1 /*
2 * Copyright (C) 2012 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <errno.h>
30 #include <inttypes.h>
31 #include <malloc.h>
32 #include <pthread.h>
33 #include <signal.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <sys/cdefs.h>
38 #include <sys/param.h>
39 #include <sys/syscall.h>
40 #include <unistd.h>
41
42 #include <mutex>
43 #include <vector>
44
45 #include <android-base/file.h>
46 #include <android-base/properties.h>
47 #include <android-base/stringprintf.h>
48 #include <bionic/malloc_tagged_pointers.h>
49 #include <platform/bionic/reserved_signals.h>
50 #include <private/MallocXmlElem.h>
51 #include <private/bionic_malloc_dispatch.h>
52
53 #include "Config.h"
54 #include "DebugData.h"
55 #include "backtrace.h"
56 #include "debug_disable.h"
57 #include "debug_log.h"
58 #include "malloc_debug.h"
59 #include "UnwindBacktrace.h"
60
61 // ------------------------------------------------------------------------
62 // Global Data
63 // ------------------------------------------------------------------------
64 DebugData* g_debug;
65
66 bool* g_zygote_child;
67
68 const MallocDispatch* g_dispatch;
69 // ------------------------------------------------------------------------
70
71 // ------------------------------------------------------------------------
72 // Use C style prototypes for all exported functions. This makes it easy
73 // to do dlsym lookups during libc initialization when malloc debug
74 // is enabled.
75 // ------------------------------------------------------------------------
76 __BEGIN_DECLS
77
78 bool debug_initialize(const MallocDispatch* malloc_dispatch, bool* malloc_zygote_child,
79 const char* options);
80 void debug_finalize();
81 void debug_dump_heap(const char* file_name);
82 void debug_get_malloc_leak_info(uint8_t** info, size_t* overall_size, size_t* info_size,
83 size_t* total_memory, size_t* backtrace_size);
84 bool debug_write_malloc_leak_info(FILE* fp);
85 ssize_t debug_malloc_backtrace(void* pointer, uintptr_t* frames, size_t frame_count);
86 void debug_free_malloc_leak_info(uint8_t* info);
87 size_t debug_malloc_usable_size(void* pointer);
88 void* debug_malloc(size_t size);
89 void debug_free(void* pointer);
90 void* debug_aligned_alloc(size_t alignment, size_t size);
91 void* debug_memalign(size_t alignment, size_t bytes);
92 void* debug_realloc(void* pointer, size_t bytes);
93 void* debug_calloc(size_t nmemb, size_t bytes);
94 struct mallinfo debug_mallinfo();
95 int debug_mallopt(int param, int value);
96 int debug_malloc_info(int options, FILE* fp);
97 int debug_posix_memalign(void** memptr, size_t alignment, size_t size);
98 int debug_malloc_iterate(uintptr_t base, size_t size,
99 void (*callback)(uintptr_t base, size_t size, void* arg), void* arg);
100 void debug_malloc_disable();
101 void debug_malloc_enable();
102
103 #if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
104 void* debug_pvalloc(size_t bytes);
105 void* debug_valloc(size_t size);
106 #endif
107
108 __END_DECLS
109 // ------------------------------------------------------------------------
110
111 class ScopedConcurrentLock {
112 public:
ScopedConcurrentLock()113 ScopedConcurrentLock() {
114 pthread_rwlock_rdlock(&lock_);
115 }
~ScopedConcurrentLock()116 ~ScopedConcurrentLock() {
117 pthread_rwlock_unlock(&lock_);
118 }
119
Init()120 static void Init() {
121 pthread_rwlockattr_t attr;
122 // Set the attribute so that when a write lock is pending, read locks are no
123 // longer granted.
124 pthread_rwlockattr_setkind_np(&attr, PTHREAD_RWLOCK_PREFER_WRITER_NONRECURSIVE_NP);
125 pthread_rwlock_init(&lock_, &attr);
126 }
127
BlockAllOperations()128 static void BlockAllOperations() {
129 pthread_rwlock_wrlock(&lock_);
130 }
131
132 private:
133 static pthread_rwlock_t lock_;
134 };
135 pthread_rwlock_t ScopedConcurrentLock::lock_;
136
137 // Use this because the sigprocmask* functions filter out the reserved bionic
138 // signals including the signal this code blocks.
__rt_sigprocmask(int how,const sigset64_t * new_set,sigset64_t * old_set,size_t sigset_size)139 static inline int __rt_sigprocmask(int how, const sigset64_t* new_set, sigset64_t* old_set,
140 size_t sigset_size) {
141 return syscall(SYS_rt_sigprocmask, how, new_set, old_set, sigset_size);
142 }
143
144 // Need to block the backtrace signal while in malloc debug routines
145 // otherwise there is a chance of a deadlock and timeout when unwinding.
