1 files changed, 109 insertions, 30 deletions

diff --git a/lib/asan/asan_thread.cc b/lib/asan/asan_thread.cc
index da28381031a5f..328ac2fcd3982 100644
--- a/lib/asan/asan_thread.cc
+++ b/lib/asan/asan_thread.cc
@@ -19,6 +19,7 @@
 #include "asan_mapping.h"
 #include "sanitizer_common/sanitizer_common.h"
 #include "sanitizer_common/sanitizer_placement_new.h"
+#include "sanitizer_common/sanitizer_stackdepot.h"
 #include "lsan/lsan_common.h"
 
 namespace __asan {
@@ -27,9 +28,8 @@ namespace __asan {
 
 void AsanThreadContext::OnCreated(void *arg) {
   CreateThreadContextArgs *args = static_cast<CreateThreadContextArgs*>(arg);
-  if (args->stack) {
-    internal_memcpy(&stack, args->stack, sizeof(stack));
-  }
+  if (args->stack)
+    stack_id = StackDepotPut(args->stack->trace, args->stack->size);
   thread = args->thread;
   thread->set_context(this);
 }
@@ -39,12 +39,16 @@ void AsanThreadContext::OnFinished() {
   thread = 0;
 }
 
-static char thread_registry_placeholder[sizeof(ThreadRegistry)];
+// MIPS requires aligned address
+static ALIGNED(16) char thread_registry_placeholder[sizeof(ThreadRegistry)];
 static ThreadRegistry *asan_thread_registry;
 
+static BlockingMutex mu_for_thread_context(LINKER_INITIALIZED);
+static LowLevelAllocator allocator_for_thread_context;
+
 static ThreadContextBase *GetAsanThreadContext(u32 tid) {
-  void *mem = MmapOrDie(sizeof(AsanThreadContext), "AsanThreadContext");
-  return new(mem) AsanThreadContext(tid);
+  BlockingMutexLock lock(&mu_for_thread_context);
+  return new(allocator_for_thread_context) AsanThreadContext(tid);
 }
 
 ThreadRegistry &asanThreadRegistry() {
@@ -84,40 +88,68 @@ AsanThread *AsanThread::Create(thread_callback_t start_routine,
 
 void AsanThread::TSDDtor(void *tsd) {
   AsanThreadContext *context = (AsanThreadContext*)tsd;
-  if (flags()->verbosity >= 1)
+  if (common_flags()->verbosity >= 1)
     Report("T%d TSDDtor\n", context->tid);
   if (context->thread)
     context->thread->Destroy();
 }
 
 void AsanThread::Destroy() {
-  if (flags()->verbosity >= 1) {
+  if (common_flags()->verbosity >= 1) {
     Report("T%d exited\n", tid());
   }
 
+  malloc_storage().CommitBack();
+  if (flags()->use_sigaltstack) UnsetAlternateSignalStack();
   asanThreadRegistry().FinishThread(tid());
-  FlushToAccumulatedStats(&stats_);
+  FlushToDeadThreadStats(&stats_);
   // We also clear the shadow on thread destruction because
   // some code may still be executing in later TSD destructors
   // and we don't want it to have any poisoned stack.
-  ClearShadowForThreadStack();
-  fake_stack().Cleanup();
+  ClearShadowForThreadStackAndTLS();
+  DeleteFakeStack();
   uptr size = RoundUpTo(sizeof(AsanThread), GetPageSizeCached());
   UnmapOrDie(this, size);
 }
 
