1 //===-- tsan_platform_mac.cpp ---------------------------------------------===//
2 //
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
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file is a part of ThreadSanitizer (TSan), a race detector.
10 //
11 // Mac-specific code.
12 //===----------------------------------------------------------------------===//
13 
14 #include "sanitizer_common/sanitizer_platform.h"
15 #if SANITIZER_APPLE
16 
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_ptrauth.h"
23 #include "sanitizer_common/sanitizer_stackdepot.h"
24 #include "tsan_platform.h"
25 #include "tsan_rtl.h"
26 #include "tsan_flags.h"
27 
28 #include <limits.h>
29 #include <mach/mach.h>
30 #include <pthread.h>
31 #include <signal.h>
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <stdarg.h>
36 #include <sys/mman.h>
37 #include <sys/syscall.h>
38 #include <sys/time.h>
39 #include <sys/types.h>
40 #include <sys/resource.h>
41 #include <sys/stat.h>
42 #include <unistd.h>
43 #include <errno.h>
44 #include <sched.h>
45 
46 namespace __tsan {
47 
48 #if !SANITIZER_GO
49 static char main_thread_state[sizeof(ThreadState)] ALIGNED(
50     SANITIZER_CACHE_LINE_SIZE);
51 static ThreadState *dead_thread_state;
52 static pthread_key_t thread_state_key;
53 
54 // We rely on the following documented, but Darwin-specific behavior to keep the
55 // reference to the ThreadState object alive in TLS:
56 // pthread_key_create man page:
57 //   If, after all the destructors have been called for all non-NULL values with
58 //   associated destructors, there are still some non-NULL values with
59 //   associated destructors, then the process is repeated.  If, after at least
60 //   [PTHREAD_DESTRUCTOR_ITERATIONS] iterations of destructor calls for
61 //   outstanding non-NULL values, there are still some non-NULL values with
62 //   associated destructors, the implementation stops calling destructors.
63 static_assert(PTHREAD_DESTRUCTOR_ITERATIONS == 4, "Small number of iterations");
ThreadStateDestructor(void * thr)64 static void ThreadStateDestructor(void *thr) {
65   int res = pthread_setspecific(thread_state_key, thr);
66   CHECK_EQ(res, 0);
67 }
68 
InitializeThreadStateStorage()69 static void InitializeThreadStateStorage() {
70   int res;
71   CHECK_EQ(thread_state_key, 0);
72   res = pthread_key_create(&thread_state_key, ThreadStateDestructor);
73   CHECK_EQ(res, 0);
74   res = pthread_setspecific(thread_state_key, main_thread_state);
75   CHECK_EQ(res, 0);
76 
77   auto dts = (ThreadState *)MmapOrDie(sizeof(ThreadState), "ThreadState");
78   dts->fast_state.SetIgnoreBit();
79   dts->ignore_interceptors = 1;
80   dts->is_dead = true;
81   const_cast<Tid &>(dts->tid) = kInvalidTid;
82   res = internal_mprotect(dts, sizeof(ThreadState), PROT_READ);  // immutable
83   CHECK_EQ(res, 0);
84   dead_thread_state = dts;
85 }
86 
cur_thread()87 ThreadState *cur_thread() {
88   // Some interceptors get called before libpthread has been initialized and in
89   // these cases we must avoid calling any pthread APIs.
90   if (UNLIKELY(!thread_state_key)) {
91     return (ThreadState *)main_thread_state;
92   }
93 
94   // We only reach this line after InitializeThreadStateStorage() ran, i.e,
95   // after TSan (and therefore libpthread) have been initialized.
96   ThreadState *thr = (ThreadState *)pthread_getspecific(thread_state_key);
97   if (UNLIKELY(!thr)) {
98     thr = (ThreadState *)MmapOrDie(sizeof(ThreadState), "ThreadState");
99     int res = pthread_setspecific(thread_state_key, thr);
100     CHECK_EQ(res, 0);
101   }
102   return thr;
103 }
104 
set_cur_thread(ThreadState * thr)105 void set_cur_thread(ThreadState *thr) {
106   int res = pthread_setspecific(thread_state_key, thr);
107   CHECK_EQ(res, 0);
108 }
109 
cur_thread_finalize()110 void cur_thread_finalize() {
111   ThreadState *thr = (ThreadState *)pthread_getspecific(thread_state_key);
112   CHECK(thr);
113   if (thr == (ThreadState *)main_thread_state) {
114     // Calling dispatch_main() or xpc_main() actually invokes pthread_exit to
115     // exit the main thread. Let's keep the main thread's ThreadState.
116     return;
117   }
118   // Intercepted functions can still get called after cur_thread_finalize()
119   // (called from DestroyThreadState()), so put a fake thread state for "dead"
120   // threads.  An alternative solution would be to release the ThreadState
121   // object from THREAD_DESTROY (which is delivered later and on the parent
122   // thread) instead of THREAD_TERMINATE.
