leak-detective: added _IO_file_doallocate to whitelist
[strongswan.git] / src / libstrongswan / utils / leak_detective.c
1 /*
2 * Copyright (C) 2013-2014 Tobias Brunner
3 * Copyright (C) 2006-2013 Martin Willi
4 * Hochschule fuer Technik Rapperswil
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the
8 * Free Software Foundation; either version 2 of the License, or (at your
9 * option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * for more details.
15 */
16
17 #define _GNU_SOURCE
18 #include <stddef.h>
19 #include <string.h>
20 #include <stdio.h>
21 #include <signal.h>
22 #include <unistd.h>
23 #include <locale.h>
24 #ifdef HAVE_DLADDR
25 #include <dlfcn.h>
26 #endif
27 #include <time.h>
28 #include <errno.h>
29
30 #ifdef __APPLE__
31 #include <sys/mman.h>
32 #include <malloc/malloc.h>
33 /* overload some of our types clashing with mach */
34 #define host_t strongswan_host_t
35 #define processor_t strongswan_processor_t
36 #define thread_t strongswan_thread_t
37 #endif /* __APPLE__ */
38
39 #include "leak_detective.h"
40
41 #include <library.h>
42 #include <utils/utils.h>
43 #include <utils/debug.h>
44 #include <utils/backtrace.h>
45 #include <collections/hashtable.h>
46 #include <threading/thread_value.h>
47 #include <threading/spinlock.h>
48
49 typedef struct private_leak_detective_t private_leak_detective_t;
50
51 /**
52 * private data of leak_detective
53 */
54 struct private_leak_detective_t {
55
56 /**
57 * public functions
58 */
59 leak_detective_t public;
60
61 /**
62 * Registered report() function
63 */
64 leak_detective_report_cb_t report_cb;
65
66 /**
67 * Registered report() summary function
68 */
69 leak_detective_summary_cb_t report_scb;
70
71 /**
72 * Registered user data for callbacks
73 */
74 void *report_data;
75 };
76
77 /**
78 * Magic value which helps to detect memory corruption. Yummy!
79 */
80 #define MEMORY_HEADER_MAGIC 0x7ac0be11
81
82 /**
83 * Magic written to tail of allocation
84 */
85 #define MEMORY_TAIL_MAGIC 0xcafebabe
86
87 /**
88 * Pattern which is filled in memory before freeing it
89 */
90 #define MEMORY_FREE_PATTERN 0xFF
91
92 /**
93 * Pattern which is filled in newly allocated memory
94 */
95 #define MEMORY_ALLOC_PATTERN 0xEE
96
97 typedef struct memory_header_t memory_header_t;
98 typedef struct memory_tail_t memory_tail_t;
99
100 /**
101 * Header which is prepended to each allocated memory block
102 */
103 struct memory_header_t {
104
105 /**
106 * Pointer to previous entry in linked list
107 */
108 memory_header_t *previous;
109
110 /**
111 * Pointer to next entry in linked list
112 */
113 memory_header_t *next;
114
115 /**
116 * backtrace taken during (re-)allocation
117 */
118 backtrace_t *backtrace;
119
120 /**
121 * Padding to make sizeof(memory_header_t) == 32
122 */
123 uint32_t padding[sizeof(void*) == sizeof(uint32_t) ? 3 : 0];
124
125 /**
126 * Number of bytes following after the header
127 */
128 uint32_t bytes;
129
130 /**
131 * magic bytes to detect bad free or heap underflow, MEMORY_HEADER_MAGIC
132 */
133 uint32_t magic;
134
135 }__attribute__((__packed__));
136
137 /**
138 * tail appended to each allocated memory block
139 */
140 struct memory_tail_t {
141
142 /**
143 * Magic bytes to detect heap overflow, MEMORY_TAIL_MAGIC
144 */
145 uint32_t magic;
146
147 }__attribute__((__packed__));
148
149 /**
150 * first mem header is just a dummy to chain
151 * the others on it...