146 // This can occur if a thread is paused while owning a malloc debug
147 // internal lock.
148 class ScopedBacktraceSignalBlocker {
149 public:
ScopedBacktraceSignalBlocker()150 ScopedBacktraceSignalBlocker() {
151 sigemptyset64(&backtrace_set_);
152 sigaddset64(&backtrace_set_, BIONIC_SIGNAL_BACKTRACE);
153 sigset64_t old_set;
154 __rt_sigprocmask(SIG_BLOCK, &backtrace_set_, &old_set, sizeof(backtrace_set_));
155 if (sigismember64(&old_set, BIONIC_SIGNAL_BACKTRACE)) {
156 unblock_ = false;
157 }
158 }
159
~ScopedBacktraceSignalBlocker()160 ~ScopedBacktraceSignalBlocker() {
161 if (unblock_) {
162 __rt_sigprocmask(SIG_UNBLOCK, &backtrace_set_, nullptr, sizeof(backtrace_set_));
163 }
164 }
165
166 private:
167 bool unblock_ = true;
168 sigset64_t backtrace_set_;
169 };
170
InitAtfork()171 static void InitAtfork() {
172 static pthread_once_t atfork_init = PTHREAD_ONCE_INIT;
173 pthread_once(&atfork_init, []() {
174 pthread_atfork(
175 []() {
176 if (g_debug != nullptr) {
177 g_debug->PrepareFork();
178 }
179 },
180 []() {
181 if (g_debug != nullptr) {
182 g_debug->PostForkParent();
183 }
184 },
185 []() {
186 if (g_debug != nullptr) {
187 g_debug->PostForkChild();
188 }
189 });
190 });
191 }
192
BacktraceAndLog()193 void BacktraceAndLog() {
194 if (g_debug->config().options() & BACKTRACE_FULL) {
195 std::vector<uintptr_t> frames;
196 std::vector<unwindstack::LocalFrameData> frames_info;
197 if (!Unwind(&frames, &frames_info, 256)) {
198 error_log(" Backtrace failed to get any frames.");
199 } else {
200 UnwindLog(frames_info);
201 }
202 } else {
203 std::vector<uintptr_t> frames(256);
204 size_t num_frames = backtrace_get(frames.data(), frames.size());
205 if (num_frames == 0) {
206 error_log(" Backtrace failed to get any frames.");
207 } else {
208 backtrace_log(frames.data(), num_frames);
209 }
210 }
211 }
212
LogError(const void * pointer,const char * error_str)213 static void LogError(const void* pointer, const char* error_str) {
214 error_log(LOG_DIVIDER);
215 error_log("+++ ALLOCATION %p %s", pointer, error_str);
216
217 // If we are tracking already freed pointers, check to see if this is
218 // one so we can print extra information.
219 if (g_debug->config().options() & FREE_TRACK) {
220 PointerData::LogFreeBacktrace(pointer);
221 }
222
223 error_log("Backtrace at time of failure:");
224 BacktraceAndLog();
225 error_log(LOG_DIVIDER);
226 if (g_debug->config().options() & ABORT_ON_ERROR) {
227 abort();
228 }
229 }
230
VerifyPointer(const void * pointer,const char * function_name)231 static bool VerifyPointer(const void* pointer, const char* function_name) {
232 if (g_debug->HeaderEnabled()) {
233 Header* header = g_debug->GetHeader(pointer);
234 if (header->tag != DEBUG_TAG) {
235 std::string error_str;
236 if (header->tag == DEBUG_FREE_TAG) {
237 error_str = std::string("USED AFTER FREE (") + function_name + ")";
238 } else {
239 error_str = android::base::StringPrintf("HAS INVALID TAG %" PRIx32 " (%s)", header->tag,
240 function_name);
241 }
242 LogError(pointer, error_str.c_str());
243 return false;
244 }
245 }
246
247 if (g_debug->TrackPointers()) {
248 if (!PointerData::Exists(pointer)) {
249 std::string error_str(std::string("UNKNOWN POINTER (") + function_name + ")");
250 LogError(pointer, error_str.c_str());
251 return false;
252 }
253 }
254 return true;
255 }
256
InternalMallocUsableSize(void * pointer)257 static size_t InternalMallocUsableSize(void* pointer) {
258 if (g_debug->HeaderEnabled()) {
259 return g_debug->GetHeader(pointer)->usable_size;
260 } else {
261 return g_dispatch->malloc_usable_size(pointer);
262 }
263 }
264
InitHeader(Header * header,void * orig_pointer,size_t size)265 static void* InitHeader(Header* header, void* orig_pointer, size_t size) {
266 header->tag = DEBUG_TAG;
267 header->orig_pointer = orig_pointer;
268 header->size = size;
269 header->usable_size = g_dispatch->malloc_usable_size(orig_pointer);
270 if (header->usable_size == 0) {
271 g_dispatch->free(orig_pointer);
272 return nullptr;
273 }
274 header->usable_size -= g_debug->pointer_offset() + reinterpret_cast<uintptr_t>(header) -
275 reinterpret_cast<uintptr_t>(orig_pointer);
276
277 if (g_debug->config().options() & FRONT_GUARD) {
278 uint8_t* guard = g_debug->GetFrontGuard(header);
279 memset(guard, g_debug->config().front_guard_value(), g_debug->config().front_guard_bytes());
280 }
281
282 if (g_debug->config().options() & REAR_GUARD) {
283 uint8_t* guard = g_debug->GetRearGuard(header);
284 memset(guard, g_debug->config().rear_guard_value(), g_debug->config().rear_guard_bytes());
285 // If the rear guard is enabled, set the usable size to the exact size
286 // of the allocation.
