use.  Those strings appear
    // in the flag variable, and the strtoul() call below will return 0, so then we can do string comparison on the
    // value of flag.  The default stack logging now is disk stack logging, since memory stack logging is not 64-bit-aware.
    if (flag) {
	unsigned long val = strtoul(flag, NULL, 0);
	if (val == 1) val = 0;
	if (val == -1) val = 0;
	if (val) {
	    malloc_logger = (void *)val;
	    _malloc_printf(ASL_LEVEL_INFO, "recording stacks using recorder %p\n", malloc_logger);
	} else if (strcmp(flag,"memory") == 0) {
	    malloc_logger = (malloc_logger_t *)stack_logging_log_stack;
	    _malloc_printf(ASL_LEVEL_INFO, "recording malloc stacks in memory using standard recorder\n");
	} else if (strcmp(flag,"both") == 0) {
	    malloc_logger = stack_logging_log_stack_debug;
	    _malloc_printf(ASL_LEVEL_INFO, "recording malloc stacks to both memory and disk for comparison debugging\n");
	} else {	// the default is to log to disk
	    malloc_logger = __disk_stack_logging_log_stack;
	    _malloc_printf(ASL_LEVEL_INFO, "recording malloc stacks to disk using standard recorder\n");
	}
	stack_logging_enable_logging = 1;
	if (stack_logging_dontcompact) {
	    if (malloc_logger == __disk_stack_logging_log_stack) {
	      _malloc_printf(ASL_LEVEL_INFO, "stack logging compaction turned off; size of log files on disk can increase rapidly\n");
	    } else {
	      _malloc_printf(ASL_LEVEL_INFO, "stack logging compaction turned off; VM can increase rapidly\n");
	    }
	}
    }
    if (getenv("MallocScribble")) {
        malloc_debug_flags |= SCALABLE_MALLOC_DO_SCRIBBLE;
        _malloc_printf(ASL_LEVEL_INFO, "enabling scribbling to detect mods to free blocks\n");
    }
    if (getenv("MallocErrorAbort")) {
        malloc_debug_flags |= SCALABLE_MALLOC_ABORT_ON_ERROR;
        _malloc_printf(ASL_LEVEL_INFO, "enabling abort() on bad malloc or free\n");
    }
#if __LP64__
    /* initialization above forces SCALABLE_MALLOC_ABORT_ON_CORRUPTION of 64-bit processes */
#else
    if (getenv("MallocCorruptionAbort")) { // Set from an environment variable in 32-bit processes
	malloc_debug_flags |= SCALABLE_MALLOC_ABORT_ON_CORRUPTION;
    }
#endif
    flag = getenv("MallocCheckHeapStart");
    if (flag) {
	malloc_check_start = strtoul(flag, NULL, 0);
	if (malloc_check_start == 0) malloc_check_start = 1;
	if (malloc_check_start == -1) malloc_check_start = 1;
	flag = getenv("MallocCheckHeapEach");
	if (flag) {
	    malloc_check_each = strtoul(flag, NULL, 0);
	    if (malloc_check_each == 0) malloc_check_each = 1;
	    if (malloc_check_each == -1) malloc_check_each = 1;
	}
	_malloc_printf(ASL_LEVEL_INFO, "checks heap after %dth operation and each %d operations\n", malloc_check_start, malloc_check_each);
	flag = getenv("MallocCheckHeapAbort");
	if (flag)
	    malloc_check_abort = strtol(flag, NULL, 0);
	if (malloc_check_abort)
	    _malloc_printf(ASL_LEVEL_INFO, "will abort on heap corruption\n");
	else {
	    flag = getenv("MallocCheckHeapSleep");
	    if (flag)
		malloc_check_sleep = strtol(flag, NULL, 0);
	    if (malloc_check_sleep > 0)
		_malloc_printf(ASL_LEVEL_INFO, "will sleep for %d seconds on heap corruption\n", malloc_check_sleep);
	    else if (malloc_check_sleep < 0)
		_malloc_printf(ASL_LEVEL_INFO, "will sleep once for %d seconds on heap corruption\n", -malloc_check_sleep);
	    else
		_malloc_printf(ASL_LEVEL_INFO, "no sleep on heap corruption\n");
	}
    }
    if (getenv("MallocHelp")) {
	_malloc_printf(ASL_LEVEL_INFO,
	    "environment variables that can be set for debug:\n"
	    "- MallocLogFile <f> to create/append messages to file <f> instead of stderr\n"
	    "- MallocGuardEdges to add 2 guard pages for each large block\n"
	    "- MallocDoNotProtectPrelude to disable protection (when previous flag set)\n"
	    "- MallocDoNotProtectPostlude to disable protection (when previous flag set)\n"
	    "- MallocStackLogging to record all stacks.  Tools like leaks can then be applied\n"
	    "- MallocStackLoggingNoCompact to record all stacks.  Needed for malloc_history\n"
	    "- MallocStackLoggingDirectory to set location of stack logs, which can grow large; default is /tmp\n"
	    "- MallocScribble to detect writing on free blocks and missing initializers:\n"
	    "  0x55 is written upon free and 0xaa is written on allocation\n"
	    "- MallocCheckHeapStart <n> to start checking the heap after <n> operations\n"
	    "- MallocCheckHeapEach <s> to repeat the checking of the heap after <s> operations\n"
	    "- MallocCheckHeapSleep <t> to sleep <t> seconds on heap corruption\n"
	    "- MallocCheckHeapAbort <b> to abort on heap corruption if <b> is non-zero\n"
	    "- MallocCorruptionAbort to abort on malloc errors, but not on out of memory for 32-bit processes\n"
	    "  MallocCorruptionAbort is always set on 64-bit processes\n"
	    "- MallocErrorAbort to abort on any malloc error, including out of memory\n"
	    "- MallocHelp - this help!\n");
    }
}