152 */
153 static memory_header_t first_header = {
154 .magic = MEMORY_HEADER_MAGIC,
155 };
156
157 /**
158 * Spinlock to access header linked list
159 */
160 static spinlock_t *lock;
161
162 /**
163 * Is leak detection currently enabled?
164 */
165 static bool enabled = FALSE;
166
167 /**
168 * Is leak detection disabled for the current thread?
169 */
170 static thread_value_t *thread_disabled;
171
172 /**
173 * Installs the malloc hooks, enables leak detection
174 */
175 static void enable_leak_detective()
176 {
177 enabled = TRUE;
178 }
179
180 /**
181 * Uninstalls the malloc hooks, disables leak detection
182 */
183 static void disable_leak_detective()
184 {
185 enabled = FALSE;
186 }
187
188 /**
189 * Enable/Disable leak detective for the current thread
190 *
191 * @return Previous value
192 */
193 static bool enable_thread(bool enable)
194 {
195 bool before;
196
197 before = thread_disabled->get(thread_disabled) == NULL;
198 thread_disabled->set(thread_disabled, enable ? NULL : (void*)TRUE);
199 return before;
200 }
201
202 /**
203 * Add a header to the beginning of the list
204 */
205 static void add_hdr(memory_header_t *hdr)
206 {
207 lock->lock(lock);
208 hdr->next = first_header.next;
209 if (hdr->next)
210 {
211 hdr->next->previous = hdr;
212 }
213 hdr->previous = &first_header;
214 first_header.next = hdr;
215 lock->unlock(lock);
216 }
217
218 /**
219 * Remove a header from the list
220 */
221 static void remove_hdr(memory_header_t *hdr)
222 {
223 lock->lock(lock);
224 if (hdr->next)
225 {
226 hdr->next->previous = hdr->previous;
227 }
228 hdr->previous->next = hdr->next;
229 lock->unlock(lock);
230 }
231
232 /**
233 * Check if a header is in the list
234 */
235 static bool has_hdr(memory_header_t *hdr)
236 {
237 memory_header_t *current;
238 bool found = FALSE;
239
240 lock->lock(lock);
241 for (current = &first_header; current != NULL; current = current->next)
242 {
243 if (current == hdr)
244 {
245 found = TRUE;
246 break;
247 }
248 }
249 lock->unlock(lock);
250
251 return found;
252 }
253
254 #ifdef __APPLE__
255
256 /**
257 * Copy of original default zone, with functions we call in hooks
258 */
259 static malloc_zone_t original;
260
261 /**
262 * Call original malloc()
263 */
264 static void* real_malloc(size_t size)
265 {
266 return original.malloc(malloc_default_zone(), size);
267 }
268
269 /**
270 * Call original free()
271 */
272 static void real_free(void *ptr)
273 {
274 original.free(malloc_default_zone(), ptr);
275 }
276
277 /**
278 * Call original realloc()
279 */
280 static void* real_realloc(void *ptr, size_t size)
281 {
282 return original.realloc(malloc_default_zone(), ptr, size);
283 }
284
285 /**
286 * Hook definition: static function with _hook suffix, takes additional zone
287 */
288 #define HOOK(ret, name, ...) \
289 static ret name ## _hook(malloc_zone_t *_z, __VA_ARGS__)
290
291 /**
292 * forward declaration of hooks
293 */
294 HOOK(void*, malloc, size_t bytes);
295 HOOK(void*, calloc, size_t nmemb, size_t size);
296 HOOK(void*, valloc, size_t size);
297 HOOK(void, free, void *ptr);
298 HOOK(void*, realloc, void *old, size_t bytes);
299
300 /**
301 * malloc zone size(), must consider the memory header prepended
302 */
303 HOOK(size_t, size, const void *ptr)
304 {
305 bool before;
306 size_t size;
307
308 if (enabled)
309 {
310 before = enable_thread(FALSE);
311 if (before)
312 {
313 ptr -= sizeof(memory_header_t);
314 }
315 }
316 size = original.size(malloc_default_zone(), ptr);