123   int res = pthread_setspecific(thread_state_key, dead_thread_state);
124   CHECK_EQ(res, 0);
125   UnmapOrDie(thr, sizeof(ThreadState));
126 }
127 #endif
128 
FlushShadowMemory()129 void FlushShadowMemory() {
130 }
131 
RegionMemUsage(uptr start,uptr end,uptr * res,uptr * dirty)132 static void RegionMemUsage(uptr start, uptr end, uptr *res, uptr *dirty) {
133   vm_address_t address = start;
134   vm_address_t end_address = end;
135   uptr resident_pages = 0;
136   uptr dirty_pages = 0;
137   while (address < end_address) {
138     vm_size_t vm_region_size;
139     mach_msg_type_number_t count = VM_REGION_EXTENDED_INFO_COUNT;
140     vm_region_extended_info_data_t vm_region_info;
141     mach_port_t object_name;
142     kern_return_t ret = vm_region_64(
143         mach_task_self(), &address, &vm_region_size, VM_REGION_EXTENDED_INFO,
144         (vm_region_info_t)&vm_region_info, &count, &object_name);
145     if (ret != KERN_SUCCESS) break;
146 
147     resident_pages += vm_region_info.pages_resident;
148     dirty_pages += vm_region_info.pages_dirtied;
149 
150     address += vm_region_size;
151   }
152   *res = resident_pages * GetPageSizeCached();
153   *dirty = dirty_pages * GetPageSizeCached();
154 }
155 
WriteMemoryProfile(char * buf,uptr buf_size,u64 uptime_ns)156 void WriteMemoryProfile(char *buf, uptr buf_size, u64 uptime_ns) {
157   uptr shadow_res, shadow_dirty;
158   uptr meta_res, meta_dirty;
159   uptr trace_res, trace_dirty;
160   RegionMemUsage(ShadowBeg(), ShadowEnd(), &shadow_res, &shadow_dirty);
161   RegionMemUsage(MetaShadowBeg(), MetaShadowEnd(), &meta_res, &meta_dirty);
162   RegionMemUsage(TraceMemBeg(), TraceMemEnd(), &trace_res, &trace_dirty);
163 
164 #if !SANITIZER_GO
165   uptr low_res, low_dirty;
166   uptr high_res, high_dirty;
167   uptr heap_res, heap_dirty;
168   RegionMemUsage(LoAppMemBeg(), LoAppMemEnd(), &low_res, &low_dirty);
169   RegionMemUsage(HiAppMemBeg(), HiAppMemEnd(), &high_res, &high_dirty);
170   RegionMemUsage(HeapMemBeg(), HeapMemEnd(), &heap_res, &heap_dirty);
171 #else  // !SANITIZER_GO
172   uptr app_res, app_dirty;
173   RegionMemUsage(LoAppMemBeg(), LoAppMemEnd(), &app_res, &app_dirty);
174 #endif
175 
176   StackDepotStats stacks = StackDepotGetStats();
177   uptr nthread, nlive;
178   ctx->thread_registry.GetNumberOfThreads(&nthread, &nlive);
179   internal_snprintf(
180       buf, buf_size,
181       "shadow   (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
182       "meta     (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
183       "traces   (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
184 #  if !SANITIZER_GO
185       "low app  (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
186       "high app (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
187       "heap     (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
188 #  else  // !SANITIZER_GO
189       "app      (0x%016zx-0x%016zx): resident %zd kB, dirty %zd kB\n"
190 #  endif
191       "stacks: %zd unique IDs, %zd kB allocated\n"
192       "threads: %zd total, %zd live\n"
193       "------------------------------\n",
194       ShadowBeg(), ShadowEnd(), shadow_res / 1024, shadow_dirty / 1024,
195       MetaShadowBeg(), MetaShadowEnd(), meta_res / 1024, meta_dirty / 1024,
196       TraceMemBeg(), TraceMemEnd(), trace_res / 1024, trace_dirty / 1024,
197 #  if !SANITIZER_GO
198       LoAppMemBeg(), LoAppMemEnd(), low_res / 1024, low_dirty / 1024,
199       HiAppMemBeg(), HiAppMemEnd(), high_res / 1024, high_dirty / 1024,
200       HeapMemBeg(), HeapMemEnd(), heap_res / 1024, heap_dirty / 1024,
201 #  else  // !SANITIZER_GO
202       LoAppMemBeg(), LoAppMemEnd(), app_res / 1024, app_dirty / 1024,
203 #  endif
204       stacks.n_uniq_ids, stacks.allocated / 1024, nthread, nlive);
205 }
206 
207 #  if !SANITIZER_GO
InitializeShadowMemoryPlatform()208 void InitializeShadowMemoryPlatform() { }
209 
210 // On OS X, GCD worker threads are created without a call to pthread_create. We
211 // need to properly register these threads with ThreadCreate and ThreadStart.
212 // These threads don't have a parent thread, as they are created "spuriously".
213 // We're using a libpthread API that notifies us about a newly created thread.
214 // The `thread == pthread_self()` check indicates this is actually a worker
215 // thread. If it's just a regular thread, this hook is called on the parent
216 // thread.