287 header->usable_size = header->size;
288 }
289
290 return g_debug->GetPointer(header);
291 }
292
293 extern "C" void __asan_init() __attribute__((weak));
294
debug_initialize(const MallocDispatch * malloc_dispatch,bool * zygote_child,const char * options)295 bool debug_initialize(const MallocDispatch* malloc_dispatch, bool* zygote_child,
296 const char* options) {
297 if (zygote_child == nullptr || options == nullptr) {
298 return false;
299 }
300
301 if (__asan_init != 0) {
302 error_log("malloc debug cannot be enabled alongside ASAN");
303 return false;
304 }
305
306 InitAtfork();
307
308 g_zygote_child = zygote_child;
309
310 g_dispatch = malloc_dispatch;
311
312 if (!DebugDisableInitialize()) {
313 return false;
314 }
315
316 DebugData* debug = new DebugData();
317 if (!debug->Initialize(options)) {
318 delete debug;
319 DebugDisableFinalize();
320 return false;
321 }
322 g_debug = debug;
323
324 // Always enable the backtrace code since we will use it in a number
325 // of different error cases.
326 backtrace_startup();
327
328 if (g_debug->config().options() & VERBOSE) {
329 info_log("%s: malloc debug enabled", getprogname());
330 }
331
332 ScopedConcurrentLock::Init();
333
334 return true;
335 }
336
debug_finalize()337 void debug_finalize() {
338 if (g_debug == nullptr) {
339 return;
340 }
341
342 // Make sure that there are no other threads doing debug allocations
343 // before we kill everything.
344 ScopedConcurrentLock::BlockAllOperations();
345
346 // Turn off capturing allocations calls.
347 DebugDisableSet(true);
348
349 if (g_debug->config().options() & FREE_TRACK) {
350 PointerData::VerifyAllFreed();
351 }
352
353 if (g_debug->config().options() & LEAK_TRACK) {
354 PointerData::LogLeaks();
355 }
356
357 if ((g_debug->config().options() & BACKTRACE) && g_debug->config().backtrace_dump_on_exit()) {
358 debug_dump_heap(android::base::StringPrintf("%s.%d.exit.txt",
359 g_debug->config().backtrace_dump_prefix().c_str(),
360 getpid()).c_str());
361 }
362
363 backtrace_shutdown();
364
365 delete g_debug;
366 g_debug = nullptr;
367
368 DebugDisableFinalize();
369 }
370
debug_get_malloc_leak_info(uint8_t ** info,size_t * overall_size,size_t * info_size,size_t * total_memory,size_t * backtrace_size)371 void debug_get_malloc_leak_info(uint8_t** info, size_t* overall_size, size_t* info_size,
372 size_t* total_memory, size_t* backtrace_size) {
373 ScopedConcurrentLock lock;
374 ScopedDisableDebugCalls disable;
375 ScopedBacktraceSignalBlocker blocked;
376
377 // Verify the arguments.