317 if (enabled)
318 {
319 enable_thread(before);
320 }
321 return size;
322 }
323
324 /**
325 * Version of malloc zones we currently support
326 */
327 #define MALLOC_ZONE_VERSION 8 /* Snow Leopard */
328
329 /**
330 * Hook-in our malloc functions into the default zone
331 */
332 static bool register_hooks()
333 {
334 static bool once = FALSE;
335 malloc_zone_t *zone;
336 void *page;
337
338 if (once)
339 {
340 return TRUE;
341 }
342 once = TRUE;
343
344 zone = malloc_default_zone();
345 if (zone->version != MALLOC_ZONE_VERSION)
346 {
347 DBG1(DBG_CFG, "malloc zone version %d unsupported (requiring %d)",
348 zone->version, MALLOC_ZONE_VERSION);
349 return FALSE;
350 }
351
352 original = *zone;
353
354 page = (void*)((uintptr_t)zone / getpagesize() * getpagesize());
355 if (mprotect(page, getpagesize(), PROT_WRITE | PROT_READ) != 0)
356 {
357 DBG1(DBG_CFG, "malloc zone unprotection failed: %s", strerror(errno));
358 return FALSE;
359 }
360
361 zone->size = size_hook;
362 zone->malloc = malloc_hook;
363 zone->calloc = calloc_hook;
364 zone->valloc = valloc_hook;
365 zone->free = free_hook;
366 zone->realloc = realloc_hook;
367
368 /* those other functions can be NULLed out to not use them */
369 zone->batch_malloc = NULL;
370 zone->batch_free = NULL;
371 zone->memalign = NULL;
372 zone->free_definite_size = NULL;
373
374 return TRUE;
375 }
376
377 #else /* !__APPLE__ */
378
379 /**
380 * dlsym() might do a malloc(), but we can't do one before we get the malloc()
381 * function pointer. Use this minimalistic malloc implementation instead.
382 */
383 static void* malloc_for_dlsym(size_t size)
384 {
385 static char buf[1024] = {};
386 static size_t used = 0;
387 char *ptr;
388
389 /* roundup to a multiple of 32 */
390 size = (size - 1) / 32 * 32 + 32;
391
392 if (used + size > sizeof(buf))
393 {
394 return NULL;
395 }
396 ptr = buf + used;
397 used += size;
398 return ptr;
399 }
400
401 /**
402 * Lookup a malloc function, while disabling wrappers
403 */
404 static void* get_malloc_fn(char *name)
405 {
406 bool before = FALSE;
407 void *fn;
408
409 if (enabled)
410 {
411 before = enable_thread(FALSE);
412 }
413 fn = dlsym(RTLD_NEXT, name);
414 if (enabled)
415 {
416 enable_thread(before);
417 }
418 return fn;
419 }
420
421 /**
422 * Call original malloc()
423 */
424 static void* real_malloc(size_t size)
425 {
426 static void* (*fn)(size_t size);
427 static int recursive = 0;
428
429 if (!fn)
430 {
431 /* checking recursiveness should actually be thread-specific. But as
432 * it is very likely that the first allocation is done before we go
433 * multi-threaded, we keep it simple. */
434 if (recursive)
435 {
436 return malloc_for_dlsym(size);
437 }
438 recursive++;
439 fn = get_malloc_fn("malloc");
440 recursive--;
441 }
442 return fn(size);
443 }
444
445 /**
446 * Call original free()
447 */
448 static void real_free(void *ptr)
449 {
450 static void (*fn)(void *ptr);
451
452 if (!fn)
453 {
454 fn = get_malloc_fn("free");
455 }
456 return fn(ptr);
457 }
458
459 /**
460 * Call original realloc()
461 */
462 static void* real_realloc(void *ptr, size_t size)
463 {
464 static void* (*fn)(void *ptr, size_t size);
465
466 if (!fn)
467 {
468 fn = get_malloc_fn("realloc");
469 }
470 return fn(ptr, size);
471 }
472
473 /**
474 * Hook definition: plain function overloading existing malloc calls
475 */
476 #define HOOK(ret, name, ...) ret name(__VA_ARGS__)
477
478 /**
479 * Hook initialization when not using hooks, resolve functions.