malloc_zone_t *
malloc_create_zone(vm_size_t start_size, unsigned flags)
{
    malloc_zone_t	*zone;

    /* start_size doesn't seemed to actually be used, but we test anyways */
    if (start_size > MALLOC_ABSOLUTE_MAX_SIZE) {
	return NULL;
    }
    if (malloc_def_zone_state < 2) _malloc_initialize();
    zone = create_scalable_zone(start_size, flags | malloc_debug_flags);
    malloc_zone_register(zone);
    return zone;
}

/*
 * For use by CheckFix: establish a new default zone whose behavior is, apart from
 * the use of death-row and per-CPU magazines, that of Leopard.
 */
void
malloc_create_legacy_default_zone(void)
{
    malloc_zone_t	*zone;
    int i;

    if (malloc_def_zone_state < 2) _malloc_initialize();
    zone = create_legacy_scalable_zone(0, malloc_debug_flags);

    MALLOC_LOCK();
    malloc_zone_register_while_locked(zone);

    //
    // Establish the legacy scalable zone just created as the default zone.
    //
    malloc_zone_t *hold = malloc_zones[0];
    if(hold->zone_name && strcmp(hold->zone_name, "DefaultMallocZone") == 0) {
	free((void *)hold->zone_name);
	hold->zone_name = NULL;
    }
    malloc_set_zone_name(zone, "DefaultMallocZone");

    unsigned protect_size = malloc_num_zones_allocated * sizeof(malloc_zone_t *);
    vm_protect(mach_task_self(), (uintptr_t)malloc_zones, protect_size, 0, VM_PROT_READ | VM_PROT_WRITE);

    // assert(zone == malloc_zones[malloc_num_zones - 1];
    for (i = malloc_num_zones - 1; i > 0; --i) {
	malloc_zones[i] = malloc_zones[i - 1];
    }
    malloc_zones[0] = zone;

    vm_protect(mach_task_self(), (uintptr_t)malloc_zones, protect_size, 0, VM_PROT_READ);
    MALLOC_UNLOCK();
}

void
malloc_destroy_zone(malloc_zone_t *zone) {
    malloc_zone_unregister(zone);
    zone->destroy(zone);
}

/* called from the {put,set,unset}env routine */
__private_extern__ void
__malloc_check_env_name(const char *name)
{
    MALLOC_LOCK();
    if(malloc_def_zone_state == 2 && strncmp(name, "Malloc", 6) == 0)
	malloc_def_zone_state = 1;
    MALLOC_UNLOCK();
}

/*********	Block creation and manipulation	************/

extern const char *__crashreporter_info__;

