1 //=-- lsan_common_mac.cc --------------------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file is a part of LeakSanitizer.
11 // Implementation of common leak checking functionality. Darwin-specific code.
13 //===----------------------------------------------------------------------===//
15 #include "sanitizer_common/sanitizer_platform.h"
16 #include "lsan_common.h"
18 #if CAN_SANITIZE_LEAKS && SANITIZER_MAC
20 #include "sanitizer_common/sanitizer_allocator_internal.h"
21 #include "lsan_allocator.h"
25 #include <mach/mach.h>
27 // Only introduced in Mac OS X 10.9.
28 #ifdef VM_MEMORY_OS_ALLOC_ONCE
29 static const int kSanitizerVmMemoryOsAllocOnce = VM_MEMORY_OS_ALLOC_ONCE;
31 static const int kSanitizerVmMemoryOsAllocOnce = 73;
38 u32 current_thread_id;
40 } thread_local_data_t;
42 static pthread_key_t key;
43 static pthread_once_t key_once = PTHREAD_ONCE_INIT;
45 // The main thread destructor requires the current thread id,
46 // so we can't destroy it until it's been used and reset to invalid tid
47 void restore_tid_data(void *ptr) {
48 thread_local_data_t *data = (thread_local_data_t *)ptr;
49 if (data->current_thread_id != kInvalidTid)
50 pthread_setspecific(key, data);
53 static void make_tls_key() {
54 CHECK_EQ(pthread_key_create(&key, restore_tid_data), 0);
57 static thread_local_data_t *get_tls_val(bool alloc) {
58 pthread_once(&key_once, make_tls_key);
60 thread_local_data_t *ptr = (thread_local_data_t *)pthread_getspecific(key);
61 if (ptr == NULL && alloc) {
62 ptr = (thread_local_data_t *)InternalAlloc(sizeof(*ptr));
63 ptr->disable_counter = 0;
64 ptr->current_thread_id = kInvalidTid;
65 ptr->cache = AllocatorCache();
66 pthread_setspecific(key, ptr);
72 bool DisabledInThisThread() {
73 thread_local_data_t *data = get_tls_val(false);
74 return data ? data->disable_counter > 0 : false;
77 void DisableInThisThread() { ++get_tls_val(true)->disable_counter; }
79 void EnableInThisThread() {
80 int *disable_counter = &get_tls_val(true)->disable_counter;
81 if (*disable_counter == 0) {
82 DisableCounterUnderflow();
87 u32 GetCurrentThread() {
88 thread_local_data_t *data = get_tls_val(false);
89 return data ? data->current_thread_id : kInvalidTid;
92 void SetCurrentThread(u32 tid) { get_tls_val(true)->current_thread_id = tid; }
94 AllocatorCache *GetAllocatorCache() { return &get_tls_val(true)->cache; }
96 LoadedModule *GetLinker() { return nullptr; }
98 // Required on Linux for initialization of TLS behavior, but should not be
99 // required on Darwin.
100 void InitializePlatformSpecificModules() {}
102 // Sections which can't contain contain global pointers. This list errs on the
103 // side of caution to avoid false positives, at the expense of performance.
105 // Other potentially safe sections include:
106 // __all_image_info, __crash_info, __const, __got, __interpose, __objc_msg_break
108 // Sections which definitely cannot be included here are:
109 // __objc_data, __objc_const, __data, __bss, __common, __thread_data,
110 // __thread_bss, __thread_vars, __objc_opt_rw, __objc_opt_ptrs
111 static const char *kSkippedSecNames[] = {
112 "__cfstring", "__la_symbol_ptr", "__mod_init_func",
113 "__mod_term_func", "__nl_symbol_ptr", "__objc_classlist",
114 "__objc_classrefs", "__objc_imageinfo", "__objc_nlclslist",
115 "__objc_protolist", "__objc_selrefs", "__objc_superrefs"};
117 // Scans global variables for heap pointers.
118 void ProcessGlobalRegions(Frontier *frontier) {
119 for (auto name : kSkippedSecNames) CHECK(ARRAY_SIZE(name) < kMaxSegName);
121 MemoryMappingLayout memory_mapping(false);
122 InternalMmapVector<LoadedModule> modules;
123 modules.reserve(128);
124 memory_mapping.DumpListOfModules(&modules);
125 for (uptr i = 0; i < modules.size(); ++i) {
126 // Even when global scanning is disabled, we still need to scan
127 // system libraries for stashed pointers
128 if (!flags()->use_globals && modules[i].instrumented()) continue;
130 for (const __sanitizer::LoadedModule::AddressRange &range :
131 modules[i].ranges()) {
132 // Sections storing global variables are writable and non-executable
133 if (range.executable || !range.writable) continue;
135 for (auto name : kSkippedSecNames) {
136 if (!internal_strcmp(range.name, name)) continue;
139 ScanGlobalRange(range.beg, range.end, frontier);
144 void ProcessPlatformSpecificAllocations(Frontier *frontier) {
145 mach_port_name_t port;
146 if (task_for_pid(mach_task_self(), internal_getpid(), &port)
153 vm_address_t address = 0;
154 kern_return_t err = KERN_SUCCESS;
155 mach_msg_type_number_t count = VM_REGION_SUBMAP_INFO_COUNT_64;
157 InternalMmapVector<RootRegion> const *root_regions = GetRootRegions();
159 while (err == KERN_SUCCESS) {
160 struct vm_region_submap_info_64 info;
161 err = vm_region_recurse_64(port, &address, &size, &depth,
162 (vm_region_info_t)&info, &count);
164 uptr end_address = address + size;
166 // libxpc stashes some pointers in the Kernel Alloc Once page,
167 // make sure not to report those as leaks.
168 if (info.user_tag == kSanitizerVmMemoryOsAllocOnce) {
169 ScanRangeForPointers(address, end_address, frontier, "GLOBAL",
172 // Recursing over the full memory map is very slow, break out
173 // early if we don't need the full iteration.
174 if (!flags()->use_root_regions || !root_regions->size())
178 // This additional root region scan is required on Darwin in order to
179 // detect root regions contained within mmap'd memory regions, because
180 // the Darwin implementation of sanitizer_procmaps traverses images
181 // as loaded by dyld, and not the complete set of all memory regions.
183 // TODO(fjricci) - remove this once sanitizer_procmaps_mac has the same
184 // behavior as sanitizer_procmaps_linux and traverses all memory regions
185 if (flags()->use_root_regions) {
186 for (uptr i = 0; i < root_regions->size(); i++) {
187 ScanRootRegion(frontier, (*root_regions)[i], address, end_address,
188 info.protection & kProtectionRead);
192 address = end_address;
196 // On darwin, we can intercept _exit gracefully, and return a failing exit code
197 // if required at that point. Calling Die() here is undefined behavior and
198 // causes rare race conditions.
199 void HandleLeaks() {}
201 void DoStopTheWorld(StopTheWorldCallback callback, void *argument) {
202 StopTheWorld(callback, argument);
205 } // namespace __lsan
207 #endif // CAN_SANITIZE_LEAKS && SANITIZER_MAC