diff --git a/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp b/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
index 14b25a8995dab..274a38390bda8 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
@@ -2146,6 +2146,7 @@ static void ReportErrnoSpoiling(ThreadState *thr, uptr pc, int sig) {
   rep.SetSigNum(sig);
   if (!IsFiredSuppression(ctx, ReportTypeErrnoInSignal, stack)) {
     rep.AddStack(stack, true);
+    rep.SymbolizeStackElems();
     OutputReport(thr, rep);
   }
 }
diff --git a/compiler-rt/lib/tsan/rtl/tsan_interface_ann.cpp b/compiler-rt/lib/tsan/rtl/tsan_interface_ann.cpp
index befd6a369026d..d16fd4cfb00d9 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_interface_ann.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_interface_ann.cpp
@@ -446,6 +446,7 @@ static void ReportMutexHeldWrongContext(ThreadState *thr, uptr pc) {
   VarSizeStackTrace trace;
   ObtainCurrentStack(thr, pc, &trace);
   rep.AddStack(trace, true);
+  rep.SymbolizeStackElems();
   OutputReport(thr, rep);
 }
 
diff --git a/compiler-rt/lib/tsan/rtl/tsan_mman.cpp b/compiler-rt/lib/tsan/rtl/tsan_mman.cpp
index 0ea83fb3b5982..3a0a6a1a4564f 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_mman.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_mman.cpp
@@ -185,6 +185,7 @@ static void SignalUnsafeCall(ThreadState *thr, uptr pc) {
   ThreadRegistryLock l(&ctx->thread_registry);
   ScopedReport rep(ReportTypeSignalUnsafe);
   rep.AddStack(stack, true);
+  rep.SymbolizeStackElems();
   OutputReport(thr, rep);
 }
 
diff --git a/compiler-rt/lib/tsan/rtl/tsan_report.h b/compiler-rt/lib/tsan/rtl/tsan_report.h
index bfe470797f8f7..50501060840a4 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_report.h
+++ b/compiler-rt/lib/tsan/rtl/tsan_report.h
@@ -12,6 +12,8 @@
 #ifndef TSAN_REPORT_H
 #define TSAN_REPORT_H
 
+#include "sanitizer_common/sanitizer_internal_defs.h"
+#include "sanitizer_common/sanitizer_stacktrace.h"
 #include "sanitizer_common/sanitizer_symbolizer.h"
 #include "sanitizer_common/sanitizer_thread_registry.h"
 #include "sanitizer_common/sanitizer_vector.h"
@@ -56,6 +58,7 @@ struct ReportMop {
   bool atomic;
   uptr external_tag;
   Vector<ReportMopMutex> mset;
+  StackTrace stack_trace;
   ReportStack *stack;
 
   ReportMop();
@@ -79,6 +82,7 @@ struct ReportLocation {
   int fd = 0;
   bool fd_closed = false;
   bool suppressable = false;
+  StackID stack_id = 0;
   ReportStack *stack = nullptr;
 };
 
@@ -89,12 +93,15 @@ struct ReportThread {
   ThreadType thread_type;
   char *name;
   Tid parent_tid;
+  StackID stack_id;
   ReportStack *stack;
+  bool suppressable;
 };
 
 struct ReportMutex {
   int id;
   uptr addr;
+  StackID stack_id;
   ReportStack *stack;
 };
 
@@ -105,6 +112,7 @@ class ReportDesc {
   Vector<ReportStack*> stacks;
   Vector<ReportMop*> mops;
   Vector<ReportLocation*> locs;
+  Vector<uptr> added_location_addrs;
   Vector<ReportMutex*> mutexes;
   Vector<ReportThread*> threads;
   Vector<Tid> unique_tids;
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl.h b/compiler-rt/lib/tsan/rtl/tsan_rtl.h
index dc32980e905f2..7122c15bb2c13 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl.h
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl.h
@@ -420,6 +420,7 @@ class ScopedReportBase {
   void AddSleep(StackID stack_id);
   void SetCount(int count);
   void SetSigNum(int sig);
+  void SymbolizeStackElems(void);
 
   const ReportDesc *GetReport() const;
 
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_access.cpp b/compiler-rt/lib/tsan/rtl/tsan_rtl_access.cpp
index 487fa490636eb..0d133aead1ee1 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_access.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_access.cpp
@@ -419,6 +419,10 @@ NOINLINE void TraceRestartMemoryAccess(ThreadState* thr, uptr pc, uptr addr,
 