480 */
481 static bool register_hooks()
482 {
483 void *buf = real_malloc(8);
484 buf = real_realloc(buf, 16);
485 real_free(buf);
486 return TRUE;
487 }
488
489 #endif /* !__APPLE__ */
490
491 /**
492 * Leak report white list
493 *
494 * List of functions using static allocation buffers or should be suppressed
495 * otherwise on leak report.
496 */
497 char *whitelist[] = {
498 /* backtraces, including own */
499 "backtrace_create",
500 "strerror_safe",
501 /* pthread stuff */
502 "pthread_create",
503 "pthread_setspecific",
504 "__pthread_setspecific",
505 /* glibc functions */
506 "inet_ntoa",
507 "strerror",
508 "getprotobyname",
509 "getprotobynumber",
510 "getservbyport",
511 "getservbyname",
512 "gethostbyname",
513 "gethostbyname2",
514 "gethostbyname_r",
515 "gethostbyname2_r",
516 "getnetbyname",
517 "getpwnam_r",
518 "getgrnam_r",
519 "register_printf_function",
520 "register_printf_specifier",
521 "syslog",
522 "vsyslog",
523 "__syslog_chk",
524 "__vsyslog_chk",
525 "getaddrinfo",
526 "setlocale",
527 "getpass",
528 "getpwent_r",
529 "setpwent",
530 "endpwent",
531 "getspnam_r",
532 "getpwuid_r",
533 "initgroups",
534 "tzset",
535 "_IO_file_doallocate",
536 /* ignore dlopen, as we do not dlclose to get proper leak reports */
537 "dlopen",
538 "dlerror",
539 "dlclose",
540 "dlsym",
541 /* mysql functions */
542 "mysql_init_character_set",
543 "init_client_errs",
544 "my_thread_init",
545 /* fastcgi library */
546 "FCGX_Init",
547 /* libxml */
548 "xmlInitCharEncodingHandlers",
549 "xmlInitParser",
550 "xmlInitParserCtxt",
551 /* libcurl */
552 "Curl_client_write",
553 /* ClearSilver */
554 "nerr_init",
555 /* libgcrypt */
556 "gcrypt_plugin_create",
557 "gcry_control",
558 "gcry_check_version",
559 "gcry_randomize",
560 "gcry_create_nonce",
561 /* OpenSSL: These are needed for unit-tests only, the openssl plugin
562 * does properly clean up any memory during destroy(). */
563 "ECDSA_do_sign_ex",
564 "ECDSA_verify",
565 "RSA_new_method",
566 /* OpenSSL libssl */
567 "SSL_COMP_get_compression_methods",
568 /* NSPR */
569 "PR_CallOnce",
570 /* libapr */
571 "apr_pool_create_ex",
572 /* glib */
573 "g_type_init_with_debug_flags",
574 "g_type_register_static",
575 "g_type_class_ref",
576 "g_type_create_instance",
577 "g_type_add_interface_static",
578 "g_type_interface_add_prerequisite",
579 "g_socket_connection_factory_lookup_type",
580 /* libgpg */
581 "gpg_err_init",
582 /* gnutls */
583 "gnutls_global_init",
584 };
585
586 /**
587 * Some functions are hard to whitelist, as they don't use a symbol directly.