static void
internal_check(void) {
    static vm_address_t	*frames = NULL;
    static unsigned	num_frames;
    if (malloc_zone_check(NULL)) {
		if (!frames) vm_allocate(mach_task_self(), (void *)&frames, vm_page_size, 1);
		thread_stack_pcs(frames, vm_page_size/sizeof(vm_address_t) - 1, &num_frames);
    } else {
	_SIMPLE_STRING b = _simple_salloc();
	if (b)
	    _simple_sprintf(b, "*** MallocCheckHeap: FAILED check at %dth operation\n", malloc_check_counter-1);
	else
	    _malloc_printf(MALLOC_PRINTF_NOLOG, "*** MallocCheckHeap: FAILED check at %dth operation\n", malloc_check_counter-1);
	malloc_printf("*** MallocCheckHeap: FAILED check at %dth operation\n", malloc_check_counter-1);
	if (frames) {
	    unsigned	index = 1;
	    if (b) {
		_simple_sappend(b, "Stack for last operation where the malloc check succeeded: ");
		while (index < num_frames) _simple_sprintf(b, "%p ", frames[index++]);
		malloc_printf("%s\n(Use 'atos' for a symbolic stack)\n", _simple_string(b));
	    } else {
		/*
		 * Should only get here if vm_allocate() can't get a single page of
		 * memory, implying _simple_asl_log() would also fail.  So we just
		 * print to the file descriptor.
		 */
		_malloc_printf(MALLOC_PRINTF_NOLOG, "Stack for last operation where the malloc check succeeded: ");
		while (index < num_frames) _malloc_printf(MALLOC_PRINTF_NOLOG, "%p ", frames[index++]);
		_malloc_printf(MALLOC_PRINTF_NOLOG, "\n(Use 'atos' for a symbolic stack)\n");
	    }
	}
	if (malloc_check_each > 1) {
	    unsigned	recomm_each = (malloc_check_each > 10) ? malloc_check_each/10 : 1;
	    unsigned	recomm_start = (malloc_check_counter > malloc_check_each+1) ? malloc_check_counter-1-malloc_check_each : 1;
	    malloc_printf("*** Recommend using 'setenv MallocCheckHeapStart %d; setenv MallocCheckHeapEach %d' to narrow down failure\n", recomm_start, recomm_each);
	}
	if (malloc_check_abort) {
	    __crashreporter_info__ = b ? _simple_string(b) : "*** MallocCheckHeap: FAILED check";
	    abort();
	} else if (b)
	    _simple_sfree(b);
	if (malloc_check_sleep > 0) {
	    _malloc_printf(ASL_LEVEL_NOTICE, "*** Sleeping for %d seconds to leave time to attach\n",
		malloc_check_sleep);
	    sleep(malloc_check_sleep);
	} else if (malloc_check_sleep < 0) {
	    _malloc_printf(ASL_LEVEL_NOTICE, "*** Sleeping once for %d seconds to leave time to attach\n",
		-malloc_check_sleep);
	    sleep(-malloc_check_sleep);
	    malloc_check_sleep = 0;
	}
    }
    malloc_check_start += malloc_check_each;
}

void *
malloc_zone_malloc(malloc_zone_t *zone, size_t size) {
    void	*ptr;
    if (malloc_check_start && (malloc_check_counter++ >= malloc_check_start)) {
	internal_check();
    }
    if (size > MALLOC_ABSOLUTE_MAX_SIZE) {
	return NULL;
    }
    ptr = zone->malloc(zone, size);
    if (malloc_logger) malloc_logger(MALLOC_LOG_TYPE_ALLOCATE | MALLOC_LOG_TYPE_HAS_ZONE, (uintptr_t)zone, (uintptr_t)size, 0, (uintptr_t)ptr, 0);
    return ptr;
}

void *
malloc_zone_calloc(malloc_zone_t *zone, size_t num_items, size_t size) {
    void	*ptr;
    if (malloc_check_start && (malloc_check_counter++ >= malloc_check_start)) {
	internal_check();
    }
    if (size > MALLOC_ABSOLUTE_MAX_SIZE) {
	return NULL;
    }
    ptr = zone->calloc(zone, num_items, size);
    if (malloc_logger) malloc_logger(MALLOC_LOG_TYPE_ALLOCATE | MALLOC_LOG_TYPE_HAS_ZONE | MALLOC_LOG_TYPE_CLEARED, (uintptr_t)zone, (uintptr_t)(num_items * size), 0, (uintptr_t)ptr, 0);
    return ptr;
}

void *
malloc_zone_valloc(malloc_zone_t *zone, size_t size) {
    void	*ptr;
    if (malloc_check_start && (malloc_check_counter++ >= malloc_check_start)) {
	internal_check();
    }
    if (size > MALLOC_ABSOLUTE_MAX_SIZE) {
	return NULL;
    }
    ptr = zone->valloc(zone, size);
    if (malloc_logger) malloc_logger(MALLOC_LOG_TYPE_ALLOCATE | MALLOC_LOG_TYPE_HAS_ZONE, (uintptr_t)zone, (uintptr_t)size, 0, (uintptr_t)ptr, 0);
    return ptr;
}

