1 //===-- tsan_platform_mac.cpp ---------------------------------------------===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // This file is a part of ThreadSanitizer (TSan), a race detector.
12 //===----------------------------------------------------------------------===//
14 #include "sanitizer_common/sanitizer_platform.h"
17 #include "sanitizer_common/sanitizer_atomic.h"
18 #include "sanitizer_common/sanitizer_common.h"
19 #include "sanitizer_common/sanitizer_libc.h"
20 #include "sanitizer_common/sanitizer_posix.h"
21 #include "sanitizer_common/sanitizer_procmaps.h"
22 #include "sanitizer_common/sanitizer_stackdepot.h"
23 #include "tsan_platform.h"
25 #include "tsan_flags.h"
27 #include <mach/mach.h>
35 #include <sys/syscall.h>
37 #include <sys/types.h>
38 #include <sys/resource.h>
47 static void *SignalSafeGetOrAllocate(uptr *dst, uptr size) {
48 atomic_uintptr_t *a = (atomic_uintptr_t *)dst;
49 void *val = (void *)atomic_load_relaxed(a);
50 atomic_signal_fence(memory_order_acquire); // Turns the previous load into
51 // acquire wrt signals.
52 if (UNLIKELY(val == nullptr)) {
53 val = (void *)internal_mmap(nullptr, size, PROT_READ | PROT_WRITE,
54 MAP_PRIVATE | MAP_ANON, -1, 0);
57 if (!atomic_compare_exchange_strong(a, (uintptr_t *)&cmp, (uintptr_t)val,
58 memory_order_acq_rel)) {
59 internal_munmap(val, size);
66 // On OS X, accessing TLVs via __thread or manually by using pthread_key_* is
67 // problematic, because there are several places where interceptors are called
68 // when TLVs are not accessible (early process startup, thread cleanup, ...).
69 // The following provides a "poor man's TLV" implementation, where we use the
70 // shadow memory of the pointer returned by pthread_self() to store a pointer to
71 // the ThreadState object. The main thread's ThreadState is stored separately
72 // in a static variable, because we need to access it even before the
73 // shadow memory is set up.
74 static uptr main_thread_identity = 0;
75 ALIGNED(64) static char main_thread_state[sizeof(ThreadState)];
76 static ThreadState *main_thread_state_loc = (ThreadState *)main_thread_state;
78 // We cannot use pthread_self() before libpthread has been initialized. Our
79 // current heuristic for guarding this is checking `main_thread_identity` which
80 // is only assigned in `__tsan::InitializePlatform`.
81 static ThreadState **cur_thread_location() {
82 if (main_thread_identity == 0)
83 return &main_thread_state_loc;
84 uptr thread_identity = (uptr)pthread_self();
85 if (thread_identity == main_thread_identity)
86 return &main_thread_state_loc;
87 return (ThreadState **)MemToShadow(thread_identity);
90 ThreadState *cur_thread() {
91 return (ThreadState *)SignalSafeGetOrAllocate(
92 (uptr *)cur_thread_location(), sizeof(ThreadState));
95 void set_cur_thread(ThreadState *thr) {
96 *cur_thread_location() = thr;
99 // TODO(kuba.brecka): This is not async-signal-safe. In particular, we call
100 // munmap first and then clear `fake_tls`; if we receive a signal in between,
101 // handler will try to access the unmapped ThreadState.
102 void cur_thread_finalize() {
103 ThreadState **thr_state_loc = cur_thread_location();
104 if (thr_state_loc == &main_thread_state_loc) {
105 // Calling dispatch_main() or xpc_main() actually invokes pthread_exit to
106 // exit the main thread. Let's keep the main thread's ThreadState.