378 if (info == nullptr || overall_size == nullptr || info_size == nullptr || total_memory == nullptr ||
379 backtrace_size == nullptr) {
380 error_log("get_malloc_leak_info: At least one invalid parameter.");
381 return;
382 }
383
384 *info = nullptr;
385 *overall_size = 0;
386 *info_size = 0;
387 *total_memory = 0;
388 *backtrace_size = 0;
389
390 if (!(g_debug->config().options() & BACKTRACE)) {
391 error_log(
392 "get_malloc_leak_info: Allocations not being tracked, to enable "
393 "set the option 'backtrace'.");
394 return;
395 }
396
397 PointerData::GetInfo(info, overall_size, info_size, total_memory, backtrace_size);
398 }
399
debug_free_malloc_leak_info(uint8_t * info)400 void debug_free_malloc_leak_info(uint8_t* info) {
401 g_dispatch->free(info);
402 }
403
debug_malloc_usable_size(void * pointer)404 size_t debug_malloc_usable_size(void* pointer) {
405 if (DebugCallsDisabled() || pointer == nullptr) {
406 return g_dispatch->malloc_usable_size(pointer);
407 }
408 ScopedConcurrentLock lock;
409 ScopedDisableDebugCalls disable;
410 ScopedBacktraceSignalBlocker blocked;
411
412 if (!VerifyPointer(pointer, "malloc_usable_size")) {
413 return 0;
414 }
415
416 return InternalMallocUsableSize(pointer);
417 }
418
InternalMalloc(size_t size)419 static void* InternalMalloc(size_t size) {
420 if ((g_debug->config().options() & BACKTRACE) && g_debug->pointer->ShouldDumpAndReset()) {
421 debug_dump_heap(android::base::StringPrintf(
422 "%s.%d.txt", g_debug->config().backtrace_dump_prefix().c_str(), getpid())
423 .c_str());
424 }
425
426 if (size == 0) {
427 size = 1;
428 }
429
430 size_t real_size = size + g_debug->extra_bytes();
431 if (real_size < size) {
432 // Overflow.
433 errno = ENOMEM;
434 return nullptr;
435 }
436
437 if (size > PointerInfoType::MaxSize()) {
438 errno = ENOMEM;
439 return nullptr;
440 }
441
442 void* pointer;
443 if (g_debug->HeaderEnabled()) {
444 Header* header =
445 reinterpret_cast<Header*>(g_dispatch->memalign(MINIMUM_ALIGNMENT_BYTES, real_size));
446 if (header == nullptr) {
447 return nullptr;
448 }
449 pointer = InitHeader(header, header, size);
450 } else {
451 pointer = g_dispatch->malloc(real_size);
452 }
453
454 if (pointer != nullptr) {
455 if (g_debug->TrackPointers()) {
456 PointerData::Add(pointer, size);
457 }
458
459 if (g_debug->config().options() & FILL_ON_ALLOC) {
460 size_t bytes = InternalMallocUsableSize(pointer);
461 size_t fill_bytes = g_debug->config().fill_on_alloc_bytes();
462 bytes = (bytes < fill_bytes) ? bytes : fill_bytes;
463 memset(pointer, g_debug->config().fill_alloc_value(), bytes);
464 }
465 }
466 return pointer;
467 }
468
debug_malloc(size_t size)469 void* debug_malloc(size_t size) {
470 if (DebugCallsDisabled()) {
471 return g_dispatch->malloc(size);
472 }
473 ScopedConcurrentLock lock;
474 ScopedDisableDebugCalls disable;
475 ScopedBacktraceSignalBlocker blocked;
476
477 void* pointer = InternalMalloc(size);
478
479 if (g_debug->config().options() & RECORD_ALLOCS) {
480 g_debug->record->AddEntry(new MallocEntry(pointer, size));
481 }
482
483 return pointer;
484 }
485
InternalFree(void * pointer)486 static void InternalFree(void* pointer) {
487 if ((g_debug->config().options() & BACKTRACE) && g_debug->pointer->ShouldDumpAndReset()) {
488 debug_dump_heap(android::base::StringPrintf(
489 "%s.%d.txt", g_debug->config().backtrace_dump_prefix().c_str(), getpid())
490 .c_str());
491 }
492
493 void* free_pointer = pointer;
494 size_t bytes;
495 Header* header;
496 if (g_debug->HeaderEnabled()) {
497 header = g_debug->GetHeader(pointer);
498 free_pointer = header->orig_pointer;
499
500 if (g_debug->config().options() & FRONT_GUARD) {
501 if (!g_debug->front_guard->Valid(header)) {
502 g_debug->front_guard->LogFailure(header);
503 }
504 }
505 if (g_debug->config().options() & REAR_GUARD) {
506 if (!g_debug->rear_guard->Valid(header)) {
507 g_debug->rear_guard->LogFailure(header);
508 }
509 }
510
511 header->tag = DEBUG_FREE_TAG;
512
513 bytes = header->usable_size;
514 } else {
515 bytes = g_dispatch->malloc_usable_size(pointer);
516 }
517
518 if (g_debug->config().options() & FILL_ON_FREE) {
519 size_t fill_bytes = g_debug->config().fill_on_free_bytes();
520 bytes = (bytes < fill_bytes) ? bytes : fill_bytes;
521 memset(pointer, g_debug->config().fill_free_value(), bytes);
522 }
523
524 if (g_debug->TrackPointers()) {
525 PointerData::Remove(pointer);
526 }
527
528 if (g_debug->config().options() & FREE_TRACK) {
529 // Do not add the allocation until we are done modifying the pointer
530 // itself. This avoids a race if a lot of threads are all doing
531 // frees at the same time and we wind up trying to really free this
532 // pointer from another thread, while still trying to free it in
533 // this function.