+// We want to create the FakeStack lazyly on the first use, but not eralier
+// than the stack size is known and the procedure has to be async-signal safe.
+FakeStack *AsanThread::AsyncSignalSafeLazyInitFakeStack() {
+  uptr stack_size = this->stack_size();
+  if (stack_size == 0)  // stack_size is not yet available, don't use FakeStack.
+    return 0;
+  uptr old_val = 0;
+  // fake_stack_ has 3 states:
+  // 0   -- not initialized
+  // 1   -- being initialized
+  // ptr -- initialized
+  // This CAS checks if the state was 0 and if so changes it to state 1,
+  // if that was successfull, it initilizes the pointer.
+  if (atomic_compare_exchange_strong(
+      reinterpret_cast<atomic_uintptr_t *>(&fake_stack_), &old_val, 1UL,
+      memory_order_relaxed)) {
+    uptr stack_size_log = Log2(RoundUpToPowerOfTwo(stack_size));
+    if (flags()->uar_stack_size_log)
+      stack_size_log = static_cast<uptr>(flags()->uar_stack_size_log);
+    fake_stack_ = FakeStack::Create(stack_size_log);
+    SetTLSFakeStack(fake_stack_);
+    return fake_stack_;
+  }
+  return 0;
+}
+
 void AsanThread::Init() {
-  SetThreadStackTopAndBottom();
+  SetThreadStackAndTls();
   CHECK(AddrIsInMem(stack_bottom_));
   CHECK(AddrIsInMem(stack_top_ - 1));
-  ClearShadowForThreadStack();
-  if (flags()->verbosity >= 1) {
+  ClearShadowForThreadStackAndTLS();
+  if (common_flags()->verbosity >= 1) {
     int local = 0;
     Report("T%d: stack [%p,%p) size 0x%zx; local=%p\n",
            tid(), (void*)stack_bottom_, (void*)stack_top_,
            stack_top_ - stack_bottom_, &local);
   }
-  fake_stack_.Init(stack_size());
+  fake_stack_ = 0;  // Will be initialized lazily if needed.
   AsanPlatformThreadInit();
 }
 
@@ -135,22 +167,33 @@ thread_return_t AsanThread::ThreadStart(uptr os_id) {
   }
 
   thread_return_t res = start_routine_(arg_);
-  malloc_storage().CommitBack();
-  if (flags()->use_sigaltstack) UnsetAlternateSignalStack();
 
-  this->Destroy();
+  // On POSIX systems we defer this to the TSD destructor. LSan will consider
+  // the thread's memory as non-live from the moment we call Destroy(), even
+  // though that memory might contain pointers to heap objects which will be
+  // cleaned up by a user-defined TSD destructor. Thus, calling Destroy() before
+  // the TSD destructors have run might cause false positives in LSan.
+  if (!SANITIZER_POSIX)
+    this->Destroy();
 
   return res;
 }
 
-void AsanThread::SetThreadStackTopAndBottom() {
-  GetThreadStackTopAndBottom(tid() == 0, &stack_top_, &stack_bottom_);
+void AsanThread::SetThreadStackAndTls() {
+  uptr tls_size = 0;
+  GetThreadStackAndTls(tid() == 0, &stack_bottom_, &stack_size_, &tls_begin_,
+                       &tls_size);
+  stack_top_ = stack_bottom_ + stack_size_;
+  tls_end_ = tls_begin_ + tls_size;
+
   int local;
   CHECK(AddrIsInStack((uptr)&local));
 }
 
-void AsanThread::ClearShadowForThreadStack() {
+void AsanThread::ClearShadowForThreadStackAndTLS() {
   PoisonShadow(stack_bottom_, stack_top_ - stack_bottom_, 0);
+  if (tls_begin_ != tls_end_)
+    PoisonShadow(tls_begin_, tls_end_ - tls_begin_, 0);
 }
 