void *
malloc_zone_realloc(malloc_zone_t *zone, void *ptr, size_t size) {
    void	*new_ptr;
    if (malloc_check_start && (malloc_check_counter++ >= malloc_check_start)) {
	internal_check();
    }
    if (size > MALLOC_ABSOLUTE_MAX_SIZE) {
	return NULL;
    }
    new_ptr = zone->realloc(zone, ptr, size);
    if (malloc_logger) malloc_logger(MALLOC_LOG_TYPE_ALLOCATE | MALLOC_LOG_TYPE_DEALLOCATE | MALLOC_LOG_TYPE_HAS_ZONE, (uintptr_t)zone, (uintptr_t)ptr, (uintptr_t)size, (uintptr_t)new_ptr, 0);
    return new_ptr;
}

void
malloc_zone_free(malloc_zone_t *zone, void *ptr) {
    if (malloc_logger) malloc_logger(MALLOC_LOG_TYPE_DEALLOCATE | MALLOC_LOG_TYPE_HAS_ZONE, (uintptr_t)zone, (uintptr_t)ptr, 0, 0, 0);
    if (malloc_check_start && (malloc_check_counter++ >= malloc_check_start)) {
	internal_check();
    }
    zone->free(zone, ptr);
}

static void
malloc_zone_free_definite_size(malloc_zone_t *zone, void *ptr, size_t size) {
    if (malloc_logger) malloc_logger(MALLOC_LOG_TYPE_DEALLOCATE | MALLOC_LOG_TYPE_HAS_ZONE, (uintptr_t)zone, (uintptr_t)ptr, 0, 0, 0);
    if (malloc_check_start && (malloc_check_counter++ >= malloc_check_start)) {
	internal_check();
    }
    zone->free_definite_size(zone, ptr, size);
}

malloc_zone_t *
malloc_zone_from_ptr(const void *ptr) {
    if (!ptr)
        return NULL;
    else
	return find_registered_zone(ptr, NULL);
}

void *
malloc_zone_memalign(malloc_zone_t *zone, size_t alignment, size_t size) {
    void	*ptr;
    if (zone->version < 5) // Version must be >= 5 to look at the new memalign field.
	return NULL;
    if (!(zone->memalign))
	return NULL;
    if (malloc_check_start && (malloc_check_counter++ >= malloc_check_start)) {
	internal_check();
    }
    if (size > MALLOC_ABSOLUTE_MAX_SIZE) {
	return NULL;
    }
    if (alignment < sizeof( void *) ||		// excludes 0 == alignment
	0 != (alignment & (alignment - 1))) {	// relies on sizeof(void *) being a power of two.
	return NULL;
    }
    ptr = zone->memalign(zone, alignment, size);
    if (malloc_logger) malloc_logger(MALLOC_LOG_TYPE_ALLOCATE | MALLOC_LOG_TYPE_HAS_ZONE, (uintptr_t)zone, (uintptr_t)size, 0, (uintptr_t)ptr, 0);
    return ptr;
}

/*********	Functions for zone implementors	************/

void
malloc_zone_register(malloc_zone_t *zone) {
    MALLOC_LOCK();
    malloc_zone_register_while_locked(zone);
    MALLOC_UNLOCK();
}

void
malloc_zone_unregister(malloc_zone_t *z) {
    unsigned	index;

    if (malloc_num_zones == 0)
        return;
  
    MALLOC_LOCK();
    for (index = 0; index < malloc_num_zones; ++index) {
        if (z != malloc_zones[index])
            continue;
      
        // Modify the page to be allow write access, so that we can update the
        // malloc_zones array.
        size_t protect_size = malloc_num_zones_allocated * sizeof(malloc_zone_t *);
        vm_protect(mach_task_self(), (uintptr_t)malloc_zones, protect_size, 0, VM_PROT_READ | VM_PROT_WRITE);

        // If we found a match, swap it with the entry on the back of the list
        // and null out the back of the list.
        malloc_zones[index] = malloc_zones[malloc_num_zones - 1];
        malloc_zones[malloc_num_zones - 1] = NULL;
        --malloc_num_zones;
        
        vm_protect(mach_task_self(), (uintptr_t)malloc_zones, protect_size, 0, VM_PROT_READ);
        MALLOC_UNLOCK();
        return;
    }
    MALLOC_UNLOCK();
    malloc_printf("*** malloc_zone_unregister() failed for %p\n", z);
}

void
malloc_set_zone_name(malloc_zone_t *z, const char *name) {
    char	*newName;
    if (z->zone_name) {
        free((char *)z->zone_name);
        z->zone_name = NULL;
    }
    newName = malloc_zone_malloc(z, strlen(name) + 1);
    strcpy(newName, name);
    z->zone_name = (const char *)newName;
}

const char *
malloc_get_zone_name(malloc_zone_t *zone) {
    return zone->zone_name;
}

/*
 * XXX malloc_printf now uses _simple_*printf.  It only deals with a
 * subset of printf format specifiers, but it doesn't call malloc.
 */

