bool debug_initialize(const MallocDispatch* malloc_dispatch, int* malloc_zygote_child) {
if (malloc_zygote_child == nullptr) {
return false;
}
InitAtfork();
g_malloc_zygote_child = malloc_zygote_child;
g_dispatch = malloc_dispatch;
if (!DebugDisableInitialize()) {
return false;
}
DebugData* debug = new DebugData();
if (!debug->Initialize()) {
delete debug;
DebugDisableFinalize();
return false;
}
g_debug = debug;
// Always enable the backtrace code since we will use it in a number
// of different error cases.
backtrace_startup();
return true;
}
void FreeTrackData::VerifyAndFree(DebugData& debug, const Header* header,
const void* pointer) {
ScopedDisableDebugCalls disable;
if (header->tag != DEBUG_FREE_TAG) {
error_log(LOG_DIVIDER);
error_log("+++ ALLOCATION %p HAS CORRUPTED HEADER TAG 0x%x AFTER FREE", pointer, header->tag);
error_log(LOG_DIVIDER);
} else {
const uint8_t* memory = reinterpret_cast<const uint8_t*>(pointer);
size_t bytes = header->usable_size;
bytes = (bytes < debug.config().fill_on_free_bytes) ? bytes : debug.config().fill_on_free_bytes;
while (bytes > 0) {
size_t bytes_to_cmp = (bytes < cmp_mem_.size()) ? bytes : cmp_mem_.size();
if (memcmp(memory, cmp_mem_.data(), bytes_to_cmp) != 0) {
LogFreeError(debug, header, reinterpret_cast<const uint8_t*>(pointer));
break;
}
bytes -= bytes_to_cmp;
memory = &memory[bytes_to_cmp];
}
}
auto back_iter = backtraces_.find(header);
if (back_iter != backtraces_.end()) {
g_dispatch->free(reinterpret_cast<void*>(back_iter->second));
backtraces_.erase(header);
}
g_dispatch->free(header->orig_pointer);
}
void FreeTrackData::VerifyAll(DebugData& debug) {
// Make sure the stl calls below don't call the debug_XXX functions.
ScopedDisableDebugCalls disable;
for (const auto& header : list_) {
VerifyAndFree(debug, header, debug.GetPointer(header));
}
list_.clear();
}
void FreeTrackData::Add(DebugData& debug, const Header* header) {
// Make sure the stl calls below don't call the debug_XXX functions.
ScopedDisableDebugCalls disable;
pthread_mutex_lock(&mutex_);
if (list_.size() == debug.config().free_track_allocations) {
const Header* old_header = list_.back();
VerifyAndFree(debug, old_header, debug.GetPointer(old_header));
list_.pop_back();
}
if (backtrace_num_frames_ > 0) {
BacktraceHeader* back_header = reinterpret_cast<BacktraceHeader*>(
g_dispatch->malloc(sizeof(BacktraceHeader) + backtrace_num_frames_ * sizeof(uintptr_t)));
if (back_header) {
back_header->num_frames = backtrace_get(&back_header->frames[0], backtrace_num_frames_);
backtraces_[header] = back_header;
}
}
list_.push_front(header);
pthread_mutex_unlock(&mutex_);
}
void FreeTrackData::LogFreeError(DebugData& debug, const Header* header,
const uint8_t* pointer) {
ScopedDisableDebugCalls disable;
error_log(LOG_DIVIDER);
error_log("+++ ALLOCATION %p USED AFTER FREE", pointer);
uint8_t fill_free_value = debug.config().fill_free_value;
for (size_t i = 0; i < header->usable_size; i++) {
if (pointer[i] != fill_free_value) {
error_log(" pointer[%zu] = 0x%02x (expected 0x%02x)", i, pointer[i], fill_free_value);
}
}
auto back_iter = backtraces_.find(header);
if (back_iter != backtraces_.end()) {
const BacktraceHeader* back_header = back_iter->second;
error_log("Backtrace at time of free:");
backtrace_log(&back_header->frames[0], back_header->num_frames);
}
error_log(LOG_DIVIDER);
}
void RearGuardData::LogFailure(DebugData& debug, const Header* header) {
GuardData::LogFailure(header, debug.GetPointer(header), debug.GetRearGuard(header));
}
bool RearGuardData::Valid(DebugData& debug, const Header* header) {
return GuardData::Valid(debug.GetRearGuard(header));
}
bool FrontGuardData::Valid(DebugData& debug, const Header* header) {
return GuardData::Valid(debug.GetFrontGuard(header));
}