534 pointer = PointerData::AddFreed(pointer);
535 if (pointer != nullptr) {
536 if (g_debug->HeaderEnabled()) {
537 pointer = g_debug->GetHeader(pointer)->orig_pointer;
538 }
539 g_dispatch->free(pointer);
540 }
541 } else {
542 g_dispatch->free(free_pointer);
543 }
544 }
545
debug_free(void * pointer)546 void debug_free(void* pointer) {
547 if (DebugCallsDisabled() || pointer == nullptr) {
548 return g_dispatch->free(pointer);
549 }
550 ScopedConcurrentLock lock;
551 ScopedDisableDebugCalls disable;
552 ScopedBacktraceSignalBlocker blocked;
553
554 if (g_debug->config().options() & RECORD_ALLOCS) {
555 g_debug->record->AddEntry(new FreeEntry(pointer));
556 }
557
558 if (!VerifyPointer(pointer, "free")) {
559 return;
560 }
561
562 InternalFree(pointer);
563 }
564
debug_memalign(size_t alignment,size_t bytes)565 void* debug_memalign(size_t alignment, size_t bytes) {
566 if (DebugCallsDisabled()) {
567 return g_dispatch->memalign(alignment, bytes);
568 }
569 ScopedConcurrentLock lock;
570 ScopedDisableDebugCalls disable;
571 ScopedBacktraceSignalBlocker blocked;
572
573 if (bytes == 0) {
574 bytes = 1;
575 }
576
577 if (bytes > PointerInfoType::MaxSize()) {
578 errno = ENOMEM;
579 return nullptr;
580 }
581
582 void* pointer;
583 if (g_debug->HeaderEnabled()) {
584 // Make the alignment a power of two.
585 if (!powerof2(alignment)) {
586 alignment = BIONIC_ROUND_UP_POWER_OF_2(alignment);
587 }
588 // Force the alignment to at least MINIMUM_ALIGNMENT_BYTES to guarantee
589 // that the header is aligned properly.
590 if (alignment < MINIMUM_ALIGNMENT_BYTES) {
591 alignment = MINIMUM_ALIGNMENT_BYTES;
592 }
593
594 // We don't have any idea what the natural alignment of
595 // the underlying native allocator is, so we always need to
596 // over allocate.
597 size_t real_size = alignment + bytes + g_debug->extra_bytes();
598 if (real_size < bytes) {
599 // Overflow.
600 errno = ENOMEM;
601 return nullptr;
602 }
603
604 pointer = g_dispatch->malloc(real_size);
605 if (pointer == nullptr) {
606 return nullptr;
607 }
608
609 uintptr_t value = reinterpret_cast<uintptr_t>(pointer) + g_debug->pointer_offset();
610 // Now align the pointer.
611 value += (-value % alignment);
612
613 Header* header = g_debug->GetHeader(reinterpret_cast<void*>(value));
614 pointer = InitHeader(header, pointer, bytes);
615 } else {
616 size_t real_size = bytes + g_debug->extra_bytes();
617 if (real_size < bytes) {
618 // Overflow.