__private_extern__ void
_malloc_vprintf(int flags, const char *format, va_list ap)
{
    _SIMPLE_STRING b;

    if (_malloc_no_asl_log || (flags & MALLOC_PRINTF_NOLOG) || (b = _simple_salloc()) == NULL) {
	if (!(flags & MALLOC_PRINTF_NOPREFIX)) {
	    if (__is_threaded) {
		/* XXX somewhat rude 'knowing' that pthread_t is a pointer */
		_simple_dprintf(malloc_debug_file, "%s(%d,%p) malloc: ", getprogname(), getpid(), (void *)pthread_self());
	    } else {
		_simple_dprintf(malloc_debug_file, "%s(%d) malloc: ", getprogname(), getpid());
	    }
	}
	_simple_vdprintf(malloc_debug_file, format, ap);
	return;
    }
    if (!(flags & MALLOC_PRINTF_NOPREFIX)) {
	if (__is_threaded) {
	    /* XXX somewhat rude 'knowing' that pthread_t is a pointer */
	    _simple_sprintf(b, "%s(%d,%p) malloc: ", getprogname(), getpid(), (void *)pthread_self());
	} else {
	    _simple_sprintf(b, "%s(%d) malloc: ", getprogname(), getpid());
	}
    }
    _simple_vsprintf(b, format, ap);
    _simple_put(b, malloc_debug_file);
    _simple_asl_log(flags & MALLOC_PRINTF_LEVEL_MASK, Malloc_Facility, _simple_string(b));
    _simple_sfree(b);
}

__private_extern__ void
_malloc_printf(int flags, const char *format, ...)
{
    va_list ap;

    va_start(ap, format);
    _malloc_vprintf(flags, format, ap);
    va_end(ap);
}

void
malloc_printf(const char *format, ...)
{
    va_list ap;

    va_start(ap, format);
    _malloc_vprintf(ASL_LEVEL_ERR, format, ap);
    va_end(ap);
}

/*********	Generic ANSI callouts	************/

void *
malloc(size_t size) {
    void	*retval;
    retval = malloc_zone_malloc(inline_malloc_default_zone(), size);
    if (retval == NULL) {
	errno = ENOMEM;
    }
    return retval;
}

void *
calloc(size_t num_items, size_t size) {
    void	*retval;
    retval = malloc_zone_calloc(inline_malloc_default_zone(), num_items, size);
    if (retval == NULL) {
	errno = ENOMEM;
    }
    return retval;
}

void
free(void *ptr) {
    malloc_zone_t	*zone;
    size_t		size;
    if (!ptr)
	return;
    zone = find_registered_zone(ptr, &size);
    if (!zone) {
	malloc_printf("*** error for object %p: pointer being freed was not allocated\n"
	"*** set a breakpoint in malloc_error_break to debug\n", ptr);
	malloc_error_break();
	if ((malloc_debug_flags & (SCALABLE_MALLOC_ABORT_ON_CORRUPTION|SCALABLE_MALLOC_ABORT_ON_ERROR)))
		abort();
    } else if (zone->version >= 6 && zone->free_definite_size)
	malloc_zone_free_definite_size(zone, ptr, size);
    else
        malloc_zone_free(zone, ptr);
}

void *
realloc(void *in_ptr, size_t new_size) {
    void		*retval;
    void		*old_ptr;
    malloc_zone_t	*zone;
    size_t		old_size = 0;

    // SUSv3: "If size is 0 and ptr is not a null pointer, the object
    // pointed to is freed. If the space cannot be allocated, the object
    // shall remain unchanged."  Also "If size is 0, either a null pointer
    // or a unique pointer that can be successfully passed to free() shall
    // be returned."  We choose to allocate a minimum size object by calling
    // malloc_zone_malloc with zero size, which matches "If ptr is a null
    // pointer, realloc() shall be equivalent to malloc() for the specified
    // size."  So we only free the original memory if the allocation succeeds.
    old_ptr = (new_size == 0) ? NULL : in_ptr;
    if (!old_ptr) {
	retval = malloc_zone_malloc(inline_malloc_default_zone(), new_size);
    } else {
	zone = find_registered_zone(old_ptr, &old_size);
        if (zone && old_size >= new_size) 
            return old_ptr;
	
	if (!zone)
            zone = inline_malloc_default_zone();
	    
	retval = malloc_zone_realloc(zone, old_ptr, new_size);
    }
    if (retval == NULL) {
	errno = ENOMEM;
    } else if (new_size == 0) {
	free(in_ptr);
    }
    return retval;
}

void *
valloc(size_t size) {
    void	*retval;
    malloc_zone_t	*zone = inline_malloc_default_zone();
    retval = malloc_zone_valloc(zone, size);
    if (retval == NULL) {
	errno = ENOMEM;
    }
    return retval;
}

extern void
vfree(void *ptr) {
    free(ptr);
}

size_t
malloc_size(const void *ptr) {
    size_t	size = 0;
    
    if (!ptr) 
    return size;
	