 ALWAYS_INLINE USED void MemoryAccess(ThreadState* thr, uptr pc, uptr addr,
                                      uptr size, AccessType typ) {
+#if SANITIZER_APPLE
+  if (thr->in_symbolizer)
+    return;
+#endif
   RawShadow* shadow_mem = MemToShadow(addr);
   UNUSED char memBuf[4][64];
   DPrintf2("#%d: Access: %d@%d %p/%zd typ=0x%x {%s, %s, %s, %s}\n", thr->tid,
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp b/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp
index 2a8aa1915c9ae..f546931ff0e56 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_mutex.cpp
@@ -62,6 +62,7 @@ static void ReportMutexMisuse(ThreadState *thr, uptr pc, ReportType typ,
   ObtainCurrentStack(thr, pc, &trace);
   rep.AddStack(trace, true);
   rep.AddLocation(addr, 1);
+  rep.SymbolizeStackElems();
   OutputReport(thr, rep);
 }
 
@@ -539,13 +540,16 @@ void ReportDeadlock(ThreadState *thr, uptr pc, DDReport *r) {
   for (int i = 0; i < r->n; i++) {
     for (int j = 0; j < (flags()->second_deadlock_stack ? 2 : 1); j++) {
       u32 stk = r->loop[i].stk[j];
+      StackTrace stack;
       if (stk && stk != kInvalidStackID) {
-        rep.AddStack(StackDepotGet(stk), true);
+        stack = StackDepotGet(stk);
       } else {
         // Sometimes we fail to extract the stack trace (FIXME: investigate),
         // but we should still produce some stack trace in the report.
-        rep.AddStack(StackTrace(&dummy_pc, 1), true);
+        stack = StackTrace(&dummy_pc, 1);
       }
+      rep.AddStack(stack, true);
+      rep.SymbolizeStackElems();
     }
   }
   OutputReport(thr, rep);
@@ -572,6 +576,7 @@ void ReportDestroyLocked(ThreadState *thr, uptr pc, uptr addr,
     return;
   rep.AddStack(trace, true);
   rep.AddLocation(addr, 1);
+  rep.SymbolizeStackElems();
   OutputReport(thr, rep);
 }
 
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp b/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp
index 0820bf1adee43..991e5c60399f0 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_report.cpp
@@ -10,6 +10,8 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include <alloca.h>
+
 #include "sanitizer_common/sanitizer_common.h"
 #include "sanitizer_common/sanitizer_libc.h"
 #include "sanitizer_common/sanitizer_placement_new.h"
@@ -187,10 +189,8 @@ void ScopedReportBase::AddMemoryAccess(uptr addr, uptr external_tag, Shadow s,
   mop->size = size;
   mop->write = !(typ & kAccessRead);
   mop->atomic = typ & kAccessAtomic;
-  mop->stack = SymbolizeStack(stack);
   mop->external_tag = external_tag;
-  if (mop->stack)
-    mop->stack->suppressable = true;
+  mop->stack_trace = stack;
   for (uptr i = 0; i < mset->Size(); i++) {
     MutexSet::Desc d = mset->Get(i);
     int id = this->AddMutex(d.addr, d.stack_id);
@@ -199,6 +199,45 @@ void ScopedReportBase::AddMemoryAccess(uptr addr, uptr external_tag, Shadow s,
   }
 }
 
+void ScopedReportBase::SymbolizeStackElems() {
+  // symbolize memory ops
+  for (usize i = 0; i < rep_->mops.Size(); i++) {
+    ReportMop *mop = rep_->mops[i];
+    mop->stack = SymbolizeStack(mop->stack_trace);
+    if (mop->stack)
+      mop->stack->suppressable = true;
+  }
+
+  // symbolize locations
+  for (usize i = 0; i < rep_->locs.Size(); i++) {
+    ReportLocation *loc = rep_->locs[i];
+    loc->stack = SymbolizeStackId(loc->stack_id);
+  }
+
+  for (usize i = 0; i < rep_->added_location_addrs.Size(); i++) {
+    if (ReportLocation *loc = SymbolizeData(rep_->added_location_addrs[i])) {
+      loc->suppressable = true;
+      // TODO: These all end up at the back of locs - line them up with their
+      //       corresponding location
+      rep_->locs.PushBack(loc);
+    }
+  }
+
+  // symbolize threads
+  for (usize i = 0; i < rep_->threads.Size(); i++) {
+    ReportThread *rt = rep_->threads[i];
+    rt->stack = SymbolizeStackId(rt->stack_id);
+    if (rt->stack)
+      rt->stack->suppressable = rt->suppressable;
+  }
+
+  // symbolize mutexes
+  for (usize i = 0; i < rep_->mutexes.Size(); i++) {
+    ReportMutex *rm = rep_->mutexes[i];
+    rm->stack = SymbolizeStackId(rm->stack_id);
+  }
+}
+
 void ScopedReportBase::AddUniqueTid(Tid unique_tid) {
   rep_->unique_tids.PushBack(unique_tid);
 }
@@ -216,10 +255,8 @@ void ScopedReportBase::AddThread(const ThreadContext *tctx, bool suppressable) {
   rt->name = internal_strdup(tctx->name);
   rt->parent_tid = tctx->parent_tid;
   rt->thread_type = tctx->thread_type;
-  rt->stack = 0;
-  rt->stack = SymbolizeStackId(tctx->creation_stack_id);
-  if (rt->stack)
-    rt->stack->suppressable = suppressable;
+  rt->stack_id = tctx->creation_stack_id;
+  rt->suppressable = suppressable;
 }
 