109 internal_munmap(*thr_state_loc, sizeof(ThreadState));
110 *thr_state_loc = nullptr;
114 void FlushShadowMemory() {
117 static void RegionMemUsage(uptr start, uptr end, uptr *res, uptr *dirty) {
118 vm_address_t address = start;
119 vm_address_t end_address = end;
120 uptr resident_pages = 0;
121 uptr dirty_pages = 0;
122 while (address < end_address) {
123 vm_size_t vm_region_size;
124 mach_msg_type_number_t count = VM_REGION_EXTENDED_INFO_COUNT;
125 vm_region_extended_info_data_t vm_region_info;
126 mach_port_t object_name;
127 kern_return_t ret = vm_region_64(
128 mach_task_self(), &address, &vm_region_size, VM_REGION_EXTENDED_INFO,
129 (vm_region_info_t)&vm_region_info, &count, &object_name);
130 if (ret != KERN_SUCCESS) break;
132 resident_pages += vm_region_info.pages_resident;
133 dirty_pages += vm_region_info.pages_dirtied;
135 address += vm_region_size;
137 *res = resident_pages * GetPageSizeCached();
138 *dirty = dirty_pages * GetPageSizeCached();
141 void WriteMemoryProfile(char *buf, uptr buf_size, uptr nthread, uptr nlive) {
142 uptr shadow_res, shadow_dirty;
143 uptr meta_res, meta_dirty;
144 uptr trace_res, trace_dirty;
145 RegionMemUsage(ShadowBeg(), ShadowEnd(), &shadow_res, &shadow_dirty);
146 RegionMemUsage(MetaShadowBeg(), MetaShadowEnd(), &meta_res, &meta_dirty);
147 RegionMemUsage(TraceMemBeg(), TraceMemEnd(), &trace_res, &trace_dirty);
150 uptr low_res, low_dirty;
151 uptr high_res, high_dirty;
152 uptr heap_res, heap_dirty;
153 RegionMemUsage(LoAppMemBeg(), LoAppMemEnd(), &low_res, &low_dirty);
154 RegionMemUsage(HiAppMemBeg(), HiAppMemEnd(), &high_res, &high_dirty);
155 RegionMemUsage(HeapMemBeg(), HeapMemEnd(), &heap_res, &heap_dirty);
156 #else // !SANITIZER_GO
157 uptr app_res, app_dirty;
158 RegionMemUsage(AppMemBeg(), AppMemEnd(), &app_res, &app_dirty);
161 StackDepotStats *stacks = StackDepotGetStats();
162 internal_snprintf(buf, buf_size,
163 "shadow (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
164 "meta (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
165 "traces (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
167 "low app (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
168 "high app (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
169 "heap (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
170 #else // !SANITIZER_GO
171 "app (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
173 "stacks: %zd unique IDs, %zd kB allocated\n"
174 "threads: %zd total, %zd live\n"
175 "------------------------------\n",
176 ShadowBeg(), ShadowEnd(), shadow_res / 1024, shadow_dirty / 1024,
177 MetaShadowBeg(), MetaShadowEnd(), meta_res / 1024, meta_dirty / 1024,
178 TraceMemBeg(), TraceMemEnd(), trace_res / 1024, trace_dirty / 1024,
180 LoAppMemBeg(), LoAppMemEnd(), low_res / 1024, low_dirty / 1024,
181 HiAppMemBeg(), HiAppMemEnd(), high_res / 1024, high_dirty / 1024,
182 HeapMemBeg(), HeapMemEnd(), heap_res / 1024, heap_dirty / 1024,
183 #else // !SANITIZER_GO
184 AppMemBeg(), AppMemEnd(), app_res / 1024, app_dirty / 1024,
186 stacks->n_uniq_ids, stacks->allocated / 1024,
191 void InitializeShadowMemoryPlatform() { }
193 // On OS X, GCD worker threads are created without a call to pthread_create. We
194 // need to properly register these threads with ThreadCreate and ThreadStart.
195 // These threads don't have a parent thread, as they are created "spuriously".
196 // We're using a libpthread API that notifies us about a newly created thread.
197 // The `thread == pthread_self()` check indicates this is actually a worker
198 // thread. If it's just a regular thread, this hook is called on the parent
200 typedef void (*pthread_introspection_hook_t)(unsigned int event,
201 pthread_t thread, void *addr,
203 extern "C" pthread_introspection_hook_t pthread_introspection_hook_install(
204 pthread_introspection_hook_t hook);
205 static const uptr PTHREAD_INTROSPECTION_THREAD_CREATE = 1;
206 static const uptr PTHREAD_INTROSPECTION_THREAD_TERMINATE = 3;
207 static pthread_introspection_hook_t prev_pthread_introspection_hook;
208 static void my_pthread_introspection_hook(unsigned int event, pthread_t thread,
209 void *addr, size_t size) {
210 if (event == PTHREAD_INTROSPECTION_THREAD_CREATE) {
211 if (thread == pthread_self()) {
212 // The current thread is a newly created GCD worker thread.