    (void)find_registered_zone(ptr, &size);
    return size;
}

size_t
malloc_good_size (size_t size) {
    malloc_zone_t	*zone = inline_malloc_default_zone();
    return zone->introspect->good_size(zone, size);
}

/*
 * The posix_memalign() function shall allocate size bytes aligned on a boundary specified by alignment, 
 * and shall return a pointer to the allocated memory in memptr. 
 * The value of alignment shall be a multiple of sizeof( void *), that is also a power of two. 
 * Upon successful completion, the value pointed to by memptr shall be a multiple of alignment.
 *
 * Upon successful completion, posix_memalign() shall return zero; otherwise,
 * an error number shall be returned to indicate the error.
 *
 * The posix_memalign() function shall fail if:
 * EINVAL
 *	The value of the alignment parameter is not a power of two multiple of sizeof( void *).
 * ENOMEM
 *	There is insufficient memory available with the requested alignment.
 */
 
int 
posix_memalign(void **memptr, size_t alignment, size_t size)
{
    void	*retval;
    
    /* POSIX is silent on NULL == memptr !?! */

    retval = malloc_zone_memalign(inline_malloc_default_zone(), alignment, size);
    if (retval == NULL) {
	// To avoid testing the alignment constraints redundantly, we'll rely on the
	// test made in malloc_zone_memalign to vet each request. Only if that test fails
	// and returns NULL, do we arrive here to detect the bogus alignment and give the
	// required EINVAL return.
	if (alignment < sizeof( void *) ||		// excludes 0 == alignment 
	    0 != (alignment & (alignment - 1))) {	// relies on sizeof(void *) being a power of two.
	    return EINVAL;
	}
	return ENOMEM;
    } else {
	*memptr = retval; // Set iff allocation succeeded
	return 0;
    }
}

static malloc_zone_t *
find_registered_purgeable_zone(void *ptr) {
    if (!ptr)
        return NULL;
    
    /*
     * Look for a zone which contains ptr.  If that zone does not have the purgeable malloc flag
     * set, or the allocation is too small, do nothing.  Otherwise, set the allocation volatile.
     * FIXME: for performance reasons, we should probably keep a separate list of purgeable zones
     * and only search those.
     */
    size_t size = 0;
    malloc_zone_t *zone = find_registered_zone(ptr, &size);
    
    /* FIXME: would really like a zone->introspect->flags->purgeable check, but haven't determined
     * binary compatibility impact of changing the introspect struct yet. */
    if (!zone)
        return NULL;

    /* Check to make sure pointer is page aligned and size is multiple of page size */
    if ((size < vm_page_size) || ((size % vm_page_size) != 0))
        return NULL;

    return zone;
}

void
malloc_make_purgeable(void *ptr) {
    malloc_zone_t *zone = find_registered_purgeable_zone(ptr);
    if (!zone)
        return;
    
    int state = VM_PURGABLE_VOLATILE;
    vm_purgable_control(mach_task_self(), (vm_address_t)ptr, VM_PURGABLE_SET_STATE, &state);
    return;
}

/* Returns true if ptr is valid.  Ignore the return value from vm_purgeable_control and only report
 * state. */
int
malloc_make_nonpurgeable(void *ptr) {
    malloc_zone_t *zone = find_registered_purgeable_zone(ptr);
    if (!zone)
        return 0;

    int state = VM_PURGABLE_NONVOLATILE;
    vm_purgable_control(mach_task_self(), (vm_address_t)ptr, VM_PURGABLE_SET_STATE, &state);
    
    if (state == VM_PURGABLE_EMPTY)
        return EFAULT;

    return 0;
}

/*********	Batch methods	************/

unsigned
malloc_zone_batch_malloc(malloc_zone_t *zone, size_t size, void **results, unsigned num_requested) {
    unsigned	(*batch_malloc)(malloc_zone_t *, size_t, void **, unsigned) = zone-> batch_malloc;
    if (! batch_malloc) return 0;
    if (malloc_check_start && (malloc_check_counter++ >= malloc_check_start)) {
	internal_check();
    }
    unsigned	batched = batch_malloc(zone, size, results, num_requested);
    if (malloc_logger) {
	unsigned	index = 0;
	while (index < batched) {
	    malloc_logger(MALLOC_LOG_TYPE_ALLOCATE | MALLOC_LOG_TYPE_HAS_ZONE, (uintptr_t)zone, (uintptr_t)size, 0, (uintptr_t)results[index], 0);
	    index++;
	}
    }
    return batched;
}