 #if !SANITIZER_GO
@@ -270,7 +307,7 @@ int ScopedReportBase::AddMutex(uptr addr, StackID creation_stack_id) {
   rep_->mutexes.PushBack(rm);
   rm->id = rep_->mutexes.Size() - 1;
   rm->addr = addr;
-  rm->stack = SymbolizeStackId(creation_stack_id);
+  rm->stack_id = creation_stack_id;
   return rm->id;
 }
 
@@ -288,7 +325,7 @@ void ScopedReportBase::AddLocation(uptr addr, uptr size) {
     loc->fd_closed = closed;
     loc->fd = fd;
     loc->tid = creat_tid;
-    loc->stack = SymbolizeStackId(creat_stack);
+    loc->stack_id = creat_stack;
     rep_->locs.PushBack(loc);
     AddThread(creat_tid);
     return;
@@ -310,7 +347,7 @@ void ScopedReportBase::AddLocation(uptr addr, uptr size) {
     loc->heap_chunk_size = b->siz;
     loc->external_tag = b->tag;
     loc->tid = b->tid;
-    loc->stack = SymbolizeStackId(b->stk);
+    loc->stack_id = b->stk;
     rep_->locs.PushBack(loc);
     AddThread(b->tid);
     return;
@@ -324,11 +361,7 @@ void ScopedReportBase::AddLocation(uptr addr, uptr size) {
     AddThread(tctx);
   }
 #endif
-  if (ReportLocation *loc = SymbolizeData(addr)) {
-    loc->suppressable = true;
-    rep_->locs.PushBack(loc);
-    return;
-  }
+  rep_->added_location_addrs.PushBack(addr);
 }
 
 #if !SANITIZER_GO
@@ -761,65 +794,91 @@ void ReportRace(ThreadState *thr, RawShadow *shadow_mem, Shadow cur, Shadow old,
   DynamicMutexSet mset1;
   MutexSet *mset[kMop] = {&thr->mset, mset1};
 
-  // We need to lock the slot during RestoreStack because it protects
-  // the slot journal.
-  Lock slot_lock(&ctx->slots[static_cast<uptr>(s[1].sid())].mtx);
-  ThreadRegistryLock l0(&ctx->thread_registry);
-  Lock slots_lock(&ctx->slot_mtx);
-  if (SpuriousRace(old))
-    return;
-  if (!RestoreStack(EventType::kAccessExt, s[1].sid(), s[1].epoch(), addr1,
-                    size1, typ1, &tids[1], &traces[1], mset[1], &tags[1])) {
-    StoreShadow(&ctx->last_spurious_race, old.raw());
-    return;
-  }
+#if SANITIZER_APPLE
+  static Mutex report_write_mutex;
+  Lock report_write_lock(&report_write_mutex);
+  ScopedReport *_rep = (ScopedReport *)alloca(sizeof(ScopedReport));
+#endif
+  // Take a new scope as Apple platforms need to release the below locks,
+  // before writing out the report, in order to avoid a deadlock
+  {
+    // We need to lock the slot during RestoreStack because it protects
+    // the slot journal.
+    Lock slot_lock(&ctx->slots[static_cast<uptr>(s[1].sid())].mtx);
+    ThreadRegistryLock l0(&ctx->thread_registry);
+    Lock slots_lock(&ctx->slot_mtx);
+    if (SpuriousRace(old))
+      return;
+    if (!RestoreStack(EventType::kAccessExt, s[1].sid(), s[1].epoch(), addr1,
+                      size1, typ1, &tids[1], &traces[1], mset[1], &tags[1])) {
+      StoreShadow(&ctx->last_spurious_race, old.raw());
+      return;
+    }
 
-  if (IsFiredSuppression(ctx, rep_typ, traces[1]))
-    return;
+    if (IsFiredSuppression(ctx, rep_typ, traces[1]))
+      return;
 