588 * Use some static initialization to suppress them on leak reports
589 */
590 static void init_static_allocations()
591 {
592 struct tm tm;
593 time_t t = 0;
594
595 tzset();
596 gmtime_r(&t, &tm);
597 localtime_r(&t, &tm);
598 }
599
600 /**
601 * Hashtable hash function
602 */
603 static u_int hash(backtrace_t *key)
604 {
605 enumerator_t *enumerator;
606 void *addr;
607 u_int hash = 0;
608
609 enumerator = key->create_frame_enumerator(key);
610 while (enumerator->enumerate(enumerator, &addr))
611 {
612 hash = chunk_hash_inc(chunk_from_thing(addr), hash);
613 }
614 enumerator->destroy(enumerator);
615
616 return hash;
617 }
618
619 /**
620 * Hashtable equals function
621 */
622 static bool equals(backtrace_t *a, backtrace_t *b)
623 {
624 return a->equals(a, b);
625 }
626
627 /**
628 * Summarize and print backtraces
629 */
630 static int print_traces(private_leak_detective_t *this,
631 leak_detective_report_cb_t cb, void *user,
632 int thresh, int thresh_count,
633 bool detailed, int *whitelisted, size_t *sum)
634 {
635 int leaks = 0;
636 memory_header_t *hdr;
637 enumerator_t *enumerator;
638 hashtable_t *entries;
639 struct {
640 /** associated backtrace */
641 backtrace_t *backtrace;
642 /** total size of all allocations */
643 size_t bytes;
644 /** number of allocations */
645 u_int count;
646 } *entry;
647 bool before;
648
649 before = enable_thread(FALSE);
650
651 entries = hashtable_create((hashtable_hash_t)hash,
652 (hashtable_equals_t)equals, 1024);
653 lock->lock(lock);
654 for (hdr = first_header.next; hdr != NULL; hdr = hdr->next)
655 {
656 if (whitelisted &&
657 hdr->backtrace->contains_function(hdr->backtrace,
658 whitelist, countof(whitelist)))
659 {
660 (*whitelisted)++;
661 continue;
662 }
663 entry = entries->get(entries, hdr->backtrace);
664 if (entry)
665 {
666 entry->bytes += hdr->bytes;
667 entry->count++;
668 }
669 else
670 {
671 INIT(entry,
672 .backtrace = hdr->backtrace->clone(hdr->backtrace),
673 .bytes = hdr->bytes,
674 .count = 1,
675 );
676 entries->put(entries, entry->backtrace, entry);
677 }
678 if (sum)
679 {
680 *sum += hdr->bytes;
681 }
682 leaks++;
683 }
684 lock->unlock(lock);
685
686 enumerator = entries->create_enumerator(entries);
687 while (enumerator->enumerate(enumerator, NULL, &entry))
688 {
689 if (cb)
690 {
691 if (!thresh || entry->bytes >= thresh)
692 {
693 if (!thresh_count || entry->count >= thresh_count)
694 {
695 cb(user, entry->count, entry->bytes, entry->backtrace,
696 detailed);
697 }
698 }
699 }
700 entry->backtrace->destroy(entry->backtrace);
701 free(entry);
702 }
703 enumerator->destroy(enumerator);
704 entries->destroy(entries);
705
706 enable_thread(before);
707 return leaks;
708 }
709
710 METHOD(leak_detective_t, report, void,
711 private_leak_detective_t *this, bool detailed)
712 {
713 if (lib->leak_detective)
714 {
715 int leaks, whitelisted = 0;
716 size_t sum = 0;
717
718 leaks = print_traces(this, this->report_cb, this->report_data,
719 0, 0, detailed, &whitelisted, &sum);
720 if (this->report_scb)
721 {
722 this->report_scb(this->report_data, leaks, sum, whitelisted);
723 }
724 }
725 }
726
727 METHOD(leak_detective_t, set_report_cb, void,