619 errno = ENOMEM;
620 return nullptr;
621 }
622 pointer = g_dispatch->memalign(alignment, real_size);
623 }
624
625 if (pointer != nullptr) {
626 if (g_debug->TrackPointers()) {
627 PointerData::Add(pointer, bytes);
628 }
629
630 if (g_debug->config().options() & FILL_ON_ALLOC) {
631 size_t bytes = InternalMallocUsableSize(pointer);
632 size_t fill_bytes = g_debug->config().fill_on_alloc_bytes();
633 bytes = (bytes < fill_bytes) ? bytes : fill_bytes;
634 memset(pointer, g_debug->config().fill_alloc_value(), bytes);
635 }
636
637 if (g_debug->config().options() & RECORD_ALLOCS) {
638 g_debug->record->AddEntry(new MemalignEntry(pointer, bytes, alignment));
639 }
640 }
641
642 return pointer;
643 }
644
debug_realloc(void * pointer,size_t bytes)645 void* debug_realloc(void* pointer, size_t bytes) {
646 if (DebugCallsDisabled()) {
647 return g_dispatch->realloc(pointer, bytes);
648 }
649 ScopedConcurrentLock lock;
650 ScopedDisableDebugCalls disable;
651 ScopedBacktraceSignalBlocker blocked;
652
653 if (pointer == nullptr) {
654 pointer = InternalMalloc(bytes);
655 if (g_debug->config().options() & RECORD_ALLOCS) {
656 g_debug->record->AddEntry(new ReallocEntry(pointer, bytes, nullptr));
657 }
658 return pointer;
659 }
660
661 if (!VerifyPointer(pointer, "realloc")) {
662 return nullptr;
663 }
664
665 if (bytes == 0) {
666 if (g_debug->config().options() & RECORD_ALLOCS) {
667 g_debug->record->AddEntry(new ReallocEntry(nullptr, bytes, pointer));
668 }
669
670 InternalFree(pointer);
671 return nullptr;
672 }
673
674 size_t real_size = bytes;
675 if (g_debug->config().options() & EXPAND_ALLOC) {
676 real_size += g_debug->config().expand_alloc_bytes();
677 if (real_size < bytes) {
678 // Overflow.
679 errno = ENOMEM;
680 return nullptr;
681 }
682 }
683
684 if (bytes > PointerInfoType::MaxSize()) {
685 errno = ENOMEM;
686 return nullptr;
687 }
688
689 void* new_pointer;
690 size_t prev_size;
691 if (g_debug->HeaderEnabled()) {
692 // Same size, do nothing.
693 Header* header = g_debug->GetHeader(pointer);
694 if (real_size == header->size) {
695 if (g_debug->TrackPointers()) {
696 // Remove and re-add so that the backtrace is updated.
697 PointerData::Remove(pointer);
698 PointerData::Add(pointer, real_size);
699 }
700 return pointer;
701 }
702
703 // Allocation is shrinking.
704 if (real_size < header->usable_size) {
705 header->size = real_size;
706 if (g_debug->config().options() & REAR_GUARD) {
707 // Don't bother allocating a smaller pointer in this case, simply
708 // change the header usable_size and reset the rear guard.
709 header->usable_size = header->size;
710 memset(g_debug->GetRearGuard(header), g_debug->config().rear_guard_value(),
711 g_debug->config().rear_guard_bytes());
712 }
713 if (g_debug->TrackPointers()) {
714 // Remove and re-add so that the backtrace is updated.
715 PointerData::Remove(pointer);
716 PointerData::Add(pointer, real_size);
717 }
718 return pointer;
719 }
720
721 // Allocate the new size.
722 new_pointer = InternalMalloc(bytes);
723 if (new_pointer == nullptr) {
724 errno = ENOMEM;
725 return nullptr;
726 }
727
728 prev_size = header->usable_size;
729 memcpy(new_pointer, pointer, prev_size);
730 InternalFree(pointer);
731 } else {
732 if (g_debug->TrackPointers()) {
733 PointerData::Remove(pointer);
734 }
735
736 prev_size = g_dispatch->malloc_usable_size(pointer);
737 new_pointer = g_dispatch->realloc(pointer, real_size);
738 if (new_pointer == nullptr) {
739 return nullptr;
740 }
741
742 if (g_debug->TrackPointers()) {
743 PointerData::Add(new_pointer, real_size);
744 }
745 }
746
747 if (g_debug->config().options() & FILL_ON_ALLOC) {
748 size_t bytes = InternalMallocUsableSize(new_pointer);
749 if (bytes > g_debug->config().fill_on_alloc_bytes()) {
750 bytes = g_debug->config().fill_on_alloc_bytes();
751 }
752 if (bytes > prev_size) {
753 memset(reinterpret_cast<void*>(reinterpret_cast<uintptr_t>(new_pointer) + prev_size),
754 g_debug->config().fill_alloc_value(), bytes - prev_size);
755 }
756 }
757
758 if (g_debug->config().options() & RECORD_ALLOCS) {
759 g_debug->record->AddEntry(new ReallocEntry(new_pointer, bytes, pointer));
760 }
761
762 return new_pointer;
763 }
764
debug_calloc(size_t nmemb,size_t bytes)765 void* debug_calloc(size_t nmemb, size_t bytes) {
766 if (DebugCallsDisabled()) {
767 return g_dispatch->calloc(nmemb, bytes);
768 }
769 ScopedConcurrentLock lock;
770 ScopedDisableDebugCalls disable;
771 ScopedBacktraceSignalBlocker blocked;
772
773 size_t size;
774 if (__builtin_mul_overflow(nmemb, bytes, &size)) {
775 // Overflow
776 errno = ENOMEM;
777 return nullptr;
778 }
779
780 if (size == 0) {
781 size = 1;
782 }
783
784 size_t real_size;
785 if (__builtin_add_overflow(size, g_debug->extra_bytes(), &real_size)) {
786 // Overflow.