void
malloc_zone_batch_free(malloc_zone_t *zone, void **to_be_freed, unsigned num) {
    if (malloc_check_start && (malloc_check_counter++ >= malloc_check_start)) {
	internal_check();
    }
    if (malloc_logger) {
	unsigned	index = 0;
	while (index < num) {
	    malloc_logger(MALLOC_LOG_TYPE_DEALLOCATE | MALLOC_LOG_TYPE_HAS_ZONE, (uintptr_t)zone, (uintptr_t)to_be_freed[index], 0, 0, 0);
	    index++;
	}
    }
    void	(*batch_free)(malloc_zone_t *, void **, unsigned) = zone-> batch_free;
    if (batch_free) {
	batch_free(zone, to_be_freed, num);
    } else {
	void 	(*free_fun)(malloc_zone_t *, void *) = zone->free;
	while (num--) {
	    void	*ptr = *to_be_freed++;
	    free_fun(zone, ptr);
	}
    }
}

/*********	Functions for performance tools	************/

static kern_return_t
_malloc_default_reader(task_t task, vm_address_t address, vm_size_t size, void **ptr) {
    *ptr = (void *)address;
    return 0;
}

kern_return_t
malloc_get_all_zones(task_t task, memory_reader_t reader, vm_address_t **addresses, unsigned *count) {
    // Note that the 2 following addresses are not correct if the address of the target is different from your own.  This notably occurs if the address of System.framework is slid (e.g. different than at B & I )
    vm_address_t	remote_malloc_zones = (vm_address_t)&malloc_zones;
    vm_address_t	remote_malloc_num_zones = (vm_address_t)&malloc_num_zones;
    kern_return_t	err;
    vm_address_t	zones_address;
    vm_address_t	*zones_address_ref;
    unsigned		num_zones;
    unsigned		*num_zones_ref;
    if (!reader) reader = _malloc_default_reader;
    // printf("Read malloc_zones at address %p should be %p\n", &malloc_zones, malloc_zones);
    err = reader(task, remote_malloc_zones, sizeof(void *), (void **)&zones_address_ref);
    // printf("Read malloc_zones[%p]=%p\n", remote_malloc_zones, *zones_address_ref);
    if (err) {
        malloc_printf("*** malloc_get_all_zones: error reading zones_address at %p\n", (unsigned)remote_malloc_zones);
        return err;
    }
    zones_address = *zones_address_ref;
    // printf("Reading num_zones at address %p\n", remote_malloc_num_zones);
    err = reader(task, remote_malloc_num_zones, sizeof(unsigned), (void **)&num_zones_ref);
    if (err) {
        malloc_printf("*** malloc_get_all_zones: error reading num_zones at %p\n", (unsigned)remote_malloc_num_zones);
        return err;
    }
    num_zones = *num_zones_ref;
    // printf("Read malloc_num_zones[%p]=%d\n", remote_malloc_num_zones, num_zones);
    *count = num_zones;
    // printf("malloc_get_all_zones succesfully found %d zones\n", num_zones);
    err = reader(task, zones_address, sizeof(malloc_zone_t *) * num_zones, (void **)addresses);
    if (err) {
        malloc_printf("*** malloc_get_all_zones: error reading zones at %p\n", &zones_address);
        return err;
    }
    // printf("malloc_get_all_zones succesfully read %d zones\n", num_zones);
    return err;
}

/*********	Debug helpers	************/

void
malloc_zone_print_ptr_info(void *ptr) {
    malloc_zone_t	*zone;
    if (!ptr) return;
    zone = malloc_zone_from_ptr(ptr);
    if (zone) {
        printf("ptr %p in registered zone %p\n", ptr, zone);
    } else {
        printf("ptr %p not in heap\n", ptr);
    }
}

boolean_t
malloc_zone_check(malloc_zone_t *zone) {
    boolean_t	ok = 1;
    if (!zone) {
        unsigned	index = 0;
        while (index < malloc_num_zones) {
            zone = malloc_zones[index++];
            if (!zone->introspect->check(zone)) ok = 0;
        }
    } else {
        ok = zone->introspect->check(zone);
    }
    return ok;
}

void
malloc_zone_print(malloc_zone_t *zone, boolean_t verbose) {
    if (!zone) {
        unsigned	index = 0;
        while (index < malloc_num_zones) {
            zone = malloc_zones[index++];
            zone->introspect->print(zone, verbose);
        }
    } else {
        zone->introspect->print(zone, verbose);
    }
}