728 private_leak_detective_t *this, leak_detective_report_cb_t cb,
729 leak_detective_summary_cb_t scb, void *user)
730 {
731 this->report_cb = cb;
732 this->report_scb = scb;
733 this->report_data = user;
734 }
735
736 METHOD(leak_detective_t, leaks, int,
737 private_leak_detective_t *this)
738 {
739 int whitelisted = 0;
740
741 return print_traces(this, NULL, NULL, 0, 0, FALSE, &whitelisted, NULL);
742 }
743
744 METHOD(leak_detective_t, set_state, bool,
745 private_leak_detective_t *this, bool enable)
746 {
747 return enable_thread(enable);
748 }
749
750 METHOD(leak_detective_t, usage, void,
751 private_leak_detective_t *this, leak_detective_report_cb_t cb,
752 leak_detective_summary_cb_t scb, void *user)
753 {
754 bool detailed;
755 int thresh, thresh_count, leaks, whitelisted = 0;
756 size_t sum = 0;
757
758 thresh = lib->settings->get_int(lib->settings,
759 "%s.leak_detective.usage_threshold", 10240, lib->ns);
760 thresh_count = lib->settings->get_int(lib->settings,
761 "%s.leak_detective.usage_threshold_count", 0, lib->ns);
762 detailed = lib->settings->get_bool(lib->settings,
763 "%s.leak_detective.detailed", TRUE, lib->ns);
764
765 leaks = print_traces(this, cb, user, thresh, thresh_count,
766 detailed, &whitelisted, &sum);
767 if (scb)
768 {
769 scb(user, leaks, sum, whitelisted);
770 }
771 }
772
773 /**
774 * Wrapped malloc() function
775 */
776 HOOK(void*, malloc, size_t bytes)
777 {
778 memory_header_t *hdr;
779 memory_tail_t *tail;
780 bool before;
781
782 if (!enabled || thread_disabled->get(thread_disabled))
783 {
784 return real_malloc(bytes);
785 }
786
787 hdr = real_malloc(sizeof(memory_header_t) + bytes + sizeof(memory_tail_t));
788 tail = ((void*)hdr) + bytes + sizeof(memory_header_t);
789 /* set to something which causes crashes */
790 memset(hdr, MEMORY_ALLOC_PATTERN,
791 sizeof(memory_header_t) + bytes + sizeof(memory_tail_t));
792
793 before = enable_thread(FALSE);
794 hdr->backtrace = backtrace_create(2);
795 enable_thread(before);
796
797 hdr->magic = MEMORY_HEADER_MAGIC;
798 hdr->bytes = bytes;
799 tail->magic = MEMORY_TAIL_MAGIC;
800
801 add_hdr(hdr);
802
803 return hdr + 1;
804 }
805
806 /**
807 * Wrapped calloc() function
808 */
809 HOOK(void*, calloc, size_t nmemb, size_t size)
810 {
811 void *ptr;
812
813 size *= nmemb;
814 ptr = malloc(size);
815 memset(ptr, 0, size);
816
817 return ptr;
818 }
819
820 /**
821 * Wrapped valloc(), TODO: currently not supported
822 */
823 HOOK(void*, valloc, size_t size)
824 {
825 DBG1(DBG_LIB, "valloc() used, but leak-detective hook missing");
826 return NULL;
827 }
828
829 /**
830 * Wrapped free() function
831 */
832 HOOK(void, free, void *ptr)
833 {
834 memory_header_t *hdr;
835 memory_tail_t *tail;
836 backtrace_t *backtrace;
837 bool before;
838
839 if (!enabled || thread_disabled->get(thread_disabled))
840 {
841 real_free(ptr);
842 return;
843 }
844 /* allow freeing of NULL */
845 if (ptr == NULL)
846 {
847 return;
848 }
849 hdr = ptr - sizeof(memory_header_t);
850 tail = ptr + hdr->bytes;
851
852 before = enable_thread(FALSE);
853 if (hdr->magic != MEMORY_HEADER_MAGIC ||
854 tail->magic != MEMORY_TAIL_MAGIC)
855 {
856 if (has_hdr(hdr))
857 {
