1 files changed, 39 insertions, 28 deletions

diff --git a/lib/tsan/rtl/tsan_platform_mac.cc b/lib/tsan/rtl/tsan_platform_mac.cc
index 7e3a47387b6d..0c2d2aa9338e 100644
--- a/lib/tsan/rtl/tsan_platform_mac.cc
+++ b/lib/tsan/rtl/tsan_platform_mac.cc
@@ -1,9 +1,8 @@
 //===-- tsan_platform_mac.cc ----------------------------------------------===//
 //
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
@@ -74,22 +73,22 @@ static void *SignalSafeGetOrAllocate(uptr *dst, uptr size) {
 // shadow memory is set up.
 static uptr main_thread_identity = 0;
 ALIGNED(64) static char main_thread_state[sizeof(ThreadState)];
+static ThreadState *main_thread_state_loc = (ThreadState *)main_thread_state;
 
-ThreadState **cur_thread_location() {
-  ThreadState **thread_identity = (ThreadState **)pthread_self();
-  return ((uptr)thread_identity == main_thread_identity) ? nullptr
-                                                         : thread_identity;
+static ThreadState **cur_thread_location() {
+  uptr thread_identity = (uptr)pthread_self();
+  if (thread_identity == main_thread_identity || main_thread_identity == 0)
+    return &main_thread_state_loc;
+  return (ThreadState **)MemToShadow(thread_identity);
 }
 
 ThreadState *cur_thread() {
-  ThreadState **thr_state_loc = cur_thread_location();
-  if (thr_state_loc == nullptr || main_thread_identity == 0) {
-    return (ThreadState *)&main_thread_state;
-  }
-  ThreadState **fake_tls = (ThreadState **)MemToShadow((uptr)thr_state_loc);
-  ThreadState *thr = (ThreadState *)SignalSafeGetOrAllocate(
-      (uptr *)fake_tls, sizeof(ThreadState));
-  return thr;
+  return (ThreadState *)SignalSafeGetOrAllocate(
+      (uptr *)cur_thread_location(), sizeof(ThreadState));
+}
+
+void set_cur_thread(ThreadState *thr) {
+  *cur_thread_location() = thr;
 }
 
 // TODO(kuba.brecka): This is not async-signal-safe. In particular, we call
@@ -97,14 +96,13 @@ ThreadState *cur_thread() {
 // handler will try to access the unmapped ThreadState.
 void cur_thread_finalize() {
   ThreadState **thr_state_loc = cur_thread_location();
-  if (thr_state_loc == nullptr) {
+  if (thr_state_loc == &main_thread_state_loc) {
     // Calling dispatch_main() or xpc_main() actually invokes pthread_exit to
     // exit the main thread. Let's keep the main thread's ThreadState.
     return;
   }
-  ThreadState **fake_tls = (ThreadState **)MemToShadow((uptr)thr_state_loc);
-  internal_munmap(*fake_tls, sizeof(ThreadState));
-  *fake_tls = nullptr;
+  internal_munmap(*thr_state_loc, sizeof(ThreadState));
+  *thr_state_loc = nullptr;
 }
 #endif
 
@@ -213,7 +211,7 @@ static void my_pthread_introspection_hook(unsigned int event, pthread_t thread,
       ThreadState *parent_thread_state = nullptr;  // No parent.
       int tid = ThreadCreate(parent_thread_state, 0, (uptr)thread, true);
       CHECK_NE(tid, 0);
-      ThreadStart(thr, tid, GetTid(), /*workerthread*/ true);
+      ThreadStart(thr, tid, GetTid(), ThreadType::Worker);
     }
   } else if (event == PTHREAD_INTROSPECTION_THREAD_TERMINATE) {
     if (thread == pthread_self()) {
@@ -240,8 +238,7 @@ void InitializePlatformEarly() {
 #endif
 }
 
-static const uptr kPthreadSetjmpXorKeySlot = 0x7;
-extern "C" uptr __tsan_darwin_setjmp_xor_key = 0;
+static uptr longjmp_xor_key = 0;
 
 void InitializePlatform() {
   DisableCoreDumperIfNecessary();
@@ -256,21 +253,35 @@ void InitializePlatform() {
 #endif
 
   if (GetMacosVersion() >= MACOS_VERSION_MOJAVE) {
-    __tsan_darwin_setjmp_xor_key =
-        (uptr)pthread_getspecific(kPthreadSetjmpXorKeySlot);
+    // Libsystem currently uses a process-global key; this might change.
+    const unsigned kTLSLongjmpXorKeySlot = 0x7;
+    longjmp_xor_key = (uptr)pthread_getspecific(kTLSLongjmpXorKeySlot);
   }
 }
 
+#ifdef __aarch64__
+# define LONG_JMP_SP_ENV_SLOT \
+    ((GetMacosVersion() >= MACOS_VERSION_MOJAVE) ? 12 : 13)
+#else
+# define LONG_JMP_SP_ENV_SLOT 2
+#endif
+
+uptr ExtractLongJmpSp(uptr *env) {
+  uptr mangled_sp = env[LONG_JMP_SP_ENV_SLOT];
+  uptr sp = mangled_sp ^ longjmp_xor_key;
+  return sp;
+}
+
 #if !SANITIZER_GO
 void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size) {
   // The pointer to the ThreadState object is stored in the shadow memory
   // of the tls.
   uptr tls_end = tls_addr + tls_size;
-  ThreadState **thr_state_loc = cur_thread_location();
-  if (thr_state_loc == nullptr) {
+  uptr thread_identity = (uptr)pthread_self();
+  if (thread_identity == main_thread_identity) {
     MemoryRangeImitateWrite(thr, /*pc=*/2, tls_addr, tls_size);
   } else {
-    uptr thr_state_start = (uptr)thr_state_loc;
+    uptr thr_state_start = thread_identity;
     uptr thr_state_end = thr_state_start + sizeof(uptr);
     CHECK_GE(thr_state_start, tls_addr);
     CHECK_LE(thr_state_start, tls_addr + tls_size);