 const char *AsanThread::GetFrameNameByAddr(uptr addr, uptr *offset,
@@ -158,8 +201,8 @@ const char *AsanThread::GetFrameNameByAddr(uptr addr, uptr *offset,
   uptr bottom = 0;
   if (AddrIsInStack(addr)) {
     bottom = stack_bottom();
-  } else {
-    bottom = fake_stack().AddrIsInFakeStack(addr);
+  } else if (has_fake_stack()) {
+    bottom = fake_stack()->AddrIsInFakeStack(addr);
     CHECK(bottom);
     *offset = addr - bottom;
     *frame_pc = ((uptr*)bottom)[2];
@@ -195,13 +238,16 @@ static bool ThreadStackContainsAddress(ThreadContextBase *tctx_base,
                                        void *addr) {
   AsanThreadContext *tctx = static_cast<AsanThreadContext*>(tctx_base);
   AsanThread *t = tctx->thread;
-  return (t && t->fake_stack().StackSize() &&
-          (t->fake_stack().AddrIsInFakeStack((uptr)addr) ||
-           t->AddrIsInStack((uptr)addr)));
+  if (!t) return false;
+  if (t->AddrIsInStack((uptr)addr)) return true;
+  if (t->has_fake_stack() && t->fake_stack()->AddrIsInFakeStack((uptr)addr))
+    return true;
+  return false;
 }
 
 AsanThread *GetCurrentThread() {
-  AsanThreadContext *context = (AsanThreadContext*)AsanTSDGet();
+  AsanThreadContext *context =
+      reinterpret_cast<AsanThreadContext *>(AsanTSDGet());
   if (!context) {
     if (SANITIZER_ANDROID) {
       // On Android, libc constructor is called _after_ asan_init, and cleans up
@@ -222,7 +268,7 @@ AsanThread *GetCurrentThread() {
 
 void SetCurrentThread(AsanThread *t) {
   CHECK(t->context());
-  if (flags()->verbosity >= 2) {
+  if (common_flags()->verbosity >= 2) {
     Report("SetCurrentThread: %p for thread %p\n",
            t->context(), (void*)GetThreadSelf());
   }
@@ -244,6 +290,20 @@ AsanThread *FindThreadByStackAddress(uptr addr) {
                                                    (void *)addr));
   return tctx ? tctx->thread : 0;
 }
+
+void EnsureMainThreadIDIsCorrect() {
+  AsanThreadContext *context =
+      reinterpret_cast<AsanThreadContext *>(AsanTSDGet());
+  if (context && (context->tid == 0))
+    context->os_id = GetTid();
+}
+
+__asan::AsanThread *GetAsanThreadByOsIDLocked(uptr os_id) {
+  __asan::AsanThreadContext *context = static_cast<__asan::AsanThreadContext *>(
+      __asan::asanThreadRegistry().FindThreadContextByOsIDLocked(os_id));
+  if (!context) return 0;
+  return context->thread;
+}
 }  // namespace __asan
 
 // --- Implementation of LSan-specific functions --- {{{1
@@ -251,8 +311,23 @@ namespace __lsan {
 bool GetThreadRangesLocked(uptr os_id, uptr *stack_begin, uptr *stack_end,
                            uptr *tls_begin, uptr *tls_end,
                            uptr *cache_begin, uptr *cache_end) {
-  // FIXME: Stub.
-  return false;
+  __asan::AsanThread *t = __asan::GetAsanThreadByOsIDLocked(os_id);
+  if (!t) return false;
+  *stack_begin = t->stack_bottom();
+  *stack_end = t->stack_top();
+  *tls_begin = t->tls_begin();
+  *tls_end = t->tls_end();
+  // ASan doesn't keep allocator caches in TLS, so these are unused.
+  *cache_begin = 0;
+  *cache_end = 0;
+  return true;
+}
+
+void ForEachExtraStackRange(uptr os_id, RangeIteratorCallback callback,
+                            void *arg) {
+  __asan::AsanThread *t = __asan::GetAsanThreadByOsIDLocked(os_id);
+  if (t && t->has_fake_stack())
+    t->fake_stack()->ForEachFakeFrame(callback, arg);
 }
 
 void LockThreadRegistry() {
@@ -262,4 +337,8 @@ void LockThreadRegistry() {
 void UnlockThreadRegistry() {
   __asan::asanThreadRegistry().Unlock();
 }
+
+void EnsureMainThreadIDIsCorrect() {
+  __asan::EnsureMainThreadIDIsCorrect();
+}
 }  // namespace __lsan