858 /* memory was allocated by our hooks but is corrupted */
859 fprintf(stderr, "freeing corrupted memory (%p): "
860 "header magic 0x%x, tail magic 0x%x:\n",
861 ptr, hdr->magic, tail->magic);
862 }
863 else
864 {
865 /* memory was not allocated by our hooks */
866 fprintf(stderr, "freeing invalid memory (%p)\n", ptr);
867 }
868 backtrace = backtrace_create(2);
869 backtrace->log(backtrace, stderr, TRUE);
870 backtrace->destroy(backtrace);
871 }
872 else
873 {
874 remove_hdr(hdr);
875
876 hdr->backtrace->destroy(hdr->backtrace);
877
878 /* clear MAGIC, set mem to something remarkable */
879 memset(hdr, MEMORY_FREE_PATTERN,
880 sizeof(memory_header_t) + hdr->bytes + sizeof(memory_tail_t));
881
882 real_free(hdr);
883 }
884 enable_thread(before);
885 }
886
887 /**
888 * Wrapped realloc() function
889 */
890 HOOK(void*, realloc, void *old, size_t bytes)
891 {
892 memory_header_t *hdr;
893 memory_tail_t *tail;
894 backtrace_t *backtrace;
895 bool before;
896
897 if (!enabled || thread_disabled->get(thread_disabled))
898 {
899 return real_realloc(old, bytes);
900 }
901 /* allow reallocation of NULL */
902 if (old == NULL)
903 {
904 return malloc(bytes);
905 }
906 /* handle zero size as a free() */
907 if (bytes == 0)
908 {
909 free(old);
910 return NULL;
911 }
912
913 hdr = old - sizeof(memory_header_t);
914 tail = old + hdr->bytes;
915
916 remove_hdr(hdr);
917
918 if (hdr->magic != MEMORY_HEADER_MAGIC ||
919 tail->magic != MEMORY_TAIL_MAGIC)
920 {
921 fprintf(stderr, "reallocating invalid memory (%p):\n"
922 "header magic 0x%x:\n", old, hdr->magic);
923 backtrace = backtrace_create(2);
924 backtrace->log(backtrace, stderr, TRUE);
925 backtrace->destroy(backtrace);
926 }
927 else
928 {
929 /* clear tail magic, allocate, set tail magic */
930 memset(&tail->magic, MEMORY_ALLOC_PATTERN, sizeof(tail->magic));
931 }
932 hdr = real_realloc(hdr,
933 sizeof(memory_header_t) + bytes + sizeof(memory_tail_t));
934 tail = ((void*)hdr) + bytes + sizeof(memory_header_t);
935 tail->magic = MEMORY_TAIL_MAGIC;
936
937 /* update statistics */
938 hdr->bytes = bytes;
939
940 before = enable_thread(FALSE);
941 hdr->backtrace->destroy(hdr->backtrace);
942 hdr->backtrace = backtrace_create(2);
943 enable_thread(before);
944
945 add_hdr(hdr);
946
947 return hdr + 1;
948 }
949
950 METHOD(leak_detective_t, destroy, void,
951 private_leak_detective_t *this)
952 {
953 disable_leak_detective();
954 lock->destroy(lock);
955 thread_disabled->destroy(thread_disabled);
956 free(this);
957 first_header.next = NULL;
958 }
959
960 /*
961 * see header file
962 */
963 leak_detective_t *leak_detective_create()
964 {
965 private_leak_detective_t *this;
966
967 INIT(this,
968 .public = {
969 .report = _report,
970 .set_report_cb = _set_report_cb,
971 .usage = _usage,
972 .leaks = _leaks,
973 .set_state = _set_state,
974 .destroy = _destroy,
975 },
976 );
977
978 if (getenv("LEAK_DETECTIVE_DISABLE") != NULL)
979 {
980 free(this);
981 return NULL;
982 }
983
984 lock = spinlock_create();
985 thread_disabled = thread_value_create(NULL);
986
987 init_static_allocations();
988
989 if (register_hooks())
990 {
991 enable_leak_detective();
992 }
993 return &this->public;
994 }