-  if (HandleRacyStacks(thr, traces))
-    return;
+    if (HandleRacyStacks(thr, traces))
+      return;
 
-  // If any of the accesses has a tag, treat this as an "external" race.
-  uptr tag = kExternalTagNone;
-  for (uptr i = 0; i < kMop; i++) {
-    if (tags[i] != kExternalTagNone) {
-      rep_typ = ReportTypeExternalRace;
-      tag = tags[i];
-      break;
+    // If any of the accesses has a tag, treat this as an "external" race.
+    uptr tag = kExternalTagNone;
+    for (uptr i = 0; i < kMop; i++) {
+      if (tags[i] != kExternalTagNone) {
+        rep_typ = ReportTypeExternalRace;
+        tag = tags[i];
+        break;
+      }
     }
-  }
 
-  ScopedReport rep(rep_typ, tag);
-  for (uptr i = 0; i < kMop; i++)
-    rep.AddMemoryAccess(addr, tags[i], s[i], tids[i], traces[i], mset[i]);
+#if SANITIZER_APPLE
+    new (_rep) ScopedReport(rep_typ, tag);
+    ScopedReport &rep = *_rep;
+#else
+    ScopedReport rep(rep_typ, tag);
+#endif
+    for (uptr i = 0; i < kMop; i++)
+      rep.AddMemoryAccess(addr, tags[i], s[i], tids[i], traces[i], mset[i]);
 
-  for (uptr i = 0; i < kMop; i++) {
-    ThreadContext *tctx = static_cast<ThreadContext *>(
-        ctx->thread_registry.GetThreadLocked(tids[i]));
-    rep.AddThread(tctx);
-  }
+    for (uptr i = 0; i < kMop; i++) {
+      ThreadContext *tctx = static_cast<ThreadContext *>(
+          ctx->thread_registry.GetThreadLocked(tids[i]));
+      rep.AddThread(tctx);
+    }
 
-  rep.AddLocation(addr_min, addr_max - addr_min);
-
-  if (flags()->print_full_thread_history) {
-    const ReportDesc *rep_desc = rep.GetReport();
-    for (uptr i = 0; i < rep_desc->threads.Size(); i++) {
-      Tid parent_tid = rep_desc->threads[i]->parent_tid;
-      if (parent_tid == kMainTid || parent_tid == kInvalidTid)
-        continue;
-      ThreadContext *parent_tctx = static_cast<ThreadContext *>(
-          ctx->thread_registry.GetThreadLocked(parent_tid));
-      rep.AddThread(parent_tctx);
+    rep.AddLocation(addr_min, addr_max - addr_min);
+
+    if (flags()->print_full_thread_history) {
+      const ReportDesc *rep_desc = rep.GetReport();
+      for (uptr i = 0; i < rep_desc->threads.Size(); i++) {
+        Tid parent_tid = rep_desc->threads[i]->parent_tid;
+        if (parent_tid == kMainTid || parent_tid == kInvalidTid)
+          continue;
+        ThreadContext *parent_tctx = static_cast<ThreadContext *>(
+            ctx->thread_registry.GetThreadLocked(parent_tid));
+        rep.AddThread(parent_tctx);
+      }
     }
-  }
 
 #if !SANITIZER_GO
-  if (!((typ0 | typ1) & kAccessFree) &&
-      s[1].epoch() <= thr->last_sleep_clock.Get(s[1].sid()))
-    rep.AddSleep(thr->last_sleep_stack_id);
+    if (!((typ0 | typ1) & kAccessFree) &&
+        s[1].epoch() <= thr->last_sleep_clock.Get(s[1].sid()))
+      rep.AddSleep(thr->last_sleep_stack_id);
+#endif
+
+#if SANITIZER_APPLE
+  }  // Close this scope to release the locks
+
+  _rep->SymbolizeStackElems();
+  OutputReport(thr, *_rep);
+
+  // Need to manually destroy this because we used placement new to allocate
+  _rep->~ScopedReport();
+#else
+    rep.SymbolizeStackElems();
+    OutputReport(thr, rep);
+  }
 #endif
-  OutputReport(thr, rep);
 }
 
 void PrintCurrentStack(ThreadState *thr, uptr pc) {
diff --git a/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cpp b/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cpp
index 8d29e25a6dd20..d7083e3dace7b 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_rtl_thread.cpp
@@ -96,6 +96,7 @@ void ThreadFinalize(ThreadState *thr) {
     ScopedReport rep(ReportTypeThreadLeak);
     rep.AddThread(leaks[i].tctx, true);
     rep.SetCount(leaks[i].count);
+    rep.SymbolizeStackElems();
     OutputReport(thr, rep);
   }
 #endif