213 ThreadState *thr = cur_thread();
214 Processor *proc = ProcCreate();
216 ThreadState *parent_thread_state = nullptr; // No parent.
217 int tid = ThreadCreate(parent_thread_state, 0, (uptr)thread, true);
219 ThreadStart(thr, tid, GetTid(), ThreadType::Worker);
221 } else if (event == PTHREAD_INTROSPECTION_THREAD_TERMINATE) {
222 if (thread == pthread_self()) {
223 ThreadState *thr = cur_thread();
225 DestroyThreadState();
230 if (prev_pthread_introspection_hook != nullptr)
231 prev_pthread_introspection_hook(event, thread, addr, size);
235 void InitializePlatformEarly() {
236 #if defined(__aarch64__)
237 uptr max_vm = GetMaxUserVirtualAddress() + 1;
238 if (max_vm != Mapping::kHiAppMemEnd) {
239 Printf("ThreadSanitizer: unsupported vm address limit %p, expected %p.\n",
240 max_vm, Mapping::kHiAppMemEnd);
246 static uptr longjmp_xor_key = 0;
248 void InitializePlatform() {
249 DisableCoreDumperIfNecessary();
253 CHECK_EQ(main_thread_identity, 0);
254 main_thread_identity = (uptr)pthread_self();
256 prev_pthread_introspection_hook =
257 pthread_introspection_hook_install(&my_pthread_introspection_hook);
260 if (GetMacosVersion() >= MACOS_VERSION_MOJAVE) {
261 // Libsystem currently uses a process-global key; this might change.
262 const unsigned kTLSLongjmpXorKeySlot = 0x7;
263 longjmp_xor_key = (uptr)pthread_getspecific(kTLSLongjmpXorKeySlot);
268 # define LONG_JMP_SP_ENV_SLOT \
269 ((GetMacosVersion() >= MACOS_VERSION_MOJAVE) ? 12 : 13)
271 # define LONG_JMP_SP_ENV_SLOT 2
274 uptr ExtractLongJmpSp(uptr *env) {
275 uptr mangled_sp = env[LONG_JMP_SP_ENV_SLOT];
276 uptr sp = mangled_sp ^ longjmp_xor_key;
281 void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size) {
282 // The pointer to the ThreadState object is stored in the shadow memory
284 uptr tls_end = tls_addr + tls_size;
285 uptr thread_identity = (uptr)pthread_self();
286 if (thread_identity == main_thread_identity) {
287 MemoryRangeImitateWrite(thr, /*pc=*/2, tls_addr, tls_size);
289 uptr thr_state_start = thread_identity;
290 uptr thr_state_end = thr_state_start + sizeof(uptr);
291 CHECK_GE(thr_state_start, tls_addr);
292 CHECK_LE(thr_state_start, tls_addr + tls_size);
293 CHECK_GE(thr_state_end, tls_addr);
294 CHECK_LE(thr_state_end, tls_addr + tls_size);
295 MemoryRangeImitateWrite(thr, /*pc=*/2, tls_addr,
296 thr_state_start - tls_addr);
297 MemoryRangeImitateWrite(thr, /*pc=*/2, thr_state_end,
298 tls_end - thr_state_end);
304 // Note: this function runs with async signals enabled,
305 // so it must not touch any tsan state.
306 int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
307 void *abstime), void *c, void *m, void *abstime,
308 void(*cleanup)(void *arg), void *arg) {
309 // pthread_cleanup_push/pop are hardcore macros mess.
310 // We can't intercept nor call them w/o including pthread.h.
312 pthread_cleanup_push(cleanup, arg);
313 res = fn(c, m, abstime);
314 pthread_cleanup_pop(0);
319 } // namespace __tsan
321 #endif // SANITIZER_MAC