787 errno = ENOMEM;
788 return nullptr;
789 }
790
791 if (real_size > PointerInfoType::MaxSize()) {
792 errno = ENOMEM;
793 return nullptr;
794 }
795
796 void* pointer;
797 if (g_debug->HeaderEnabled()) {
798 // Need to guarantee the alignment of the header.
799 Header* header =
800 reinterpret_cast<Header*>(g_dispatch->memalign(MINIMUM_ALIGNMENT_BYTES, real_size));
801 if (header == nullptr) {
802 return nullptr;
803 }
804 memset(header, 0, g_dispatch->malloc_usable_size(header));
805 pointer = InitHeader(header, header, size);
806 } else {
807 pointer = g_dispatch->calloc(1, real_size);
808 }
809
810 if (g_debug->config().options() & RECORD_ALLOCS) {
811 g_debug->record->AddEntry(new CallocEntry(pointer, bytes, nmemb));
812 }
813
814 if (pointer != nullptr && g_debug->TrackPointers()) {
815 PointerData::Add(pointer, size);
816 }
817 return pointer;
818 }
819
debug_mallinfo()820 struct mallinfo debug_mallinfo() {
821 return g_dispatch->mallinfo();
822 }
823
debug_mallopt(int param,int value)824 int debug_mallopt(int param, int value) {
825 return g_dispatch->mallopt(param, value);
826 }
827
debug_malloc_info(int options,FILE * fp)828 int debug_malloc_info(int options, FILE* fp) {
829 if (DebugCallsDisabled() || !g_debug->TrackPointers()) {
830 return g_dispatch->malloc_info(options, fp);
831 }
832
833 // Make sure any pending output is written to the file.
834 fflush(fp);
835
836 ScopedConcurrentLock lock;
837 ScopedDisableDebugCalls disable;
838 ScopedBacktraceSignalBlocker blocked;
839
840 // Avoid any issues where allocations are made that will be freed
841 // in the fclose.
842 int fd = fileno(fp);
843 MallocXmlElem root(fd, "malloc", "version=\"debug-malloc-1\"");
844 std::vector<ListInfoType> list;
845 PointerData::GetAllocList(&list);
846
847 size_t alloc_num = 0;
848 for (size_t i = 0; i < list.size(); i++) {
849 MallocXmlElem alloc(fd, "allocation", "nr=\"%zu\"", alloc_num);
850
851 size_t total = 1;
852 size_t size = list[i].size;
853 while (i < list.size() - 1 && list[i + 1].size == size) {
854 i++;
855 total++;
856 }
857 MallocXmlElem(fd, "size").Contents("%zu", list[i].size);
858 MallocXmlElem(fd, "total").Contents("%zu", total);
859 alloc_num++;
860 }
861 return 0;
862 }
863
debug_aligned_alloc(size_t alignment,size_t size)864 void* debug_aligned_alloc(size_t alignment, size_t size) {
865 if (DebugCallsDisabled()) {
866 return g_dispatch->aligned_alloc(alignment, size);
867 }
868 if (!powerof2(alignment) || (size % alignment) != 0) {
869 errno = EINVAL;
870 return nullptr;
871 }
872 return debug_memalign(alignment, size);
873 }
874
debug_posix_memalign(void ** memptr,size_t alignment,size_t size)875 int debug_posix_memalign(void** memptr, size_t alignment, size_t size) {
876 if (DebugCallsDisabled()) {
877 return g_dispatch->posix_memalign(memptr, alignment, size);
878 }
879
880 if (alignment < sizeof(void*) || !powerof2(alignment)) {
881 return EINVAL;
882 }
883 int saved_errno = errno;
884 *memptr = debug_memalign(alignment, size);
885 errno = saved_errno;
886 return (*memptr != nullptr) ? 0 : ENOMEM;
887 }
888
debug_malloc_iterate(uintptr_t base,size_t size,void (* callback)(uintptr_t,size_t,void *),void * arg)889 int debug_malloc_iterate(uintptr_t base, size_t size, void (*callback)(uintptr_t, size_t, void*),
890 void* arg) {
891 ScopedConcurrentLock lock;
892 if (g_debug->TrackPointers()) {
893 // Since malloc is disabled, don't bother acquiring any locks.