void
malloc_zone_statistics(malloc_zone_t *zone, malloc_statistics_t *stats) {
    if (!zone) {
	memset(stats, 0, sizeof(*stats));
        unsigned	index = 0;
        while (index < malloc_num_zones) {
            zone = malloc_zones[index++];
	    malloc_statistics_t	this_stats;
            zone->introspect->statistics(zone, &this_stats);
	    stats->blocks_in_use += this_stats.blocks_in_use;
	    stats->size_in_use += this_stats.size_in_use;
	    stats->max_size_in_use += this_stats.max_size_in_use;
	    stats->size_allocated += this_stats.size_allocated;
        }
    } else {
	zone->introspect->statistics(zone, stats);
    }
}

void
malloc_zone_log(malloc_zone_t *zone, void *address) {
    if (!zone) {
        unsigned	index = 0;
        while (index < malloc_num_zones) {
            zone = malloc_zones[index++];
            zone->introspect->log(zone, address);
        }
    } else {
        zone->introspect->log(zone, address);
    }
}

/*********	Misc other entry points	************/

static void
DefaultMallocError(int x) {
#if USE_SLEEP_RATHER_THAN_ABORT
    malloc_printf("*** error %d\n", x);
    sleep(3600);
#else
    _SIMPLE_STRING b = _simple_salloc();
    if (b) {
	_simple_sprintf(b, "*** error %d", x);
	malloc_printf("%s\n", _simple_string(b));
	__crashreporter_info__ = _simple_string(b);
    } else {
	_malloc_printf(MALLOC_PRINTF_NOLOG, "*** error %d", x);
	__crashreporter_info__ = "*** DefaultMallocError called";
    }
    abort();
#endif
}

void (*
malloc_error(void (*func)(int)))(int) {
    return DefaultMallocError;
}

/* Stack logging fork-handling prototypes */
extern void __stack_logging_fork_prepare();
extern void __stack_logging_fork_parent();
extern void __stack_logging_fork_child();

void
_malloc_fork_prepare() {
    /* Prepare the malloc module for a fork by insuring that no thread is in a malloc critical section */
    unsigned	index = 0;
    MALLOC_LOCK();
    while (index < malloc_num_zones) {
        malloc_zone_t	*zone = malloc_zones[index++];
        zone->introspect->force_lock(zone);
    }
	__stack_logging_fork_prepare();
}

void
_malloc_fork_parent() {
    /* Called in the parent process after a fork() to resume normal operation. */
    unsigned	index = 0;
	__stack_logging_fork_parent();
    MALLOC_UNLOCK();
    while (index < malloc_num_zones) {
        malloc_zone_t	*zone = malloc_zones[index++];
        zone->introspect->force_unlock(zone);
    }
}

void
_malloc_fork_child() {
    /* Called in the child process after a fork() to resume normal operation.  In the MTASK case we also have to change memory inheritance so that the child does not share memory with the parent. */
    unsigned	index = 0;
	__stack_logging_fork_child();
    MALLOC_UNLOCK();
    while (index < malloc_num_zones) {
        malloc_zone_t	*zone = malloc_zones[index++];
        zone->introspect->force_unlock(zone);
    }
}

/*
 * A Glibc-like mstats() interface.
 *
 * Note that this interface really isn't very good, as it doesn't understand
 * that we may have multiple allocators running at once.  We just massage
 * the result from malloc_zone_statistics in any case.
 */
struct mstats
mstats(void)
{
    malloc_statistics_t s;
    struct mstats m;

    malloc_zone_statistics(NULL, &s);
    m.bytes_total = s.size_allocated;
    m.chunks_used = s.blocks_in_use;
    m.bytes_used = s.size_in_use;
    m.chunks_free = 0;
    m.bytes_free = m.bytes_total - m.bytes_used;	/* isn't this somewhat obvious? */

    return(m);
}

/*****************	OBSOLETE ENTRY POINTS	********************/

#if PHASE_OUT_OLD_MALLOC
#error PHASE OUT THE FOLLOWING FUNCTIONS
#else
#warning PHASE OUT THE FOLLOWING FUNCTIONS
#endif

void
set_malloc_singlethreaded(boolean_t single) {
    static boolean_t warned = 0;
    if (!warned) {
#if PHASE_OUT_OLD_MALLOC
        malloc_printf("*** OBSOLETE: set_malloc_singlethreaded(%d)\n", single);
#endif
        warned = 1;
    }
}

void
malloc_singlethreaded() {
    static boolean_t warned = 0;
    if (!warned) {
        malloc_printf("*** OBSOLETE: malloc_singlethreaded()\n");
        warned = 1;
    }
}

int
malloc_debug(int level) {
    malloc_printf("*** OBSOLETE: malloc_debug()\n");
    return 0;
}