217 typedef void (*pthread_introspection_hook_t)(unsigned int event,
218                                              pthread_t thread, void *addr,
219                                              size_t size);
220 extern "C" pthread_introspection_hook_t pthread_introspection_hook_install(
221     pthread_introspection_hook_t hook);
222 static const uptr PTHREAD_INTROSPECTION_THREAD_CREATE = 1;
223 static const uptr PTHREAD_INTROSPECTION_THREAD_TERMINATE = 3;
224 static pthread_introspection_hook_t prev_pthread_introspection_hook;
my_pthread_introspection_hook(unsigned int event,pthread_t thread,void * addr,size_t size)225 static void my_pthread_introspection_hook(unsigned int event, pthread_t thread,
226                                           void *addr, size_t size) {
227   if (event == PTHREAD_INTROSPECTION_THREAD_CREATE) {
228     if (thread == pthread_self()) {
229       // The current thread is a newly created GCD worker thread.
230       ThreadState *thr = cur_thread();
231       Processor *proc = ProcCreate();
232       ProcWire(proc, thr);
233       ThreadState *parent_thread_state = nullptr;  // No parent.
234       Tid tid = ThreadCreate(parent_thread_state, 0, (uptr)thread, true);
235       CHECK_NE(tid, kMainTid);
236       ThreadStart(thr, tid, GetTid(), ThreadType::Worker);
237     }
238   } else if (event == PTHREAD_INTROSPECTION_THREAD_TERMINATE) {
239     CHECK_EQ(thread, pthread_self());
240     ThreadState *thr = cur_thread();
241     if (thr->tctx) {
242       DestroyThreadState();
243     }
244   }
245 
246   if (prev_pthread_introspection_hook != nullptr)
247     prev_pthread_introspection_hook(event, thread, addr, size);
248 }
249 #endif
250 
InitializePlatformEarly()251 void InitializePlatformEarly() {
252 #  if !SANITIZER_GO && SANITIZER_IOS
253   uptr max_vm = GetMaxUserVirtualAddress() + 1;
254   if (max_vm != HiAppMemEnd()) {
255     Printf("ThreadSanitizer: unsupported vm address limit %p, expected %p.\n",
256            (void *)max_vm, (void *)HiAppMemEnd());
257     Die();
258   }
259 #endif
260 }
261 
262 static uptr longjmp_xor_key = 0;
263 
InitializePlatform()264 void InitializePlatform() {
265   DisableCoreDumperIfNecessary();
266 #if !SANITIZER_GO
267   CheckAndProtect();
268 
269   InitializeThreadStateStorage();
270 
271   prev_pthread_introspection_hook =
272       pthread_introspection_hook_install(&my_pthread_introspection_hook);
273 #endif
274 
275   if (GetMacosAlignedVersion() >= MacosVersion(10, 14)) {
276     // Libsystem currently uses a process-global key; this might change.
277     const unsigned kTLSLongjmpXorKeySlot = 0x7;
278     longjmp_xor_key = (uptr)pthread_getspecific(kTLSLongjmpXorKeySlot);
279   }
280 }
281 
282 #ifdef __aarch64__
283 # define LONG_JMP_SP_ENV_SLOT \
284     ((GetMacosAlignedVersion() >= MacosVersion(10, 14)) ? 12 : 13)
285 #else
286 # define LONG_JMP_SP_ENV_SLOT 2
287 #endif
288 
ExtractLongJmpSp(uptr * env)289 uptr ExtractLongJmpSp(uptr *env) {
290   uptr mangled_sp = env[LONG_JMP_SP_ENV_SLOT];
291   uptr sp = mangled_sp ^ longjmp_xor_key;
292   sp = (uptr)ptrauth_auth_data((void *)sp, ptrauth_key_asdb,
293                                ptrauth_string_discriminator("sp"));
294   return sp;
295 }
296 
297 #if !SANITIZER_GO
__tsan_tls_initialization()298 extern "C" void __tsan_tls_initialization() {}
299 
ImitateTlsWrite(ThreadState * thr,uptr tls_addr,uptr tls_size)300 void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size) {
301   const uptr pc = StackTrace::GetNextInstructionPc(
302       reinterpret_cast<uptr>(__tsan_tls_initialization));
303   // Unlike Linux, we only store a pointer to the ThreadState object in TLS;
304   // just mark the entire range as written to.
305   MemoryRangeImitateWrite(thr, pc, tls_addr, tls_size);
306 }
307 #endif
308 
309 #if !SANITIZER_GO
310 // Note: this function runs with async signals enabled,
311 // so it must not touch any tsan state.
call_pthread_cancel_with_cleanup(int (* fn)(void * arg),void (* cleanup)(void * arg),void * arg)312 int call_pthread_cancel_with_cleanup(int (*fn)(void *arg),
313                                      void (*cleanup)(void *arg), void *arg) {
314   // pthread_cleanup_push/pop are hardcore macros mess.
315   // We can't intercept nor call them w/o including pthread.h.
316   int res;
317   pthread_cleanup_push(cleanup, arg);
318   res = fn(arg);
319   pthread_cleanup_pop(0);
320   return res;
321 }
322 #endif
323 
324 }  // namespace __tsan
325 
326 #endif  // SANITIZER_APPLE
327