894 for (auto it = PointerData::begin(); it != PointerData::end(); ++it) {
895 callback(it->first, InternalMallocUsableSize(reinterpret_cast<void*>(it->first)), arg);
896 }
897 return 0;
898 }
899
900 // An option that adds a header will add pointer tracking, so no need to
901 // check if headers are enabled.
902 return g_dispatch->malloc_iterate(base, size, callback, arg);
903 }
904
debug_malloc_disable()905 void debug_malloc_disable() {
906 ScopedConcurrentLock lock;
907 g_dispatch->malloc_disable();
908 if (g_debug->pointer) {
909 g_debug->pointer->PrepareFork();
910 }
911 }
912
debug_malloc_enable()913 void debug_malloc_enable() {
914 ScopedConcurrentLock lock;
915 if (g_debug->pointer) {
916 g_debug->pointer->PostForkParent();
917 }
918 g_dispatch->malloc_enable();
919 }
920
debug_malloc_backtrace(void * pointer,uintptr_t * frames,size_t max_frames)921 ssize_t debug_malloc_backtrace(void* pointer, uintptr_t* frames, size_t max_frames) {
922 if (DebugCallsDisabled() || pointer == nullptr) {
923 return 0;
924 }
925 ScopedConcurrentLock lock;
926 ScopedDisableDebugCalls disable;
927 ScopedBacktraceSignalBlocker blocked;
928
929 if (!(g_debug->config().options() & BACKTRACE)) {
930 return 0;
931 }
932 pointer = UntagPointer(pointer);
933 return PointerData::GetFrames(pointer, frames, max_frames);
934 }
935
936 #if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
debug_pvalloc(size_t bytes)937 void* debug_pvalloc(size_t bytes) {
938 if (DebugCallsDisabled()) {
939 return g_dispatch->pvalloc(bytes);
940 }
941
942 size_t pagesize = getpagesize();
943 size_t size = __BIONIC_ALIGN(bytes, pagesize);
944 if (size < bytes) {
945 // Overflow
946 errno = ENOMEM;
947 return nullptr;
948 }
949 return debug_memalign(pagesize, size);
950 }
951
debug_valloc(size_t size)952 void* debug_valloc(size_t size) {
953 if (DebugCallsDisabled()) {
954 return g_dispatch->valloc(size);
955 }
956 return debug_memalign(getpagesize(), size);
957 }
958 #endif
959
960 static std::mutex g_dump_lock;
961
write_dump(int fd)962 static void write_dump(int fd) {
963 dprintf(fd, "Android Native Heap Dump v1.2\n\n");
964
965 std::string fingerprint = android::base::GetProperty("ro.build.fingerprint", "unknown");
966 dprintf(fd, "Build fingerprint: '%s'\n\n", fingerprint.c_str());
967
968 PointerData::DumpLiveToFile(fd);
969
970 dprintf(fd, "MAPS\n");
971 std::string content;
972 if (!android::base::ReadFileToString("/proc/self/maps", &content)) {
973 dprintf(fd, "Could not open /proc/self/maps\n");
974 } else {
975 dprintf(fd, "%s", content.c_str());
976 }
977 dprintf(fd, "END\n");
978 }
979
debug_write_malloc_leak_info(FILE * fp)980 bool debug_write_malloc_leak_info(FILE* fp) {
981 // Make sure any pending output is written to the file.
982 fflush(fp);
983
984 ScopedConcurrentLock lock;
985 ScopedDisableDebugCalls disable;
986 ScopedBacktraceSignalBlocker blocked;
987
988 std::lock_guard<std::mutex> guard(g_dump_lock);
989
990 if (!(g_debug->config().options() & BACKTRACE)) {
991 return false;
992 }
993
994 write_dump(fileno(fp));
995
996 return true;
997 }
998
debug_dump_heap(const char * file_name)999 void debug_dump_heap(const char* file_name) {
1000 ScopedConcurrentLock lock;
1001 ScopedDisableDebugCalls disable;
1002 ScopedBacktraceSignalBlocker blocked;
1003
1004 std::lock_guard<std::mutex> guard(g_dump_lock);
1005
1006 int fd = open(file_name, O_RDWR | O_CREAT | O_NOFOLLOW | O_TRUNC | O_CLOEXEC, 0644);
1007 if (fd == -1) {
1008 error_log("Unable to create file: %s", file_name);
1009 return;
1010 }
1011
1012 error_log("Dumping to file: %s\n", file_name);
1013 write_dump(fd);
1014 close(fd);
1015 }
1016